The NSF has been taking polls of students for decades, asking whether they believed in Evolution and The Big Bang. They dropped that question this year, because it was getting too many "false negatives", people who were well-educated but didn't believe in one or the other. This drives some science educators nuts, who want naturalism and science to be equated to each other. The reluctance to buy into evolution is well-documented, but perhaps you are a bit fuzzy about the Big Bang reluctance. A news item this week reveals just how uncertain these cosmology theories are, but don't tell that to the NSF.

Here's the scoop on the Big Bang. Back when Einstein was alive, he wanted his field equations to reveal a steady state universe. This is simply because there are two answers to "Why are we here?" and he didn't like the "Because there is a Creator" answer, so he opted for the "There is neither beginning nor end" answer formulated by Epicurus and Democritus some 2500 years ago. Gravity, you see, was an attractive force that could not be neutralized, and so the universe was predicted to collapse at some point in the future. Newton solved this problem by having God tweaking things to keep them uniformly distributed so that everyone is pulled equally in all directions, but Einstein had ruined Newton's solution by demonstrating that space itself would collapse under the weight of galaxies, no matter how much tweaking was done.

So Einstein invented the "Cosmological Constant", an anti-gravity term in his equations that wasn't proportional to matter (like real gravity), but proportional to space (sorta like a pressure.) This balanced out gravity and if everyone's galaxy was well-behaved and sitting quietly, then collapse could be postponed. Unfortunately Hubble showed that everyone was screaming away from everyone else at a fairly good clip. Einstein called this constant "his greatest mistake" and we all became "Big Bang" believers. Well when space expands as you're pushing on it, there is work being done, and work is the same as energy, so this mysterious anti-gravity pressure thingy acquired the name "Dark Energy", a relabelling to avoid the bad press of Einstein's recant.  Same mistake, new name.

Fast forward 50 years, and "dark energy" is all the rage. As far as I can tell, it is because the cosmology models that have enough bang to explain the data, mess up the distribution of galaxies. And if we scale the bang down, then we fall into a black hole. So "dark energy" is another dial that enables modellers to achieve agreement with the data using both "bang" and "balloon". The current consensus is 75% is "balloon" and the rest is "bang".

Now relying on models to tune your theory is about as risky as using the IPCC climate change predictions to buy a waterfront property in Vermont. We'd really like some data on this "dark energy" thingy, and a provocative paper came out 10 years ago that said "distant supernovae are dimmer than expected" which they then claimed was evidence for an accelerating "dark energy" term. NASA got into the act, and said they would spend a $1bn on finding the cause of dark energy, and suddenly Einstein's "biggest mistake" is looking like a cash cow.

"Not so fast", said some astronomers, who coincidently are ineligible for NASA funding, "we can construct Einstein-model universes that have no dark energy." (I've blogged on Penrose's version too.) To get agreement with the models and the data, all they needed to do was to put a large bubble in the cake, and put the Milky Way in the middle of the bubble. That is, they sacrificed "homogeneity" to get rid of "dark energy".  Who is right? It's hard to work up a frenzy for "belief in homogeneity", which is why the press releases started calling it "The Copernican Principle," but I would trade any number of inhomogeneous data sets for the modellers current penchant for "dark energy & the Copernican principle".

Well, now we have some data on this bubble theory, and not surprisingly (considering where the funding is going), it supports the status quo "dark energy" theory. The presser says that bubbles are out, dark energy is in. And while I'm disappointed that standard physics doesn't explain our current "acceleration", I'm not surprised because I don't think we are actually being accelerated at all. The real message is not that "status quo wins again" but ratherthat over-hyped claims for acceleration haven't really eliminated all the simpler explanations that are out there. We don't hear about all these challenges to the status quo until they are "decisively disproven", but why the claimed certainty on the original model then? It is reminiscent of the thousandth time we read that "Darwin has finally been proved by the discovery of this essential missing link..." Well, if it was so essential, then why are just hearing about it for the first time? In the same way, if standard cosmology is so certain, then why is this result so important?

I'm a big fan of scientific consensus, but the big budget programs have been the biggest distortion of science since the Manhattan Project. How about honesty in advertising? Why not say, "Our current model of cosmology..." or "The Neo-Darwinian Theory of evolution?" How can a little humility be bad for science? It certainly might improve the NSF.