Julia Thompson wrote: > Are we going through spacetime at the speed of light, basically? > Warren Ockrassa wrote: > > Yes -- the combined velocity along the space and time vectors is > > lightspeed. (I don't recall when exactly this realization was made > > clear to me, but when it did get clarified, it made it a lot easier to > > understand why FTL travel isn't possible in this universe. It also kind > > of freaked me out.)
For me, the proof was provided by a professor who went through a long derivation of the equations of special relativity - which ended with him showing that the energy of a moving object (Not the rest mass. He referred to it as the "relativistic mass," or m-prime, but also made it clear that this was only a mathematical convenience.) would keep increasing as the speed increased. That is, the relativistic mass increases as you move at increasing relativistic speeds. And to attain a speed of c you need to pump infinite energy into your propulsion system, because you'd be hauling around something that had effectively infinite mass. This was just before lunch, and I remember thinking that he'd effectively slowed down time for the whole class, because everyone couldn't wait to get out of there. ;-) Still, this was one of the few times that physics touched on stuff I'd read about in science fiction, so I remembered it. > > Asking, though, what the speed of time is is a lot like (exactly like) > > asking what the speed of space is. Time, being a dimension, doesn't > > have a speed. It's only your motion through it that applies the measure > > of speed. > > > > When you're at rest, your motion in time is maximized to light's > > velocity. When you move, some of the velocity on the time axis is > > diverted to velocity in the spatial axes. That's why, if you're moving > > at a significant velocity, you get the (relative) effects of time > > slowdown, but of course only compared to the framework of others not > > moving so quickly. As far as you're concerned, time is still moving at > > the same rate. I'm still confused by this. Are you talking about Minkowski Diagrams? As I understand it, time is just something we define as a way to separate different events. As Alberto said, the speed of time is one second per second for every observer, because that's the definition. How can one move through time at a different velocity than that? Kevin Street -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.338 / Virus Database: 267.10.13/78 - Release Date: 8/19/2005 _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
