In Quest of Infinity - Part 1a

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Star In Quest of Infinity - Part 1a

Post by Admin on Wed Jul 23, 2008 5:28 am

MUSINGS from prasanthi nilayam
IN QUEST OF INFINITY - PART ONE
By Prof. G Venkataraman

Getting Started
Sai Ram and warm greetings. Starting with this issue, I would like to take you on an interesting journey in which we shall together SEARCH FOR INFINITY. The search for “Infinity” is nothing new, and has been going on for a long, long time. However, we shall do it in a different way, starting with the Universe we live in and examining what Modern Physics has to say about it. From there we shall travel still further, to things beyond, to the doorstep of True Infinity!

From The Seen to the Unseen




The vastness of space in the night sky
Our tour is going to be long, and so that you have an idea of where we are headed, let me tell you that though we start with the Seen, later we shall wander into the mysterious realm of the Unseen! So be prepared for a dizzy tour!
In our long tour, we shall encounter many things we barely understand, but of one thing you can be sure; wherever we turn, we cannot fail to see the glory and the majesty of God! Hence, even if there are things we do not quite understand, let us not be deterred by that; instead, let us, at every opportunity possible, simply drink in the glory of God and experience Ananda!
All set to go? Have you fastened the seat belt? OK, we take off right now!

Stargazing

Let us go out into the open and look above. It is a clear, cloudless and beautiful night and the sky is full of stars. We should be thankful that we are able to see the stars.
In many places on earth, people can no longer see stars. You know why? Two reasons; one is too much pollution and second there is too much of man-made light that obscures the light from the stars.
The sky is so beautiful, is it not? And we can see it for free, without buying any tickets or making any advance reservations! Yet, how many of us take time to do this? That is the tragedy of modern times! We all know the nursery rhyme that starts with the words:
Twinkle, twinkle little star,
How I wonder what you are!
We also delight in making our kids repeat this rhyme before visitors, in order to impress them. But do we wonder about these stars anymore? Let us spend time doing exactly that! Let us gaze deep into the sky. Do you know what we would see?
I’ll tell you! We would see all sorts of things, and here is a brief description of the scale and size of things we would catch a glimpse of.

Measuring Distance Using Light Years




The speeding light
A few words about the size of our Universe: It is huge, and I really mean huge. It is so huge, we need a measure of length much larger than the kilometre which is what we normally use for describing distances. It is ok to give the distance form Puttaparthi to New York in km, but when it comes to distances in the Universe, the km is too small.
We shall instead use a measure called the light year [LY], which is the distance light travels in one year. You probably know that light travels [approximately] 300,000 km in one second, yes one second! Light takes about eight minutes to reach us after leaving the surface of the Sun.
Obviously, a LY represents a much greater distance. In terms of numbers, it is 300,000 x 3,600 x 24 x 365 km; you can do the arithmetic! If you are too lazy to the arithmetic, let me tell you that one LY is roughly nine trillion km. If you think that is a lot of km, just wait; you are going to be stunned!
Let us start with our own Solar system. The Sun, which is the focus of the solar system, is a star. As I told you, light from the Sun takes about eight minutes to reach the Earth. On the other hand, it you take planet Pluto, light from the Sun takes about five and a half hours to reach that planet.
Like our Sun, there are at least a billion stars, yes, at least a billion, that form a part of our own galaxy known as the Milky Way. The diameter of the Milky Way is roughly 100,000 light years. That is big; yes it is, but, as they say: “You ain’t seen nothin’ yet!”

Swami: Chancellor of our Galaxy and Beyond




A typical galaxy cluster
Looking beyond the galaxy, there are the Local Groups [LG]. A Local Group may consist of about ten to fifty galaxies. The Milky Way belongs to a group of about twenty galaxies.
The Andromeda galaxy, about which you must have surely heard, forms a member of the LG to which the Milky Way belongs. Based on the diameter of the Milky Way, we can say that typically, an average LG will have a size of about three million light years. We are now talking long distances, aren’t we?
We move on and look at a bigger structure, the Galaxy Cluster. A typical cluster would have something like a thousand galaxies and a linear dimension of about fifteen million light years.
Next comes the Supercluster, which is about ten times larger than a cluster, i.e., it has a linear extension of about one fifty million light years. Things sure are getting bigger and bigger, aren’t they?
Structures of even larger scales are seen in the sky, and recently, astronomers have noted that something like filaments of bright objects exist. One of them has even been named the Great Wall! It is made up of several Superclusters.



The Divine Chancellor of the cosmos!
What comes beyond?
I am not too sure, but way beyond all this comes what we might call the edge of the Physical Universe! According to current estimates, what I refer to as the edge of the Universe is about fourteen billion LY away! What it means is that if light leaves the edge of the Universe right now, it would take fourteen billion years to reach the Earth (that is, if it is still there at that time!) Just for comparison, recall that light from our Sun takes about eight minutes to reach us.
As we let all of this sink in, let us take a moment to do a bit of philosophical reflection. Swami is sometimes described not only as the Chancellor of the Sri Sathya Sai Institute of Higher Learning, but also as the Chancellor of the Universe. I wonder whether people who use this description have any idea of how big the Universe we are in actually is!

Our Ego: An Insignificant Spec in the Cosmos




Our tiny home in the Milkyway galaxy
Swami comments on the fact that man is so insignificant and yet has aHimalayan ego. We might take a moment to reflect on that, too. The Physical Universe may be finite but it is vast nevertheless. In this vast Universe, there are billions and billions of galaxies, each galaxy having billions and billions of stars.
Our Sun is one such star in one particular galaxy that we call the Milky Way. And in the planetary system that exists around the Sun, our Earth is one small planet. And in that planet there are so many countries. If we take all these factors into consideration, then each of us is one incredibly insignificant spec in Cosmos. And yet, how much ego we tend to have! Any time we tend to feel egoistic, it would do us some good to look at the starry sky and reflect on the enormity of the Universe in which we are embedded! What should be huge within us is not ego but Divine Love, which the merciful Lord has deposited in full measure!
OK, let us get back on our tour. Did you realise that we are taking a peek into distant parts of the Universe, without even leaving planet Earth? How come I am able to talk so confidently about the various objects in the Universe? How do we know where and what exactly it is? Believe it or not, just by looking! Just by looking from the Earth? Am I serious? Yes, just by looking, and I am dead serious when I say that.
Believe it or not, staying on the Earth and looking out all the time, man has discovered an incredible amount – that one fact alone ought to make clear the incredible power God has put into man, as opposed to the other living species.
Understanding Our Place in the Universe



Hevelius at his telescope, 1647
The question now arises: “How exactly does man go about ‘looking’ out into the sky as it is said?” In ancient times, man had only the eyes as God gave him. Even with this, he was able to do quite a lot. Thus, astronomers in ancient India, Greece, Egypt and China knew a lot about the constellations of stars and the way planets moved amongst them. They could predict eclipses, and a number of other rare planetary configurations. Basically, all such information related to stellar movements and groupings. It was very useful and gave us the first idea of the solar system. Incidentally, this also gave the first almanacs.
The first quantum jump in this entire process of “looking” came with the invention of the optical telescope. Where astronomy was concerned, it was almost like the discovery of America. It is barely four centuries since the telescope was invented and what an extra-ordinary amount of information it has contributed! The moment man had the telescope, he could see so much more; not only that, he could see objects bigger and often more clearly – we have all wonderful pictures of the Moon complete with craters; that alone is sufficient to help us appreciate what a tremendous job the telescope has done.
As years went by, the telescopes kept getting not only bigger but also better and better all the time. What is the meaning of getting better? Basically there are two things that determine the quality of a telescope – its light gathering power, and its resolution. The bigger the lens, the greater is its light-gathering power; and the greater the light-gathering power, the farther one can see with the telescope. Next, the better the design of the lens, the clearer the picture one gets with the telescope – this we know from our experience with cameras. These two parameters, size and quality are what have pushed up the costs of telescopes; but all that expenditure has been very worth while.

Technology Helps Us See Further Faster




The Hubble Space Telescope
Today, technology has been pushed to the farthest limit and we may even say that further improvement for earth-based telescopes would entail enormous cost with very little return. What is it that sets this limit? The atmosphere! Atmosphere? Yes, atmosphere; we don’t realise that it is the atmosphere that makes the stars twinkle, as the nursery rhyme so beautifully describes. You see, atmospheric density is not constant, being disturbed by all kinds of factors related to weather, wind, dust. etc. The net result is that the light rays reaching us from distant stars wobble a bit [due to refraction], giving the impression of twinkling. While the twinkling phenomenon is very nice for poets, for astronomers it is a terrible headache, especially when they want to photograph weak stars.
How to get rid of this botheration with twinkling? One way is to put the telescope in space, and that is how the idea for the Hubble telescope was born. This telescope was launched by America and put in space by one of Space Shuttle flights. It is fully automated and controlled remotely from the ground. In space there is no atmosphere and so no nuisance due to twinkling and all that – the pictures are therefore much better. I am sure you have all heard of the Hubble telescope and the wonderful pictures it has provided to astronomers.
Now even as the telescopes kept getting better all the time, astronomers discovered better ways of using them. In the good old days of Newton, one had to literally to sit up all night and peer through the telescope. If one was looking at a nearby object like say Mars, it would move relatively rapidly across the sky and so the old-time observer was obliged to keep turning the telescope to keep the object in sight. In due course, a gadget based on clockwork was invented that automatically turned the telescope. This was particularly useful where big telescopes where concerned.
The next intelligent idea was to replace the eye with a camera. A telescope with automatic movement and a camera attached meant that the astronomer could set it all up and even go away to have his dinner or whatever. Meanwhile, the telescope would be “staring” at the star or galaxy and keep on collecting the light coming from it. In this way, the photographic plate in the camera could be exposed for several hours at a time. This meant that one could catch very faint stars and find out what they were doing.

... Continued in next post 1b ...
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Star In Quest of Infinity - Part 1b

Post by Admin on Wed Jul 23, 2008 5:30 am

Fraunhofer Lines

Another very interesting trick that astronomers regularly employ is based on a finding by the German astronomer Fraunhofer way back in the early part of the nineteenth century. Fraunhofer directed his telescope to the Sun and found that when he introduced a prism, then not only was the sunlight split into seven colours but also that the multi-coloured spectrum had dark lines. These lines are now called Fraunhofer lines. No one knew at that time what they meant. Today we know why there are such lines. These dark lines are the “bar codes” of atoms in the Sun, as one scientist graphically describes them.

Visible light spectrum with Fraunhofer Lines
Fraunhofer lines tell us many things about the celestial object studied. In the case of the Sun, they have revealed an enormous amount – the types of chemical elements present in the Sun and the surface temperature, for example. Indeed, the study of spectral lines has been pushed to a very fine art and today, astronomers can examine spectral lines associated with light coming from the most distant objects in space called quasars (short for Quasi-stellar objects), which are almost at the edge of the Universe.

Photo of the Sun taken with an x-ray telescope
And where distant objects are concerned, spectral lines also tell us about how fast the concerned object is moving! In fact, it is from a careful study of this nature that astronomer Edwin Hubble was able to establish that our Universe is actually expanding. That story later.
The optical telescope has been the workhorse of astronomers for centuries, and with fancy attachments like the CCD camera, it is continuing to do wonders. But a telescope no longer means just tubes and lenses or mirrors made of glass.
Today there are all kinds of telescopes like the radio telescope, the microwave telescope, the infrared telescope, the x-ray telescope and the gamma-ray telescope. And in the not too distant future we might even have neutrino telescopes and gravity telescopes – the progress made in the second half of the twentieth century is simply unbelievable!

Visible and Non-Visible Light Radiation

Well, what do all these mean? To understand this in a simple manner, we start with sunlight. As all school-children know, when sunlight is passed through a glass prism it splits into the familiar seven rainbow colours.
We describe this by saying that the Sun emits light at several wavelengths ranging from the red at one end to the violet at the other. OK, this range represents a certain band of wavelengths from about say 6000 Å [Angstroms; one Angstrom is one tenth of a trillionth part of a metre!] to about say 3000 Å. Does the Sun emit radiation at other wavelengths also? If so, why can’t we see it? We seem to see only seven colours all the time. Glass-prism

Visible and non-visible light radiation spectrum
This is an interesting point, and shows the way God “designs” systems! Actually, the Sun emits radiation at all wavelengths, but God in His Wisdom has considered it sufficient if our eyes are sensitive to that portion of the spectrum where the Sun’s light is brightest!
Something similar happens in the case of sound also. All of us can hear sounds with frequencies only in a certain limited range. We cannot hear high frequency sound and likewise we cannot also hear sound of very low frequency. However, some animals can hear sound frequencies we cannot.
God has designed the hearing system to suit the animal. Similarly, God has designed man’s sensory systems to aid his survival (in the external world that is!) Man is intended to be a day bird, and that is why his eyesight has been designed to suit daylight and the sensitivity of the human eye is limited to the spectral regions where Sun shines brightest. On the other hand, there are animals that move about mainly in the night, and their eye-sensitivity is quite different. Who can deny that God is Great!
OK, what is the point of all this? Simply that objects in the Cosmos can emit radiation at many different wavelengths, which means that to study celestial objects we must really look at them at as many wavelengths as possible. Thus, while the early studies of our Sun were performed entirely on the basis of visible radiation, today astronomers study the Sun at all sorts of frequencies ranging from the infra-red to the x-ray region. This is possible on account of various developments in technology, thanks to which we now have all kinds of telescopes as I mentioned earlier. Such wide-spectrum and broad-band studies reveal a lot more. Some celestial objects do not emit visible radiation at all, in which case one has no choice but to resort to non-visible astronomy like radio astronomy, for example.

The Places to Appreciate the Glory of God


Giant Metre Radio Telescope, Mumbai
Advances in technology have also altered the culture of astronomical research. For example, optical telescopes are best located at high altitudes so that the disturbance form the atmosphere is minimised. At the present time, two favourite locations are Hawaii, and the Andes mountains in Chile. Telescopes located here have been built at very great expense, and research time is allotted on the basis of scientific proposals submitted by various research groups. There is, near Bombay/Mumbai, a huge radio telescope known as the GMRT (Giant Metre Radio Telescope.)This telescope has an array of antennas that look like TV satellite dishes, only they are much larger. There are over thirty of these, spread across an area of about thirty sq. km. This telescope has been designed to receive radio waves of 1 metre wavelength – many celestial objects emit at this wavelength. Radio astronomers from all over the world bid for time, and observation time is allotted, based on selections made by an international peer group. Has all this been worth it? One would think so, judging by the amount of scientific information and knowledge that has been gained.
One might ask, and this is often done: “Why spend so much money on all this when people are dying of starvation, hunger etc.?” This does seem like a pertinent question, but this must be considered against the proper perspective. If one examines the world budget on exploring the Cosmos, that would be peanuts compared to the money spent on violent and unproductive ventures like war, harmful ventures like spreading profanity, gambling, etc. It is therefore not correct to dismiss all scientific research in one breath. Knowledge of the Universe that the merciful Almighty created for us to live in should be welcomed. In fact, such knowledge, though it is only about the physical Universe, would still help in appreciating the Glory of God and the wonders He has packed into Creation.
That is all for this instalment, and let me mention that we have barely started on our journey! There is so much more to come. Meanwhile, do spend a few moments looking up at the sky (if in your part of the world it is not covered with smoke and filled with man-made light.) There is God in all His Glory looking down, shining and smiling, and blessing us. Have His Darshan.


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Star In Quest of Infinity - Part 2a

Post by Admin on Wed Jul 23, 2008 5:38 am

MUSINGS from prasanthi nilayam
IN QUEST OF INFINITY - PART two
By Prof G. Venkataraman

How it all Began
Sai Ram and warm greetings again. I am happy to resume with you our joint quest for Infinity! Last time, I gave you a brief glimpse of the Universe we live in and how man, without moving out too much, mostly by gazing, wondering and thinking, combined with a lot of ingenuity of course, has assembled so much information about the Universe. In this issue, I would like to tell you something about what we know about the birth of the Universe.


From ‘Steady State’ to ‘Big Bang’
The Big Bang

You may not believe, but even as late as the twenties of the 20th Century, people including astronomers thought that the Milky Way in which we are placed, was the only galaxy in the Cosmos, that the Universe always existed, and that the Universe would always be in a steady state, that is, without any change of size.

The first half of the twentieth century saw all those concepts give place to something totally different. Most importantly, we now believe that the Physical Universe we live in had a definite birth, an event that is popularly referred to as the Big Bang.

The idea of the Big Bang is in some measure due to George Gamow. It must be said that Gamow did not actually ask questions about the birth of our Universe. He was more interested in the question: “How did the very first elements form in the cosmic cauldron that came into existence after the birth of the Universe?”

Although people had considered models relating to the Universe earlier, the question of the actual birth of the Universe did not acquire importance till Gamow got into the act. However, the earlier story is interesting in its own way, and maybe I should give a glimpse of it, before I get back to Gamow and the trigger he provided.

The Gravity of Einstein’s Theory
Sir Albert Einstein

Cut to the year 1915, when Einstein, already famous and soon to become almost a rock star, developed his Theory of General Relativity and Gravitation. This is a very important development and maybe I should say a few words about it. We all know that it was Newton who first told us that matter attracts matter due to a force called the gravitational force; that a stone falls to the earth when thrown up because of the force of gravity, and that the Earth goes round the Sun and the Moon goes round the Earth because of gravity. But what exactly is this gravity? That was the question that Einstein answered, though not in full, at least in great measure.

Einstein’s Theory of General Relativity [GR] is quite complicated; in fact at the time it was developed, very few scientists understood it, let alone ordinary people. However, we are not concerned with the technical details but an interesting story related to GR. The core of GR is a set of equations and fooling around with them, Einstein applied them to the whole of the Universe. And what did he find? Something unbelievable: the Universe had a birth and thereafter expanded.

Einstein was shocked and could not believe what his own equations told him. He said to himself, “There is something wrong with my equations. How can the Universe be born? It has always been there; and this expansion business, it is utter nonsense. So, to get the facts right, let me fix my equations so that they tell the truth.” And Einstein “fixed” his equations by adding what he called the Cosmological Constant, and presto, the equations behaved “well”, meaning they did not predict a birth for the Universe nor any expansion. Einstein felt satisfied and relaxed.

Today, even schoolboys know that the Universe had a beginning and is expanding all the time, but around 1920, people had a very different idea about the Universe. Some scholars say it was all due to the subtle influence of religion; I do not know about that, but the fact is that in those days, people, including astronomers [!], thought the Milky Way represented the whole of the Universe!

Friedman Theory Sheds New Light
Scientist Alexander Friedman

The story now develops two parts, one revolving round Alexander Friedman and the other revolving round Edwin Hubble. We shall take them one by one, starting with Friedman in Russia. Friedman was a young man at that time [1922] and became fascinated by Einstein’s Theory of General Relativity. Like Einstein, he too began playing with Einstein’s equations and found that depending upon the circumstance, the Universe could have different histories. These are described separately. But common to all of them was a birth, and expansion [in one model, in the first stages only].

Einstein being the Grand Master, Friedman sent a letter to big man, submitting his results and requesting Einstein to have the paper published in Germany in a leading Physics journal. As I told you earlier, Einstein had already encountered this business of the Universe being born and had dismissed it. So he wrote a short note to Friedman saying that he was all wrong. Young Friedman was disappointed but did not give up. He checked his work all over again and found he had made no mistake whatsoever and that his findings were true. He wrote a second letter to Einstein, pleading that since there was no mistake, his results deserved publication.

Einstein was travelling at that time, and in fact, on account of his travels, he missed going to Stockholm to receive the Nobel Prize in December 1922 [those days, they had to travel by ship and the journey took weeks]. So it is but natural that Einstein missed seeing Friedman’s second letter. However, when Einstein returned to Berlin [where he was those days], a Russian scientist named Krukov managed to meet Einstein personally and argue on behalf of Friedman. Thereupon, Einstein studied Friedman’s work, found that there was no mistake in the Russian’s work, and admitted that Friedman’s work shed new light.

Edwin Hubble
US astronomer Edwin P. Hubble

We now come to the second part of the story, which takes us to America and deals with Hubble. Edwin P. Hubble was born in Missouri, USA in 1889. After earning a B.S degree from the University of Chicago in 1910, Hubble trained to become a lawyer. However, through the influence of friends, he also developed a strong interest in astronomy. After getting his B.S degree, Hubble went to Oxford as a Rhodes Scholar. At Oxford, Hubble showed the world that he was a good athlete too, by becoming an Oxford Blue in athletics. In addition, he also trained as a heavy weight boxer and even defeated champion George Carpentier in an exhibition fight!

On return to America in 1913, Hubble was admitted to the Bar in Kentucky. For a while, he practiced as a lawyer. However, his interest in astronomy prevailed, and Hubble got ready to return to Chicago for graduate studies in astronomy. Meanwhile, the First World War intervened, and Hubble enlisted in the U.S Army. He saw action in France, and rose to the rank of a Major.

After the war was over, he returned to pursue his interest in astronomy; and thus began a most fruitful career. Hubble was a very keen observer and made many important discoveries.

Discovering the Expansion of the Universe

By this time, astronomers had shown that the Universe contained billions of galaxies, and in 1924, Hubble developed an important way of measuring the distances of galaxies, especially the distant ones.
An Expanding Universe

His greatest discovery came some years later when he found that galaxies were all moving away from each other, showing that the Universe was actually expanding. Commenting on this, Hubble wrote:

"[all this] should furnish a clue as to the exact nature of the Universe. It may then be possible ….. to say if the Universe and space itself is expanding at a rapid rate and in a remarkable manner. And finally, it may be possible to describe the nature of the expansion and to determine the time at which the expansion began – that is to say, the age of the Universe."

The idea of the Universe expanding was now clearly established by observation, confirming what Einstein’s equations had predicted earlier.

When Einstein learnt of Hubble’s discovery, he regretted trying to fix his equations earlier by introducing the Cosmological Constant, and described that move as his greatest blunder.

But you know what? God has ordained that the Cosmological Constant has a place in His Creation, and it is now back in a new Avatar, without disturbing the expanding Universe!
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Star In Quest of Infinity - Part 2b

Post by Admin on Wed Jul 23, 2008 5:40 am

Georges Lemaitre Rediscovers Friedman Theory
Father Georges-Henri Lemaitre:
priest and scientist

It often happened in Science in those days, partly I presume because of lack of communications, that many facts were re-discovered independently by many people.

Earlier I told you how Friedman in Russia had discovered what Einstein had found earlier, namely that the Universe might have had a beginning. Same story once more, this time the person involved being a Belgian priest named Georges Lemaitre. Born in 1894, Lemaitre attended a Jesuit College and entered in 1911, the University of Louvain to study engineering. When the First World War broke out in 1914, Lemaitre joined the Belgian Army and was decorated for bravery. In 1918, after the war was over, he resumed his university studies but switched from engineering to mathematics and physics. Simultaneously, he also enrolled in courses in philosophy. His ambition was to specialise in physics and metaphysics!

In 1923, Lemaitre wrote a thesis on relativity and gravitation and this won for him a scholarship from the Belgian Government, enabling him to travel to Cambridge. There he came into contact with a famous astronomer named Eddington and this spurred his interest in Cosmology. From England, Lemaitre went to America, made the acquaintance of many astronomers there, and spent some time in the famous MIT in Boston. In October 1925 Lemaitre returned to the University of Louvain, where he remained for the rest of his life.

By 1920, Lemaitre had become strongly interested in Einstein’s Theory of General Relativity, which he mastered entirely by self-effort. By the mid-twenties, Lemaitre, unaware of the work done in Russia by Friedman, examined critically some earlier work of de Sitter on Cosmology, and derived some new results. He published these in an obscure journal, and not surprisingly, the results went unnoticed. In 1927, there was a big conference on physics held in Brussels [the capital of Belgium] attended by all the bigwigs, including Einstein. Naturally, as a Belgian, Lemaitre was present, and he took the opportunity to catch the attention of Einstein and tell him about his results. The Master’s reaction was cold. He simply said [in French], “Your calculations are correct but your physical insight is abominable.”
Artist's rendition of the Primeval Atom

In January 1930, there was a meeting of the Royal Astronomical Society in London, during which there was a lot of discussion about Hubble’s new discovery about the expanding Universe. All this was duly reported in the February issue of the journal The Observatory, which Lemaitre read in full. Immediately he dashed off a letter to Eddington reminding him that as early as 1927, he had sent him [Eddington] a paper that predicted an expanding Universe. Eddington then remembered that indeed he had received a copy of a paper but had completely forgotten about it. He now made amends by writing a letter to the journal Nature drawing attention to Lemaitre’s brilliant work three years before. Suddenly, Lemaitre became a celebrity.

In May 1931, Lemaitre published in Nature, a paper that ventured to suggest that the Universe was born from an infinitesimal supreme state of matter condensation, the Primeval Atom as Lemaitre called it. The explosion of this Primeval Atom was what later started off the expansion of the Universe. Rather colourfully, Lemaitre referred to this explosion as a “day without yesterday”. Lemaitre’s theory has also been referred to as a “fireworks theory of the beginning”. In some respects, Lemaitre rediscovered what had already been found earlier by Friedman, though perhaps with a bit more physics than just bare Cosmology. No wonder Russians are annoyed with the credit given to Lemaitre, overlooking the claims of their scientist.

George Gamow
Physicist and cosmologist Georges Gamow

All this happened before World War II. During the war years, basic science naturally took a back seat but when the war was over, scientists went back to their passion with renewed vigour. It is time to bring George Gamow back into the picture. Gamow, by the way, was a student of Friedman, and he achieved early fame with some brilliant work in radioactivity. In those days, Russia was a tightly-controlled dictatorship. Gamow found the atmosphere too stifling. He and his wife then planned an escape. They purchased a small canoe and hoarded food for months. They then managed to wangle permission for having a holiday on a Black sea port. And one day, they tried to row out of Russia – they had to paddle nearly 250 km and they thought they would be able to do it. But it did not work that way; the canoe was caught in a storm and blown back to the shore, forty eight hours later! The chance to leave Russia came two years later when the Government sent him to Brussels to attend a conference. From there Gamow went to America in 1934, where he stayed for the rest of his life. During the Second World War, Gamow worked on the atom bomb project. After the war, he turned to Physics and began to wonder about the origin of elements in the early Universe.

An Infant Universe

It was while trying to answer this question, Gamow reasoned that first there must have been an infant Universe. Next, he said that this baby Universe must have been very, very hot. After this he argued that this was the ideal setting for the cosmic cooking of elements; that was Gamow’s line of reasoning. All this happened around 1948 or so.

It was only after Gamow’s seminal work that physicists began to accept the notion that the Universe did have a definite birth. Later, thanks to a casual remark by the British astrophysicist Fred Hoyle, the term Big Bang gained currency and came to be associated with the primordial event that signified the birth of the Physical Universe. By the way, Hoyle never believed in the Big Bang himself, and he, in fact, introduced the term somewhat in a sarcastic vein in a popular talk on Science over the BBC; but the name has stuck, and the belief in the concept too!
A hot, expanding infant universe

One important fall-out of Gamow’s conjecture is the following: “OK, the Universe was born in a hot Big Bang. Then a lot of heat must also have been radiated at that time. If so, is there any remnant of that heat still left now?” The basic argument in favour of such a remnant goes as follows: The Baby Universe must have been extremely hot with a temperature in the range of trillions, yes trillions, of degrees! So the radiation emitted at that time must also have had an astronomically high temperature. But since then the Universe has expanded enormously and since expansion always produces cooling, the original radiation too must have cooled down considerably.

Gamow’s student estimated that at the present time the radiation surviving from then must have an absolute temperature of about 5 degrees absolute, or - 268 C! For comparison, the lowest temperature recorded on the face of the Earth is about – 60 C. The predictions we are mentioning were made way back in 1948 or so. In 1960, two scientists in America named Arno Penzias and Robert Wilson accidentally discovered this Cosmic Background Radiation that had been predicted on the basis of Gamow’s theory. One may say that Penzias and Wilson actually heard the OM of Creation! And for their [chance] discovery, they later received the Nobel Prize! The discovery of this Cosmic Background radiation was a landmark event in Cosmology for it provided clear evidence that the Universe did originate in a Big Bang.

Three Alternative Scenarios Discovered by Alexander Friedman

When Friedman worked with Einstein’s equations of General Relativity and applied them to the Universe [tough mathematics one must say!] he found that there were three possible scenarios. They are as sketched below:
Three scenarios described by Friedman

In scenario 1, the Universe has a beginning and thereafter expands endlessly. In scenario 2, the Universe is born, expands for some time, and then begins to shrink. Eventually, it disappears in a Big Crunch, even as it was born in Big Bang. In scenario 3, the Universe is born, and then expands. However, with the passage of time, the expansion slows down and after literally infinite time, the Universe has a fixed size.

Two questions arise: a) Why three scenarios, and b) which of these actually applies to our Universe? Let us take the first question first. Three scenarios exist depending upon the amount of “matter” contained in the Universe. The issue is a bit complicated and so I shall avoid the technicalities. Let us turn now to question (b). After years of speculation, it would now appear that 95 % or even more, the Universe is headed for scenario 3 described above. Maybe in a subsequent article, I shall add some more comments on this very important issue.



I have lots more to tell you but that would have to wait till the next time. By the way, please note that though I am presently dealing with the physical Universe, later we shall go beyond Physics to Meta-Physics and then on to Vedanta and so on. Waiting for us at the end of it all would be the Cosmic Infinity! It’s a long way to go and there are plenty of exciting journeys ahead of us! Till we meet again, all the best! Jai Sai Ram.
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Star In Quest for Infinity - Part 3a

Post by Admin on Sat Jul 26, 2008 8:20 am

MUSINGS from prasanthi nilayam
IN QUEST OF INFINITY - 03
By Prof G. Venkataraman

THE BIRTH AND DEATH OF STARS
Sai Ram and warm greetings again. I hope you are finding this journey exciting. Last time, I introduced you to some facts relating to the birth of our Universe. Today, I would like to tell you something about the birth and death of stars. Stars may not have life the way we have, but there is such a thing as coming into existence of a star, and the end of life as a star. Believe it or not, like us humans, stars too have rebirth! So, there is a fascinating exploration ahead of us.


In The Beginning….
Artisit's rendition of the Big Bang

Where humans are concerned, the Bible says it all began with Adam and Eve. In the same way, we must start by discussing how the very first stars in the Universe came into existence. For this purpose, we have to go back to the very beginning of the Universe, namely the so-called Big Bang. I shall skip for the moment the complex sequence of events that took place within the first one second after birth. This first one second is extremely important and incredibly fascinating but for our present purposes, it is better to start after the first one second. So what was the Universe like, when it was a one-second old baby?

First about the size. At the age of one second, the Universe had a radius of roughly 10 billion km [or one thousandth of a light year]; for comparison, the distance of Pluto from the Sun is roughly 6 billion km. Today, the size of the Universe is about 15 billion light years. Just to remind you, one light year equals a distance of 10 trillion km; so today, the radius of the Universe is ten trillion times fifteen billion km! That is a real WOW, is it not? And so, at one second, the Universe was really small compared to what it is today.

OK, now what was the Universe made up of when it was just one second old? Were there stars, planets, etc? None of these. The Baby Universe was made up of electrons and atomic nuclei, that is to say nuclei of simple elements like hydrogen and a bit of helium, that is all. For the next several thousand years or so, nothing much happened except that the baby kept on growing, and while this expansion took place, the Universe was basically filled with gas of hydrogen and a bit of helium. Of course, the distribution of the gas was not uniform; in some places there was more and in others there was less; even so, it was gas everywhere, though with varying density.

Gravity Takes Hold

About a million or so years after the birth [by this time the Universe was much bigger] in some places where there was a big concentration of gas, the gas cloud began to shrink. How come? Because of gravity. I suppose you know that gravitational force, discovered by Newton, is an attractive force. Matter attracts matter, and that is what gravity is all about. Now a hydrogen gas cloud is made up of hydrogen atoms and atoms being matter, can attract each other. True, the hydrogen atom is extremely small and therefore its pulling power too is very, very small. And when two atoms are say a million km apart, the attraction may seem nothing to write home about. But this is where Nature stuns us. Thanks to sheer numbers, the little pulls all add up, and eventually the gas cloud behaves as if someone is massively squeezing it from outside. No one really is; what is actually happening is that every atom pulls every other atom and the net result is that all of them start coming closer and closer together. To someone outside, this might seem as if there is a squeeze that is being applied; it is just self-squeeze, operated by gravity.

For the record, I should mention that while gravity pulls inwards, the cloud does try to diffuse due to gas pressure like all clouds do. I am sure you have seen fluffy clouds in the sky becoming bigger through diffusion caused by outward gas pressure and then sort of melting away. However, this gas pressure is peanuts and gravity simply overwhelms it. Gravity is really amazing. It appears weak and insignificant but on the scale of the Universe, it calls the shots because its reach is so long!

OK, so the big hydrogen cloud is getting squeezed more and more. What happens? Does it get crushed into a point? Not really, because something starts happening when the cloud really begins to shrink. You see, the shrinking process is accompanied by a heating process also, the heating being greatest at the centre of the cloud. Now when I say the cloud is getting hot, do not imagine temperatures like what we experience during a hot summer day. Believe it or not, at the centre of the cloud, the temperature can become as high as a MILLION degrees! WOW!! Now that is some temperature, is it not? Of course it is, and sure enough things start happening.

Devices for Thermo-Nuclear Fusion

I must clarify that when I say that the temperature in the compressed gas cloud can go as high as a million degrees, what I mean is that it does so at the core of the cloud. As one moves away from the centre, the temperature starts falling. However, the fact that the temperature rises to a million degrees and above near the centre, makes interesting things happen. Basically, the astronomically high temperature makes hydrogen nuclei to fuse together to form the nuclei of helium. I will skip the details, which belong to the realm of nuclear physics; but this I must say – this coming together of hydrogen nuclei to form helium nuclei is called nuclear fusion, and because this fusion of light nuclei to become bigger nuclei is driven by high temperature, it is often called thermo nuclear fusion.

The important and interesting thing about this nuclear fusion is that it is accompanied by the release of a lot of energy. This energy then flows outwards towards the outer surface which is cooler – I guess you are aware that heat always flows from a region of high temperature to a region of low temperature. From the surface of the cloud, the energy is radiated into space as heat and light.

To repeat, first there is gravitational compression of the hydrogen gas cloud. This leads to heating, especially at the centre. When very high temperatures are attained, there is thermo-nuclear ignition. This is a process where small nuclei fuse to form bigger nuclei, and in the process heat is also released. This process is sustained and a star is born. This sequence of events is schematically illustrated in Fig. 1.

Question: Initially, there was compression that then led to thermo-nuclear ignition. Does compression continue after the ignition is triggered?

No! What happens is that while gravity tries to compress the gas cloud, radiation flowing outwards exerts an outward pressure that tries to expand the gas cloud. So there is a tussle between the inward force due to gravity that tries to compress the gas cloud and the outward force due to radiation [that is substantial] that tries to expand the gas cloud. A balance is reached, then we then have a gas cloud of stable size that is hot at the centre and radiates energy into space.

So that is how a star is born out of a gas cloud that is large and cold to start with. By the way, in a hydrogen bomb, enormous energy is released via thermo-nuclear fusion. However, in the bomb, it is all over in less than a millionth of a second, whereas a star keeps releasing thermo-nuclear energy for millions if not billions of years. Our Sun is thus nothing but a self-sustaining thermo-nuclear device!

OK, a star is born. Will it burn forever or does it have a finite life? If the latter is indeed the case, then how long does a star live? The answer to that is simple. A star is like a burning fire; just as a log of wood would burn as long as there is some wood left, so also a star would burn as long as there is fuel. When the fuel supply starts running down, the temperature starts coming down and cooling starts. Then a whole new ball game starts. That story next.

The Stellar Cycle: Birth, Death and Rebirth

I said that when the fuel gets exhausted, burning or thermo-nuclear ignition stops and the star starts cooling down. Two things happen then. First in the inner regions of the burnt out star, where density is high, gravity begins to dominate and a contraction process sets in. The outer layers on the other hand try to diffuse away like a cloud. So the net result is that the cloud as a whole appears very large from the outside; however, the inner region starts contracting and getting hot once again. By the way, when our Sun “dies” and starts expanding, it is expected to become so large as to extend all the way close to Earth; it would become a real giant with a dull red glow when seen from outside. See Fig. 2. Astronomers have detected many red giants, and that is why the hypothesis is believable.

OK, so we have this red giant, large and thin on the outside but the core contracting and getting hot again. What happens next? That is an interesting story. You see, in the first generation stars, hydrogen nuclei fused to form helium nuclei and when the supply of hydrogen runs down, thermo-nuclear burning stops.
A red giant star many times bigger than our sun

That is when the star becomes a red giant with the core again contracting and getting hot. Any likelihood of ignition? Yes there is, and this time the temperature must rise to a level where helium can act as the fuel.

So you see, in the first attempt, the star is a cauldron in which hydrogen is converted into helium. After a “rest” period it starts all over again, with the same sort of story repeating.

First there is a contraction due to the influence of gravity, then the core heats, and when the temperature is right, there is thermo-nuclear ignition once more, this time helium nuclei fusing to make up a slightly heavier nucleus, releasing energy in the process.

This energy flows outwards and is finally radiated into space. This is the daughter star so to speak. From the daughter is born another star, the grand-daughter so to speak, and so on it goes, generation after generation.

In short, a star is born, it burns, dies, is reborn, dies, is reborn, dies and so on. Every time the star becomes a cauldron where elements get cooked, light elements get fused into heavier elements, and in this way, newer and newer elements [see Fig. 3] that chemistry students learn about came into existence in the Universe.
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Star In Quest for Infinity - Part 3b

Post by Admin on Sat Jul 26, 2008 8:22 am


Discovering What Happens Next

Any end to this process of stars being born, dying, being born again, etc? Yes there is, and that is when the core, after having evolved through many stages is substantially made of iron. Thereafter, thermo-nuclear ignition with continuous release of energy is ruled out by the laws of nuclear physics, and the birth-death-rebirth process stops - there is no more chance of heavier elements being formed through stellar cycles.
A massive star with a core of iron

You might wonder: “But on earth we find silver, gold, uranium etc., all of which are much heavier than the iron nucleus; where from did they come?" That is a very interesting question to which we shall return may be in the next issue. By the way, I hope you would have noticed how nuclear physics is helping astrophysics. All this understanding of stellar physics through the injection of nuclear physics that I am now describing started happening in the period between 1930 and 1940. This is one remarkable aspect of the development of modern physics. Different specialisations often come together in an amazing and unexpected way to push forward the frontiers of knowledge.

Thus far, what I have told you is the following: For the first million years or so, there were no stars. Thereafter, the first stars were born. They lived for some time and stopped burning fuel inside when the supply of hydrogen became small. After a “rest” period, another sequence of burning started, this time helium [produced in the first generation stars] acting as the fuel. After helium is burnt out, there is again a rest period, and a rebirth in which helium becomes a slightly heavier element and so on, it is punarapi jananam stuff playing out here in the Cosmos!

Question: “What happens to a star when it finally ceases to burn?” This is exactly where the story becomes even more interesting!
The Prodigious Subramanyan Chandrasekhar



That story is connected with a famous scientist who started it all when he was a mere eighteen-year old college student. His name is S. Chandrasekhar. He later became a world famous scientist, and won the Nobel Prize too. But as someone said, he did not become great with the Prize; already he was so renowned that it was the Nobel Prize that gained in prestige by getting awarded to him. There is, by the way, a NASA satellite carrying an x-ray observatory in space named CHANDRA, launched in 1996, that has provided spectacular images and insight into stellar physics.

The story of the discovery that young Chandra made goes as follows. In the late twenties of the twentieth century, Chandra was a Physics Honours student in Presidency College in Madras. His uncle, Sir. C.V. Raman, who had studied earlier in the same college, had become world famous with his discovery of the Raman Effect for which he won the Nobel Prize in 1930. Chandra was clearly out of the ordinary, and even when he was a student, he had already published a scientific paper, unusual in India then, and indeed even now.
Sir. C.V. Raman
The Prestigious Presidency College, Madras

Chandra was totally focussed on physics and received as a prize a book entitled The Internal Constitution of Stars, written by the famous English astrophysicist, Arthur Eddington. The best way of describing Eddington’s stature would be to say that he was then the David Beckham of astrophysics! This book made a deep impact on young Chandra and got him to think intensely about stars and problems in astrophysics. That was when an event happened that was to change his life.
Professor Arthur Eddington
Arnold Sommerfeld

On Raman’s invitation, a famous German Physicist named Arnold Sommerfeld, who was a master teacher and who nursed nearly half a dozen Nobel winners [!] in Munich, was visiting India in 1928, and giving lectures in various places. One of his stopovers was Madras, and there in the Presidency College, Sommerfeld gave a lecture on the newly emerging quantum physics and its implications. Chandra of course was present in the audience, but one wonders whether anyone in the audience, Chandra being the exception, followed what Sommerfeld spoke about.
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Star In Quest for Infinity - Part 3c

Post by Admin on Sat Jul 26, 2008 8:23 am

Leaving for Cambridge

After the lecture, Chandra who was then thinking a lot about stars had a meeting with Sommerfeld and asked him many questions. There was one particular problem that preoccupied him most and when, after studies were over, his father asked him to appear for a competitive examination that would qualify him for a big government job, Chandra flatly refused – thank God he did! Instead, he headed for Cambridge, then the Mecca of Physics. And Cambridge, by the way, was where Eddington was at that time.

The year was 1930. In those days, there were no jet planes, and one had to travel to England by ship. The journey took about two weeks, and to keep passengers engaged, the Captain of the ship usually organised all kinds of games and parties. Young Chandra, however, kept himself busy thinking about what happens to stars when they finally end their lives. Now there are a class of astro-objects known as White Dwarfs. They are supposed to be dead stars, that is, stars where thermo-nuclear ignition has totally ceased; in other words, a White Dwarf is really a stellar corpse. Chandra was interested in the physics of White Dwarfs. The interesting thing about a White Dwarf is that matter there is very dense. You want to know how dense? Imagine taking a small piece of material from the White Dwarf, about the size of a tennis ball. That small piece would weigh as much as 25 elephants! That is some density, is it not? See Fig. 4.


What Chandra did on board was to think hard about the physics of White Dwarfs, and this he did via his favourite way, writing down complex mathematical equations and cracking them. In the process, Chandra made a discovery. It was kind of weird, and Chandra was not too sure. He would have to analyse more carefully, and then check and cross check; all that was going to take time.

The Problem of White Dwarfs
A white dwarf slightly smaller than Jupiter
next to the Earth

Chandra landed in England and enrolled in Cambridge as a student. In between his regular work as a student, Chandra kept himself busy with his obsession, constructing a proper theory for White Dwarfs. Now White Dwarfs are not fictitious objects. Astronomers had detected such objects in the sky, and they suspected that these White Dwarfs were the corpses of stars that had finally come to rest. There arose a question. From the classical physics point of view, when a star finally dies and there is no burning of any sort within, then, given the mass of the star, gravity ought to dominate.

If it does, then the star would slowly get crushed more and more and start shrinking. This shrinking would go on relentlessly till the star is crushed to almost a point with infinite density. It seemed as if there was nothing to stop the dead star from shrinking to a point. But the White Dwarfs, which everyone agreed represented stellar remains, did not have point size. So clearly, something was stopping gravity in its relentless crush. What was that force and how did it operate? That was one of the major problems of the day.

Now words like a geometrical point, infinity, etc. are OK in mathematics, but in physics, they are not good words. After all, matter is made up of atoms and atoms have a finite size. What then does it mean to say that all atoms are crushed together to be reduced to a point? Physicists were not at all comfortable with the idea of matter getting crushed to a geometrical point. But then, if one accepts classical physics, that fate is inevitable. It was around this time that quantum mechanics had been discovered [1925-1930], and people said, “Ah, we cannot trust classical physics entirely when it comes to physics in small scales of length. We have to look to quantum physics. Maybe, quantum physics would somehow save White Dwarfs from being crushed to a geometric point.”

Guess what? It did and the way that happened was pointed out by William Fowler of Cambridge. Fowler used Fermi-Dirac statistics [that Sommerfeld explained to Chandra in Madras] to argue that quantum physics did intervene and save the dead star from the fate of being ruthlessly crushed to a geometric point. By the way, the term Fermi-Dirac statistics is shorthand for the mathematical description of how electrons in large number behave, when huddled close to each other. Fowler pointed out that thanks to the quantum nature of electrons and their allegiance to Fermi-Dirac statistics, when matter is crushed to very high densities [as happens in a White Dwarf], a pressure is generated due to the electrons in the White Dwarf.

This quantum mechanical pressure is called degeneracy pressure and acts outwards. In other words, in the dead star, while gravity pulls inwards, degeneracy pressure pushes outwards, and there is a tussle. Eventually equilibrium settles in, and the dead star assumes a finite size; it is saved from being reduced to a point – see Fig. 5. That was Fowler’s finding, and everyone breathed a sigh of relief. Except young Chandra!

Chandra began having doubts about the total validity of Fowler’s theory, even when he was a student. Remember his discussions with Sommerfeld as a student of Presidency College? Chandra essentially asked Sommerfeld: “In a White Dwarf, the density of electrons is very, very high. At such densities, the electrons no doubt obey Fermi-Dirac statistics. But since the density is high, the electrons must also obey Einstein’s Relativity; however, Fowler’s analysis ignores the relativistic aspect of electron behaviour. Should not the application of quantum statistics be combined with appropriate relativistic considerations?” It would seem that Sommerfeld said yes, adding that such an analysis would be worthwhile. That was the line of investigation Chandra started and kept at for years, even while he was going through the mill, to meet his routine obligations as a student.
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Star In Quest for Infinity - Part 3d

Post by Admin on Sat Jul 26, 2008 8:24 am

Chandra Unveils His Masterpiece

In Madras, Chandra was alone; there was no one there other than him interested in astronomy and physics nor understood it in depth. In Cambridge, however, it was very different; all the top shots were there, including the great hero, Eddington, and of course, Fowler too. So Chandra worked hard for five years, perfecting his theory of White Dwarfs, checking every detail – he was always like that, perfect and ever meticulous – and finally had his theory all ready. All that now remained was to formally unveil the theory. And the opportunity for it came in January 1935.

That month, there was to be a meeting of the Royal Astronomical Society in London. These meetings were big affairs, with top experts attending and presenting the outcomes of their scholarly researches. Chandra was given half an hour; that was arranged by Eddington himself. But what Eddington had failed to tell Chandra was that he also was going to speak, and about Chandra’s theory!

The day was January 11th, and Chandra went to London fully charged up. He spoke, a young unknown Indian, and sat down. I suppose there was just a smattering of polite applause, though the discovery was phenomenal. I must now say a few words about Chandra’s discovery before I go on the rest of the drama surrounding the London meeting.

You will recall that Fowler’s investigations showed that dead stars were saved from the fatal destiny of being crushed to the totally unacceptable state of a geometrical point. Chandra’s finding showed that if relativity was included in the analysis – and there was no way it could be kept out – then if the collapsing object had a mass less than 1.44 times the mass of our Sun [the mass of our Sun is called a solar mass], the dead star would indeed collapse to a finite size. But if the mass of the dead star was 1.44 solar mass, then according to Chandra’s analysis, nothing can save that dead corpse; it had no option but to shrink to a point, whatever that meant!

One might ask: “OK, agreed that a dead star of mass 1.44 times the solar mass shrinks to a point. What happens if the dead star has a mass greater than 1.44 solar mass, say five times or ten times the solar mass. After all, such stars do exist. What would their corpses be like?” Chandra himself anticipated this question in his lecture and said, “A star of large mass cannot pass into the White Dwarf stage, and one is left speculating on other possibilities.” At this point, the physics of dead stars becomes mighty interesting, but let me put that on hold, till I finish with the great drama of 11th January, 1930.

Opposition to the Theory Grows

After the “kid” finished giving his paper and sat down, Eddington, the “giant” stood up with much relish, and started to tear down the “stupid” theory. Actually, Eddington relied on his stature and rhetoric rather than on hard science. But people listened to him because he was a top shot. Mercilessly he tore down Chandra’s theory, cracking many jokes in the process. The audience roared with laughter. Along the line, Eddington even cast aspersions on quantum mechanics. He could get away with it then, because quantum mechanics was still new and even Einstein was suspicious of it at that time.

Getting back to Chandra, he was completely shattered by the experience. He simply did not expect that Eddington would demolish him down like that in public. They had met so many times back in Cambridge; why did he not discuss his reservations then? Where was the need to humiliate a young student like that in public?
Sir Arthur Eddington with Sir Albert Einstein at Cambridge

After the meeting, Chandra talked to a few who had attended the meeting. Some sympathised, while some others preferred to side with Eddington; few cared to examine the scientific merits of the two arguments. Chandra then wrote to many big shots all over Europe; most sympathised privately but refused to come out in the open and do so. Meanwhile, Eddington went to America where he said, speaking in Harvard,

“All seemed well until certain researches by Chandrasekhar brought out the fact that the relativistic formula put the stars back in precisely the same difficulty from which Fowler had rescued them. The small stars cooled down alright and ended their days as dark stars in a reasonable way. But above a critical mass, …heaven knows what becomes of it [the star]. That did not worry Chandrasekhar; he seemed to like stars to behave that way, and believes that that is what really happens.”

Let us get back to the rest of the story of the fateful January 11th meeting. As I told you, after the meeting, young Chandra felt utterly demolished, with a few sympathising with him, some very critical, and most astronomers totally indifferent. Let us hear Chandra recall those moments. He says:

“I had gone to the meeting thinking I would be proclaimed as having found something very important. Instead, Eddington made a fool of me. I was distraught. I didn’t know whether to continue my career.

I returned to Cambridge late that night, probably around one o’clock . I remember going to the common room. There was still a fire burning, and I remember standing in front of it and repeating to myself, “This is how the world ends, not with a bang but with a whimper.”

A True Frontiersman
A young Subramanyan Chandrasekhar

The story does not quite end here, though round one certainly went to the giant, Eddington. Chandra got his degree and had to decide what to do next. He wanted to stay in England and work perhaps as a lecturer somewhere, but the shadow of Eddington would stretch everywhere and he was not sure if he would get a job. So he decided to leave England and go to America, where he was offered a position at the University of Chicago. There he stayed for the rest of his life, and rose to become a Distinguished Professor. Later, the University actually created a Chair named after Chandra. Reflecting on his migration, Chandra later said,

“I had to make a decision. Am I going to continue the rest of my life fighting or change to other areas of interest? I said, well, I will write a book and then change my interest. So I did.”

In fact, this became Chandra’s style throughout his life. He would enter an unknown area, literally create a new subject, write a scholarly book on his research, and move on to discover a new field. He did this time and again, blazing trails all the time. He was basically a loner, very disciplined, very meticulous, very thorough in everything he did, including in the way he dressed, the way he ordered meals in a restaurant [he was a vegetarian till the end], and in the way he “enjoyed” music. Martin Schwarzchild, an astrophysicist at the Princeton University says:

“Chandrasekhar’s concentration is unbelievable. He combines sheer mathematical intelligence and phenomenal persistence. There is not one field in which he has worked where we are not now daily using some of his results.”

Chandra collected innumerable awards, and about how he got them, he once narrated a story. It seems there was a General who had won many awards and medals. As you know military officers wear their medals over their uniform; so did this General. Once when the General went to a party, a young lady came by and started admiring the medals. She then asked, “General! How did you win all these?” The General smiled, pointed to a tiny medal in the middle and said, “Do you see this medal? I was awarded this by mistake, and after that, all the others followed!” That was Chandra, very focussed on his work and making light of his awards.

Chandra lived to eighty plus and worked hard till the very end, preoccupied with frontier problems in astrophysics. Almost single handed, he built up the famous journal, Astrophysical Journal, a peer journal in the field of Astrophysics. When he stepped down from the Editorship, there was a small party at which the man in charge of the Press [a typical, no-nonsense, hard-core American] said, “We have printed many papers dealing with the so-called Chandrasekhar limit. I do not know what that means, but as far as I am concerned, this Prof has no limits where work is concerned.”

The Birth of a New Physics

So much for the interlude about the great drama involving Chandra and what followed. Let us get back to the science before we wrap up this segment of our joint quest. To understand this, we must take a look at Fig. 6 that places Fowler’s result and Chandra’s results together. There are two graphs, both showing how the radius of the final object varies with the mass of the collapsing object.

Let us try and understand this figure slowly. We start with a star that is dead; there is this corpse and it has a certain mass. It now starts shrinking in size, crushed relentlessly by gravity.

Question: “What would be the radius of the final object?” Classical physics said zero, a result unacceptable. Then came Fowler of Cambridge who said that quantum degeneracy pressure would save the corpse from the fate of vanishing to a geometrical point. True, the larger the mass, the smaller would be the size of the end object, but beyond a certain mass, the final size would be more or less the same, irrespective of the mass of the collapsing object. Everyone breathed a sigh of relief. And then along comes a young upstart from India, and sitting there in Cambridge, right under the nose of the famous Eddington, he dares to say, “Ah, but you see, Fowler forgot to build relativity into his analysis. If that is included, we get a different story altogether.”

Chandra’s finding was, yes, the star starts shrinking to a smaller and smaller radius, once “it runs out of gas.” The larger the mass, the smaller is the radius of the final object/corpse. That was the finding of Fowler too; but here is where Chandra and Fowler differ. Whereas Fowler said that beyond a point, all dead stars, no matter what their mass is to start with, settle down to more or less the same final radius. Chandra said NO! When the dead star has 1.44 solar mass to start with, the final radius actually becomes zero. Maybe Nature will not tolerate a zero radius corpse and many other things might intervene to prevent the corpse from having that fate.

But Chandra asserted that Fowler’s version is not the end of the story, that relativity has a role to play and that his version of the story of stellar corpses is the first chapter in a new and exciting story in the life and death of stars. I shall reserve for later narration what happens to stars with large mass when they die. But this much I can say at present – Chandra’s investigations started a whole new and most exciting ball game; watch out for all that in the next issue!
Chandra’s investigations opened the door to a new age of physics

Getting back to our young hero who was badly bruised when he made his shy debut, way back in 1930, few believed in Chandra and those who did, did not dare or care to speak out openly because of Eddington’s stature. When the Pope says NO, who can stand up to the Pope even if he is wrong? But TIME proved that the Pope was utterly wrong and that Chandra had actually opened a new door leading to a fascinating vista [all that next time]. Before I conclude, I must get back to the relationship between Chandra and Eddington.

You will recall, when Chandra was still a mere college student, he won Eddington’s book as a prize which did much to stir his interest in astronomy and astrophysics. Later in Cambridge, Eddington actually stood in the way of Chandra’s research and literally drove him out of England. However, Chandra and Eddington continued to exchange letters, mostly of a personal nature and when Eddington died in 1944, Chandra said, speaking in a memorial meeting in the University of Chicago:

“I believe that anyone who has known Eddington will agree that he was a man of the highest integrity and character. I do not believe, for example, that he ever thought harshly of anyone. That was why it was so easy to disagree with him on scientific matters. You can always be certain that he would never misjudge you on that account. That cannot be said of others.”

In 1982, Cambridge University invited Chandrasekhar to deliver a series of lectures on the occasion of Eddington’s centenary. Chandra titled his lectures: Eddington: The Most Distinguished Astronomer of His Time. Isn’t that amazing that the very person who suffered most at the hands of Eddington was asked to give these lectures? But it is not surprising that Chandra praised Eddington handsomely; for him, the disappointment of the past was over and done with a long time ago.

Well this is where we must part company until we meet again. Meanwhile I invite you to reflect on the wonderful mysteries the Lord has packed into our beautiful Universe. I am sure you would agree that the Lord is stunningly beautiful and so also is His Universe, every bit of it.

Jai Sai Ram.
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