Thursday, June 07, 2007

The breaking of modern physics: space with non-zero energy

I came across this older article via a blog comment. Shame that this article doesn't have a date on it (a common web page error), but I think it's probably from 2006. It's not news, but I liked the overview of what it's meant to find that empty space has non-zero energy (or equivalently, non-zero mass):
Edge: THE ENERGY OF EMPTY SPACE THAT ISN'T ZERO: A Talk with Lawrence Krauss

.... The energy of empty space had to be precisely zero. Why? Because you've got these virtual particles that are apparently contributing huge amounts of energy, you can imagine in physics, how underlying symmetries in nature can produce exact cancellations — that happens all the time. Symmetries produce two numbers that are exactly equal and opposite because somewhere there's an underlying mathematical symmetry of equations. So that you can understand how symmetries could somehow cause an exact cancellation of the energy of empty space.

But what you couldn't understand was how to cancel a number to a hundred and twenty decimal places and leave something finite left over. You can't take two numbers that are very large and expect them to almost exactly cancel leaving something that's 120 orders of magnitude smaller left over. And that's what would be required to have an energy that was comparable with the observational upper limits on the energy of empty space....

... every measure we've made right now is completely consistent with a constant energy in the universe over cosmological time. And that's consistent with the cosmological constant, with vacuum energy....

... because of this energy of empty space — which is so inexplicable that if it really is an energy of empty space, the value of that number is so ridiculous that it's driven people to think that maybe, maybe it's an accident of our environment, that physics is an environmental science — that certain fundamental constants in nature may just be accidents, and there may be many different universes, in which the laws of physics are different, and the reasons those constants have the values they have might be — in our universe — might be because we're there to observe them.

This is not intelligent design; it's the opposite of intelligent design. It's a kind of cosmic natural selection....

... Right now we're floundering. We're floundering, in a lot of different areas.

...Fundamental physics is really at kind of a crossroads. The observations have just told us that the universe is crazy, but hasn't told us what direction the universe is crazy in. The theories have been incredibly complex and elaborate, but haven't yet made any compelling inroads.

... On the largest scales, when we look out at the universe, there doesn't seem to be enough structure — not as much as inflation would predict. Now the question is, is that a statistical fluke?

... when you look at CMB [cjf: osmic microwave background] map, you also see that the structure that is observed, is in fact, in a weird way, correlated with the plane of the earth around the sun. Is this Copernicus coming back to haunt us? That's crazy. We're looking out at the whole universe. There's no way there should be a correlation of structure with our motion of the earth around the sun — the plane of the earth around the sun — the ecliptic. That would say we are truly the center of the universe.

The new results are either telling us that all of science is wrong and we're the center of the universe, or maybe the data is imply incorrect, or maybe it's telling us there's something weird about the microwave background results and that maybe, maybe there's something wrong with our theories on the larger scales...
Space isn't what it once was. We used to think space separated things, but now we know it doesn't. If you collapse the probability wave on an electron in Kansas, then the probability wave on its entangled partner 200 billion light years away collapses at the same "time". (The catch being what is meant by time in this context.)

Physics isn't what it once was. Physicists seem a bit demoralized, and stunned. I don't blame 'em at all. This reality looks less plausible all the time.

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