The development of science this century 2 - from 1946 to 1970 by Victor F. Weisskopf

only at sub-nuclear distances. How­ design of the proximity fuse. Scien­ ever, a crucial difference between the tists who previously were mainly strong force and the electromagnetic This is the second in a series of interested in basic physics, con­ force lies with the fact that while the three articles which together are a ceived and constructed the nuclear photon itself has no electric charge, slightly revised version of a talk bomb under the leadership of one of the gluons carry colour. This means delivered at the meeting of the the most 'esoteric' personalities, J.R. that gluons can interact among American Association for the Oppenheimer. E. Fermi constructed themselves, with fascinating conse­ Advancement of Science, in the first nuclear pile, E. Wigner was quences for the strong force. Boston, on 14 February 1993, and instrumental in designing the reactors A virtual photon emitted by an at a CERN Colloquium, on 5 that produced plutonium, and J. electron can in principle travel off August 1993, entitled 'Science - Schwinger developed a theory of towards infinity, unaffected by other yesterday, today and tomorrow'. waveguides, essential for radar. It nearby photons. A gluon, however, Together they describe the tre­ was more than that: some of these feels the influence of any other mendous growth of scientific people were excellent organizers of gluons, and their interaction can knowledge and insights acquired large-scale research and develop­ indeed lead to more gluons. So a since the beginning of this century. ment projects having good relations virtual gluon emitted by a quark, say, In a highly abridged form, some of with industry, such as the aforemen­ cannot proceed far before it is in these ideas were used in an tioned military projects. effect caught in a net created by its earlier CERN Courier article When World War II was over, the interactions with other gluons. The ('Crisis - the Weisskopf view'; public was under the impression that result is that the strong force has a October 1993, page 22). Because the physicists had won it. Of course, short range. of the restrictions of a single issue this was a vast exaggeration, but it is In summary, the Standard Model of the CERN Courier, the text has a fact that radar saved the United sees the world as built from two sets been repackaged as three articles, Kingdom and reduced the submarine of particles, the quarks and leptons, each covering an identifiable threat to transatlantic convoys, and whose interactions are described by historical epoch. The first, covering that the atomic bomb led to an two similar theories, electroweak the period from 1900 to World War immediate end of the war with Japan. theory and QCD. In these theories, II, was published in the May issue. Physics and science in general forces are transmitted by messenger The third article will cover the earned a high reputation. This led to particles - the gauge bosons - some period from 1970 to the end of the of which acquire mass through their century. interactions with an additional field, the higgs field. The model is a curious amalgam, evolved over years he time from 1946 to about 1970 of wrong turns and dead ends. So T was a most remarkable period far, it has worked much better than for all sciences. The happenings of we have any right to expect. World War II had a great influence, especially on physics. To the aston­ ishment of government officials, physicists became successful engi­ neers in some large military research and development enterprises, such as the Radiation Laboratory at MIT, the Manhattan Project, and the

Eugene Wigner - instrumental in designing reactors that produced plutonium. (Photo Kathleen Blumenfeld)

CERN Courier, June 1994 9 The development of science this century

While the US almost monopolized natural science in the 1950s, the establishment of CERN was a signpost to the future. The picture shows a 1953 session of the provi­ sional CERN Council in Amsterdam. (Photo CERN 4.10.52) higher salaries and to generous financial support from government sources such as the Office of Naval Research (ONR), the creation of the National Science Foundation (NSF) with the purpose of supporting basic research, the National Institutes of Health (NIH) supporting biology and medical research, and the Atomic Energy Commission (AEC) support­ ing basic research in nuclear and particle physics. The rationale for the support of basic science by govern­ ment sources, irrespective of military and other applications, was twofold. First, the war experience engendered a strong belief that any basic science research will lead to useful applica­ tions; second, the desire to keep scientists happy and numerous since they might be needed again. The lavish support, without any regard as states, the existence of unstable utes of the Universe, the galaxy clus­ to the type of research, lasted for heavy electrons and of several types ters and the 3K radiation as the opti­ about a decade after the war; later of neutrinos (two were discovered in cal reverberation of the Big Bang, government sources became in­ Period II, the third in the next period), and the discovery of quasars and creasingly interested in more specific the discovery of parity violation in pulsars. In chemistry: the synthesis research directed at military or weak interactions, and the unification of complex organic molecules, the commercial applications. Still basic of electromagnetic and weak forces determination of the structure of very science fared well until the seventies. as components of one common force large molecules with physical The results of this support were field. In nuclear physics: the nuclear methods such as X-ray spectroscopy truly amazing. The progress of natu­ shell model, an extensive and de­ and nuclear magnetic resonance, ral science in the three decades after tailed theory of nuclear reactions, and the study of reaction mecha­ the war was outstanding. Science ac­ and the discovery and analysis of nisms using molecular beams and quired a new face. It would be impos­ rotational and collective states in lasers. In biology: the emergence of sible in this essay to list all the signifi­ nuclei. In atomic physics: the Lamb molecular biology as a fusion of cant advances, We must restrict shift, a tiny displacement of spectral genetics and biochemistry, the identi­ ourselves to an account of a few of lines which could be explained by the fication of DNA as carrier of genetic thi most striking ones without men­ new quantum electrodynamics, the information followed by the discovery tioning the names of the authors, The maser and the laser with its vast of its double helical structure, the choice ii arbitrary and influenced by applications, optical pumping, and decipherment of the genetic code, my restricted knowledge, In quantum non-linear optics. In condensed mat­ the process of protein synthesis, field theory: the invention of the ter physics: the development of semi­ and the detailed structure of a cell ^normalization method in order to conductors and transistors, the with its cellular organelles. In geol­ avoid thi infinities of field theory that explanation of superconductivity, sur­ ogy: the development and refine­ madt It possible to extend calcula­ face properties, and new insights into ment of plate tectonics using newly tions to any desired degree of accu­ phase transitions and the study of available precision instruments, and racy, In particle physics; the recogni­ disordered systems. In astronomy the discovery of ocean floor spread­ tion of the quark structure of hadrons and cosmology: the Big Bang and its ing by means of sonar and other establishing order in their excited consequences for the first three min­ electronic devices.

10 CERN Courier, June 1994

The development of science this century

The 1962 discovery at Brookhaven by Leon Lederman, Jack Steinberger and Mel Schwartz that neutrinos came in two kinds was one of the fruits of the support for US basic science in the 1960s. Long tracks in the experiment's spark chambers showed when neutrinos produced muons, rather than electrons.

'central' in science. After the 1960s, European and Japanese science became more independent, and could compete with the USA. A number of European international organizations were created, such as CERN in particle physics, the European Molecular Biology Laboratory (EMBL) in biol­ ogy, and the European Southern Observatory (ESO) in astronomy. A standard of research was developing in Europe and Japan which was equal and even superior to the USA in some fields. Important changes in the social structure of science took place, especially in particle physics, nuclear physics, and astronomy. The rapid developments in these fields required larger and more complex accelera­ Many of the new results and discov­ tors, rockets and satellites in space, Character and sociology of science in eries were based upon the instru­ sophisticated detectors, and more Period II mental advances in the field of complex computers. The government electronics and nuclear physics due funding was ample enough to provide to war research. One of the most Striking in the first two decades of the means for such instruments. The important new tools decisive for all Period II is the preponderance, size and complexity of the new sciences was the computer. The almost monopoly, of the USA in facilities required large teams of development and improvements of natural science. Most of the amazing scientists, engineers, and techni­ this tool are perhaps the fastest that advances in science during the cians, to exploit them. Teams of up to ever happened in technology. It period 1946-1960 were made in the sixty members were organized, brought about new methods of USA. Obviously, the leading cause especially in particle physics. (In evaluation of experimental data, new was the condition of the other coun­ Period III the sizes of teams reached ways to model and simulate natural tries after the ravages of the war. several hundred.) Other branches of processes. To quote a remark of S. Europe and East Asia had to be science, such as atomic and con­ Schweber: There are now three rebuilt. All the more we must admire densed matter physics, chemistry types of scientists: experimental, certain pioneering efforts carried out and biology, did not need such large theoretical and computational.' mainly in England, Italy, and France, groups; these fields could continue In spite of the tremendous boost such as cosmic-ray research in their research more or less in the old- that all sciences owe to computers, England under Powell and in France fashioned way in small groups at a there are dangers connected with the under Leprince-Ringuet, and the table top with a few exceptions, for use of them. If the computer is used important Italian meson absorption example, in the biomedical field, to determine the consequences of a experiments by Conversi, Pancini where larger teams are sometimes theory, then who has understood it, and Piccioni. The situation was the necessary. the computer or the scientist ? The opposite of that in the 1920s. Euro­ The large teams brought about a computer sometimes replaces pean and East Asian scientists had new sociology. A team leader was thinking and understanding. The to spend some time in the USA in needed who had the responsibility same danger occurs in the overuse order to play a role at home. Europe not only for intellectual leadership, of computers in science education. was 'provincial' and the USA was but also for the organization of

12 CERN Courier, June 1994 The development of science this century

The ultra-sensitive and discriminating detec­ tors that had to be developed in high energy physics turned out to be most useful in medicine, biology, and materials science. In 1992 Georges Charpak was awarded the Nobel prize for his detector achievements, particularly his 1968 invention of the multi-wire proportional counter. (Photo CERN 62.10.92) subgroups with specific tasks, and for financial support. A new type of personality appeared in the scientific community with character traits quite different from the scientific leaders of the past. The participation in these large teams of many young people, graduate students and postgradu­ ates, creates certain problems. It is hard for them to get recognition for their work, since their contributions get lost in the overall effort of the team. In order to attract young researchers to join big teams, the subgroups must have some inde­ pendent initiative for well-defined tasks, so that the performers of these tasks can claim credit for their work. The development of huge research enterprises caused a split in the character of science into 'small' science and 'big' science. Small applications are visible today. The fields may be referred to as 'terres­ science consists of all those fields philosophical and intellectual signifi­ trial sciences'. The processes studied that can be studied with small groups cance is not counted as an 'applica­ in the cosmic sciences are too far at relatively small cost, whereas big tion'. One can never exclude that away in time and space to be of science is found in particle physics, some present or future discoveries immediate interest under terrestrial in some parts of nuclear physics and may lead to applications after several conditions, such as the Big Bang and astronomy, in space exploration, and years or decades of further develop­ its consequences, or the discovery of in plasma physics. There is also big ments. This is why we will use the mesons, quarks, and heavy elec­ science in condensed matter physics term 'presently non-applicable'. trons. Unquestionably, it is a great and in biology: the use of synchrotron Applicable science includes parts of achievement to be able to study the radiation in the former and the nuclear physics dealing with reactors formation of galaxies in the Universe, human genome project in the latter. and radioactivity, atomic and molecu­ or what goes on in the interior of Big science needs large financial lar physics, certainly condensed stars and, in particular, to be able to support, so that the question of matter physics, plasma physics, create conditions at the targets of our justification plays a decisive role. chemistry, the earth sciences, and, of accelerators that existed fractions of This has led to another kind of split, course, biology with its vast applica­ seconds after the Big Bang. Naturally related to the applicability of a branch tions in medicine, agriculture and this kind of research is expensive. It of science in industry, in medical food production. is hard to establish cosmic conditions practice, and also in being useful for Particle physics, some parts of on Earth. But these phenomena are other sciences by providing tools and nuclear physics, astronomy and in many ways detached from human insights. Thus, we may distinguish cosmology are examples of sciences environments, and decoupled from 'applicable' and 'non-applicable' extremely important intellectually and other sciences. (The point of view science. Both of these terms must be philosophically but whose applica­ expressed here is different from the qualified. We understand 'applicable' tions are not presently tangible. They one I expressed twenty years ago in science as research for which appli­ are characterized by what may be an article The significance of sci­ cations are obvious or easily fore­ called a 'leap into the cosmos'. Let us ence', Science 176 , 138 (1972). At seen; 'non-applicable' is meant to call these topics 'cosmic sciences' that time I was more optimistic as to indicate that no or only very few whereas the obviously applicable possible future applications of parti-

CERN Courier, June 1994 13 Around the Laboratories

cle physics and astronomy.) istic of the lower levels. Thus, the The division into applicable and internal composition of those units is CERN presently non-applicable fields is not not important for these levels. There as sharp as indicated here. Even are 'effective' theories describing the LHC dipole prototype particle physics has led to applica­ conditions at each level that disre­ success tions; it almost did a few decades gard the internal structure of the ago when L. Alvarez suggested that units. For example, certain parts of hydrogen molecules made of protons nuclear physics deal with protons n a crash programme, the first and muons could perhaps initiate and neutrons as quasi-elementary prototype superconducting dipole fusion processes, but it turned out to particles, whose quark structure is magnet for CERN's LHC proton- be impossible. Most of the applicable irrelevant; atomic and molecular proton collider was successfully items come from what is sometimes physics deals with interacting elec­ powered for the first time at CERN on called 'spinoff. Techniques used to trons and atoms and nuclei, the inner 14 April, eventually sailing to 9T, satisfy the unusually severe de­ structure of the nuclei being insignifi­ above the 8.65T nominal LHC field, mands of accuracy and reliability do cant. Certainly the quark structure of before quenching for the third time. have some use in other fields. In nucleons is irrelevant for biology, The next stage is to install the particular, the ultra-sensitive and which has its own concepts, laws, delicate measuring system for discriminating detectors that had to and relations. In every step from a making comprehensive magnetic be developed in high-energy physics higher to a lower level, complexity field maps in the 10 m long, 50 mm turned out to be most useful in increases; new laws and regularities diameter twin-apertures of the medicine, biology, and material appear that are not in contradiction magnet. These measurements will science. G. Charpak was awarded with the more 'basic' laws at higher check that the required LHC field the Nobel prize for this. Furthermore, levels, but they emerge from the quality has been achieved at both the some of the intricate mathematical complex interactions of the relevant nominal and injection fields. developments in quantum field theory units without being directly derivable This first valuable prototype will be have been successfully applied to from the laws at a high level. When trained to its maximum field, ex­ problems of condensed matter the Universe cooled down and pected to be close to 10T, only after physics. There are good reasons to expanded, it seemingly went through completion of the magnetic field expect more of such spinoffs in the stages from the highest levels up to measurements. Seven prototypes future. lower ones, creating at each step have been ordered from four different The present non-applicability of new diversity and complexity, until it industrial consortia. All are expected cosmic science is connected with an reached life on Earth and perhaps on to be complete before the end of the interesting phenomenon that oc­ other planets. year. The first prototype was ordered curred in the physical sciences, a The existence of more or less by the Italian INFN and built by hierarchy of different subjects that decoupled levels of physics had an Ansaldo. have become to an increasing extent undesirable effect: over-specializa­ On 15 April, while the magnet was decoupled from each other. We tion. The scientists working in one being put through its paces, a special distinguish particle physics on the level do not know much of what is session of CERN's governing body, 'highest' level (no value judgment going on in other levels because they the Council, adopted the following intended), nuclear physics, atomic mostly do not need that knowledge resolution on the LHC and CERN's and molecular physics, condensed for their research. Furthermore, the long-term scientific programme matter, etc., being consecutive lower pressure of competition and the need pending final approval. levels. Each level has its own laws to follow the ever-increasing literature "Council, confirming its belief as and concepts based upon the inter­ in their own fields does not give them stated in the Council's December action of quasi-elementary units that time to be interested in other levels. 1991 resolution that the LHC is the are composed of more elementary right machine for particle physics and units of a higher level, but remain for CERN, and being impressed by fixed in their ground states under the the scientific case and by the eco­ weaker energy exchanges character­ nomical utilization in the LHC project

14 CERN Courier, June 1994