Arcadian Functor

occasional meanderings in physics' brave new world

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Marni D. Sheppeard

Wednesday, January 24, 2007

The Time Machine

I immediately thought of Louise Riofrio when I saw this post on light cones at Asymptotia. In 1895, H. G. Wells wrote The Time Machine.

"Scientific people," proceeded the Time Traveller, after the pause required for the proper assimilation of this, "know very well that Time is only a kind of Space".

Rod Taylor then promptly dives into the leather seat and pushes the lever to accelerate into Time. Popular conceptions of time travel have evolved little since H. G. Wells' story. The fact is that 20th century physics, after Relativity, did little to alter our notions of time. Moreover, even Relativity could not cure us of this charming delusion, in which The Time Traveller is almost always depicted hopping into a futuristic vehicle, as if about to drive down the road. Is this not itself a hint that GR might fail when it comes to cosmological scales?

In M-Theory, the picture must change. When quantum information content defines Epoch, there is the idea that humans (or things of a similar complexity) can only have arisen in this environment, in this now. Now must become a time, a time we understand better than a distant time, like a Planck time we cannot see.


Blogger L. Riofrio said...

Thanks for the mention. The Rod Taylor movie was much more fun than the expensive remake. Asymptotia was thoughtful enough to link back, with the caveat that he doesn't think c change works. There are ways of controlling time, perhaps they will be revealed.

January 25, 2007 10:10 AM  
Blogger CarlBrannen said...

Even my buddy's little white dog can tell the difference between space and time. Space means she has to walk. Time means she has to wait.

The gravity theories that are built on a locally flat manifold make more sense to me. The philosophical reason is that these theories do not allow man's puny manipulation of small amounts of matter in a tiny corner of the universe, to rip apart the manifold of the universe.

As soon as you put gravitation on a locally flat space you have to allow the speed of light to depend on the gravitational potential. Once you've done that, there's no reason to suppose that it is constant over time.

And from the point of view of particle physics, one way of breaking certain symmetries is by assuming that the speed of light is a Clifford algebra number instead of a real number.

January 25, 2007 12:50 PM  
Blogger Kea said...

There are ways of controlling time...

Oh, yes, I agree. But I can't say I have a good handle on the theory myself yet! I await more interesting posts, Louise.

January 25, 2007 1:33 PM  

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