Monday, February 28, 2005

Leaking Gravity

Dark energy always struck me as a rather odd idea. Now an alternative hypothesis explaining the nature of the cosmos has been released: leaking gravity.

We all know from our lessons in string theory that gravity is a very weak force in the dimensions that we can observe. (Try this: Drop something. Which force wins? The gravity pulling the object toward the earth or the electromagnetic force holding the tiny bits of floor together?) So if gravity is actually the same type of force as everything else, it is therefore acting in dimensions we cannot observe.

This leaking gravity idea says that with extreme distances, more and more of the gravity goes off into these other dimensions. And this explains why the universe is accelerating its expansion.

So why is this so much more believable to me than the dark energy theory, which says there's negative mass-energy pushing the universe apart with anti-gravity? Because I'd really like to believe in anti-gravity. That'd be cool. I got a bunch of uses for it. (Although the anti-gravity shoes might be difficult to walk in. I always end upside-down in my test-runs.)

2 comments:

FragileKitty said...

Chuckles at the contest of forces. On the surface, this idea of leaking gravity sounds like a stretch (ah look, here's these extra dimensions -- let's sweep some gravitons under the extra-dimensional rug!). And I believe that while string theory (actually its quantum theory aspects) does allow for gravitons to escape to other dimensions, the probability is extremely small that enough particles would escape to make any noticable difference. As superstring theorist Brian Greene says, the odds that you'll marry Nicole Kidman and win the lottery in every state next week are enormous by comparison. The part of the article I'm not grokking is how vast distances means more leakage -- his hammer and metal sheet example eludes me.

Besides, we need negative-energy mass so we can hold open wormholes and travel though them :)

Sotosoroto said...

I thought the majority of the gravitons acted in the different dimensions just as a matter of course.

As for the leaking with distance, I assumed that it was just a compound thing. For every so far, a certain amount is lost, and it just adds up (or squares up, whatever. Cubes? How many dimensions are we talking about?).

negative energy and negative mass have so many useful applications...