(urth) Travelling North aka miscellaneous thoughts on Wolfe

[Jeff Wilson]

On 6/10/2010 8:54 AM, Paul Zinn-Justin wrote:
> That is incorrect. Some quantities might become imaginary but that is a
> mathematical artefact.
> The real point is, if you combine faster than light travel and Lorentz
> invariance of the laws of physics (the invariance principle that is the
> basis of Einstein's theory of special relativity), then you can indeed
> have trajectories which connect two arbitrary points of spacetime i.e.
> in a given reference frame it will look like you can move freely forward
> or backwards in time (you're not going ``straight'' into the past --
> you're making little loops, like travelling to a distant star faster
> than light and then coming back the same way).

Yes, the limerick is not just cute but technically accurate:

There was a young lady named Bright
Whose speed was much faster than light;
She set out one day,
In a relative way
And returned on the previous night.

- Inflicted by Arthur Henry Reginald Buller, in the December 19, 1923 
issue of Punch

-- 
Jeff Wilson - jwilson at io.com
IEEE Student Chapter Blog at
< http://ieeetamut.org >