BOOK REVIEWS Moves Around Earth, Bending of Light
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BOOK REVIEWS moves around earth, bending of light. Let me close with an apology. I have about him and their reactions to the good What bends is space not light, light free- taken liberty in discoursing on some is- and the bad events of his life. However, ly floats on it and hence we measure sues of concepts and principles (enclosed as we see in this latest compilation, the bending of space by means of light. in parentheses) that could though be con- contemporary biographies unfold his Though wrong, it has got currency and strued as transgressions but at the same potential as an untiring seeker of truth; so we carry on with it. time that may perhaps be illuminating. his mind and hands worked brilliantly Another misconception is that in a leaving us wonder if some unpublished strong gravitational field light slows NARESH DADHICH material may still be hiding somewhere down. That too is utterly wrong. What escaping the eyes of historians. slows down is the clock in strong gravity The Inter-University Centre for Stefano Gattei is a well-known name and that would result in increasing light Astronomy and Astrophysics (IUCAA), among the historians. The book was frequency and thereby energy but its Post Bag 4, Ganeshkhind, eagerly awaited by historians as the pub- speed remains the same universal con- Pune 411 007, India lications of a series of papers on Galileo, stant. When light is tunnelling out of a e-mail: [email protected] especially the one1 in 2017. This critical strong gravitational field, it loses energy edition comprises the biographical through decrease in its frequency or in- sketches of Galileo during his life time crease in wavelength. This is the pheno- or just after his death by people within menon of gravitational red-shift. his circles. Some of them are translated This otherwise excellent book, I into English for the first time opening up have to say, suffers from this misconcep- our views on his public image – his life tion. which was entangled in controversies of Let me also underline one of the pro- science and religion. found statements the author makes: light Stefano Gattei gives a detailed intro- travels as a wave but arrives as a particle. duction clearing our blurred views of the It should rather be enlarged to say that contemporary society. The original Ital- not only does it arrive but it also departs ian, French and Latin texts follow with a as a particle. It is a wave through the very faithful translation and abundant journey while it is a particle at both ends. notes. The resources available (in Eng- At first sight, I must confess I was a lish) hitherto, were mainly based on the bit taken aback, why should such a fasci- book by Viviani Vincenzo, the last stu- nating book end with such a speculative dent of Galileo. Thus historians were note? What the author is seeking is fur- longing for access to other original re- ther synthesis between gravity and quan- sources providing the historical context tum theory. We are again faced with the of the making of Galileo. wave–particle like duality. Gravity is de- On the Life of Galileo: Viviani’s Histo- The introduction titled ‘Shaping the scribed by curvature of space–time rical Account and Other Early Biogra- myth’ begins with the poem by Primo which is a continuum while the basic phies. Edited, translated and annotated Levi in 1984, with ‘Before the Sun elements of quantum theory are discrete. by Stefano Gattei. Princeton University burned my eyes/I had to yield and say/I How to make the two compatible is the Press, 41 William Street, Princeton, New did not see what I saw’, a very concise most challenging question over half a Jersey 08540. 2019. lxviii + 348 pages. picture we have of Galileo. The ‘Galileo century discrete/digital nature of events Price: US$ 49.95/£42.00. affair’2 gained enough publicity especially induces non-locality and acausal trans- after the church vindicated him in 1992. mission of information. What is hinted at Galileo Galilei (1564–1642) is one of the He was well respected for his engaging is that new synthesis would arise as and most well-known scientists as the father thoughts on the experiments with the in- when we have quantum theory of gravity of mechanics and dynamics; however a clined plane, the introduction of the ideas or space–time. commoner would identify him as an on gravity, the analysis of tidal motions. In other words, how do we synthesize ‘eye-opener’ for astronomy by the intro- His books on physics were popular all Planck’s constant, which is universal like duction of telescope. It provided a turn- over Europe and therefore, one would be velocity of light, with space–time? All ing point for the observations of the curious to know how this ‘affair’ was universal entities must be related and night sky, and for a strong foundation for treated. Segre3 made an effort on these synthesized. This is the most profound a heliocentric planetary model. His bio- lines to analyse the context in light of open problem over half a century, and we graphy is so well publicised that we im- limited tools accessible to Galileo. are nowhere near the solution. agine that his life story was created Gattei narrates the individual texts of As I said in the beginning, it is a fasci- rather easily as he left behind his own this volume, fourteen in all. Viviani’s nating and engaging story of one of the works. Some documents (for example, original biography (1654), the ‘Letter to most exciting and challenging feats of letters) would have supplemented the the Prince Leopoldo de Medici on the observation and experiment. It is being write ups with many ifs, buts and may Application of the Pendulum Clock’ told with a lot of feeling, insight and be’s, providing scope to classify some (1659) and ‘Report on Galileo’s Later care, and it is indeed a must read for not anecdotes to ‘hero worship’ category. Works’ (1674) are reproduced with only physicists but scientists in general Thus it becomes all the more important translations and comparison of the style as well as curious audience at large. to know what his contemporaries felt of writing with other contemporary 1210 CURRENT SCIENCE, VOL. 119, NO. 7, 10 OCTOBER 2020 BOOK REVIEWS biographers, Gherardini and Vasari (who avoids the trial completely. His emphasis tion has perhaps retained the emotions sketched the life of Michelangelo). It is is on the mathematical foundation laid to set in the original – here is one ‘Some important to note that many biographers philosophy. Lorenzo Crasso writes a people look up at the rising evening followed this style as a formality. very brief essay and declares that the star/And the dreadful star of Mars, and The complete text on the pendulum troubles were ‘self-invited’ by Galileo the track coloured with brightness of clock and related drawings has been because of his reckless opinions. The milk/Others look up at your light, Cyno- made available. Galileo was aware that writer from Germany Joachim von San- sura/Still others marvel at the Scor- this would be of great help for navigators drart is well recognized for his language, pion/or the brightest star of the Dog/or which turned out to be true. He also men- but more important is his description of a Jupiter’s attendants, or his father Sa- tions about the application of the ‘Medi- visit he paid when the Inquisition was in turn’s, which you discovered/through cian stars’ (satellites of Jupiter) for the progress. He has specifically mentioned your telescope, learned Galileo.’ determination of longitude as a very apt about the interest Galileo had in arts. There are some ‘failed’ biographical alternative to eclipses. About 40 years of While some essays like Leo Allatius are sketches as disclosed by correspon- observational data on these satellites very passive, appreciation by most of the dences. There are 24 illustrations very were lost as reported here. The method other scientists hint at a positive deve- beautifully reproduced with utmost care. indeed gained the confidence of naviga- lopment. The ideas on mechanics, gravity As can be expected, it has no place for tors. Many explorers used his idea of the and mass are well appreciated and had a the famous quote – ‘E pur si muove’ or timings of the eclipses of the satellites of wide range of audience. Galileo was in- ‘And yet it moves’, which has been Jupiter for longitude estimates till late deed received whole heartedly by the traced to an artwork from Spain4. 18th century. He was the first to toy with scientific community in general and that Stefano Gattei has compiled, trans- the idea of a magnifying glass – the speaks of his legacy. lated and annotated all the fourteen microscope – and succeeded. The short essays by Paul Freher and works that were published in the seven- Girolamo Ghilani wrote the first trace- the details of inscriptions engraved by teenth century with great care. With all able biography in 1632 probably prior to Vincenzio Viviani in 1702 as ‘Testimony the original languages occupying the left the trial. He gives an elaborate discus- of a Grateful Soul’ complete the availa- hand pages, reading in English is sion on the science of Galileo and dec- ble sources in this volume. The poem by smooth. lares ‘As these most learned works are of Maffeo Barnerini, ‘Adulatio perniciosa’, This volume provides an inspiration the highest value to scholars and teachers in Latin is the best part of the book; writ- for the beginners of the study on history in that science, they are very highly ten in 1620 by the same individual who, of science and also for those aiming at praised and offer me the opportunity to as Pope Urban VIII, became Galileo’s understanding the legacy of Galileo, who honor Galileo’s precious merits by giv- prosecutor, later.