This is a book that amazed and awed me from the preface itself. On the first page of the preface it states thus:
"...the universe as a dynamic place, expanding at an accelerating rate, whose principal mysterious constituents, dark matter and dark energy are unseen. The remainder, all the elements in the periodic table, the matter that constitutes stars and us, contributes a mere 4 percent of the total inventory of the universe."
That, what we all know as the stuff that make matter - is just 4% of the total inventory makes one feel insignificant. If that makes one insignificant and infinitesimal in terms of size, this next makes one feel that all our worries about the challenges we face as modern men and women, not worth the daily calories we burn in worrying about them. Hear this :
"Today we have images and data of several million galaxies, many of them so distant that the light we see originated from them when the universe was in its infancy, a mere billion years old, barely a fraction of its current age of 13.8 billion years."
These astounding facts hint of the wonders to expect in the seven chapters that make up the book, and it made me look forward to it.
Chapter one titled "Early Cosmic Maps", inform us of that, mapping the celestial objects in order to predict a pattern, which could help us terrestrial beings with their terrestrial affairs seem to have interested us from around 2000-1600 BCE (i.e. Nebra Sky Disk from the Bronze Age Unetice culture ). It then carries us on a journey in which
- the celestial interests of the Babylonians ( 7th C. BCE),
- Greek interpretations ( World resting on the back of a turtle),
- Anaximander deducting that earth was freely suspended,
- Greek Eratosthenes' calculation of the circumference of earth,
- Ptolemy's world map (1478) thanks to the spherical trigonometric developed by the Arabs and Indians.
- challenging Ptolemic view of an earth centric cosmos, with the sun at the center, as presented by Copernicus, and the subsequent Catholic inquisition.
- Kepler who strove to describe the elliptical motion of planets,
all the way to Newton, whose "boldest leap" is identified by the author as "uniting the terrestrial and the celestial with a universal law of gravitation".
Chapter Two is titled, The Growing Border: The Universe Expands. This chapter is very interesting since it is not confined to the science of how the discovery of the expansion of the Universe came about. Yes, that discovery is remarkable too - the work done by Edwin Hubble towards its discovery, although somewhat reluctant to believe it himself; but more importantly those who theorized it like Georges Lemaitre, who was never recognized for the speculative theoretical solution during his life time. No less than the great Albert Einstein opposed the challenge to the model of a static universe. More importantly, it has now come to light that he has behind the scenes tried his level best to prove that the universe was static even after he accepted the newer theory, upon conceding he had erred. While Einstein appears to have been attached to the flawed theory due to his earlier cosmological theory, Hubble the reluctant champion of the new finding possibly couldn't come to terms, challenging, what for him was "a fact".
"He (Hubble) felt that a choice was being made between accepting a small-scale universe and accepting a potentially new principle of physics. He really preferred the conclusion that his observationally measured systematic redshift effect was probably due not to a true Friedmann-Lemaître expansion but driven by an as yet undiscovered fundamental principle of nature."
The Third Chapter is on Black Holes. She starts with the origin of the term ( it is from Calcutta, and there is nothing Astrophysical about it) and goes on to explain that the origin of the concept of a dark star (1783) can be attributed to a country parson polymath by the name of John Mitchell.
"Michell proposed that massive stars could gravitationally attract and slow down light particles, much as they attract other astronomical passersby, such as comets. Since the more massive the star, the stronger its gravitational pull, some extremely massive stars, he noted, might stop light entirely."
There is a beautiful explanation here, that one can only find in a book of this nature. That is on Einstein's general theory Relativity. Am going to copy it in verbatim to make any possible readers ( if there are any, this further down this article) awe at it.
"Part of physicists’ unadulterated admiration for Einstein is due to his development of the entire theory of general relativity ex nihilo, not to provide an explanation for any observed phenomenon but as a self-sufficient, fundamentally new theory of gravity. This is as pure as theory gets in physics. General relativity is an homage to the power of speculative thought and the possibilities of deep mathematical understanding. The theory offers profound insights into the nature of gravity, the mysterious attractive force that holds the solar system and the entire universe together.....
The need for general relativity to explain compact compact objects did not emerge for some time, although it was successfully used to describe the overall properties of the universe within a decade of its invention. Because the observational effects of this theory are small unless the objects studied have extreme gravity, it was not until astronomers discovered exotica such as neutron stars, pulsars, and quasars that its full explanatory power was revealed. So when astronomers detected these heavyweights in the universe in the 1960s, Einstein’s theory was already firmly in place to describe their properties."
Such is the genius of Einstein, and his theory is fundamental to modern application like GPS. The chapter goes on to explain the limitations of Newton's theory as well.
Another beautiful ( pardon the repeated use of the word, in writing about a book on science - but it is appropriate, here - and as a layman, I was awestruck, and left slack jawed most of the time )
"Einstein’s theories do not invalidate Newton’s conception of gravity—they both have their domains of validity. Each theory has its place and offers adequate and accurate descriptions, in certain regimes. As Einstein once said, 'The most beautiful fate of a physical theory is to point the way to the establishment of a more inclusive theory, in which it lives as a limiting case.' Newton showed gravity’s universality; Einstein’s theory explains why this is so in terms of the curvature of space-time. ( And here is a place where an alternate view to that of Nalin de Silva is apparent - His premise that Newton stated "absolute falsehood", is inaccurate. ) The chapter then moves to explain why a Theory of Everything is necessary, but has been elusive for many a decade. It further elaborates on the demarcation between a white dwarf, Neutron Star and a Black Star. The chapter then adds the "human element" to show how Madras' Subrahmanyan Chandrasekhar was "back stabbed", academically by Edington. Why ? Because Eddington wanted currency for his own work. Letters discovered since have revealed that Chandra himself was hardly a saint, as he too had tried to refute Edington's theories while remaining the closest of colleagues.
If there is one chapter which emphasise on the amount of work that people have to do, to get new knowledge - knowledge that is pioneering, and is in total contrast to what has been accepted hitherto, it has to be chapter 4 - titled "The Invisible Grid", sub-titled "Coping with Dark Matter". The Scientist draws comparison to the discovery of dark matter to that of Holmes or Poirot discovering the evidence, motive and the scene, but minus the victim. Dark matter as has been calculated accounts for almost all of the total matter in the universe.
All the known elements in the periodic table, including those of which we are composed, constitute a paltry 4 percent of the universe’s total contents, including matter and energy, utterly insignificant compared to the amount of dark matter. Dark matter provides the scaffolding within which stars and galaxies form, aggregate, and evolve. The list of names of the scientists who dedicated their lives towards discovering ( and rediscovering ) this phenomenon is quite lengthy.
Chapter Five, discusses the finding that the expansion of the Universe is at an acceleration. Hubble's finding that the universe was expanding was accepted by Einstein publicly, finally accepting that the universe is unmoored. It now transpired that the "lambda" in Einstein's field equations holds the key, and in fact any deviation from it's set value in the equation cause the universe into an accelerated expansion. The "gravity" ( no pun intended ) of this lambda (i.e. Cosmological constant ) was discovered by Eddington. The chapter continues to discuss on the value of Omega - the ratio which represents the density of all matter and energy in the universe and the cosmological constant to the critical density. To describe this any further would possibly warrant me to copy large parts of the texts in verbatim - hence in summary let me say that astronomers had means of calculating the value of Omega from the relic radiation resulting from the big bang, and there was a gap of 0.7 from the values resulting from the aggregate of matter from the universe. This I found awe striking. That indirect factors could be used to such a degree as to take measurements of these far off galaxies. There was no way that I could even come close to understanding how this was done, unless I spend a considerable time on this discipline. So alas, it will have to remain a mind boggling read, as a measure of how small, insignificant and trivial we are - and against the time duration we speak of here, a mere a momentary passing presence in this universe.
Chapter six is dedicated to the discussion of the race to discover, if the universe resulted from a big bang or if it was a steady state universe all along. CMBR, or the cosmic microwave background radiation was instrumental in predicating the Big Bang theory. There were many people who were instrumental in discovering CMBR, some of whom were recognised and others not (i.e. Alpher) until after their death. Again it is nothing but with awe that someone with average faculties like me, can think of these amazing individuals who spent their whole lives in projecting and formulating their theories. The passion that these people had for what they aimed at finding is clearly amazing.
The concluding chapter attempts to give an idea about what the future holds with respect to cosmology. I found one paragraph in particular, quite up to tune with what I feel ( possibly since it was in more layman's language, relatively, than when the authoress tries to present us with cosmology explained in simple terms throughout the book.)
"We have found our significance continuously diminished, a species inhabiting one planet among eight ( previously nine ) in the solar system among several thousand others, in a galaxy among several billion others growing increasingly distant."
Today we search for "life" (?) in other worlds. But life itself is vague in its definition. I conclude this rather difficult write up with this paragraph which serve as food for thought.
"The biologist Harold Blum had earlier labeled this point of view “opportunistic” and the opposing stance “deterministic.” According to the deterministic argument, evolution unfolds in the same sequence everywhere in the universe, with complexity growing with time. The opportunistic view holds that life has many possible courses. Simpson noted that most exobiologists take the deterministic view, for which there is no empirical evidence, while evolutionary biologists tend to take the opportunistic one, which the fossil record on earth amply supports. Fossils reveal that most early life-forms went extinct and that evolutionary processes have had a considerable random component. Simpson argued that life, should it arise elsewhere in the universe, need not follow the arc that we are familiar with, from protozoa to human."
Clearly most details that this book carries went over my head. I could understand what it was talking about at most times, but had no notion of how it was calculated. For example I could understand Doppler effect, but clearly had no idea how the calculations that reveal its consequent findings was carried out. Clearly the very little engineering mathematics that I knew ( and is rusty by now) wasn't going to help me here - and I had no other option but to believe the good offices of the much knowledgeable authoress. And in a sense it is a little sad for me, since at my age a change of discipline or an abundance of time for self study in this fascinating area is most unlikely.
In concluding I am eternally grateful to Mr. Sunil Koswatta for educating us about this book, without which I would never have got this opportunity to read this wonderful account, of the universe, of man ( who by themselves have a fleeting presence in the scale of time ) whose determination to understand this phenomenon, and the breakthroughs he has had, It leaves me quite clearly speechless, and in deep reflection.
No comments:
Post a Comment