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TÊT SEASON GREETINGS1

Being asked to express wishes on the occasion of the coming Têt reminds me of the British Embassador who received a phone call on New Year’s Eve from a radio station : – Your Highness, you have been collaborating with us for so many years, we would much appreciate if you could let us know of your wishes for the New Year. – That is very kind of you, the Embassador answered, I really do not know what to say ; but if you really insist, a box of chocolates would do very well. The morning after, the Embassador listened to the radio : – On the occasion of the New Year we asked a few of the Embassadors in town to tell us about their wishes. The UN Embassador said that nothing was more valuable for the world than peace, his wish was to have at last a year without wars; the Indian Embassador wished that everyone around the planet could have enough to eat ; the British Embassador... Indeed, being able to keep our sense of humour intact in spite of adversity may be the most valuable wish we might formulate... But if you really insist, as the British Embassdor would say, I should like to express two more wishes. First that the Vietnamese youth, and in particular the many talented Vietnamese students who value knowledge and wisdom more than dollars, be offered in their country a chance to have the bright future which they deserve having. My second wish is of a more modest reach but very close to my heart; recently, those of us in Vietnam who wish to promote research and teaching of modern astrophysics in the country have got together and joined effort to this aim (see http://ftri.fpt.edu.vn/APG.html). I wish to see our small group develop and strengthen and Vietnam recognize the importance of supporting fundamental research in general and astrophysics, which is the current branch of natural sciences that develops fastest, in particular.

COMMENTS ON RECENT US VIEWS ON VIETNAMESE HIGHER EDUCATION

In summer last year an APEX University report by Vallely and Wilkinson2 was widely publicized both in Vietnam and abroad. In the autumn, it triggered very hostile comments by another American citizen, Professor Koblitz3 from Seattle. The controversy that has resulted can only distract us from addressing the real problems and does not serve Vietnamese interests. While the reader is expected to know about both documents, let me recall that the APEX report is a very severe, yet reasonably objective, analysis of the Vietnamese situation in matters of higher education. Unfortunately, while the substance is essentially true to the facts, the style is arrogant and ignorant of the recent history. It makes the reader who loves science and Vietnam feel uncomfortable. On the contrary, Koblitz' paper shows a deep sensitivity to the Vietnamese reality but is essentially a virulent attack against the authors of the APEX report. It is mostly an attack on the form, very few of the facts concerning today's universities in Vietnam are denied. While being essentially in agreement with Koblitz' paper, I fear that its publication will not help those, and they are many, who are fighting in Vietnam for a better higher education. It will be taken as an argument for continuing a sterile step by step approach that has been adopted for now several decades and that has been shown to lead nowhere. What is needed today is a phase transition, a real revolution in the approach to the problems. It is not an easy task, it takes unusual doses of vision, courage and

1 Published in Tia Sang, 2011 2 www.hks.harvard.edu/.../asia/.../HigherEducationOverview112008.pdf 3 www.math.washington.edu/~koblitz/vnhigheredE.pdf 1 determination. The APEX report had at least the advantage of stirring up the hornets' nest and making the Government aware of the emergency. As a foreigner living in Vietnam − for now over ten years during which I have spent my time between teaching and training Vietnamese physics students and done my best to fight for better Vietnamese universities − I know how delicate it is to be critical of institutions of a country which is not mine. Many Vietnamese voices are more competent, more experienced and much wiser than mine. Such voices should be heard before those of foreign observers such as Vallely, Wilkinson and Koblitz. We, foreigners, have not suffered the hardship which our Vietnamese colleagues have suffered; on the contrary, we have usually enjoyed excellent working conditions and good wages during our academic careers. Whatever we may say must be said with extreme humility. Yet, to the extent that my comments are constructive and well founded, to the extent that they are expressed without arrogance, I consider it a duty towards my students to say what I think. I must do all what I can for them to have, in their home country, the future which they deserve having. This is more important than the colour of my passport. The country has been − and still is − suffering a catastrophic brain drain, two to three generations of university professors have been essentially lost by three decades of wars, pains and hardship, a fraction of the most learned population has joined the diaspora, the wages offered to teachers and researchers are blatantly too low, the universities are desperately short of the atmosphere of intellectual excellence one expects to find within their walls. Moreover, the democratization of higher education triggers in the minds of people unrealistic hopes for social promotion, a socio-cultural problem which is present everywhere around the world and has nowhere found a satisfactory solution. If anything it is more acute in Vietnam where the illiteracy rate has dropped from 95% in 1944 to 6% in 2004. All this is well known and it is not of much use to repeat it over and over; rubbing salt on the wound does not help. It seems today that one has become conscious at all levels of the delay accumulated over the years between Vietnamese universities and those of major foreign countries. It seems also that the importance of catching this delay as soon as possible has been recognized as a national emergency. The Government has made it clear on several occasions that it was strongly determined to act towards a significant improvement of the quality of Vietnamese universities. It is no longer time to denounce their deficiencies − although keeping a clear view of the nature of such deficiencies remains essential − but rather to make sure that the remedy will be efficient. And we should not close our eyes: the task is immensely difficult. In such a context, the Vallely-Wilkinson-Koblitz controversy is out of place. The emergency, today, is to unite efforts coherently and at all levels, placing the collective interest above personal interests, to help the Government with leading the revolution that is required. The danger of chaos is real in the absence of a clear policy, one cannot drive a harness when every one is pulling in his own direction, and the Government cannot implement a sound and efficient policy without the coherent support of the whole academic and research community. What we need today is to catch all possible opportunities that have a chance to contribute positively to the phase transition that is called for. In particular, while being in full agreement with Koblitz' reservations on foreign contributions to the edification of the new university − Vietnam should not copy what is being done abroad because the boundary conditions are different, not to mention the many failures experienced by foreign universities − I am convinced that the decision of the Government to establish four new universities of high level with the help of foreign countries is an opportunity that should not be missed. It is up to us, in the Vietnamese community of researchers and teachers, to make it a success. I argued elsewhere that the young generation should be playing a major role in such endeavour. They will be the professors of tomorrow's university which is now starting to be built. It is on their shoulders that it will rest. Its success will depend on them. It is their duty, starting today, to unite efforts to give the Government the coherent support that it needs to successfully accomplish its difficult task. They must become conscious without delay of the role they have to play in the construction of the new University. Without their active participation, the Government would be unable to elaborate alone the higher education and research policy which the Nation needs. They can count on a massive support from the generations of their parents and grand parents. 2

NGO BAO CHAU, PRIDE OF VIETNAM AND A CHANCE FOR ITS SCIENCE4

The first time I heard of Ngo Bao Chau was in March 2009. Having been invited to spend a month in Orsay, I paid a visit to my friend Annick Suzor-Weiner who was at the time responsible for international relations at University Paris-Sud and in the chair of the Committee for Scientific and Technical Cooperation with Vietnam. She told me about his work and it was already clear at the time that he was likely to be awarded the Fields Medal. The second time was a few weeks ago, just before the official announcement of the award. He had learned of our small research team and we invited him to spend the morning and have lunch with us. We were aware of the chance and honor it was for us to meet him, the students were very proud to have an opportunity to listen and talk to him. We had a fruitful exchange of views on science and training in Vietnam and on how to help their progress. We were impressed by the depth of his vision of the problems and the promptitude with which he was catching our messages. After just a few minutes, we knew that we were talking to a man of great culture, generosity and intellectual rigor. We kept as a gift the example of his excellence. I was out of the country on the day of the award but I could catch the wave of happiness and pride that it had triggered through the avalanche of messages in my mail box. Vietnam was rightly proud of the success of one of its children and happy to express its joy and pride. We, the Vietnamese scientific community, should catch this opportunity to take actions in favor of the progress of scientific research and training in the country. The mediatic visibility of the event and the wave of sympathy that it triggered give us a chance to make our case louder and clearer than we could otherwise. There are not many Ngo Bao Chau, but there are many excellent Vietnamese young students who should be given a chance to become, even if it is at a less prestigious level, the pride of their country. The outstanding example of Ngo Bao Chau should not be used to give us a good conscience and hide our inability to contain the brain drain. We should tell these young talents that the country needs them, that they are its future, that plans are presently being set up to welcome them in disciplines that are vital to the long range future of the country, such as science and technology in the nuclear, space and environmental domains, as well as in condensed matter physics, chemistry and, most importantly, the various branches of modern life sciences. The scientific policy of the country should be made known as clearly as possible and guidelines and milestones should be given in each of the above branches for the future scientists to know what they can expect and what their country is prepared to offer them. It is urgent to stop the present situation where Vietnamese parents are spending fortunes to send their children study abroad, where Vietnamese universities are just a waiting room for more advanced studies in foreign universities, where the students that have studied abroad and obtained a PhD in prestigious foreign universities are not welcome back home with the dignity which they deserve and consequently are encouraged not to return to Vietnam. After eleven years spent in the country, I have seen so many examples of postdocs having returned to Vietnam and not having been given a chance to start research of their own nor to set up a research team. To a large extent, their talents are being wasted, as is the investment which the country has put in their education and training. Ngo Bao Chau cannot be expected to solve alone all the problems but, together with other eminent Vietnamese scientists, whether working abroad or in the country, and even possibly some non Vietnamese scientists, to take part in a task force giving advice to the Government on the actions to be urgently taken for Vietnamese science to leap forward. The members of the task force should be selected on the only criterion of their having given major and internationally recognized contributions to science. The issues at stake are so general, and to some extent so obvious, that I am convinced that such a task force would very promptly and unanimously spell out a set of guidelines for the Government to elaborate its policy. Anyone who loves science and who loves Vietnam – this, by definition, would be the case of the members of the

4 Published in Tia Sang, xxx 3 task force – has clear views on what should be done and on the ethics, morality and intellectual rigor that it implies. When Ngo Bao Chau went first to France, he was the guest of a man of high intellectual and scientific stature, Henri Van Regemorter, who had been at the origin of the renewal of scientific cooperation between France and Vietnam. He had met General Giap and Pham Van Dong in several occasions. He died in 2002 and a book has been published to pay tribute to his action. Ngo Bao Chau has contributed a few moving lines to this token of respect. Having lived in such an environment, in the wake of prestigious intellectual figures of the after-war period, including Jean-Paul Sartre and Bertrand Russell as well as Laurent Schwartz, Alexander Grothendieck and Jean-Pierre Kahane, Ngo Bao Chau has inherited values of morality and intellectual rigor which he can most efficiently exert at the service of Vietnamese science at a time when money is too often more respected than knowledge.

LETTER FROM NIBIRU5

Being an astrophysicist, I am often asked about Planet Nibiru and the prediction made by the Mayas that it will collide with Earth on 21st December 2012 and cause the end of the world. My first reaction was to ignore such questions but, being blamed by journalists for not being attentive to the concerns of my fellow-citizens, I decided to find out. I pointed the radio telescope which we recently acquired in our Ha Noi laboratory in the direction of Nibiru and, after having fought a while against interferences produced by taxi drivers using a close by frequency, I was able to record the following message: Dear Bac Pierre, Let me introduce myself: I am a young Maya girl living on Nibiru for nearly five centuries of your years. I moved here, together with my family and some friends of ours, on the occasion of a major migration caused by the Spanish invasion of our continent and the genocide that ensued. Millions of us, mostly Aztecs and Incas, were killed and our Gods decided to take a few of us to Nibiru in order to preserve our cultures. We were fortunate enough to be among the elect. They used tornados to lift us out of Earth and flights of bright colourful phœnixes dropped us off gently on a fertile plain where we have been living happily and peacefully since then. As you may know, time on Nibiru passes much more slowly than on Earth and, while I was ten when we landed here, I am only fifteen today. Contrary to what has been said on Earth – we have access to Internet and are well informed about you – our planets will not collide in year 2012 of your calendar, nor in any later year. Such statements are the consequence of a poor translation of ancient Maya texts that has caused major misunderstandings. What is said in these texts is that starting December 2012 the influence of Nibiru on Earth will keep increasing. Evil will progressively disappear from Earth and leave room to the better Nibiruan practices which we have happily experienced for many of your centuries. I am sure that Earth will much benefit from this cultural encounter. Nevermore will an army invade another country preventively, pretending that the said country is collecting dangerous weapons and planning massive destruction; Nevermore will an army invade another country to grab its wealth, ores, oil or others, with the excuse of protecting its people against some alleged evil, such as not having the ―right‖ religion, not having the ―right‖ political system, with the word ―right‖ meaning ―same as ours‖; Nevermore will a country appropriate a piece of land that belongs to another by simply drawing on the map a line of the required shape; Indeed, in Nibiru, we have no army any longer; long ago, our soldiers have been trained as artists such as poets or painters, of which the planet was in deep need; Nevermore will money rule your planet; nevermore will the rich become richer and the poor become poorer;

5 Published in Tia Sang on the occasion of Têt 2012. 4

Nevermore will speculation, wild capitalism and other economic devils cause millions of death of starving children all over the planet; Indeed, in Nibiru, we have no bankers any longer; long ago, they have been trained as artists such as singers, musicians or dancers, of which the planet was in deep need; Nevermore will anyone, any Big Brother, decide what is good for you; Nevermore will women be harassed and oppressed by men; nevermore will children be exploited by adults; Nevermore will corruption, favouritism and nepotism spoil the relations between people; nevermore will politicians lie, say white and do black, abuse your naivety and candour; nevermore will the thirst for power rule the game; Indeed, in Nibiru, the mighty of yesterday have been trained as buffoons and clowns for the entertainment of their former subjects.

The message was then blurred by parasites for a while. I tried many times, to re-establish contact with my young Maya friend. Only once did I succeed. As I had asked her: ―How can I believe that so many good things might happen to our planet?‖ she simply answered ―If you believe in Nibiru, why not believe in these other things?‖ She bursted out laughing cheerfully and wished me a happy New Year. The contact was then cut, for ever I am afraid.

ON HAPPINESS AND OTHER MOTTOS6

Têt is approaching, and with it the wishes of happiness that we use to dispense on this occasion to our loved ones. Happiness: isn’t it indeed the most valuable gift we may be hoping for? Vietnam is one of the very few countries to have had the courage, or may be the candour, of including it in the national motto. Other countries prefer to underline specific values, which they see as the best keys to open wide the gates of happiness. They probably think that it gives a more serious impression to praise glory, or honour, than simply praising happiness, which may sound a bit childish to them. The most popular of these values is, by far, unity. Next come, in this order, God, freedom, homeland, justice... and many others. Last, strangely enough, is the motto of a tiny European country7: “We want to stay as we are”, possibly the only country in the world where happiness has been reached already... Obviously, the values that a country selects to include in its motto owe much to the context in which it was born. Those having suffered decades of oppression under the colonial yoke praise independence and freedom; those having suffered internal fights and civil wars for centuries, and finally got together, often to fight a common enemy, praise unity; those having always suffered poverty, and usually being still suffering it, praise wealth; those suffering desertification praise the rain, the only word making the motto of Botswana; I am not sure what those who praise God are really after, I have always been suspicious of mottos such as In God we trust, or Gott mit uns (God with us); we can read the former on dollar banknotes, which seem to me emblematic of a devil more than of a god; and the latter was the motto of the army which killed millions of Jews during World War II. Not to mention the Allah is great which we now read on the banners brandished by the children killers of the so-called Islamic State. Reading through all these national mottos reveals the diversity of the roads that are supposed to lead to happiness; they have only one thing in common: what they aim at. They all converge to a same place: happiness. Starting from different points, they are bound to cross different landscapes. Never mind the way you need to follow as long as you reach happiness at the end of the journey. Remember Hô Chí Minh8 ―If the country is independent, but the people cannot enjoy happiness and freedom, that independence is meaningless‖. May be, some day in the far future, there will no longer be borders

6 Published in Tia Sang, January 2015. 7 Luxemburg. 8 Hô Chí Minh: Complete Work. National Political Publishing House, Hanoi, 2000, Vol: 4, p. 56. 5 between countries; the planet will be our common homeland. Then, for sure, its motto will be made of a single word: Happiness. Reading through these mottos also reveals how relative happiness is. We could not give of it a definition, which could apply to all places and at all times. Most of the time, to measure happiness, we use as a stick yard the misfortune of our fellows. And if we are asked what could make us happier, we can only think of what we do not have, which others may have. To the slave, happiness means freedom; to the poor, it means wealth; to whom is sick, it means good health. We all make the same mistake, we think that what happiness has meant to us is also what it will mean to our children and grand children, and we take it as granted that happiness is universal, which it is far from being. I count, among my dearest Vietnamese friends, men who have given their life to serve the ideal that the motto of the country expresses so well: independence, freedom, happiness. They have gone through all the miseries of the world, wars and starvation, to reach this goal. They have seen many of their friends die, they have seen others flout the ideal for which they were fighting, they have often been disillusioned and disappointed by the cruelty of the real world. But I think that I know them well enough to say that they are happy, that they can make their these words of Aragon9: In spite of all, I can say nothing but thank you, in spite of all, for how good this life has been. They were born oppressed, humiliated and exploited, they leave as legacy to their grand children a free, peaceful and independent country. I count also, among my dearest Vietnamese friends, young colleagues of mine who are of the generation of the grand children of my older friends. They are children of the Doi Moi, they have received the country in heritage. They do not know what it means not to be independent, they do not know what it means not to be free, they do not know what it means to starve, they do not know what it means to endure a war. This is why not having to suffer all what their parents and grand parents have suffered cannot mean happiness to them. But there is still a long way to go for them to be happy. They need more justice, more dignity, more morality, more skills. They want to fight corruption, bureaucracy, incompetence. They want for the country a better place on the international scene, better universities, less brain drain, skilful engineers and scientists, talented artists and writers. This is what they like to fight for on the road to happiness, with all the energy and generosity of their young age. Camus said that the fight for the summits is enough to fill the heart of a man. It might even be that the hearts of men need fighting for a summit in order to reach happiness. We should keep these points in mind when we claim to make other people happy. So much harm can be done by those who use this as an excuse to impose on others the values that are their, the gods in which they believe, the political doctrines to which they adhere. Each day, children are killed and women are raped in the name of Allah. Millions of Jews were exterminated by Hitler in the name of the purity of the white race, millions of American Indians by the Spaniards in the name of God, millions of innocents by Stalin, Mao Zedong and Pol Pot in the name of the class struggle and the dictatorship of the proletariat. Giordano Bruno was burned at the stake in the name of the Church of Rome. In the name of democracy, the United States have bombed Vietnam, in the name of liberalism, the rich exploits the poor. So often in the past, the words that make the mottos of nations have been diverted from what they initially meant and twisted in such a way to serve the interests of a few. Such words may become dangerous if they are used as a doctrine or a dogma. We must be prepared to take our distances with them when their way no longer leads to happiness. In the thirties, the friends of Phan Chau Trinh and Phan Van Truong were blaming Hô Chí Minh for having become an apparatchik of the Komintern and having betrayed the nation and the homeland. At the same time, Tran Phu and Ha Huy Tap were blaming him for being a nationalist and an opportunist and having betrayed the ideal of communism and the class struggle. Hô Chí Minh had not betrayed anyone, nor anything; he simply had not forgotten that his only aim was the happiness of his people, and nothing, no doctrine, no dogma, could divert him from pursuing it.

9 Malgré tout je vous dis que cette vie fut telle/Qu'à qui voudra m'entendre à qui je parle ici, N'ayant plus sur la lèvre un seul mot que merci,/Je dirai malgré tout que cette vie fut belle. 6

Let us leave the young generation decide for themselves their way to happiness. And encourage them to look carefully around before making their choice, to open wide their eyes to avoid taking a wrong road. It is not up to us to tell them where to go, it is up to us to give them the means and the tools to take the best possible decision. I said before that there is no universal happiness; fortunately, it is not quite true; the smile of a child, the love of a woman, a glass of cool water when we are thirsty, the majesty of a sunset... no one can take these away from us. Happiness may be simply to be content with just that...

BRAVE GENIUS10

A bit over a year ago, biologist Sean B. Carroll published11 “Brave Genius”, subtitled “A Scientist, a Philosopher, and their Daring Adventures from the French Resistance to the Nobel Prize”. The Scientist is Jacques Monod, one of the founding fathers of molecular biology, the philosopher is Albert Camus. Making a parallel between the two men is a great idea, indeed. Not only because they knew and respected each other, shared many convictions and had the courage of fighting for them. But because they can be taken as emblematic figures of the revolution that the progress of science in the second half of the past century has meant for our approach to metaphysics and ontology. What do I mean by this ? Monod, as one of the pioneers of modern biology, has helped spreading its main message – in the wake of evolution theory – which Francis Crick called12 “the Astonishing Hypothesis” in 1994 and which we might rename today “the astonishing evidence”: it is the physics and chemistry of our cells that rule our bodies and minds, our feelings and our consciousness. Searching for the seat of soul is no longer on the agenda. Moreover, recent progress in astronomy, with the discovery of exoplanets, of which, in all likelihood, an enormous number are, as one says, “habitable”, suggests that life is likely to be ubiquitous and that, most probably, civilizations as advanced as ours, and may be more, exist, or have existed, elsewhere in the Universe. Understanding, not to say accepting, such statements requires a solid scientific culture in the domains of contemporary natural and life sciences. Lacking it leads to deep misunderstandings and to complete incommunicability between the “two cultures” of humanities and sciences13. Such is the case today of the vast majority of those whose knowledge is limited to the writings of philosophers. As deep and bright thinkers as they may be, they suffer of a major infirmity: their blindness to the light that modern science is shedding on metaphysics and ontology. The case of Jean-Paul Sartre, devoting 700 pages in “L’Être et le Néant” to considerations14 that seem somewhat futile from this point of view, is a good illustration. Such is also the case of scientists whose knowledge is limited to mathematics or natural sciences, either because they came too early, I mean before the last quarter of the past century, or because they are not familiar with the recent progress of contemporary biology, in particular neurobiology. The former look at the world from the point of view of an external observer, or, if one prefers, the point of view of its creator; the latter make themselves guilty of arrogance by claiming15, as Stephen Hawking does in “The Grand Design”, that science can explain why the world exists rather than nothing: this is not making a service to science. Indeed, while the recent progress of science helps drawing an ever more accurate, ingenious, complete and faithful picture of the world, including of the human species, which is but a part of it, it surely cannot explain why the world exists, rather than nothing. The world observes itself – we play the major role in this observation – and writes itself the story of what it sees, a story that tells how science tells a story that tells how science tells a story that tells... a perfect self-reference loop in which we are

10 Published in Tia Sang 11 Sean B. Carroll, Brave Genius, Broadway Books, New York, 2013. 12 Francis Crick, The Astonishing Hypothesis, Touchstone, New York, 1995. 13 Charles P. Snow, The Two Cultures, The Rede Lecture 1059, Cambridge University Press, New York, 1961. 14 Jean-Paul Sartre, L’Être et le Néant, 15 Stephen Hawking and Leonard Mlodinow, The Grand Design, Bantam Books, 2010. 7 imprisoned. Wittgenstein had a clear intuition of such circularity, when he wrote16: “It is not how is the world that is the Mystery, but its mere being. [...] The proper method in philosophy would be to say nothing that stands to reason, namely the statements of natural sciences, something having nothing to do with philosophy [...] Of what we cannot speak, we must keep silent.” Contemporary science leaves us in front of a mystery that appears much deeper now than it might have earlier, when questions about how is the world were confusedly mixed in our mind with the fundamental question which Wittgenstein is alluding to, why something rather than nothing? The strength of Camus, in spite of his lack of scientific culture, is to have grasped so clearly how inescapable the mystery is. Contrary to Sartre, he would not spend a word to ramble on it. For him, it is a fact with which we have to cope, whether we like it or not. What matters then is to know how to conduct our lives in such an “absurd” context, with no metaphysics on which to base our ethics. The interest of philosophers for metaphysics and ontology has always had its source in the ultimate hope to find a meaning, a finality, to our lives. But they do not skip the metaphysical exploration phase, as Camus does, and consider him as a lower grade philosopher for skipping it; Camus, on his side, does not like to think of himself as a philosopher and considers their rambling rhetoric as verbose. It is in this sense that the pair Monod-Camus is emblematic of the roles that can be assigned today to science and philosophy for them to act coherently in the enrichment of the culture of our century. What makes Camus such a likeable character, is his humanism, his generosity, his tenderness toward the human condition. “Absurd and happiness, he says17, are children of the same Earth. The fight for the heights is enough to fill a man’s heart”. And, comparing the human destiny to that of Sisyphus rolling indefinitely a rock to the top of a mountain, “we must think of Sisyphus as being happy.” I think that the Vietnamese reader would enjoy reading Carroll’s book and get better acquainted with two characters of such an outstanding stature. Both joined the communist party after World War II but left it after some time, Camus when the Soviet troops entered Budapest in 1956 and Monod when the Lysenko fraud was revealed. Both opposed the French colonialism, both fought for more justice and freedom in the world, both refused being indoctrinated in dogmas that would run against their convictions.

TET 2016: SEASON GREETINGS18

Tithonos was a Trojan prince, a brother of Priam. Eos, the goddess of Dawn, fell in love for him while he was tending his herd. Happy times, when princes were also young and handsome shepherds! Eos, rising each morning from the bed of her lover, was apparently enjoying her nights and asked Zeus, the king of gods, to confer Tithonos immortality. So did He. But Eos had neglected to specify that she meant eternal youth, not simply eternal life. And Tithonos went on aging, beyond reason, always hashing and rehashing the same old stories. And Eos got so tired of him that she changed him into a cicada, eternally rambling the same song. I fear that, as Tithonos (needless to say, the comparison applies only to my old age), I am boring the reader with my endless plea for what I think to be the better… A more proper comparison might be with Cato the Elder, the Roman senator who kept ending all his speeches by the famous sentence: “In my opinion, Carthage has to be destroyed”. Carthage was indeed destroyed finally, in 146 BC, but Cato had died three years earlier… At the same time as I wish a happy new year to all Tia Sang readers and to Tia Sang’s editorial staff, let me express the hope that the coming year will offer the Vietnamese youth better chances than the elapsed year has been doing. Better chances for them to blossom, for making good use of their energy, their generosity, their enthusiasm, their skills and their talents. To fulfil such a wish, we need to adopt a new style: more intellectual and moral rigor, a deeper sense of the duties implied by living together, more

16 Ludwig Wittgenstein, Tractacus Logico-Philosophicus, Gallimard, Collection Tel, 1993. 17 Albert Camus, Le Mythe de Sisyphe, Gallimard, 1942.

18 Published in Tia Sang 8 solidarity and less selfishness, more professionalism and a stronger faith in the future. I know that such changes take generations, not simply years, but we may be able to help with speeding up their pace if we are determined to do so. We, scientists and engineers, should feel responsible for playing a major role in such changes. Moral and intellectual rigor, team spirit, professionalism are qualities inherent to our professions. And our community has been traditionally always present in history, in all countries, to promote progress, peace and a science without borders.

From the deepest of my heart, I wish all of us to have the courage, the strength and the determination to help progressing along such a line.

ON EXILE19

Ông tơ ghét bỏ chi nhau, Chưa vui sum họp dã sầu chia phôi! Nguyen Du (Kiêu)

Could it be that we cannot conceive love without separation? Is it really unavoidable that Kim Trong has to leave Kieu just after having met her for the first time? Why should To Thi, transformed into a rock, eternally waiting for the return of her Beloved, be the emblematic image of Vietnamese love? May be because wars and sorrow are so deeply imprinted in Vietnam’s history that they became part of its culture. From the Chinh phụ ngâm of Dang Tran Con and Doan Thi Diem to the Noi Buon Chien Tranh of Bao Ninh, to love and to part are but a same thing. Such thoughts came to my mind recently when reading so-called motivation letters of candidates applying for a fellowship to study abroad. In principle, it should be a good idea to ask for such letters; in practice, however, they all read the same, I imagine they have been copied-and-pasted from Internet. The stereotype reads something like: ―Since prime childhood, I have had a passion for (nanotechnology/differential equations/cosmology…) and I would like now to realize my dream: to study in a country famous for its culture and its education system. After having worked for a master, I would apply for a PhD and do research abroad in prestigious research institutes. Later, I could then come back to my beloved Vietnam and contribute with my experience to the development of science and technology in the country, which is my dearest ambition…‖ Viet Nam, I love you so much that I must leave you! Is it really the best way to show one’s love? Curiously, I remarked that the children of parents holding a high position in the country, professors, high level civil servants and various kinds of leaders, far from being spared by the disease are among the most infected. Should not their parents be in the best possible position to have confidence in the ability of the country to give its youth good education and opportunities? More seriously, I know well the role that exiles have played in Vietnamese history, starting, between 1912 and 1920, with the so-called “five dragons”, Phan Châu Trinh, Phan Văn Trường, Nguyễn Thế Truyền, Nguyễn An Ninh and Nguyễn Ái Quốc. I know well that the very word, exile, cannot be pronounced without pang and emotion when thinking of all the pains and sorrows that it carries with it. But the only remedy against such past suffering is to look forward. Today, it is at home that we need to build the new landscape that will look attractive enough to the youth to prevent them from thinking that happiness can only be on the other side of the fence. It is at home that we need to build better universities, with knowledgeable, integer and hard-working scholars. It is at home that we need to raise the level of scientific research on the international scene and give it the place that it deserves having. It is at home that we need to restore respect for culture. I think that it no longer makes sense to waste so much money in sending our children abroad and maintaining too high a level of brain drain. Rather than spending so much in fellowships of various kinds,

19 Published in Tia Sang 9 we would be much better off by keeping this money to support those who stay at home with the determination to change things to the better. Of course, it would imply a change of style in our practice: we should be much more selective in choosing, on the sole basis of their talents, those who have such ability; and we should offer them resources, both in terms of wages and of working environment, that can attract them. They should see their action in the framework of a long term policy, clearly spelled out, giving them confidence in a sustainable support, giving them reasons to be proud of their achievements, giving them a sense of serving a country which recognizes their efforts. Recently, I met a young Vietnamese who studies accounting in Singapore. Don’t you think that Viet Nam should be able to teach accounting to her children at home? We recurrently hear seminars from young Viet Kieus who do research abroad. They go on and on giving us advice on what we should be doing, often without understanding what the working conditions and the situation of fundamental research are in the country, but when they are asked why don’t they come back to the country and take part in the revival of science and technology they are at best silent. As I often say, we invest in concrete and in expensive instruments rather than investing in brains, as we should be doing. Again, it would imply a major change of style in our practice: much more professionalism, much more intellectual and moral rigor, but, at the same time, confidence in the talents of the youth. We must give them a chance to learn, by themselves, at home; we must give them a chance to make the unavoidable mistakes that are part of the learning process. We should invite more systematically foreign and Viet Kieu professors to teach at home, and stop sending so many of our children abroad. We should encourage the formation of teams of young people teaching each other, making ample use of Internet and of the skills of the most talented among them. I am not saying that we should stop altogether sending students abroad to be trained. We should simply exert a better judgment of when it is justified. And, when we do so, we should make the best of it: by instrumenting a proper follow-up at home to make the best possible use of the skills that they have acquired abroad and of the resources that have been invested in their training; we should encourage and favour the transfer of such skills to their colleagues who stay in Viet Nam by asking them to give lectures and organize training sessions and by making use of co-supervision agreements for PhD students. For over twenty years we have been sending abroad young students for a PhD in particle physics; but we have been unable to build and support a research team at home: isn’t that a waste? Long ago, and recurrently, I have been advocating the practice of co-supervision of PhD students between a professor at home and a professor abroad. The benefit for Viet Nam is double: the student maintains close contact with the home country, sharing his/her time between the two countries, and what he/she learns is also learned by the whole Vietnamese team. But I have not been heard. The conditions for such co-supervision agreements have become more rigid, rather than more flexible as deputy minister Bui Van Ga had told me that they would; recently, I had a chance to plead the case with the Vietnamese rector of one of the Ha Noi universities, he told me that it is not his business to change the rules in Viet Nam, his role is to apply them... I am currently working in an Institute having as a mission the development of space technology in Viet Nam. Many young engineers have been recruited and have been given two-year training in Japanese universities. They are now coming back to the country, full of energy and enthusiasm. We must give them a chance to make use of such assets by giving them projects that will make the best of their new skills, motivate them for working hard and for obtaining successes which they can be proud of. They should be given the chance to construct small satellites in Viet Nam, which they could use to record images of the Earth. We must not underestimate the importance of giving them such an opportunity; this is the only way to have them grow in competence and efficiency. Failing to do so would be a waste. The young people around me are perfectly able to train and teach young astrophysics students in Viet Nam, all they need is being given the confidence to do so and the resources that it implies: possibility to attend conferences, to invite foreign lecturers, and, what they need most, recognition of their talents by their authorities, moral support and encouragements.

10

MATHEMATICS AND PHYSICS20

Marvellous Mathematics Who is not familiar with science, mixes up physics and mathematics, seeing in the former nothing but esoteric and abstract formulae without relation with the real world. But, as Feynman wrote, “the mathematician prepares reasoning ready to be used by the physicist who aims at describing the world […] he helps the physicist but, in physics, you need to understand the link between words and the real world.” No doubt, mathematics is fascinating. You start from apparently innocent hypotheses and discover an unsuspected and marvellous world. You count 1, 2, 3… and here come prime numbers, Riemann zeta function, Mersenne numbers, magic squares, Fermat theorem, perfect numbers and the puzzling infinite. The same way as language makes it possible for us to play with words and imagine magic universes, mathematics makes it possible for us to play with axioms and create a hierarchy of infinites, Peano curves, undecidables and a host of other wonders. Such richness obtained from such simple hypotheses at the source! Such beauty and elegance of their constructions, giving such a feeling of purity! At variance with science, which is dependent on the phenomena that it aims at describing and at understanding, mathematics can abstract itself from such phenomena, making axioms of the helping hand that nature gives it to start its explorations. While science must constantly revise its hypotheses, mathematics is immortal.

Theory or observation? Before illustrating the use that physicists make of mathematics, allow me to correct a few misconceptions that one commonly meets. The distance between theory and observation is not that big. When I say: “The Sun sets in the west”, is it a theory or an observation? To name the Sun, I must have imagined that these red circles that I see disappearing behind the horizon in the evening are the same thing as those that I see rising on the other side in the morning: to name the Sun implies having a theory of the Sun. As soon as we attempt at describing what we observe, we translate it into sentences, numbers, information that our brains store and handle and which already make up a theory. Think to the new-born child who learns to recognise the face and voice of his mother, what else is he doing if not constructing a theory of his mother? The theory that I have digested since childhood, I call it common sense. The theory that I have not yet studied, I call it mystery.

Immortal mathematics, ever changing physics One often says that the role of a physical theory is to establish relations between the quantities that we use to describe phenomena, like E=mc2 or F=ma. But this implies an essential preliminary: having defined such quantities. Whether talking of material points, or vector forces, or space-time four-vectors, or Hilbert space quantum states, or superstrings, such concepts are far from being obvious, they must first have been conceived in some human brain. We must be aware that such conceptions are somewhat ad hoc and lack rigour; they are abstractions that may need to be revised. The elegance and apparent perfection of the completed theory are often such that we tend to forget it. It would be a mistake to see a physical theory as absolute truth. We must always be prepared to revise the bases on which it has been built if new bases make it possible to build a better one, more general and/or more accurate. Newtonian Mechanics is not as good a theory as Special Relativity but it is not less abstract. It only looks this way to who is so familiar with it that he forgot that it rests on abstractions and that he let it become his common sense. All physical theories are abstract; their role is to make abstractions. Common sense is nothing but the theory that we have already digested, it is a subjective concept, even if it is collective: it is the theory that has been digested by the majority. Science is always prepared to accept a new theory, never mind the effort of

20 Published in Tia Sang 11 abstraction that it implies, as long as it is better than the old one. An obvious corollary is that it cannot claim that the current theory is the ultimate theory; it must give up any ambition to reach some kind of absolute truth.

Infinities and infinitesimals in physics Let me now turn to some examples of the use that physicists make of mathematics. The idea of infinity and of infinitesimals has always intrigued mathematicians and philosophers. Think of Hilbert’s paradox of the hotel with an infinite number of rooms that can accommodate an infinite number of new guests. As an illustration, I prefer the demonstration that there exist as many integers as rational numbers, by placing rational numbers in a table having the numerator for columns and the denominator for rows. It was not until the beginning of the last century, with Dedekind, Cantor, Frege and others that the issue was clarified. Physics makes a heavy use of infinitesimals and infinites, but only as tools. But for the concepts it uses to describe the world, physics needs no infinity. An infinitely small material point is unphysical in quantum mechanics. The universe is not infinite but contains some 1080 elementary particles. Saying that it is infinite simply means that, from what we know of it within the horizon (the distance from which we can receive a light signal emitted at the time of the big bang, 14 billion light years away), there is no reason to assume that it does not continue the same way outside.

Groups in physics Group theory offers a particularly fertile ground to physical theories. The whole so-called “Standard Model” that describes particle physics is built on Lie groups: the Poincaré group (rotations and translations in space-time, including Lorentz transformations) and the product SU(3)C×SU(2)L×U(1) generates the basic fermions. Gauge invariance generates the gauge bosons and a symmetry breaking generates the Higgs boson. The Poincaré group is the Lie group of translations and rotations in space time with the metric of special relativity. It implies the existence of particles and antiparticles described by energy-momentum four-vectors with invariant mass and spin. The product of groups SU(3)C×SU(2)L×U(1) describes symmetries obeyed by these particles, namely invariances of the physics phenomena under exchanges of two particles sharing similar representations in these groups, such as changing a proton into a neutron for example. At this stage, all fermions (spin ½) and their properties are properly described, namely all particles that make up matter. Requiring in addition gauge invariance (the phase of a quantum state can be arbitrarily fixed at any point in space-time) implies the existence of massless vector bosons, namely light-like particles: photon, weak bosons and gluons. Symmetry breaking gives masses to the gauge bosons and generates a new scalar, the Higgs boson, that was recently discovered and that completes the list of elementary particles in the Standard model.

Extra dimensions A third example of a mathematical concept that turns out to be very successful in physics is extra- dimensions. The taboo was lifted when special relativity introduced space-time implying the energy- momentum four-vector, the notions of mass, of spin and of antiparticle. It went on with general relativity that describes gravity by relating the stress-energy tensor to the distortion of space that it induces (implying that the graviton has spin 2). Then, Kaluza introduced a fifth dimension to include Maxwell equations of electromagnetism (vector and scalar potentials). It was considered as a mathematical trick without concrete physical interpretation until Klein had the idea that the fifth dimension could be so much curled up (one says compactified) as to make it invisible. Today’s most modern theory, M-theory, requires 10 space dimensions (of which 7 are compactified) and one dimension of time.

Mathematics is not the magic wand Dirac always insisted that he thought of his famous equation (describing electrons and positrons) guided by the ambition to build a mathematically beautiful theory. Unfortunately, it does not always work 12 out so nicely. In the sixties Chew, Mandelstam, Frautschi and Regge exploited the analyticity of the S matrix (relating the final state of a system to its initial state) and the idea of crossing symmetry (relating the properties of an interaction a+b↔c+d to those of a+c↔b+d, with some particles changed into their antiparticles) proposed the concept of nuclear democracy, implying that no particle would have been more “elementary” than the others and that all particles could be generated by a bootstrap mechanism, from the image of someone lifting himself up by his bootstraps. The idea was extremely popular, it was the theory that I was taught when I was a student, but it never worked concretely and was abandoned a decade later. Today, the idea of Supersymmetry, a most mathematically beautiful symmetry that couples bosons and fermions, is so appealing that it is difficult to imagine that Nature could ignore it. But, until now, we failed to see any sign of it.

Physics today Attempts to reveal deviations from the Standard Model have constantly failed for now 40 successive years. At the same time, recent major discoveries in astrophysics, dark matter and dark energy, are a challenging puzzle to contemporary theoretical physics. Today’s main puzzle in physics is our failure to describe what we call the Planck scale, at ~10−32 cm, corresponding to the state of the Universe at the time of the big bang, when gravitation was so strong that Heisenberg’s uncertainty relations, the basis of quantum physics, could no longer be obeyed. The modern approach to the problem is to replace particles by string loops, with the string tension defining the Planck scale. It modifies Heisenberg’s uncertainty relations as requested but requires 9 dimensions of space to be practicable, six of which must be compactified. Four such theories can be conceived, for open or closed strings, and oriented or not. But these four theories are in fact expressions of a single so-called M-theory, having 10 dimensions of space, with seven compactified. They are related by duality, a concept that has become central to the game because it gives evidence for the equivalence of theories that were meant to apply in very different domains (small vs large distances, strong vs weak couplings). The so-called AdS/CFT duality (Maldacena 1997) relates string theories in an Anti-De Sitter space to conformal Yang-Mills field theories. The mathematical description of a 10 dimensional space is obviously of an extreme topological complexity, with multidimensional membranes (called p-branes) generalising the concept of string loops. As a result, physics is in a phase where theory and experiment considerably drifted away from each other at the Planck scale, where mathematics dominates theoretical physics. As a spectacular evidence for this evolution, one of the gurus of modern theoretical physics, Ed Witten, was awarded the Fields medal in 1990! Today, a student of advanced theoretical physics, especially string theory, must become familiar with a long list of mathematical topics: real analysis, complex analysis, group theory, differential geometry, Lie groups, differential forms, homology, cohomology, homotopy, fibre bundles, characteristic classes, index theorems, supersymmetry and supergravity. K-theory, which generalises cohomology from differential forms to vector bundles, and non- commutative geometry are two chapters of mathematics that are at the current cutting edge of superstring research. The reader familiar with the work of Ngo Bao Chau will have noticed that his contributions to the field, in particular the resolution of the fundamental lemma, are not without relation with the mathematics hosted by the M-theory. It is very interesting, but beyond the scope of the present article, to read how he sees their link with the development of modern physics.

Where is God hiding? Much nonsense has been and is still being said and written on this subject in this context, with the idea to produce bestsellers. Think of the Grand Design of Steve Hawking or the God Particle of Leon Lederman. Dirac, Wigner, Einstein wondered why the Universe is “understandable”. Like Chandrasekhar, they ask: “How can it be that the human mind invents abstract concepts and finds them beautiful? And why such concepts happen to have their exact equivalents in Nature?” But how the world, that observes 13 itself, could use the third person to speak of itself? It has forged logics and mathematics precisely with the aim of observing and describing itself, why should it wonder about its miraculous efficiency? Which yardstick should it use to measure the size of this miracle? For a long time, unconsciously, scientists have given in to the illusion of realism, the existence of an external reality. But the circularity of science, the universe looking at itself and explaining itself in its own terms, which it has invented precisely for this purpose, prevents it to answer the basic question: Why something rather than nothing? If we see clearer into such matters today than yesterday, it is not to the credit of mathematicians and physicists, but to that of biologists, in particular of neurobiologists: the 1994 “astonishing hypothesis” of Francis Crick, that we are made of nothing but atoms and that the physics and chemistry of our cells govern our body and our mind has become today an evidence. Leibniz was wondering that there must be a reason in Nature for this world to exist rather than nothing. We now have given up the hope that there might be a “reason”, we prefer to say with Ludwig Wittgenstein: “The Mystery is not how is the world, but that it is. The proper method in philosophy should be to say nothing but what can be said, namely the statements of natural sciences, which have nothing to do with philosophy. On what we cannot speak about, we must keep silent”. Modern biology has made the mystery of the mere existence of something rather than nothing even deeper than it used to be. Anyone can feel free to give it the name of a God.

NOSTALGIA21

I keep writing, in these columns, that we must look forward, ahead of us, and stop searching the past for whom to blame as responsible of our present problems. Allow me today to make an exception. Not to claim that it was so much better in the good old times, neither to argue that it is so much better now. Simply to illustrate how much the world changes in a single lifetime. Each of us tends to divide history in two well distinct periods: before we were born, a kind of prehistory that we learn about from books; and after we were born, the real time. I thought that the young generation might be interested in reading what it was like to be a physicist when I was their age. I realize that during the time I am talking about, the first half of the sixties, Viet Nam war was starting to escalate, with Johnson bombing the North in 1965. At that time, I did not know much of Viet Nam; like many of my student friends, I had been demonstrating against the wars, first in Algeria, then in Viet Nam, but this was simply the expression of the generosity inherent to our young age. But what I want to write about today has nothing to do with the pains and sorrows that have marked the lives of my old Vietnamese friends, and I hope that they will allow me to address the young generation by making abstraction of what they had to endure. The first computer I worked with was an IBM 650. My task was to integrate the differential equation that describes the propagation of sound waves in water given the vertical distribution of temperatures. The machine was not yet transistorized; it used vacuum tubes and occupied a room as large as the two offices which host our present research team. The heart of it was a rotating magnetic drum, with memories arranged on 40 generators of the cylinder, each including 50 words. Two fixed rows of 50 memories were facing the cylinder, one to read from the drum, the other to write onto it. To add two numbers, a and b, we had to write three instructions. Each started with its own ID number, usually given in sequence, and ended with the ID number of the instruction to execute next. The first would say to fetch number a from drum memory m1 and to write it into the adder (it was called the “distributor”). The second would say to fetch number b from drum memory m2 and to write it into the second memory of the adder. The third would say to fetch the result of the addition from the adder and to write it on the drum in memory m3. Input and output were on punched cards, which we were punching ourselves; to obtain a paper output, we had to process the deck of cards in a huge printer, which was as slow as noisy, printing only a single line per second. At Berkeley, Saclay and CERN, there were big computing centres hosting more modern (transistorized!) and powerful machines, to which we would submit our “job”, namely a

21 Published in Tia Sang 14 deck of cards including the code (at that time FORTRAN had just appeared) and the input data cards; we would get the result the morning after, printed on paper. By making friends with the operators – there may have been half a dozen of them at any single time − it was sometime possible to jump the queue and have one’s program run in priority. It was not until the seventies that we started to see pocket calculators. I remember Carlo Rubbia, who was teaching in Harvard and coming back to CERN at the end of each week, showing us with pride the first Hewlett-Packard, which could fit in his hand and was doing much more than the IBM 650 could do, and orders of magnitude faster. There were no online computers on the first experiments on which I have been working. We were storing numbers in gas-filled tubes called dekatrons and printing the result on paper. Online computers started to appear at the end of the decade. To analyse our data, we were using large millimetre paper sheets, both linear and log scales, mechanical adding machines, slide rules and tables of logarithms (I remember the names of the authors: Bouvart and Ratinet). Drawers filled with IBM punched cards were everywhere in our offices. It was not before the next decade that magnetic tapes became the standard data storage medium. The first thing I would do in the morning was to pay a visit to the workshop. Workshops were the pride of the institutes I was working in at the time; they were the first place one would show to visitors. Very busy places, with many machine tools. They were manually operated, with lots of small handles; numerical control did not arrive before the next decade. The more skilled of the workers would operate large lathes or milling machines. I would go to the man (I must confess that there were not many women in mechanical workshops) who was machining a small piece of equipment for me on the basis of a sketchy drawing that I had made. He would suggest some changes that would make it easier for him to do the job. Of course, I would agree. Electronic workshops were another hotbed of research institutes. There, all was analogic; nothing was numeric at that time. Oscilloscopes and soldering irons, printed circuit boards and individual components were the only tools. Integrated circuits and the first electronic chips would only arrive in the next decade. Next, I would go to the drawing office: drawing tables equipped with two rulers at right angle sliding over the table surface, and a large ozalid UV machine to print on paper A0 size drawings that were first drawn on transparent sheets. The tools were China ink, capillary “Rotring” pens and various templates to draw letters and geometric shapes. I would discuss with a draftsman working on a major piece of equipment for our next experiment. Then I would talk with another, who was drawing the figures of our next publication in Physical Review. I would stop by the library before going to my office and glance through the recent publications that they had received, and which were exposed. I might have asked the librarian to order for me a reprint of an article which I wanted to study; I would get it by mail two or three weeks later. I would also pass by the secretariat to say hello to the ladies. One of them, who is typing an article of ours and fixing the English and the spelling, would ask me some questions. Typewriters were no longer of Bac Ho’s old Remington type, they had been electrified in such a way that each letter was hammered with a same strength on paper. The first font-ball IBM typewriters were starting to appear on the market in the mid sixties, but only a very few of the ladies had got one. The tools were scissors and glue, when a paragraph had to be moved to another place, erasers, white ribbons used to erase a letter by retyping on it. Carbon paper and stencils were the way to make multiple copies. There were no photocopy machines at that time. I remember the first Xerox at CERN in the early seventies. At that time, small teams of Russian physicists were visiting for short periods. Each team included a kind of security agent, who had nothing to do with physics but was supposed to watch after his countrymen and make sure that they behaved according to soviet regulations. They would spend the whole night making photocopies of documents that were not available on the other side of the iron curtain, and take them back home. Was it better or was it worse? In terms of what we are able to do, it is obviously infinitely better now. Yet, I can’t stop thinking that the environment in which we lived then was at a more human scale than it has now become. All these workers, technicians, draftsmen, computer operators, secretaries, where 15 have they gone? One thing to which I can bear witness, is that they liked their job, they were proud of what they were doing and they were highly respected for their skills. At that time we were not judged for the number of quotations that our articles had generated, nor by the quotation index, eigenindex, h-index or God knows what of the journal in which we were publishing. There was no Shanghai ranking for universities, no International Student Assessment Schemes, no PISA, no ISTD. There were fewer forms to be filled and less bureaucracy. We were not obsessed by the need to reduce everything into numbers, in such a way that they can be handled by computers, and that we do not need real people any longer, robots could do the job. Today, when I enter a room and see everyone seating in front of a PC screen, or when I see people typing on their mobile while walking in the street, driving their xe-may or having lunch in a restaurant with their boy- or girl-friend, I sometimes wonder. I wonder whether this idea we had, that computers would free us from the slavery of degrading tasks and give us free time during which we could climb on the scale of human dignity, was realistic. I know, I am speaking as an old man, I should stop now; I promise that nevermore will I look back to the past when writing for Tia Sang. In the hope of being forgiven, may I offer the reader the cartoon below that I found on the web and which is very much to the point.

JIM CRONIN, FRIEND OF VIET NAM, OUTSTANDING PHYSICIST, EXAMPLE OF HUMAN DIGNITY22

James Watson Cronin, 1980 Nobel laureate, passed away on August 25th, 2016. By having added elegance to his extreme intellectual and moral rigour, by having added grace to his generosity and tolerance, Jim will remain for all of us an outstanding example of human dignity. I have been close to Jim over the past fifty years. The first time I met him was in Princeton a couple of years after he and Val Fitch, together with René Turlay and James Christenson had discovered CP violation in kaon decays. Their experiment had measured the magnitude of the CP violating decay amplitude and several new experiments were then busy measuring its phase. At that time, I had just switched from nuclear physics to particle physics and I had joined one such experiment at CERN, led by Carlo Rubbia and Jack Steinberger. Later on, I had again the good fortune to work in the same domain as Jim was, the production of large transverse momentum bosons in hadron collisions, a probe of the quark and gluon structure of nucleons. It gave us several opportunities to meet, such as in a working group on a possible proton-antiproton collider in the US that Jim had convened. At the end of the last century, Jim,

22 Published in Tia Sang 16 together with Alan Watson, designed a major observatory near the Argentinean Andes, the Pierre Auger Observatory, aimed at detecting the very highest energy cosmic rays reaching the Earth. It was in this context that Jim became close to Viet Nam, of which he had been a long time friend, and close to the small research team that we had put together in Ha Noi. Rather than reporting on his life and scientific achievements, which has been done superbly in recent accounts [1], I shall concentrate on this period of his life, and particularly on his relation with Viet Nam, mostly on the basis of personal recollections [2]. Jim and Alan had convinced themselves in the early 1990s that progress in cosmic ray physics was requiring the construction of a very large observatory, which would have sufficient sensitivity to detect the highest energy extra galactic cosmic rays and sufficient angular resolution to reconstruct where they were pointing from. Remembering the time when they were working on such a proposal, Jim said: “I was very idealistic and very very discouraged with the role of our government in the Viet Nam war; so I was determined to somehow engage Viet Nam and other developing countries in this proposal to really make a very large experiment to measure the very highest energy cosmic rays. It had to be large because the rate of high energy events is something like one per square kilometer per century, so you need a very large area in order to catch some of these rays. So Alan Watson and I made a trip to Viet Nam in 1994 to try to get the Vietnamese interested in working on this experiment; and the thing we offered was to have them select somebody to come and work on the design of the experiment which was being planned.” Jim had always been allergic, in his earlier career, to very large experiments that bring together physicists by the hundreds, as “big science” had been more and more demanding in the recent years. However, in the present case, there was no other choice: “Once you have the passion to do something, he said, you have to do whatever it is that is necessary to achieve your goal.” His trip to Viet Nam had resulted in having a young physicist from the nuclear institute in Da Lat, Huỳnh Đông Phương, join him and his team for six months to work on the observatory design studies. It also had initiated, with the help of Tran Thanh Van and Nguyen Van Hieu, steps that would soon lead to a framework agreement of possible collaboration, to the writing of which Vo Van Thuan had played an important role. Around that time, Tran Thanh Van, in the context of the Rencontres du Viet Nam, had organized a school in Ha Noi, aimed at introducing young Vietnamese students to the physics of cosmic rays. However, as Jim said, “The point was that although the Vietnamese students were interested in the experiment, they really had nobody of any experience nor did they have any leadership to really get them involved. So it was very very disappointing for me. ” I remember, at that time, while I had just completed my term as director of research at CERN and was working on superconductivity, having traveled with Jim from Orsay to Paris. He had told me about his effort to get support from UNESCO to help science blossom in developing countries, in particular in Viet Nam, which, for both of us, was a symbol of resistance to the unjust cruelty that history had made it to endure. He also told me about his contact with Pierre Auger’s daughter and the admiration he had for her father who had died on Christmas eve in 1993. I happened to have met Pierre Auger on several occasions – he was already nearly blind at the time – in the context of a radio programme, Les Grandes Avenues de la Science Moderne, which he was running and to which I had contributed. I told Jim about this experience. Jim welcomed the birth of our small team, at the turn of the century, as what he called a “miracle”, much exaggerated and much too kind a word. We were at that time hosted at the Institute of Nuclear Science and Technology, on Hoang Quoc Viet, and had chosen as name VATLY, both meaning physics in Vietnamese and being an acronym for Vietnam Auger Training LaboratorY. Again quoting from Jim: “Vietnam, for wanting to reestablish basic fundamental research in Viet Nam; Auger, a very good focus for training because cosmic rays are everywhere – you don’t have to go to an accelerator – that is a most beautiful thing; Training, it was the main point, training youngsters in a country that had been ravaged by wars for many many years and where all around you find enthusiastic bright young people”. Jim was highly appreciative, exaggeratedly I must say, of what we had achieved at the time, in particular our detailed measurements of the cosmic muon flux, which had enjoyed an unexpected interest because Ha 17

Noi happens to sit on the geomagnetic equator where the rigidity cut-off is maximal. He also highly praised our implication, in addition to analyses of the Auger data, in measurements performed at home, using instruments that we had assembled on the roof of the institute, such as “the beautiful curve in Nhung’s master thesis showing proportionality between Cherenkov light and path length”. He commented in this context “What they are doing is not just sitting in front of computer screens – this is a most important thing to get people away from the computer – they have been very succssful at adopting as a kind of philosophy the idea that you can make calculations and so forth, but if you don’t build a beautiful apparatus to collect the data you will never be able to replace them by any amount of software work ”. The first important results of the Pierre Auger Observatory made the front page of the Science magazine, a prestigious American scientific journal, and, on the same day, November 9th, 2007, Tien Phong was posting a picture of our small team on its front page, commenting about our participation in the Observatory research. Jim was very proud about that and I heard him mention it on several occasions.

In Summer 2006, Tran Thanh Van and the Rencontres du Viet Nam organised a conference in Ha Noi that brought together physicists from all over the world, to discuss recent advances in particle-, astroparticle- and astro-physics. Diep reported about the work of our young team. On this occasion, Jim, together with Nobel laureate Klaus von Kitzing, met the President of the state, Nguyen Minh Triet. They told him that the time had come for Viet Nam to contribute more to the world’s scientific and technological development. Jim gave a lecture at the Viet Nam National University in which he emphasized that Viet Nam needs to provide more profound scientific education and create more favorable opportunities for scientists while developing appropriate policies on working conditions and salaries in order to attract talented people and avoid the brain drain of excellent domestic scientists leaving for foreign countries. This 2006 visit to Viet Nam was also for us the opportunity to show Jim around Ha Noi, to take him to Ha Long Bay and to spend with him unforgettable moments. Jim used to say how thrilled he had been to see us develop and realise his dream of trying to get the country involved in a little bit of science of very high quality. We will always remember him with great respect and devotion, aware as we are of the immense debt we owe to him and to the Pierre Auger collaboration, without whom our young research team would have been unable to come of age.

[1] Here are a few relevant references: http://www.nature.com/nature/journal/v537/n7621/full/537489a.html https://news.uchicago.edu/article/2016/08/27/james-w-cronin-nobel-laureate-and-pioneering-physicist- 1931-2016 http://www.nytimes.com/2016/08/31/science/james-cronin-who-explained-why-matter-survived-the-big- bang-dies-at-84.html? http://physicsworld.com/cws/article/news/2016/aug/26/nobel-laureate-james-cronin-dies-at-84 https://www.nobelprize.org/nobel_prizes/physics/laureates/1980/cronin-bio.html His Nobel lecture is found at https://www.nobelprize.org/nobel_prizes/physics/laureates/1980/cronin-lecture.html [2] Most quotes are from an address given by Jim in Orsay (France), a video of which can be found at http://webcast.in2p3.fr/videos-lagarrigue_2008_auger_jim _cronin?cmb_video_liste=5746

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From left to right and top to bottom: Jim lecturing at VNU and visiting President Nguyen Minh Triet in August 2006; Val Fitch and Jim at the Nobel ceremony in December 1980; the picture of our small team that was posted on the front page of Tien Phong in November 2007; a recent picture of Jim.

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From left to right and from top to bottom: On the roof of the Institute (wuth Jim Beatty, Dong and Diep; at dinner in Diep’s place; on the boat in Ha Long Bay; in the telescope shed on the roof of the institute; at the Museum of ethnography. All these pictures were taken in Summer 2006 on the occasion of Jim’s visit to Ha Noi. The last picture (bottom right) was taken in 2008 in Orsay on the occasion of my being awarded the André Lagarrigue prize.

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Other pictures of Jim at different periods of his career.

MATHEMATICS AND POETRY

To two of my closest friends, Hoang Tuy, a mathematician, and Viet Phuong, a poet

Many mathematicians have alluded to a kind of complicity between mathematics and poetry. Two of the most famous quotes are “It is impossible to be a mathematician without being a poet in soul” (Sofia Kovalevska) and “It is true that a mathematician who is not somewhat of a poet, will never be a perfect mathematician” (Karl Weierstrass). At first glance, such statements may sound surprising to many. What is usually meant is that mathematics and poetry share the power of imagining new worlds, at variance with science that has as a mission to describe the “real” world (even if scientists better have a good imagination, but that is not the point). The ability of imagining new worlds gives mathematics and poetry the power of making us feel that they give access to a kind of knowledge different from pure rational knowledge, deeper, closer to the mystery of the world; we are prompt to oppose the pure perfection of mathematical constructions and the moving beauty of some verses to the cold materialism of science. Let us explore what this is hiding.

Early days Both mathematics and poetry are considered to be born in Mesopotamia (today’s Iraq) some 5 to 6 millennia ago where writing first appeared. In fact they were inheriting from an oral tradition that had started long before, some ten millennia ago. Soon after Mesopotamia, Egypt hosted a civilisation of similar advancement as Mesopotamia but less richly documented, papyrus being much less resilient than clay tablets. In addition to documents used in the daily life, such as inventories or technical manuals, both include many texts of a religious or mythical nature that obey formal constraints characteristic of poetry. The mystery surrounding the creation of the world has always been a major source of inspiration and an incentive to imagine mythical and legendary new worlds. Mathematics also were well advanced, but they were utility-driven, mostly recipes aimed at solving practical problems. Some three millennia later, China and Greece will be first to produce curiosity-driven mathematics. In Mesopotamia, some five millennia ago, writing evolved from ideograms to a syllabic alphabet. Namely, ideograms were no longer used exclusively to name an object or some concept, but also as syllables from which to construct plurisyllabic words having nothing to do with the original object or concept. Several hundreds of clay tablets are known to us. At the same epoch, the themes addressed expanded from technical manuals and lexical lists to include history reports, moral lessons, religious hymns, prayers and lamentations, myths and epics. Among the most famous texts is the Gilgamesh epics (12 tablets), that tells about the fights of a king who was seeking immortality; while succeeding in defeating the gods, he failed to become immortal. Mesopotamians, like most early civilisations, believed in a multitude of gods who had created men and the Universe, which they were ruling, and were fighting among themselves for power. Poetry fills a major part of Mesopotamian literature, with constraints in the form and the rhythm revealing a long oral tradition preceding the apparition of writing. Mesopotamian arithmetic was also quite advanced but, at variance with literature, it was purely utility-driven. It was based on sexagesimal numbering (we inherited from it our way to measure angles and time) with a sign for 1 and a sign for 10 but no sign for zero. The sign for 1, the unit, might mean 60n for any integer n, including negative: it might mean 1/60 or 1 or 60 or 3600, etc. Only the context was telling its value. There were no formulas, no equations, only practical algorithms based on tables (of squares, of cubes, of reciprocals, of power laws, etc). For example, a tablet shows a calculation of √2 to 3 sexagesimal figures as 1+24/60+51/602+10/603=1.41421296. Geometry also was quite advanced, again in a purely practical form. Mesopotamians knew how to calculate simple areas and volumes and used either 3 or

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3+7/60+30/602=3.125 for π. They knew how to convert lengths into solar time and were recording eclipses as well as rising and setting stars and planets. From what we know of Egyptian mathematics, they were in a state very similar to Mesopotamian, except for using a decimal numbering system and for being behind by a (very) few centuries. For ancient Egyptians, to name was to give life, they had a strong belief in the power of words. Scribes were forming a literate elite. As many of the documents available to us are paintings found in tombs, numerous funerary poems designed to protect and nurture souls in their after-life add to the themes found in Mesopotamia. In China, during the first millennium BC, under the Zhou dynasty, mathematics evolved from a set of recipes, similar to what they were in Mesopotamia and Egypt, to a more modern form. They were one of the Six Arts that students were required to master. Chinese have been first to use negative numbers and decimals and to develop algebraic geometry. They faced the zero/infinity issue by addressing the problem of defining what is a geometrical point. They demonstrated Pythagoras theorem. They developed arithmetic and algebra to a high level of sophistication to serve the needs of astronomy. The Zhou Yi, based on hexagrams related to binary numeration, was used for divination, to determine divine intent. The Shijing is the oldest existing collection of Chinese poetry, compiled by Confucius, with 305 poems from 11th to 7th centuries BC. It contains short lyrics in simple language, and hymns and eulogies which praise the founders of the Zhou dynasty or are used in sacrificial rites or at banquets. The former are often ancient folk songs that speak of love, longing for an absent lover, soldiers on campaign, farming and housework, and even political satire and protest. They are written in four syllables meters, with a caesura in the middle and end rhyming. Homer and Hesiod dominate Greek poetry in the eighth century BC. Real or legendary, Homer was going from village to village, singing his poems, accompanied by a musician; he was blind and is remembered as the author of Iliad and Odyssey, first pieces of western poetry, of a particularly noble and strong style. Hesiod wrote Theogony, concerned with the origins of the world and of the gods, and Works and Days, praising honest labour, hard work, honour and non-violence. It is a major source on Greek mythology, farming techniques, early economic thinking and astronomy. In the sixth century BC, Thales has been first to lay down guidelines for the abstract development of geometry and Pythagoras first to realize that a complete system of mathematics could be constructed, where geometric elements correspond with numbers. Problems related with irrational numbers (squaring of the circle, doubling of the cube) and with infinity (Zeno paradox of Achilles and the tortoise) were addressed. The Hellenistic period (starting at the fourth century BC) witnessed one of the most important revolutions in mathematical thought of all time. In 387 BC, Plato established the Academy where Aristotle’s work on logics dominated the following thousand years. The most important contribution of the Greeks has been the idea of proof, and the deductive method of using logical steps to prove or disprove theorems from initial assumed axioms. In summary, over two millennia ago, mathematics and poetry had reached a level of perfection enabling them to imagine/create new worlds in a purely curiosity-driven mental process. The power of words in triggering strong emotions had made poetry a privileged instrument for religions and metaphysics to make us believe that they could shed light on the mystery of the world. The feeling of beauty and perfection conveyed by mathematical constructions could also make us think that they are providing evidence for the divine nature of creation. Right or wrong, this has been imparting to both mathematics and poetry a role of utmost importance to mankind as making us feel to approach in their company the borders of the unknown.

The magic of mathematics The whole of mathematics is made of inventing new concepts, new structures. At variance with science, which is dependent on the phenomena that it aims at describing and at understanding, mathematics can abstract themselves from such phenomena, making axioms of the helping hand that nature gives them to start their explorations. While science must constantly revise its hypotheses, mathematics are immortal. One starts from the real world, and imagines new worlds: positive integers, 22 negative integers, rational numbers (fractions), real numbers (irrationals), complex numbers, quaternions… One starts from three dimensions and imagine a fourth one, or more; one starts from our familiar (Euclidean) way of measuring distances and imagine different metrics; one invents structures such as groups, rings, ideals, metric spaces, topological spaces, knots, fibre bundles, etc. Sometimes, imagination is utility-driven; sometimes it is curiosity-driven. Sometimes (indeed quite often) the new concepts find applications in describing the real world, some other times, they don’t. As an illustration of how far mathematicians can push their imagination, they even question the very bases of the logics on which traditional mathematics are constructed. To understand it in simple terms, think of the liar paradox, which simply says “This statement is false” (A). If A is true, then “This statement is false” is true. Therefore A must be false. If A is false, then “This statement is false” is false. Therefore A must be true. Either way, A is both true and false, which is a paradox. It triggered many comments among contemporary mathematicians and logicians and is related to Gödel’s and Tarski’s theorems on indefinability. Essentially, arithmetical truth cannot be defined in arithmetic. Along this line, multiple-valued logics have been explored, in which there are more than two truth values (true and false), including “fuzzy” logics in which truth values may be any real number between 0 and 1. Another illustration is infinity and infinitesimals, which have always intrigued mathematicians and philosophers. Just count 1,2,3… and here it comes, with its counter-intuitive properties, such as there existing as many integers as rational numbers. Incidentally, think of Hotentots who use only three numbers, one, two and many: how could they think of infinity? It was not until the beginning of the last century, with Dedekind, Cantor, Frege and others that the issue was clarified. Physics makes a heavy use of infinitesimals and infinites, but only as tools. For the concepts it uses to describe the world, physics needs no infinity. In the middle of the 17th century, Descartes argued that “It is necessary to conclude that God exists because I, a finite being, could not have the idea of something infinite, unless it has been put in me by something that is really infinite”. It is difficult for us, in the 21st century, to adhere to such a twisted argument but this idea that the purity of mathematics carries something of a divine nature is still with many of us: a few decades ago Dirac, Wigner, Einstein and Chandrasekhar wondered why the Universe is “understandable”: “How can it be that the human mind invents abstract concepts and finds them beautiful? And why such concepts happen to have their exact equivalents in Nature?” If we see clearer into such matters today, it is not for being cleverer than they were; we simply understand better how our brain works. This is to the credit of neurobiologists: the 1994 “astonishing hypothesis” of Francis Crick, that we are made of nothing but atoms and that the physics and chemistry of our cells govern our body and our mind has become today an evidence. We are no longer afraid to be taken for obtuse materialists when we try to take this evidence seriously. In particular, this made us better aware than we could have been earlier of the circular, self-referential nature of knowledge: we tell ourselves a story that tells us how we tell ourselves a story that tells us… Rather than lessening the mystery of the existence of the world, it has made its profound nature more apparent: to the question: “Why a world rather than nothing?” we know now that we will never be able to give an answer, indeed we are unable to give a meaning to the question within the circular nature of our knowledge. Leibniz was wondering that there must be a reason in Nature for this world to exist rather than nothing. We now have given up the hope that there might be a “reason”; reasons are invented by us. To Chandrasekhar and his friends, we object that we have forged (not discovered) logics and mathematics precisely with the aim of observing and describing the world (of which we are part): why should we wonder about their miraculous efficiency? Which yardstick should we use to measure the size of this miracle? Wittgenstein wrote that “The Mystery is not how is the world (it is the role of natural sciences to tell) but that it is; of what one cannot speak, one must keep silent”. This invitation to keep silent addresses philosophers: pretending to understand the Mystery can only generate waffling. But poets and mathematicians are welcome to make us feel that they take us close to the border with the unknown, that they make us feel the breeze that is blowing from the other side.

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There have been many attempts to relate beauty to mathematics, in order to free ourselves from its apparent subjectivity. One of the most famous is the Fibonacci sequence, where each member is the sum of the two preceding members, Fn=Fn-1+Fn-2. The ratio of two successive members approaches quickly what was known as the “divine proportion” or “Golden ratio”, φ=½(1+√5). Many philosophers and artists have seen it as the basic yardstick that governed the creation of the world.

The magic of poetry There exist obvious similarities between the development of mathematics and poetry in the collective mind of mankind (our culture) and in the mind of a young child. Indeed, ten millennia ago, the human brain was already genetically the same as it is today: we are talking of acquired knowledge, not innate. But mankind had to learn the hard way, it took millennia, while the young child is being taught by his parents, family, friends and teachers, all pre-digested. Yet, I find it interesting to note how early children (and adults of low education) are accessible to puns, to songs, how easily they are moved by poetry. How important a role playing has in their way of learning. How easily they are intrigued by questions raised by mathematical creations, infinities, higher dimensions, time reversal machines, etc. Simply think of the very popular success of science-fiction to be convinced of it. The constraint of extreme rigour is the only, but fundamental constraint that mathematical creation needs to obey. On the contrary, constraints imposed on poetry are diverse and imposed by the poet himself. What is surprising is that instead of degrading the quality of poetic creation by restricting its freedom, they enhance it by imposing the use of images, metaphors and suggestions that exalt its beauty. Such constraints take very different forms in different languages. For example, an important part of the beauty of Chinese and Japanese poetry is in the harmonious arrangement of the ideograms. Allow me to use two poems of Hô Chi Minh as an illustration:

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Chiều tối Chim mỏi về rừng tìm chốn ngủ, Chòm mây trôi nhẹ giữa từng không. Cô em xóm núi xay ngô tối, Xay hết, lò than đã rực hồng. Nghe tiếng giã gạo Gạo đem vào giã, bao đau đớn Gạo giã xong rồi, trắng tựa bông. Sống ở trên đời, người cũng vậy, Gian lao rèn luyện mới thành công.

While there is much more in poetry than playing with words, there is a close complicity between the two. A famous example is a poem, Đi thuyền, written by Hàn Mặc Tử (1912-1940), which can be read backward as well as forward, or even omitting the first two or four syllables of each verse.

Bèo trôi nước giợn sóng mênh mông Cỏ mọc bờ xa bóng liễu trông Chèo vững thiếp qua vời khổ hải Chí bền chàng đến vận trung không Theo lần nguyệt xế mây mờ mịt Hoạ đáp thông reo trống não nồng Neo thả biết đâu nơi định trước Bèo trôi nước giợn sóng mênh mông

Mông mênh sóng giợn nước trôi bèo Trước định nơi đâu biết thả neo Nồng não trống reo thông đáp hoạ Mịt mờ mây xế nguyệt lần theo Không trung vận đến chàng bền chí Hải khổ vời qua thiếp vững chèo Trông liễu bóng xa bờ mọc cỏ Mông mênh sóng giợi nước trôi bèo

Parallel sentences, which are omnipresent in Vietnamese culture, are another notorious example of this kind of skills. In a famous poem, Ông đồ, written in 1936, Vũ Đình Liên deplores the loss of interest of the young generation for this form of poetry23:

Năm nay đào lại nở Không thấy ông đồ xưa Những người muôn năm cũ Hồn ở đâu bây giờ?

A last Vietnamese example is a poem by Thanh Hai that has the right tones to be transcribed as a song without any change:

Mọc giữa dòng sông xanh Một bông hoa tím biếc

23 This year anew blossom the peach trees/But Old scholar is not coming/ Souls of these days gone by/Where did you go? Nobody knows. 25

Ơi con chim chiền chiện Hót chi mà vang trời Từng giọt long lanh rơi Tôi đưa tay tôi hứng.

Playing with words has a long history: witness a plate found in Pompei, dated 79 AD, listing five words arranged in a nice symmetric pattern, which can be read indifferently in any direction. When I was a kid, I learned at school a poem meant to make me remember the first 125 decimals of π! The idea is to count how many letters there are in each word. Of course, a completely useless exercise, but I still remember the first two verses:

Que j’aime à faire apprendre ce nombre utile aux sages! Immortel Archimède, artiste ingénieur,

In France, the Oulipo movement, founded by Raymond Queneau and François Le Lionnais, a poet and a mathematician, is famous for prowess of a same kind: La Disparition is a novel containing no e, the vowel that is most used in French language; Hundred thousand billion poems are made of ten poems of which you may choose at will the verses to build your own; there exist novels which can be read in billion different ways by using unnumbered pages. Holorhyme poems are made of verses that sound the same but have different meanings, such as: Par les bois du djinn, où s'entasse de l'effroi, Parle et bois du gin, ou cent tasses de lait froid, which means: By the woods of the djinn, where fear abounds,/Talk and drink gin, or a hundred cups of cold milk. Palindromes are sentences that read the same backward as forward, such as: Do geese see God? Was it Eliot's toilet I saw? Murder for a jar of red rum. Never odd or even. Lewis Caroll (1832-1898) was both a poet and a mathematician and is famous for having written Alice’s Adventures in Wonderland and Through the Looking-Glass. See how, in The Hunting of the Snark, the Butcher explains to the Beaver why 2 + 1 = 3: ―Taking Three as the subject to reason about— A convenient number to state We add Seven, and Ten, and then multiply out By One Thousand diminished by Eight. The result we proceed to divide, as you see, By Nine Hundred and Ninety and Two: Then subtract Seventeen, and the answer must be Exactly and perfectly true.” To those who did not appreciate his sense of humour, he answered: “Some perhaps may blame me for mixing together things grave and gay, but I do not believe God means us thus to divide life into two halves”. Playing with words has often be used as a way to turn around censorship; remember these verses aimed at wishing long life to Bac Hô at a time when it was not politically correct to do so:

Cụ già thong thả buông cần trúc, Hồ rộng trời in mặt nước hồng. Muôn vạn đài sen hương bát ngát, Tuổi già vui thú với non sông.

More recently, Cao ni ma (which has an obscene meaning other than the official “Horse of grass and mud”) has been a symbol of the fight against Internet censorship in China.

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One could go on endlessly quoting examples of mathematicians and poets playing with words for their pleasure. But what makes us feel moved by a verse? A mixture of what it says and what it does not say but simply suggests, a mixture of its music and of its rhythm. Rather than trying to analyse it, which would be making insult to poetry, I would like to end this exploration by simply quoting a random sample of some of the most famous verses that come to my mind24. However, I am unfortunately unable to do so in Vietnamese. All I can do instead is to simply remark how many of the verses of Kieu are deeply imprinted in the heart of my Vietnamese friends, and to quote two for them:

Cỏ non xanh rợn chân trời Cành lê trắng điểm một vài bông hoa Nguyen Du

The Two Cultures and the Scientific Revolution In 1959 British scientist and novelist C.P. Snow delivered a famous and influential lecture arguing that the intellectual life of the whole of western society was split into two cultures – sciences and humanities – and that this was a major hindrance to solving the world's problems. “So the great edifice of modern physics goes up, and the majority of the cleverest people in the western world have about as much insight into it as their Neolithic ancestors would have had‖. More constructive and less provocative reactions to Snow’s comments have been expressed in the recent years towards reintegration of literary and scientific thinking. It remains true that in many domains of human activity the two communities speak a different language and fail to understand each other. Our brief stroll across the landscapes of mathematics and poetry should have made us aware that both deserve our appreciation: we must teach our children to love both humanities and sciences, both techniques and arts, both poetry and mathematics! It will make them better equipped to face the difficulties that the globalised and constantly changing world keeps in store for them. It will make the world friendlier.

Mesopotamian tablets: one of the Gilgamesh epics (left) and one showing the value of √2 (right).

24 For the reader familiar with western languages, here are a few of these: To see a world in a grain of sand,/And a heaven in a wild flower,/To hold infinity in the palm of your hand,/And eternity in an hour/William Blake. I know that I shall meet my fate/Somewhere among the clouds above;/Those that I fight I do not hate,/Those that I guard I do not love/William Butler Yeats. Ariane, ma sœur, par quel amour blessée/Vous mourûtes aux bords où vous fûtes laissée?/Jean Racine. Ich weiß nicht, was soll es bedeuten,/Daß ich so traurig bin,/Ein Märchen aus alten Zeiten,/Das kommt mir nicht aus dem Sinn./Heinrich Heine. Nel mezzo del cammin di nostra vita,/Mi ritrovai per una selva oscura,/Ché la diritta via era smarrita/Dante Alligheri. And when wind and winter harden/All the loveless land,/It will whisper of the garden,/You will understand/Oscar Wilde.

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Ancient China: Zhou Yi hexagrams used for divination (left) and a poem of the Shijing (right)

Ancient Greece: Homer (left), a scene of Odyssey (centre) and Hesiod (right)

Plato’s Academy as imagined by Raphael, including Epicures (2), Pythagoras (6), Socrates (12), Plato (14), Aristotle (15) and Euclid or Archimedes (18).

Playing with words: Raymond Queneau’s Hundred thousand billions of poems (left), Vietnamese parallel sentences (1906, centre) and a stone plate found in Pompeii (79 AD, right)

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Fibonacci sequence: analogy between Fibonacci spirals and the core of a sun flower (left); representation of Fibonacci sequence as the size of successive squares (right) in a ratio that tends to the Golden ratio.

VIET PHUONG PASSED AWAY25

It was Hoang Tuy, some ten years ago, who introduced me to Viet Phuong. At the time, our small research team was working at the Institute of Nuclear Science and Technology and we had invited them to visit us. We spent two hours or so listening to them talking about their experiences and memories of the times when the young nation was coming of age, and telling them about our concerns and hopes, before sharing a lunch with them. For me, to meet a witness of Ho Chi Minh’s times who had been so close to Pham Van Dong for over half a century was an immense privilege and I was eager to hear from him how he felt when looking back at all these years. The respect that he was inspiring to me could have kept us distant from each other; but, on the contrary, we immediately became close friends. The main reason was, I guess, the passion he had for the French language and the love I have for poetry. It soon became for us, Hoang Tuy, Viet Phuong and I, an habit to share lunch together, once in a while. I would bicycle to Tuy’s home, leave my bicycle there, and we would take a taxi to pick up Phuong at his place and go to a restaurant, never the same. Phuong was vegetarian, it was a challenge to discover a new vegetarian restaurant each time we met. I am ten years younger, I should rather say less old, than they are, and I was hanging on every of their words. We were sharing amazingly close views on the world in general, and on Vietnam in particular: humanism and love for the country, a critical but constructive mind, determination to progress and to see the good side of things rather than lamenting about what is wrong. I do not remember we ever disagreed on anything but Tuy was prompter to rebell and be offended about injustices and dysfunctions, Phuong was more tolerant; he had since long sorted out the good from the bad and concluded that the balance sheet leant on the positive side, which made him a kind of wise old man looking from a distance at present turbulences. In several occasions, I heard him quote Aragon’s poem, Que la vie en vaut la peine, as a profession of faith. This poem in my mind sums up so faithfully how he felt, allow me to quote two stanzas that take today a particularly deep dimension26:

C'est une chose au fond, que je ne puis comprendre Cette peur de mourir que les gens ont en eux Comme si ce n'était pas assez merveilleux Que le ciel un moment nous ait paru si tendre.

Oui je sais cela peut sembler court un moment Nous sommes ainsi faits que la joie et la peine Fuient comme un vin menteur de la coupe trop pleine

25 Published in Tia Sang 26 It is something, after all, that I cannot understand/ this fear of death that people have in them/as it were not wonderful enough/that the sky, for a while, looked to us so tender./ Yes, I know, it may sound too short, a while;/ We are made in such a way that joy and sorrow/ leak out of the overflowing cup as a deceiving wine/ and the sea for our thirst is but a beginning. 29

Et la mer à nos soifs n'est qu'un commencement.

Often, I tried to convince Phuong to write his Memoirs, conscious as I was of the treasure they would have meant for the history of Viet Nam. But I failed; when I was asking him for the reason for his reluctance, he was remaining evasive; to each possible reason I might imagine and suggest, he would simply agree that there was a bit of it. I am at an age when one sees one’s friends disappear, one after the other; tomorrow may be my turn; I am at an age when the past takes more room than the future in our thoughts and feelings; and each death takes away a bite of them, it is a crual experience; with Phuong being no longer with us, a big piece of Viet Nam’s memory disappears into oblivion. For us, his friends who loved him tenderly, it means deep sadness and sorrow.

WISHES FOR TÊT 201827

Têt is the time to express our wishes for the New Year. My dearest wish this year is to see the nation progress on the way to free expression and free speech. I know a young Vietnamese scientist, doing research in Viet Nam, who recently submitted an article on Vietnamese fundamental scientific research to a magazine specialized in science and technology (it was not Tia Sang). It was an excellent article, well documented, intelligently organized and identifying clearly points that deserve some effort to achieve improvement. The article was rejected. The reason given was that it was painting too black a picture of Vietnamese science. It is not by painting reality in pink that we shall progress. It is by having the courage to face the truth and the determination to bring light into the dark. The censor who prevents the young generation to identify openly the flaws and weaknesses that need to be fixed for the nation to progress is an enemy of the country. On the contrary, who has the courage to face the truth and the determination to progress is its friend. Gagging the young generation is castrating the nation intellectually. Inventing taboos and hiding the truth is counter-productive. Viet Nam can be proud of its past and present history and has nothing to hide. We all make mistakes some time; rather than hiding them, we need to learn from them. Wisdom is for the old age, enthusiasm is for the young age, we need both. There will be no progress in the country toward more human dignity if we keep preventing the young generation to express themselves. We should not only stop doing so but even more, encourage them to speak up. The nation has to face outstandingly difficult challenges in a constantly changing world. To succeed, it needs to open its eyes and to open its mind. In 2017, Viet Nam ranked 175 in the World Press Freedom Index of Reporters without Borders, just in front of China, Syria, Turkmenistan, Eritrea and North Korea. My dearest wish this year is to see Viet Nam jump out of this rear guard and restore freedom for the young generation to identify clearly what they need to fight for in order to make the country progress on the way to intellectual and moral rigour and on the way to human dignity. I know that we can count on Tia Sang to help with

27 Pronounced at Tia Sang, Têt 2018. 30 such a move and, at the same time as I thank its staff for welcoming us and making us feel at home among them, I wish them to find the strength to do so.

WISHES FOR TÊT 201928

Last night, I dreamt I had died. I was proceeding toward a large gate decorated with multi-coloured light-emitting-diodes that started flickering as I was approaching. At the same time, a sweet feminine voice, of the kind of those that make announcements in airports, emerged from an invisible loudspeaker: “Welcome to the afterlife world. Before entering, be kind to proceed to the keyboard on the right side of the entrance gate and type in the required information. The gate will open automatically as soon as you are done.” There was indeed a keyboard and a screen in a niche carved in the wall next to the door. I entered my name, I ticked on “male” although I doubted that such qualification was still appropriate, and I entered my birth date; but I did not know what to type for my death date. After three unsuccessful attempts, I clicked on the FAQ option where I learned that if I did not know my death date, I might leave the field blank, which I did. Next question was: “Mobil-phone number*?” The asterisk, as was explained in a footnote, meant that it was compulsory to provide the information. As I never had such a gadget, I typed in 999 but it was refused as having insufficient number of digits; so I added random numbers until the information was accepted. Next question was “Religion?” I typed “none” but a new message appeared: “Please enter one of these: Buddhist, Muslim, Christian”. There was no asterisk, I left the field blank. Next was: “Nationality*?” I typed “French” but it was refused with the mention: “You have not been a French resident for over fifty years; please type proper information”. Well, I tried “Vietnamese” and, to my surprise, it worked. A Vietnamese flag covered the whole screen and below the central star one could read: “If you are member of the Party type 1, of the Fatherland Front, type 2”. I typed 0. Next came, accompanied by a few tones of Beethoven’s Ode to Joy: “If you registered at Lac Hong Vien cemetery29 in Ky Son enter your password and ID number, the gate will open automatically”. At the same time a smiley face appeared with a Google ad saying “Lac Hong Vien Eternity online, over 100’000 followers, as many likes”. Next came: “Profession?” As soon as I had typed “physicist” I was asked whether I had paid my yearly fee to the Vietnamese Physical Society; as I had said that I was Vietnamese, I felt it would be too complicated to explain that I was in fact French and that the VPS excludes foreign members… I left the field blank. Next, I was asked if I had ever read books promoting politically incorrect ideas; I was afraid to confess that I did, I left the field blank. The last question was “Social class?” Fortunately, I remembered article 2 of the Vietnamese Constitution mentioning the alliance between the working class, the peasantry and the intelligentsia; but I felt that it would have been too pretentious to claim being either a worker or an intellectual and, remembering that my grand-grand-parents were peasants in the south-west of France, I typed “peasantry”, hoping that their legacy could be sufficient an excuse. But the screen complained: “Please provide correct information”… and again, I had to leave the field blank. I was then relieved to read that I was through filling the form, but a new message appeared: “In order to secure the information you have provided, please answer at least one of the three questions below*: 1) what was the name of your first friend? 2) what was the name of your first pet? 3) which is your favourite football team?” I never had a pet and I am not fan of football, but I remembered several friends in my early childhood: Philippe, Eric, Jacques… As soon as I finished typing “Jacques” and pressed “Enter” the screen flashed: “Sorry, we cannot let you in, too many fields have been left blank”.

28 Published in Tia Sang 29 https://english.vietnamnet.vn/fms/vietnam-in-photos/109099/photos--the-largest-cemetery-in-southeast- asia.html

31

I woke up, somewhat relieved I must confess, and I remembered the invitation of the Tia Sang editorial team to write a few words to wish a happy Têt to our readers; the theme this year was “Society in the digital era”. I did not know what to write. I had the impression that the world, digitized or not, was a bit out of control. Too many of our dreams have become the “past of an illusion”, such as the illusion that “all countries” could “unite”: Trump’s US are building a wall on their southern border and Nigel Farage’s UK turns its back to Europe. Even democracy is turning into an illusion in so many places in the world; in Trump’s US it has become plutocracy with a government in the hands of billionaires and everywhere populism is on the rise, demonstrating how easy it is to fool people. Vietnam fails to stop, or even to slow down the brain drain that it is enduring and to give the young generation the support they need to open their eyes and their minds on a world that keeps changing. Globalisation has brought to light the deep injustice that rules our planet, triggering migrations and wars. To fake optimism in such a situation seems to me irresponsible but pessimism also is out of place: Têt should be for all of us an opportunity to express our hopes, loud and clear, to prevent our dreams from becoming illusions, to make them “lift-off” as says the motto of the institute where I am working. Vietnam also has a nice motto: Independence, Freedom Happiness. Let us not be too ambitious, let us simply wish that these three words do not fall on deaf ears, do not go unheeded; let us make them become more than just words. Independence from the neo-colonialism of multinational companies eager to exploit our cheap labour. Freedom to say what we mean and to mean what we say, to inform ourselves of what others think in order to be better equipped to fight injustice and to defend the values in which we believe. Happiness to see a child smiling or the sun rising, happiness to live in peace with those we love, happiness to be still alive.

HOANG TUY, MY ELDER FRIEND30

I first met Hoang Tuy some sixteen years ago; I was in my fourth Vietnamese year; I met him several times in his office in the basement of the Institute of Mathematics and we immediately became friends, sharing the same views on the need for Viet Nam to improve the quality of its higher education, the same views on the difficult challenge that it represents, the same views on how to approach the problem. Since that time, our friendship has never failed. I am ten years younger than Tuy; short enough a time for us to understand each other in depth; but long enough a time for me to listen to him with the respect one owes to an elder friend. I was barely eight years old, enjoying the recent peace in a France that had just been freed from the German occupation, when he was eighteen years old, having to interrupt his university studies in Ha Noi because of the French war and to move to the South; he then started teaching mathematics in high school and entered the four decades of wars, starvation, pain and torment that Viet Nam was going to endure. Soon after we met, Tuy introduced me to Viet Phuong and the three of us got rapidly in the habit of sharing a lunch once in a while. By sharing with me what they have gone through over the past seven decades, they have made me love their country deep in my heart. These lunches were the occasion for us to exchange views on the situation of the country in general and of education and research in particular. The intellectual and moral values to which we attached importance were the same. It was also for me the occasion to learn about the state of mind in Vietnamese intellectual circles, to become familiar with the ideas expressed by people such as Nguyen Ngoc or Chu Hao, to whom they introduced me. It was also the occasion to learn about the debates in the Institute of Development Studies that Hoang Tuy had contributed to create and was chairing. It had to be dissolved two years after its foundation for being accused of making statements that were not in conformity with the Party line. I still do not understand such opposition to intellectuals who devote their life to the love of their country and to making it progress and develop; their in-depth understanding of its recent history, of which they have been actors, places them in a privileged position to know where to go next, which road to follow; their objectivity, their

30 Published in Hoang Tuy, Xin duoc noi thang, Nha xuat ban The Gioi, 2019 32 knowledge and their wisdom makes their analyses and their vision of the future highly respectable and worth of serious consideration; while true to the ideal of independence, freedom and justice that governed the birth of the nation, they understand that the world is changing: they know that instead of making the doctrine of yesterday become a rigid dogma, nations need to adapt its letter to the current social and geopolitical environment while respecting and preserving its spirit and the moral values on which it rests. In 2007, I had the honour to meet General Giap, who was eager to see education develop and its level improve in quality. I had listened to him plead for a change of style in Vietnamese universities; having taken my hand in his, he had told me to keep fighting. To me, Hoang Tuy and the circle of intellectuals to whom he was close were the heirs of his legacy. A few days ago, chatting with Tuy about what I intended to write in the present lines, he told me that his pride was to have never departed from his determination to say and write what he thinks. He added that such frankness had been, in occasions, causing him some trouble but that he never regretted it. To me, such demonstration of human dignity is calling for utmost respect: I see Hoang Tuy as a model to be followed at the same time as I have for him friendship and tenderness. The admiration that I have for Tuy and those of his generation who have contributed to the early years of the young Vietnamese nation is immense. The hopes they had, when they were young, for brighter tomorrows may have been partly deceived, but so much has been accomplished. Foreigners, including many Viet Kieus, who look at today’s Vietnam from far away, and young Vietnamese ignorant of the recent history of their country, as unfortunately quite a few are, wear blinkers: they are short- sighted, they only see what is close to them in time and in space; they lack the broad vision that is required to understand the country in depth. The lesson that Tuy and his friends teach us is a lesson of humility and optimism; an encouragement at looking always forward in a positive and constructive way rather than complaining about the many flaws that still need to be taken care of; an encouragement at pursuing what they have been tirelessly fighting for, while staying always true to the basic values of intellectual and moral rigour that make human dignity. When I think of Hoang Tuy, of Viet Phuong, of Dang Van Viet and of their destiny, I often remember a famous novel by Tomasi di Lampedusa: Il Gattopardo, The Leopard in English. The novel became famous in the mid-sixties when Luchino Visconti based on it one of the most beautiful movies of the past century, with Burt Lancaster, Claudia Cardinale and Alain Delon in the leading roles. Don Fabrizio, a Prince of the Sicilian aristocracy, witnesses the insurrection of Garibaldi’s red shirts, the ruling class abdicating their privileges and power to the middle class; he sees with tenderness and indulgence his nephew join the insurgents, animated by the romantic dream of a brighter tomorrow; he sees with sorrow and sadness the mediocrity and selfishness of some of the nouveaux riches replacing the tradition of nobleness and the sense of honour that had been his creed all along; he sees with a mixture of resignation and hopeful optimism his nephew getting engaged with the marvellous daughter of Sedara, a corrupted and ambitious dignitary of the new regime; and he muses with nostalgia, disenchantment and melancholy on the eternal return of history; all seems to be changing but in fact it all remains the same. In 2005, I had invited Tuy to visit our young astrophysics research team at the Institute of Nuclear Science and Technology that was hosting us. His exchanges with my young colleagues left a deep impression on them and they expressed the desire to learn more from him. At that time, he had been implied in advising the Government on matters of science and education and we had heard of his deep and thoughtful analysis of the weaknesses of the Vietnamese university system and of his pertinent recommendations aiming at overcoming the many obstacles. We asked him whether he would accept to answer a few questions for us, we would then publish the interview in our Newsletter, and he immediately and very kindly agreed. I have read it again before writing these few lines and I have been impressed by the acuity of the vision he had of the problems that need to be solved, by the pertinence of his comments and by the rightness of his analysis. At the same time, I must confess how depressing it is, when reading such documents, to note how little progress has been accomplished in more than thirteen years. The

33 interview can be accessed on the web31 and here I quote only a few sentences that I find still very much inspiring thirteen years after they were stated: […] In short, the style and atmosphere of university training differs deeply from what it is in most, at least in the better, universities around the world. This is probably why there is not a single Vietnamese university in the regional (South East Asia) list of the top 60’s. The problem is that this situation has now been lasting for decades. It has been like that for such a long time that many people consider it normal and do not even imagine that it might change. Today, in particular, several persons holding important responsibilities in the university system still think that an education of high quality is possible without research activities. […] If we want to modernize our universities and develop science, it is necessary to send a number of young talents abroad. […] However, this has generated a disastrous brain drain: those who are the most successful are offered attractive jobs abroad, both financially and in terms of independence and responsibility, and most of them do not return to the country. Under such conditions how could science, research and education, develop in Vietnam? In order to stop such a brain drain we must first recognize our failure to give our young talents sufficient motivation and loyalty to the country. The main reason is the absence of science centres of high enough a level, where they could do research in a good intellectual environment and with sufficient resources. […] The main weakness and the most negative factor in Vietnamese education and science, from kindergarten to university (including master and PhD training), is that teachers and researchers receive a salary that covers only one quarter of their needs, taking in due account the cost of living in the country and the standard of living that fits their position and role in the society. The remaining three quarters have to be found elsewhere. And of course they usually are. This means that it is not the money that is lacking but the way in which it is handled. We often hear ―everybody is complaining about low salaries, but they are still properly living‖ being used as an argument to preserve the present situation. This kind of management is so irresponsible that many suspect that the only reason for its being preserved is the need to hide corruption. Having had such an insane salary policy for decades, many bad habits have developed, some officers have become deceitful. […] We have seen in the past many good ideas that had been accepted higher up, fail badly once incompetent bodies had been entrusted with their realisation. Seven years ago, we invited Hoang Tuy and Viet Phuong to spend some time with us before sharing a lunch at a nearby restaurant. Nguyen Thi Thao, a young member of our research team, reported about the event in an issue of our Newsletter that starts with a quotation of Hoang Tuy: Our wage policy has no equivalent in the world. It despises those who are devoting themselves in the shadow to teaching and to growing fruits that others will harvest. Strange paradox of a country, which thinks nothing of its teachers and which, according to tradition, is supposed to praise teaching and highly respect knowledge. The account by Thao of Tuy’s and Viet Phuong’s visit can be read on the web32. She says how Tuy was talking about the need for a better education: Past and present were intertwining in his words, with morality and integrity as a leitmotiv, illustrated by many examples. He told us how essential it was for us, young scientists, to adhere to strict intellectual and moral rigour. The conversation was jumping over generations, mixing white and black hairs, united on the front of fighting for a better education. Happiness was radiating from our smiling faces. And Thao finds the right words to summarize the impression the visit had left on them: The youth in their words and in their hearts and the lucidity with which they were looking at the world around them were contrasting with their old age. We shall never forget the message that they handed down to us: integrity, creativity, freedom, democracy. Indeed, Tuy has kept in him this ability at marvelling which children have but which so many adults have lost; he has kept in him the freshness of emotions and the purity of judgement that are the assets of the youth. When blended with the wisdom of age and the experience of the outstanding chapter

31 https://vnsc.org.vn/dap/files/VATLYNEWSLETTER5.pdf 32 https://vnsc.org.vn/dap/files/VATLYNEWSLETTER15.pdf 34 of Vietnamese history that he has been witnessing over so many years, they make him the most lovable of men.

Hoang Tuy in 2005. Left: visit to our small observatory on top of the Institute for Nuclear Sciences and Technologies; he is seen there with Nhung and I. Right: in his office at the Institute of Mathematics, being interviewed by Diep.

Hoang Tuy and Viet Phuong in 2012, visiting us at the Institute for Nuclear Sciences and Technologies. From left to right: Hoai, Nhung, Pierre, Diep, Thao, Viet Phuong, Hoang Tuy and Hiep.

PRONOUNCED ON THE OCCASION OF THE AWARD OF A MEDAL BY THE MINISTRY OF SCIENCES AND TECHNOLOGIES

It is a great honour for me to receive this distinction and I am deeply grateful to those who had the kind attention to award it to me. I should like to start by thanking them from the deepest of my heart. Knowing that one has friends is the strongest support one can dream of. I should like to start by thanking Doctor Vo Van Thuan, the Head of the Institute where our laboratory is installed, for his entire and unconditional support, both material and moral, to our research. These thanks should include his staff and particularly Doctor Dao Tien Khoa who is responsible for fundamental research in the Institute and who follows very closely and friendly our progress. We are spending much effort in creating close links between our laboratory and the University because we are convinced that for research to progress such contacts are essential. In particular we are trying to help the creation of a programme of astrophysics lectures in Vietnamese Universities. It is not 35 always easy but I wish to thank those who give us their full support in this endeavour, I am mainly thinking to the Vice rector, Professor Bui Duy Cam, and to Professor Pham Quoc Hung. The support we are getting from the Ministry of Science and Technology, from the Academy of Sciences and Technology and from the Vietnam Atomic Energy Commission are of course gratefully acknowledged. To the help and support which we receive from Vietnam, I must add those which we receive from abroad from many friends we have around the world. First from the members of the international Auger Collaboration, with which we are associated, and particularly its funding fathers, Professors Jim Cronin and Alan Watson, who do their utmost to help us grow. Jim Cronin will spend the first week of August with us, and you will have an opportunity to meet him at this occasion. But also many other physicists who follow our progress with interest through the Newsletters which we issue regularly and who give us not only moral support but also, in many cases, very valuable material support: I am particularly thinking to the French CNRS, the World Laboratory with Professor Antonino Zichichi, the Rencontres du Vietnam with Professor Tran Thanh Van, the University of Catania, the Asialink programme and the Odon Vallet fellowships. Finally, from the deepest of my heart, I wish to thank my students for their enthusiasm and my wife for her patience. This award is for me the sign that our effort to create a group of fundamental research is welcome at the highest level in the country, something which pleases me enormously. In a country like Vietnam, which is developing so rapidly, one can understand that the priority goes to applied research rather than to fundamental research. However it would be very short-sighted to neglect completely fundamental research, it would mean that one does not understand that the quality of applied research rests on a solid basis of fundamental research, it would mean that one does not understand the importance for the country to support a program of excellence in order to increase the quality of research and of University training. In receiving this award, an award that really goes to the VATLY laboratory at least as much as to me, I hear the clear message that those who are responsible for science policy in the country are well aware of the importance of fundamental research and are willing to give it the support it deserves. I do not want to take too much of your time. But, having now spent many years in Vietnam doing my best to help the country and its science, I have of course many ideas and opinions, right or wrong, on what I think could be done to help Vietnam having the laboratories and the Universities that it deserves. It is not the place, nor do I have the time, to present them but I thought that I should take advantage of addressing such a prestigious audience to let you know of one of my strongest wishes. The students whom we are training are bright, they are enthusiastic, they like science, they like their country and they are determined to do their best to help its progress. My wish is that their country will offer them the future which they deserve, will give them the responsibilities that they are able to assume, will not deceive their enthusiasm and motivation and will prevent them from adding to the catastrophic brain drain that Vietnam has been enduring for so many years. If the efforts which we are making could not concretize in such a way, they would be lost for Vietnam, if not for science, and I would then consider that I have failed.

PRONOUNCED ON THE OCCASION OF THE AWARD OF A MEDAL BY THE VIETNAMESE PHYSICAL SOCIETY

It is a great honor for me personally to receive this medal, and I should like to express my gratitude to Professor Khoi on behalf of the Vietnam Physics Society and the Vietnam Union of Science and Technology. But, more importantly, it is for all of us in VATLY evidence that we have friends in Vietnam who have confidence in us, who trust us and who encourage us to continue. Such a testimony of confidence is an invaluable asset to help us fight our way against all the difficulties and obstacles that we invariably meet in this kind of enterprise. What we are trying to do is to create and establish in Vietnam a team of experimental astrophysicists having an international stature and being able to have its place within the international 36 collaboration of a prestigious experiment conducted at the Pierre Auger Observatory in Argentina and aiming at solving the puzzle of the so-called ultra high energy cosmic rays that reach up to 1020 eV. It is a challenge in many respects. First, and most importantly, it implies establishing a nucleus of four or so talented and knowledgeable physicists at PhD level who can guarantee the stability and the continuity of the team. Only then does it become possible to have incoming and outgoing fluxes of students joining us to be trained in research and leaving us after having obtained their degree. This implies, among other, establishing proper working conditions and offering reasonable wages. Second, we have to overcome the prejudice which is present in many developing countries against experimental physics that is often considered as a lower level activity compared to theoretical physics. We all know that physics is made of both, that they complement each other, that they feed each other, that a good theorist must understand experiments and know about them before trying to explain them, as a good experimenter must understand theory to guide his research. Third, we must overcome another prejudice, which I have often met, that Vietnam does not need astrophysics. Clearly, astrophysics, and fundamental research in general, cannot be a strong priority in Vietnam where the emphasis toward applied physics is a necessity. However, we all know that there is no good applied research in a country that neglects fundamental research and that the main criterion to be applied in fundamental research is simply excellence. From that point of view, astrophysics is in a particularly privileged situation. In the past few years the sum of knowledge we have of the Universe has simply exploded, revealing at the same time an even larger sum of ignorance. Astrophysics is probably the field of physics that is advancing fastest today. Before I came to Vietnam, seven years ago, most people doubted the presence of black holes in the Universe. Today we have good reasons to believe that there is one in the centre of each spiral galaxy, we have studied in great detail the one that is at the centre of our Milky Way and that has a mass of three million solar masses. We know that we do not understand 95% of the energy content of the Universe, dark matter and dark energy, the discovery of the latter being less than ten years old. A similar prejudice concerns the possibility for Vietnam to engage into research in so-called big science. We all know that this is not a problem and VATLY is proving it. We have the same immediate access to the Auger data as our colleagues in Chicago, Karlsruhe, Paris or Rome. Astrophysics is made today in very expensive laboratories either in space or in huge ground installations. The data are not analyzed in situ but in the universities of the teams collaborating on the experiments being made there. There is no bad physics for the poor countries and good physics for the rich countries: we all have access to the data. As I often like to put it, the sky belongs to all of us; we are all made of the same stardust. Fourth, the fact that modern astrophysics is not being taught in Vietnam is a further important difficulty. Two weeks ago, a very good school of astrophysics was organized in the University of Education and those of us who gave lectures on that occasion, including two prestigious professors from the US and from France, had a chance to have lunch with the President of the University and with the Head of the physics department who told us of their intention to introduce astrophysics in the curriculum of their University. I am myself giving lectures, at a modest level, at the National University and the number of obstacles which have to be overcome is simply enormous. Let us hope that the Universities of Vietnam will soon become aware of such needs and that the changes that are necessary to give the country the Universities which it deserves will soon be accomplished. Just to mention an example, let me quote the question of giving PhD degrees under joint supervision of a Vietnamese University and a foreign University, what is referred to as cotutelle in French. It is an opportunity that is obviously excellent for Vietnam, strengthening links with prestigious foreign Universities, giving a guarantee of quality and of honesty, etc. Yet, while the necessary procedure took less than a month in France and Italy, it is still unclear whether it can be applied to Vietnam after many months of discussion. Fortunately, in order to overcome these difficulties, we have many friends abroad who are helping us, in particular the members of the Pierre Auger Observatory, with particular mention of their funding fathers, Jim Cronin and Alan Watson, who both have visited Vietnam on several occasions. But also many 37 other scientists, including organizations such as the French CNRS, the World Laboratory, the Rencontres du Vietnam, CERN, Riken and many others. In Vietnam also we get invaluable support from the Institute where VATLY is installed, the Institute for Nuclear Science and Technology, and in particular from Doctors Vo Van Thuan and Dao Tien Khoa who do their utmost to ensure VATLY with good working conditions. We get very strong support, both material and moral, from the Vietnam Academy of Sciences, the Ministry of Science and Technology and the Vietnam Atomic Energy Commission. Finally Vice Rector Bui Duy Cam is giving us unconditional moral support and helping us efficiently to overcome the obstacles that we have to face in the University. I am pleased here, on behalf of VATLY, to express to all of them our deepest gratitude. I personally wish to extend these thanks to all my colleagues in the Institute and particularly to those in VATLY. Thank you again for this token of confidence and for the encouragement it implies. I can ensure you that together with the VATLY members we shall continue to do our utmost to serve as well as we can the interests of Science and the interests of Vietnam.

ADDRESS GIVEN ON THE OCCASION OF MY ACCEPTANCE OF THE 2016 PHAN CHAU TRINH AWARD33

The prize, which I have the great honour to receive today, is much too prestigious in comparison with my modest contribution to the advancement of fundamental science in the country. I understand my nomination as a manifestation of friendship rather than as the recognition of successes which I failed to achieve; at best may it be a recognition of the effort that I have been devoting, for now sixteen years, to helping with the development of science in the country and with the cultural change of style that it requires. The cultural and educational development of the country is indeed a prerequisite to its progress. I am deeply convinced that if we succeed in its achievement, the rest will follow. It remains as true today as it was a century ago, when Phan Chau Trinh and his companions, the so-called Five Dragons, were fighting for cultural and educational emancipation of the Vietnamese people as the best way toward independence and freedom.

Our universities are modelled on what universities were fifty years ago in developed countries. But fifty years have passed and we are a country that is still struggling for its development after decades of wars and starvation, the scars of which are still with us. We must rethink which kind of higher education we need in order to best serve the interests of the nation. We must give much more importance to vocational guidance. We must understand how many workers, how many technicians, how many engineers, the country needs for its progress; and how they must be distributed among the various professions. How many medical doctors, how many nurses, how many architects, how many teachers, how many farmers. Today, so many university students waste four or five years, among the most precious in their life, in the illusory hope of some kind of social promotion, listening to lectures that are miles away from what we should be teaching them. Nuclear physics classes are still teaching the same nuclear physics as I learned as a student sixty years ago and in over twenty years, we have not yet been able to train the team of engineers and scientists who could master the construction, operation, exploitation and maintenance of our future nuclear power plants.

Today, we are training many too many students in the tertiary sector, in marketing, in banking, in management, names which often hide feeding the cheap labour that globalisation requires from developing countries in a regime of market economy. Before teaching marketing, we need to teach how to produce what we may need marketing for; before teaching management, we need to teach the skills that will require being managed. Otherwise we shall train managers who will have no one to manage but themselves.

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We are spending fortunes to send many of our young students study abroad for a master or a PhD. But we do not exert enough judgement in deciding which kind of skills we wish them to acquire. We do not invest enough effort in following up on their training when they are back home and much of the investment that the country devotes to such training abroad is simply wasted. Worse, it feeds a brain drain that is fatal to the country. It no longer makes sense to waste so much money in sending our children abroad and maintaining too high a level of brain drain. We would be much better off by keeping this money to support those who stay at home with the determination to change things to the better. Of course, it would imply a change of style in our practice: we should be much more selective in choosing, on the sole basis of their talents, those who have such ability; and we should offer them resources, both in terms of wages and of working environment, that can attract them. They should see their action in the framework of a long term policy, clearly spelled out, giving them confidence in a sustainable support, giving them reasons to be proud of their achievements, giving them a sense of serving a country which recognizes their contribution.

The world around us keeps changing, much faster today than it used to, even in the recent past. We need to raise young responsible citizens, who look around them with wide open eyes, who can exert their own judgement, who can adapt swiftly to a new environment. We need to raise young responsible citizens who reject doctrines and dogmas, who fight inertia, bureaucracy and conservatism, who get outraged when they witness events that run against their convictions. We need to raise young responsible citizens who are able to change the regulations that govern our society when the changing world around us requires it, not simply to blindly apply rules that have become obsolete and a cause of paralysis and of sclerosis.

The change of style that is required for such progress implies a restoration of moral and intellectual rigour and of professionalism in our habits and practices that we, scholars, scientists, intellectuals have the duty to foster. We need to restore respect for knowledge, for integrity, for the primacy of serving the interests of the community over serving one’s own interests. Failing to do so ineluctably means failing to open the country to progress.

Culture does not mean conservatism, nor does it mean exclusion. On the contrary, it means progress and tolerance. The respect which we owe to our ancestors, who have made us who we are, to our country, to our traditions does not mean that we should not respect the cultures and traditions of our brothers and sisters in the world. On the contrary, it should make us curious of learning about these. We should have the ambition to learn from other cultures as much as to give our own as an example to the world. Such an attitude of curiosity, of rigour, of tolerance and of foresight is inherent, in particular, to scientific culture and we, scientists, must be committed to it. We must feel the duty of fighting for restoring these intellectual and moral values that contribute to the elevation of human dignity. We must feel responsible for promoting a science without border.

In order to succeed, we need to trust the young generation much more than we are presently doing. We need to rely on their enthusiasm, their energy, their talents, their skills, their generosity, their faith in a future of which they are the main actors. We need to give them a chance to bring to the country the fresh air which we need so much in order to breathe deeper. We need to give them opportunities to change things to the better, encouragements to take initiatives that will contribute to the progress and development of the nation. Its future is in their hands, the hands of the Doi Moi generation. They have not suffered the wars, the starvations, the pains, the sorrows, the oppression that their parents and grandparents had to endure. They inherited from them independence and freedom. Their fight is no longer for winning wars, but for winning the peace. It is as noble a cause to serve as was the cause for which their parents and grandparents have fought. As noble and as challenging. We must do our utmost to give

39 them the support and encouragements that the task requires; we need to do our utmost to equip them with the tools that will make it possible for them to overcome the many obstacles that they will have to face.

I may sound arrogant in speaking the way I do. Who am I to think that I know what we should be doing? Having convictions is one thing, being right is something else. My only excuse for speaking so freely, is that I don’t do so for me, I am an old man, but for the young colleagues whose lives I share day after day. My only motivation is to see the country give them the opportunities that their talents and generosity deserve having. What I say is not original, it is simply the expression of common sense and of the courage of facing the truth.

Before closing this address, allow me to express my deep gratitude to those whose indefectible friendship has made time pass by so happily over these past sixteen years: my wife, of course, without whom I would not have come to Vietnam; my young colleagues, who are present behind each of my efforts; and my friends Viet Phuong, Hoang Tuy and Pham Duy Hien, of whom I share the convictions and for whom I have as deep a respect as profound a devotion. Finally, allow me to thank Madam Nguyen Thi Binh, Mister Nguyen Ngoc and Professor Chu Hao, who have placed in me their confidence with the award of a prize, which, I repeat, my modest merits do not deserve. I will do my best to be worthy of their confidence and of the example set by my prestigious predecessors.

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