“The discovery caught astronomers by surprise”, begins an article that hit the newswires last summer. The release continues:
The universe has a huge hole in it that dwarfs anything else of its kind . . . The hole is nearly a billion light-years across . . . Astronomers don't know why the hole is there.
"Not only has no one ever found a void this big, but we never even expected to find one this size," said researcher Lawrence Rudnick of the University of Minnesota.
Rudnick's colleague Liliya R. Williams also had not anticipated this finding.
"What we've found is not normal, based on either observational studies or on computer simulations of the large-scale evolution of the universe," said Williams, also of the University of Minnesota.
The article goes on to explain that the void was discovered by analyses of Cosmic Background Radiation (CMB) observations conducted by the Very Large Array (VLA) radio telescope. The VLA observation was confirmation of this anomalous ‘cold spot’ first detected by NASA's Wilkinson Microwave Anisotopy Probe (WMAP) satellite. We’re also told that The CMB is an imprint of radiation left from the Big Bang, the theoretical beginning of the universe.
It turns out observations that ‘catch astronomers by surprise’ are not exactly unique. In fact, an hour or so researching the archives at any astronomy site will lead the researcher to ascertain that many recent discoveries are deeply puzzling to those in the field. Examples from just a brief exercise of this nature include galaxies with arms spinning in opposing directions, a huge portion of our own galaxy rotating the wrong way, the unusual composition of comet dust, bizarre galactic concentrations, well . . . do I really need to go any further to make the point?
As I began to explore these and other astronomy articles, I was regularly reminded that astronomers know that the universe began with a ‘Big Bang’ approximately 14 billion years ago, when all of the matter in the universe was concentrated into an unimaginably small ‘singularity’ which, conveniently for us, exploded. So, at least we’re on the right track, and as our tools improve over time, these unusual discoveries will all be explained to everyone’s satisfaction. After all, the universe is a big place and it’s only to be suspected that we’ll run into occasional issues as we figure it all out, right?
Perhaps. Interestingly enough, not a month after the article above was published, Michael Disney, emeritus professor in the School of Physics and Astronomy at Cardiff University in Wales, U.K., published a short column in the Sept/Oct 2007 issue of American Scientist, entitled Modern Cosmology: Science or Folktale? A web search for this title did not bring up any immediate reference to it on the mainstream astronomy websites regularly frequented by the general public.
In language appropriate for a layman, which your correspondent admittedly is, Professor Disney explores the history of the Big Bang Theory (BBT). Also as a layman, I can say that I was not just a little intrigued to discover that Big Bang cosmology is not quite as decided as I’d been led to believe. Disney opens by explaining that our current understanding of the universe began with Einstein’s Theory of General Relativity. When this was combined with Edwin Hubble’s theory of redshift in the light spectrum of distant objects equating to distance, and the accidental discovery of the aforementioned CMB in 1965, astronomers were provided with a hypothesis that could be tested by subsequent observations. So far, so good. But as Disney explains, we soon came upon certain significant bumps in the road; observations weren’t matching up well with theory. To begin with, and with occasional emphasis added:
Opposite sides of the cosmos look very much the same, even though they had never been sufficiently close to equilibrate—indeed they had never been sufficiently close for any kind of information (which is limited to the speed of light) to travel between them. This difficulty was virtually unadmitted until 1981, when Alan Guth suggested a vague conceptual solution called "inflation": a slow start to expansion, followed by a rapid acceleration . . . If inflation actually happened, sufficient stretching during that period of rapid acceleration would have lowered the local curvature today so that it would look flat to the observer, even if it wasn't so on a much larger scale (just as the Earth looks flat to someone with a limited horizon).
If inflation actually happened? Hmm. Professor Disney continues:
At about this time in Holland, Albert Bosma discovered that spiral galaxies are spinning far too rapidly to be held together by the mutual gravitational tugs of their observable contents. Astronomers concluded that there had to be far more dark than ordinary, visible matter around to keep galaxies (and galaxy clusters) together. Most cosmologists welcomed the possibility of such dark matter, because it might be lumpy enough to get the galaxies formed in the early universe—another serious problem for theorists. The apparent uniformity of the cosmic background radiation had cosmologists struggling to figure out how the present uneven structure of galaxies and clusters evolved out of such a smooth beginning.
They thus posited the existence, of primordial "seeds" of unknown origin, which somehow survived the early, hot era when radiation would tear material things apart. Cosmologists argued that these seeds would grow over time, finally collapsing into the galaxies seen today. A type of dark matter that ignored radiation ("cold dark matter") would be the ideal stuff for such seeds. It could condense into lumps, thereafter dragging the much lesser amounts of ordinary matter in afterwards, matter that would eventually light up as stars. By the 1980s the theoreticians' universe was entirely dominated by such invisible material.
How are we doing with that “observation conforming to theory” thing we mentioned earlier? As Disney elucidates, it does get better, with more emphasis added:
Meanwhile, observations of distant supernovae in the late 1990s told an astonishing, almost shocking, story. The results suggested that the expansion, far from being slowed by gravitation, as was expected, had instead accelerated. Moreover, this acceleration had started only in comparatively recent times (7 billion years ago). The physics responsible for this seeming acceleration is entirely unknown and goes under the deliberately inscrutable name "dark energy," which may or may not have something to do with Einstein's cosmological constant.
Well, okay. These are the best and brightest among us, though. So we’re correct in assuming that the concepts of dark matter and dark energy are correct. The mathematics prove the existence of these things, even though they can’t be directly observed, right?
Professor Disney’s conclusion is interesting:
In its original form, an expanding Einstein model had an attractive, economic elegance. Alas, it has since run into serious difficulties, which have been cured only by sticking on some ugly bandages: inflation to cover horizon and flatness problems; overwhelming amounts of dark matter to provide internal structure; and dark energy, whatever that might be, to explain the seemingly recent acceleration. A skeptic is entitled to feel that a negative significance, after so much time, effort and trimming, is nothing more than one would expect of a folktale constantly re-edited to fit inconvenient new observations.
Ugly bandages? Ouch. I must admit that after stumbling upon Professor Disney’s piece in American Scientist, your intrepid correspondent took it upon himself to assume the role of a skeptic and explore a little further. I discovered numerous tidbits, of which I will share just a few.
First, I learned that the core assumption of redshift corresponding to distance has been seriously questioned by many, and foremost among them is Halton Arp. Arp has spent his entire career cataloging instances of unusual correlations between quasars and galaxies, and has proposed that certain galactic objects may contain intrinsic redshift, which if true, would imply that the entire idea of an expanding universe is flawed. Arp had been a fast track astronomer early in his career, his work even mentioned as potentially problematic to the then developing BBT by Carl Sagan, but his insistence on pursuing this particular line of inquiry led to revocation of his telescope time in the States and banishment to Europe, where he continues his work today.
Next, I discovered that there are some scientists who are intrigued by the overwhelming amounts of free plasma in space. It turns out that plasma, most easily described as a type of gas that has been stripped of an electron, comprises over 99.9% of the known universe. Plasma is unique in that it will carry an electric charge. It’s also everywhere, distributed not only throughout galaxies, but throughout the vast intergalactic expanses as well. The vast clouds of ‘gas’ referenced in many astronomy articles are actually plasma. There are some scientists, mostly electrical engineers or plasma physicists, who think that there are massive electrical charges in space that may explain many anomalous observations, but these potential explanations are apparently dismissed out-of-hand by the institutions and scientists who control the funding for cosmology research. The concept of Plasma Cosmology is clearly derided on Wikipedia, while the related concept of the Electric Universe was successfully tagged for removal by a particularly vigorous Wiki contributor on the grounds it represented pseudoscience. The discussion as to the reasons this decision were made left me feeling a little concerned, given that Disney’s piece had left the clear impression that there were more questions than answers revolving around current theory. But then, I’m a layman, and I’m sure that the decision was made from a position of neutrality and fairness, and wholly in the interest of objective truth.
I then came across another interesting article that was reported with some trepidation by the mainstream. A lone radio astronomer had noticed that clouds of neutral hydrogen gas local to the Milky Way galaxy matched up very closely with the cornerstone CMB of the Big Bang Theory:
Astronomers are abuzz because if Gerrit Verschuur of the University of Memphis is right, one of the most important theories developed in the past 15 years -- one that won a Nobel Prize -- would be toppled. The world’s top astronomical publication, Astrophysical Journal, will publish Verschuur's research December 10 . . . Verschuur's research asserts that the seeds are not located on the edge of the universe at all. Rather, he says, the so-called seeds are very nearby: They're just previously unmapped clouds of "neutral hydrogen" gas located inside the Milky Way. In other words, astronomers who mistook the "seeds" for objects on the edge of the universe are like someone who looks outdoors through a window and mistakes smudges on the glass for clouds in the sky.
The article goes on to quote several astronomers deriding these findings. One who wasn’t so quick to dismiss it was George Smoot, who had been awarded the Nobel Prize for his work on mapping the CMB. Smoot wrote in an email, "One would have to do a very careful (statistical) study to see if this (correlation between hydrogen filaments and cosmic seeds) could happen by simple chance or is truly convincing."
The article concludes that Verschuur’s paper will live or die on statistical analyses, which is likely to take several years, if not forever.
Shortly after discovering this little nugget, further exploration uncovered something interesting about the origins of the Big Bang Theory itself. Hans Alfven, an early advocate of Plasma Cosmology and another Nobel laureate, had once made the following comment about Georges LeMaitre, who had originated what he termed the 'hypothesis of the primeval atom' which would eventually become today’s Big Bang Theory:
To Alfven, the Big Bang was a myth - a myth devised to explain creation. "I was there when Abbe Georges Lemaitre first proposed this theory. Lemaitre was, at the time, both a member of the Catholic hierarchy and an accomplished scientist. He said in private that this theory was a way to reconcile science with St. Thomas Aquinas' theological dictum of creatio ex nihilo or creation out of nothing.
"There is no rational reason to doubt that the universe has existed indefinitely, for an infinite time. It is only myth that attempts to say how the universe came to be, either four thousand or twenty billion years ago.
"Since religion intrinsically rejects empirical methods, there should never be any attempt to reconcile scientific theories with religion. An infinitely old universe, always evolving, may not be compatible with the Book of Genesis. However, religions such as Buddhism get along without having any explicit creation mythology and are in no way contradicted by a universe without a beginning or end. Creatio ex nihilo, even as religious doctrine, only dates to around AD 200. The key is not to confuse myth and empirical results, or religion and science."
Well, this raised my eyebrows. I couldn’t help but wonder how many of the astronomers working today realized that the Big Bang had been originated to bring about reconciliation with Christian doctrine. I reflected upon the conclusion of the article reporting Vershcuur’s paper, which stated:
For astronomers, the problem now is to decide who's "seeing" things -- Verschuur? Or themselves?
And then I considered that Professor Disney had wrapped up his piece by saying:
The historian of science Daniel Boorstin once remarked: "The great obstacle to discovering the shape of the Earth, the continents and the oceans was not ignorance but the illusion of knowledge. Imagination drew in bold strokes, instantly serving hopes and fears, while knowledge advanced by slow increments and contradictory witnesses." Acceptance of the current myth, if myth it is, could likewise hold up progress in cosmology for generations to come.
At this point, your weary explorer of modern cosmology was ready to conclude that we had been spending billions of dollars simply to arrive at wild metaphysical speculations designed to support a seriously flawed hypothesis. I was thrilled to see that the stalwart defenders of the BBT had proposed an explanation for the massive hole in the universe that began this investigation, emphasis added:
IN AUGUST, radio astronomers announced that they had found an enormous hole in the universe. Nearly a billion light years across, the void lies in the constellation Eridanus and has far fewer stars, gas and galaxies than usual. It is bigger than anyone imagined possible and is beyond the present understanding of cosmology. What could cause such a gaping hole? One team of physicists has a breathtaking explanation: "It is the unmistakable imprint of another universe beyond the edge of our own," says Laura Mersini-Houghton of the University of North Carolina at Chapel Hill.
It is a staggering claim. If Mersini-Houghton's team is right, the giant void is the first experimental evidence for another universe. It would also vindicate string theory, our most promising understanding of how the universe works at its most fundamental level. And it would do away with the anthropic arguments that have plagued string theorists in . . .
It’s breathtaking, alright. I felt so much better that I decided there was no reason to pay for the full article. They have not only vindicated the Big Bang Theory, but the equally perplexing string theory as well.
I’m now certain cosmology and physics are in perfectly capable hands. Aren’t you?
Note - 6/9/08 - Updated link to American Scientist article.