Aug 14 2010

Maybe we can go really fast after all?

Category: science,spaceharmonicminer @ 8:10 am

Rethinking Einstein: The end of space-time Much more at the link.

IT WAS a speech that changed the way we think of space and time. The year was 1908, and the German mathematician Hermann Minkowski had been trying to make sense of Albert Einstein’s hot new idea – what we now know as special relativity – describing how things shrink as they move faster and time becomes distorted. “Henceforth space by itself and time by itself are doomed to fade into the mere shadows,” Minkowski proclaimed, “and only a union of the two will preserve an independent reality.”

And so space-time – the malleable fabric whose geometry can be changed by the gravity of stars, planets and matter – was born. It is a concept that has served us well, but if physicist Petr Horava is right, it may be no more than a mirage. Horava, who is at the University of California, Berkeley, wants to rip this fabric apart and set time and space free from one another in order to come up with a unified theory that reconciles the disparate worlds of quantum mechanics and gravity – one the most pressing challenges to modern physics.

Since Horava published his work in January 2009, it has received an astonishing amount of attention. Already, more than 250 papers have been written about it. Some researchers have started using it to explain away the twin cosmological mysteries of dark matter and dark energy. Others are finding that black holes might not behave as we thought. If Horava’s idea is right, it could forever change our conception of space and time and lead us to a “theory of everything”, applicable to all matter and the forces that act on it.

OK, I admit it. Whenever I run across one of these stories suggesting Einstein might be wrong about some aspect of relativity, I get excited, because if he was wrong about something, maybe he was also wrong about the speed of light being an absolute speed limit for everything except maybe “communication” between entangled particles and other exotica.

Because if we can’t ever go faster than the speed of light, it’s hard to see how interstellar travel ever becomes popular, and I like the idea of somebody someday zipping over to the next star system for lunch.

Of course, if interstellar travel really is impossible, we don’t have to sweat visits from unfriendly aliens who got mad at us when we didn’t write, and blew up the solar system, or just sterilized it.  On the other hand, if there AREN’T any aliens, or unfriendly ones anyway, it would be cool to terraform a few dozen other earthlike worlds (if there are any) and get a little lebensraum.  And it’s a cinch there aren’t any earthlike worlds (besides earth, of course) in our solar system.

So maybe I’m cheering the relativity revisionists, hoping one of them will find a loophole in the cosmic speed limit.

Who needed dark matter anyway?  And there is already enough dark energy in faculty meetings to keep the universe flying apart for the indeterminate future.