Tuesday, May 13, 2008

Book review-- "Big Bang: The Origin of the Universe"

A review from the Telegraph:

In his forthcoming book, bestselling author Simon Singh rewrites the history of the most important scientific discovery of all time.

The Big Bang is perhaps the most famous and fundamental theory in the whole of science. As the American cosmologist Carl Sagan put it: "If you want to make an apple pie from scratch, you must first create the universe."

But who deserves credit for the Big Bang theory, a theory that explains the creation and evolution of the universe? The honest answer is that the theory was developed by dozens of physicists, astronomers and cosmologists over several decades, with contributions from famous names such as Edwin Hubble and Albert Einstein. However, perhaps the man who deserves most credit is also one of the least well known.

Ralph Alpher, now 83, lives a quiet life in upstate New York. Few of his neighbours realise that Alpher, despite the cryptic clue in his name, pioneered the theory that describes the start of the universe. Even a straw poll among my physicist friends showed that nobody had heard of Alpher, despite the fact that he transformed the theory from mere wishful thinking into a viable, testable and realistic model of the universe.

Alpher's academic career started in 1937, when the 16-year-old prodigy received a scholarship to the Massachusetts Institute of Technology. Unfortunately, while chatting to one of the institute's alumni, he casually mentioned that his family was Jewish – the scholarship was promptly withdrawn. It was a terrible shock for the aspiring teenager: "My brother had told me not to get my hopes up and he was damn right. It was a searing experience. He said it was unrealistic to think that a Jew could go anywhere back then."

He kept his academic ambitions alive by holding down a day job and attending evening classes at George Washington University, where he became fascinated with cosmology and the Big Bang theory.

The idea that the universe started with a Big Bang had been proposed by the Belgian cosmologist and priest Georges Lemaître in 1927. He did not use the expression "Big Bang", but he did believe in "a day without a yesterday". He pictured a single massive primeval atom, which suddenly fractured and exploded, throwing out the smaller atoms that we see today. However, the majority of cosmologists rejected the notion of a Big Bang, which would have resulted in an evolving and expanding universe. Instead, the establishment believed in an eternal and largely unchanging universe.

Alpher and his PhD supervisor George Gamow, however, were convinced by the Big Bang theory. Indeed, they wanted to prove that the theory was true by seeing if the Big Bang could explain the various abundances of the elements in the universe. Some elements, such as hydrogen and helium, are very common, whereas others, such as silver and gold, are very rare. If the Big Bang could explain this, then it would be evidence in favour of this theory of creation.

In short, Gamow and Alpher wanted to model the hypothetical environment following a supposed Big Bang to see how the particles in the primordial soup would have reacted to form heavier elements. They hoped that the furnace of the Big Bang would explain the high abundances of hydrogen and helium.

Gamow and Alpher spent several months performing nuclear calculations, taking into account the fall in temperature and density that would have occurred as the universe expanded after the Big Bang. Their results suggested that the universe should indeed be dominated by hydrogen and helium. Furthermore, the Big Bang theory implied that there should be 10 atoms of hydrogen for every one atom of helium. This was a huge success for the Big Bang model, because 10:1 was exactly the ratio observed by astronomers looking at stars and galaxies.

This result was Alpher's PhD thesis, so the young student had the honour of presenting it at his public doctoral defence in the spring of 1948. Rumours had spread that the 27-year-old novice had made a major breakthrough, so the auditorium was packed with 300 people, including newspaper reporters. The following day the Washington Post announced "world began in five minutes".

For a few weeks, Alpher enjoyed a degree of celebrity. Academics showed interest in his work, a curious public sent him fan mail and religious fundamentalists prayed for his soul. However, Alpher's name was destined to be forgotten, partly thanks to a mischievous joke played by his supervisor. Gamow and Alpher should have been the only authors on the official paper announcing the result, but Gamow decided to invite the physicist Hans Bethe to become a third co-author. This resulted in authorship by Alpher, Bethe and Gamow, which was a pun on the Greek letters alpha, beta and gamma.

Gamow and Bethe were then both famous names in the world of physics, so scientists assumed that it was they who had done the bulk of the work, which meant that young Alpher was ignored. In the decades ahead, the formation of helium in the wake of the Big Bang would become one of the key pieces of evidence to support the Big Bang hypothesis, but few would remember Alpher's contribution.

To conduct one great piece of research and to be ignored was a great injustice, and yet Alpher was destined to suffer further torment. He would make an even greater breakthrough and he would be ignored again. In the late Forties he and Gamow were joined by Robert Herman, and together they realised that the Big Bang would have released an echo, which should still be present in today's universe as omnipresent radio waves. This radio echo would be a relic of the Big Bang and Alpher urged astronomers to search for it, as its discovery (or not) would settle the Big Bang versus eternal universe debate.

However, the community ignored Alpher's claims. The majority of astronomers were not convinced by the notion of a Big Bang, so why should they search for the echo from an event that they did not believe in? And those that did support the Big Bang theory did not think that it was technically possible to detect the radio echo. Alpher later complained: "We expended a hell of a lot of energy giving talks about the work. Nobody bit; nobody said it could be measured."

Faced with such apathy, Alpher left academia in 1955 and joined General Electric. His research papers languished in the journals and were soon forgotten.

Nothing much happened for almost a decade until an incident involving a radio receiver, pigeon poo and serendipity. In 1964, Arno Penzias and Robert Wilson, researchers at Bell Laboratories in New Jersey, were trying to calibrate a radio receiver and pointed it out into empty space on the assumption that it would pick up no signal. Annoyingly, they detected a constant hiss at all times and from all directions. They suspected that a pair of pigeons nesting in the radio receiver might be the cause of the problem, because they had deposited a "white dielectric material". But cleaning the receiver made no difference – the hiss persisted.

At roughly the same time, a group of theorists at Princeton University had followed in Alpher's footsteps, completely unaware of his earlier research, and they also proposed that there might be a radio echo from the Big Bang. When Penzias and Wilson heard about the Princeton research, it became clear what they had detected. They had accidentally stumbled upon the oldest known relic of the universe, emitted soon after the Big Bang, when the universe was less than 0.01 per cent of its current age.

However, by this time everybody had forgotten about Alpher and his original prediction of the Big Bang radio echo, so his name was absent from Penzias and Wilson's research paper. Alpher's name was also omitted from the front-page newspaper stories that appeared all over the world. On May 21, 1965, the New York Times ran the headline "Signals imply 'Big Bang' universe".

When Alpher was later asked if he felt offended by Penzias and Wilson's failure to acknowledge his contribution, he spoke his mind: "Was I hurt? Yes! How the hell did they think I'd feel? I was miffed at the time that they'd never even invited us down to see the damned radio telescope. It was silly to be annoyed, but I was."

In Genesis of the Big Bang, written with his colleague Herman, Alpher gave a more considered reaction: "One does science for two reasons: for the thrill of understanding or measuring something for the first time and, having done so, for at least the recognition if not approbation of one's peers. Some colleagues argue that the progress of science is all that matters and that it is of little consequence who does what. Yet we cannot help noticing that these same colleagues are nevertheless pleased with recognition of their work and accept with pleasure and alacrity such approbation as election to prestigious scientific academies."

Meanwhile, recognition for Penzias and Wilson culminated with the award of the Nobel Prize for Physics in 1978. Penzias used his Nobel lecture as an opportunity to help set the record straight, explicitly acknowledging and praising the contribution made by Gamow, Alpher and Herman. He gave a historical overview of the development and proof of the Big Bang model, based largely on a very lengthy discussion with Alpher. It seemed that Alpher had at last found a way of making his peace with the physics community. Just a month later, however, Alpher suffered a severe heart attack. Perhaps he had become overwhelmed by the stress of fighting for recognition. Perhaps the utter disappointment of not having a share of the Nobel prize proved too much.

Although dogged by ill health ever since, Alpher has gradually recovered from his heart attack and has lived to see further vindications of his Big Bang predictions. His work on the formation of the light elements in the wake of the Big Bang has been consolidated and estimations of hydrogen and helium abundances remain in very close agreement with observations. Cosmologists can now also explain the abundances of all the other elements. And the radio echo of the Big Bang (technically known as the "cosmic microwave background radiation"), as proposed by Alpher, has been at the centre of several experiments designed to probe the early history of the universe.

In 1992, the Cosmic Background Explorer satellite discovered tiny variations in the echo of the Big Bang. This was evidence of density fluctuations in the early universe, which were responsible for seeding the formation of today's galaxies. Yet another piece of the Big Bang picture of the universe had fallen into place. Stephen Hawking said: "It's the discovery of the century, if not of all time."

And in the last year, the WMAP satellite has studied the Big Bang echo in even greater detail. Consequently, cosmologists now estimate the universe to be 13.7 billion years old, and it seems that the first stars formed after just 200 million years. Also, WMAP measurements of the echo imply that only four per cent of the universe is ordinary matter. So-called dark matter and dark energy account for the rest, but the nature of these dark entities remains a mystery.

Because this Big Bang echo is our oldest relic of the early universe, cosmologists already have plans to examine it in even finer detail. The European Space Agency is building the Planck Surveyor satellite to be launched in 2007, which hopes to find clues to the true nature of dark energy and dark matter. Planck also wants to find evidence of the inflationary phase of the universe. According to inflation theory, the early universe doubled in size 100 times every billionth of a billionth of a billionth of a billionth of a second, and this process dictated the subsequent evolution of the universe. If the theory is true, then the Planck satellite should see evidence of inflation imprinted on the Big Bang echo.

Meanwhile, Ralph Alpher enjoys his retirement, content in the knowledge that his research 50 years ago pointed towards the Big Bang echo, the best proof that there was a Big Bang. When I met him just a few months ago, he no longer seemed bitter about the lack of recognition. He proudly showed me cuttings, photographs and other mementos from the Forties, smiling fondly as he reminisced about the time when he first grappled with the notion of a universe that was created and evolving. Also, he follows with interest the latest satellite measurements of the Big Bang echo and he even continues to dabble in physics. His current interest is the biggest question of all – what came before the Big Bang? And to his delight, he occasionally receives letters about the Big Bang. Sometimes the letters are from undergraduates who are interested in cosmology, sometimes they are from religious fundamentalists who continue to pray for his soul. Either way, Alpher is pleased. He has not been forgotten.

[Ralph Alpher passed away August 12th, 2007]

Big Bang: The Origin of the Universe


Simon Singh

ISBN-10: 0007162200

Credit where credit is due--"Big Bang"

Mr. Tompkins-George Gamow

Rudi Peieris...physicist's physicist

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