Ahhh...The sweet smell of controversy... Questioning the Big Bang
A handful of researchers posit an alternative theory of origin — the universe has no beginning
By William Orem
(August 2, 2006)
TIMELESS THEORY: Researcher Geoffery Burbidge argues that the universe streches beyond the bounds of time.
(Source: NASA/Wikimedia Commons)
Many, if not most, people assume that certain aspects of nature’s workings are absolutely known. Outside of intelligent design circles, no modern biologist doubts the theory of evolution by natural selection; it is too well established by harmonious data across a multiplicity of fields. No credible doctor questions the germ theory of disease. And, one might think, no serious cosmologist disagrees with the standard cosmological model.
The SCM is the official designation of what is informally called “the big bang”: that relatively recent but almost universally accepted notion that the present universe is the result of a primordial fireball that occurred some 13 billion years ago in which time, space and matter were born. While significant details remain to be worked out — witness the surprise insertion of a superluminal inflationary period by cosmologist Alan Guth in the 1980s — common wisdom is that we already know, in basic form, how the universe began.
Not so, says Geoffrey Burbidge, who is a professor of physics at the University of California, San Diego. Burbidge is one of only a tiny handful of researchers who resolutely disputes the SCM more than half a century after it has reached general acceptance. As such, he is pitted against the whole of contemporary cosmological orthodoxy.
“People like a beginning,” Burbidge said, citing what he sees as an intellectual prejudice in favor of the bang that has prevented other ideas from gaining traction. “The beginning was something that was attractive because, after all, it’s in Western religion,”said Burbidge.
Though philosophically familiar, Burbidge contends, the SCM has always been observationally forced. And fealty to observation, he argues, is the cosmologist’s primary duty. “I believe that cosmology is an observational science; it is not a theoretical science,” he said.
The alternative he posits is at once simpler and stranger. For Burbidge, we live in a universe with no beginning at all.
A universe without a beginning
The widespread use of “big bang” is an irony, originally intended as a put-down. The term was coined by noted astronomer Fred Hoyle when describing the notion that the universe was born from a primeval atom. The idea of an exploding atom at the beginning of time was originally proposed by astronomer and Roman Catholic priest Georges Lemaître. While Lemaître based his work on Einstein’s equations, the primeval atom was certainly not an idea Einstein embraced, and Hoyle thought the whole thing an unreasonable extrapolation.
Burbidge began his long career in the shadow of just such debates. Now in his 80s and a recent winner of the Astronomical Society of the Pacific’s Bruce Medal, given for outstanding lifetime contributions to cosmology, he worked in the 1950s with Hoyle himself on nucleosynthesis, or the question of how heavier elements formed.
“They all began to think it must have something to do with the big bang,” Burbidge said. “All of them but Hoyle. But Hoyle in 1946 wrote a very important paper in which he showed that the form of the abundances of the heavier elements suggested that this took place under very high temperatures, and he came up with the idea that this must have taken place inside stars.” Burbidge, his wife, astrophysicist Margaret Burbidge, and experimental nuclear physicist William Fowler worked out the theory in detail based on Hoyle’s insight. The 1957 publication of their paper, has bcome so famous in scientific circles it now has its own nickname: B2FH, after the names of the contributors. Fowler would ultimately go on to receive the Nobel Prize for his contributions to the understanding of element formation, an honor Burbidge said should have included Hoyle.
It was only a few years after this period — though, according to Burbidge, the thought process was “quite disconnected” — that Hoyle, mathematical cosmologist Hermann Bondi and astronomer Thomas Gold proposed a model of cosmic history that was equally unexpected. Their model flatly disagreed with the premise of the primeval atom, proposing instead a universe with no edges in time.
For a proposal with such a pedigreed source, the resulting applause was less than resounding. Instead, what is now called the “classical steady-state theory” was simply allowed to languish as the SCM gained adherents. While B2FH had made history, the steady-state vision seemed doomed to become history.
“There are very unfortunate stories that go around,” Burbidge said, “including one by Robert Oppenheimer, who always was down on the steady state, and said, ‘Well, the only good thing that came out of it was the origin of the elements.’”
Relying on redshift
Though commonly assumed by textbooks and professionals alike, the idea of an expanding universe with a discrete beginning in time but not space is by no means intuitive. The popular image of things starting off small and exploding outward is a weak metaphor, as it almost invariably suggests a pre-existent space into which a three-dimensional object swells. More technical descriptions, such as that of the pre-bang singularity as already infinite but occupying no space, can be equally unsatisfying.
Einstein thought a steady state likely enough that he famously sought to correct for the aspects of general relativity that implied cosmic expansion, plugging that hole in his theory of gravitation with a “cosmological constant.” His assumption that the universe was static remained unchanged until 1929, when astronomer Edwin Hubble announced the observed correlation that would come to be known as Hubble’s law.
“There was one fundamental observation which completely changed everybody’s view,” Burbidge said. Hubble’s law states that redshift — the degree to which light from a receding source drifts into the red end of the spectrum — is proportional to distance, so that the farther galaxies are from Earth, the redder they appear. It is a strong indication that everything is moving away, and the farther, the faster. If galaxies are all receding, then in the past they must have been closer together. Wind the tape back far enough and they must all have been at a single point: the singularity.
However, this conclusion rests on the idea that redshift is a reliable indicator of distance and speed. Since Hubble’s time, that interpretation has been as basic to cosmology as Newton’s laws of motion. But what if it were untrue?
Questioning redshift
“Redshift only tells you how old the galaxy is that you see,” said Halton Arp, a radical astronomer at the Max Planck Institute in Germany and another who opposes the SCM. “It tells you nothing about its distance from us.”
Arp, who for almost 30 years worked at the Mount Palomar and Mount Wilson Observatories in California, has raised eyebrows by suggesting that quasars (extremely energetic astronomical objects) are not the super-distant bodies they are generally taken to be, but are in fact ejecta from the centers of active galaxies. Images he took while at the observatories, he contends, show high-redshift quasars physically connected to low-redshift galaxies — an impossibility if redshift is an accurate measure of distance.
Though extreme, Arp’s claim touches on a difficulty with which astronomy is fraught: We can’t go there, we can only look at it from here. Like the moon seeming to rest on a nearby tree, if a quasar appears proximal to a galaxy, it might actually be vastly farther away in time and space. Alternatively, Arp suggests, it could be right next door.
General consensus takes Arp’s images as visual anomalies. But then, consensus must do so, as accepting his interpretation is questioning the use of redshift as a measurment technique. And to do that is to dismantle the SCM.
“Galaxies and everything in them start from a small seed in parent galaxies, are ejected as quasars and grow through observed stages to normal galaxies such as our own,” Arp said. He has spent a good deal of time cataloging galaxies and has no compunction arguing for a position that flies against the very groundwork of his field.
“The current data overwhelmingly contradicts the current big bang, expanding-universe model in my opinion,” he said.
Oscillations without end
“My personal view is that spacetime expansion is still the best explanation for the observed redshift,” said José B. Almeida, a physicist at the University of Minho in Portugal and a member of the Alternative Cosmology Group. “However, there are many assumptions in the standard model which go beyond that and seem like ad hoc amendments to fit the theory to observations. Those I find unacceptable.”
Last June, this group hosted the first Crisis in Cosmology conference in Monção, Portugal, with a focus on the continued viability of the SCM. Several dozen physicists and astronomers argued pros and cons, including Eric Lerner, author of
The Big Bang Never Happened, and Riccardo Scarpa of the European Southern Observatory.
“I personally like the idea of a beginning of the universe,” Scarpa said. “However, I am more and more convinced that the description of the evolution of the universe from the beginning to today is plain wrong.”
Almeida shares the concern, characterizing the present state of cosmology as “unsatisfactory.” If the big bang never happened, though, what are the alternatives?
“The universe is an oscillating universe,” Burbidge said. “It expands to a certain extent and then it falls back on itself, but it doesn’t fall all the way.”
This is “quasi-steady-state cosmology,” a contemporary, updated version of classical steady state. In quasi-steady state, spacetime expansion does indeed account for redshift, but vastly distinct elements are also incorporated, such as the continuous creation of matter.
“What really happens is that the pressure exerted by the created matter in the centers of galaxies is pushing against the universe, trying to contract, so it never goes back down to the dimensions where we don’t know what physics is,” Burbidge said. “We believe in an oscillating universe but we don’t believe that it goes to that extent.”
Such a pre-singularity rebound, if real, would preclude the question of quantum effects, which are the main thrust of the quantum cosmologies currently spearheaded by such luminaries as Stephen Hawking at the University of Cambridge and Thomas Hertog at CERN, the famed nuclear research facility in Switzerland. Also erased would be St. Augustine’s famous question of what God was doing before he created time. In an oscillatory universe, time extends infinitely far into both past and future. And once again emerges the conceptual difficulty Burbidge noted with reference to the classical version.
“Most astronomers really didn’t like the steady-state,” he said. “They liked evolution. And there were a few who had some [observational] basis in not liking it, but many of them didn’t like it probably for philosophical reasons.”
The smoking gun of cosmic microwaves
The general consensus in favor of the bang, though, is not overtly philosophical. Rather, the issues pointed to by SCM adherents are much more pragmatic, such as its predictive power in explaining the cosmic microwave background radiation, or CMBR.
“The CMBR’s origin in the big bang is about as well attested as anything in astronomy, these days,” said Matthew Colless, the director of the Anglo-Australian Observatory in Epping, Australia. The CMBR is the omnipresent energy signature generally understood to be the faded remnants of the fireball itself. Its discovery in 1965 signaled the end, for most cosmologists, of steady-state theories. The feeling was that the smoking gun of the big bang had been discovered, a sense that has not diminished as new and finer tests of the CMBR have come in.
“The Wilkinson microwave anisotropy probe satellite, the latest in a long line of CMBR experiments, has returned data of exquisite quality that are in beautiful agreement with big-bang theory,” Colless said.
Alternative models also seek to account for the CMBR, as they must do with redshift, the relative abundances of the elements, and other lines of information. Still, supporters feel the convergence of data upon the standard model has passed the point whereby it merits general acceptance. Like the theory of natural selection, too many data sources converge on the same conclusion for it to be written off without considerable strain.
“The data and theory are in such good agreement that, for example, the age of the universe is estimated to be 13.7 billion years with an uncertainty of less than 0.2 billion years — a figure in good agreement with the latest estimates based on old stars,” Colless said.
“That’s not to say that everything is understood, but the basic paradigm is in excellent shape and has now passed such a wide range of tests that any theory that replaced it would have to look, in most essentials, very similar indeed.”
And therein lies the rub. As long as the data fit multiple theories, as long as no critical prediction is disconfirmed, there can be no definitive judgment on alternative cosmologies. Some, such as steady-state models, may die the death of scientific indifference with the passing of their last promoters. But their progeny may continue to evolve, adopting the SCM’s strengths but chipping away at its perceived weaknesses. Indeed, like the timeless cosmos some posit, anti-bang theories may continue indefinitely, hovering in the background of mainstream cosmology and serving, if nothing else, as a reminder of the provisional nature of discovery.
William Orem is science editor at Science & Theology News.
~Tesla
Big Bang? -
08-06-2006, 02:14 AM
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08-06-2006, 07:56 AM
