Wednesday, September 24, 2008

One for kavips--and my bid for my own science Kavipsian

The news today in science is the discovery of a dark flow of energy in the universe unrelated to the general inflationary expansion:

Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow."

The key to this is not the description of the flow or how it was found, but this:

The stuff that's pulling this matter must be outside the observable universe, researchers conclude.

When scientists talk about the observable universe, they don't just mean as far out as the eye, or even the most powerful telescope, can see. In fact there's a fundamental limit to how much of the universe we could ever observe, no matter how advanced our visual instruments. The universe is thought to have formed about 13.7 billion years ago. So even if light started travelling toward us immediately after the Big Bang, the farthest it could ever get is 13.7 billion light-years in distance. There may be parts of the universe that are farther away (we can't know how big the whole universe is), but we can't see farther than light could travel over the entire age of the universe.

This is literally earth-shattering, for one particular reason.

The inflationary theory suggests that our observable universe is only one infinitesimal part of the larger whole: we exist essentially in a bubble universe within the larger multiverse.

Foundational to this theory is an assumption I have never liked: that we can never exchange information or actually directly observe anything about those areas beyond the observable universe. Sure, we can hypothesize, but we can never even really theorize in a scientific sense, because real theories have to be falsifiable. That means that a real theory has to include a mechanism for proving it's not true. If you don't have any way to test it, it's a conjecture or a hypothesis, but not a theory.

This possibility that we can see the indirect impact of a force external to the observable universe plays hell with that idea.

If we can deduce that a flow of dark matter is being caused by forces external to the known universe, we will eventually begin to be able to deduce the parameters of that force--and then we will have what we have long been told we could never have: direct, testable information about a part of the universe apparently separated from us by the light-speed barrier.

And--this is the critical piece--if we can get one piece of information from there, there is no effective barrier to getting other descriptive information from that region, even if only by finding other more subtle impacts of that external region.

In other words, if this proves out, it is a breakthrough of momentous proportions, because it holds out the hope that the light-speed barrier is not--at least for the purposes of passing information--an ultimate barrier.

Warp Seven in that direction, Mr. Data. Let's find out what's out there.

1 comment:

Anonymous said...

So far I think, this puts you in first place for the scientific kavipsian....

An amazing breakthrough, and to think, I saw it on this site first.

Nice analysis towards the end, but you don't seem to be a proponent of string theory I gather?

Good job with explaining Guth's inflationary theory by the way...