Wednesday, February 4, 2015

Big Bang Theory Expands, Then Contracts

Since the Big Bang theory of the creation of the universe has been generally accepted by scientists, more empirical evidence (i.e., astronomical observations and inferences) has been gathered to explain the details of the event and its aftermath. Here's a fascinating timeline of the history of the universe from the very beginning until now.
Researchers studying cosmic "inflation" used instruments housed on this building, located near the geographic South Pole in Antarctica, among the best places on Earth for observing space because it is so clear and so dry.
National Science Foundation

As the Physics of the Universe site notes, "Since the Big Bang, 13.7 billion years ago*, the universe has passed through many different phases or epochs. Due to the extreme conditions and the violence of its very early stages, it arguably saw more activity and change during the first second than in the all the billions of years since."

(*Note: The age of the universe is still not certain; current science speculation puts it somewhere between 13.7 and 13.82 billion years.)


About a year ago  (March 2014), some astronomers announced they had further proof of the expansion of the universe after the Big Bang.

As The New York Times reported at the time, 
"Reaching back across 13.8 billion years to the first sliver of cosmic time with telescopes at the South Pole, a team of astronomers led by John M. Kovac of the Harvard-Smithsonian Center for Astrophysics detected ripples in the fabric of space-time — so-called gravitational waves — the signature of a universe being wrenched violently apart when it was roughly a trillionth of a trillionth of a trillionth of a second old. They are the long-sought smoking-gun evidence of inflation, proof, Dr. Kovac and his colleagues say, that Dr. Guth was correct.

"Inflation has been the workhorse of cosmology for 35 years, though many, including Dr. Guth, wondered whether it could ever be proved.

"If corroborated, Dr. Kovac’s work will stand as a landmark in science comparable to the recent discovery of dark energy pushing the universe apart, or of the Big Bang itself. It would open vast realms of time and space and energy to science and speculation."

Another Web article explained, "'Before this work, the earliest period we had direct evidence for was a few minutes after the Big Bang,' says Dr. Mac Low. 'Now we have data from the first 10-36 seconds.'” In this video, Dr. Low explains about cosmic microwave background.


He explains that right after the Big Bang, "the observable universe was minute and as dense as the interior of a black hole." But then, the "inflation" happened: The "the universe appears to have expanded at astonishing velocity.” 

This violent expansion, researchers hypothesized, formed the “ripples” --- gravitational waves that today still permeate the universe.  The evidence, from observations of the cosmic microwave background, was "the light had been polarized in a pattern that could only have been produced by the hypothesized gravitational waves."

Okay, so what's my point? All this supposed evidence of the supposed "inflation" right after the supposed "Big Bang" has turned out to be "far weaker" than originally claimed; and, in fact, it is disappointing to astronomers who initially greeted the research with accolades.

As Phil Platt writes, all this hoopla was based on preliminary and insufficient  evidence:
And here’s the bummer part: They were using preliminary Planck data. When better data from Planck were released, the astronomers used that, and found that the amount of galactic dust in their view was much higher than they previously thought. That weakens their case considerably.

The bottom line is that they do still see some evidence for gravitational waves affecting the light from the early Universe, but it doesn’t look like it rises to being statistically significant, and it’s certainly not as strong as they first thought.
And here's one reason I enjoy reading Mr. Platt's columns: He's so honest and forthright, as, in this case, he admits: 
"On a personal note, I reported on this last year as straight news. I assumed that such an announcement had been vetted and the results peer-reviewed. They hadn’t been at that time. As such, I think it’s up to the scientists making the claim to make that clear, and to be more circumspect in their announcement … just as it’s up to those of us reporting on big news to be skeptical and make sure that the process of peer review has been fully respected. That’s on me, and I blew it."

He adds that he doesn't mind it when scientists announce preliminary data, but he wishes they would make it clear that the data are preliminary:
"Mind you, I don’t necessarily have a problem with big announcements that are made when the scientists themselves aren’t sure what they mean. Specifically, I’m remembering the faster-than-light neutrino announcement, when the scientists said, basically, “Look, we’ve investigated this as much as we can, and we know it sounds crazy, but our results seem to say that FTL particles are possible. What did we miss?” They were very skeptical, and were asking for others to pitch in and see what they found. It turns out there was a loose cable in the equipment (yes, seriously), that messed up their timing experiments.
 Mr. Platt concludes:

"And there’s a final irony here: This new announcement was made by the BICEP2 team, but their results aren’t yet published. They’ve been submitted to a physics journal, and the Planck data they used will be made public next week. So even these results aren’t peer-reviewed yet!

"The difference, though, is that this is not a paradigm-shifting announcement, but a retraction. The bar is set lower for such things, so I feel safe enough reporting on it. If, however, someone else comes along and says the retraction needs to be retracted, well, we’ll deal with that if it comes up.
"Science is messy sometimes, and it’s made messier by the need and pressure to announce results … and the need and pressure on some of us to write about them. We all need to be more careful in the future."

So, why am I making a big deal out of this? Because it's a new and fresh illustration of how science, our understanding of the universe, expands (get it, expands!) --- and then retreats, or contracts, or goes back to a new starting point, as researchers continue to make new observations and refinements on earlier conclusions.

And, since I'm thinking and writing about all these issues as a way of approaching the issues that seem to divide science from religion, I'm asking:

Is this in any way like religion? Well, yes, it is very much like my understanding of religion. I'm going to write about that soon. Because I think that the people who see a huge conflict between science and religion are biased by their view of religion and the claims of religion.


1 comment:

Jeff Wynn said...

BINGO!

First, five stars for Platt (out of a possible 3) for being refreshingly honest.

Second, 10 star to YOU for linking the growth towards Truth (= permanently correct knowledge) as being growth on BOTH sides of Gould's "Magisteria."

From the get-go, Joseph (and the other 12 who handled the gold plates) all said that fully a 3rd of the plates were sealed with some sort of metal band, thus forbidding access.

I can't WAIT for new knowledge to pop up - and any reasonable person acquainted with history knows they can count on it being on both sides of the (very artificial) divide.