trollface,

This is interesting, and I've not heard it before. Can you explain your reasoning here, please?

As you approach a very high percentage of the speed of light spacetime around you warps and begins to take on the geometry of a sphere. From inside the warped spacetime everything outside appears to be directly ahead of you (imagine your eyeball in that area of spacetime, warped into a sphere - you can see everything around you 360 degrees in the x, y and z planes simultaneously).

The Observer, at rest WRT you, sees you stretch infinitely and warp into a sphereoid shape (it would be impossible for the Observer to see this but if he/she could that's what would be seen). Your ruler stretches to infinity from the Observer's POV.

Your POV is the opposite. Not only do you see the universe collapse to a point but you also see the Observer's measuring rod shrink in length to virtually zero.

That measuring rod describes the length of all of spacetime that you observe outside your ship. You would still measure the speed of light both inside and outside your ship as 300,000 km/sec. But the universe outside your ship, like the measuring rod, shrinks to virtually zero radius. Every photon ever emitted over the ~10 billion years since the Big Bang is on a collision course with your nose. Because of your velocity they have been blue shifted far past the cosmic ray spectrum and they are coming from almost zero distance. The radiant energy of the entire universe strikes you in an instant.

Traveling at light speed isn't the answer to time travel.

Another more mundane problem with extremely high velocities is friction. Space is only a vacuum in relative terms. If you travel slowly enough you say that space only has an atom or so in every cubic meter of space and an occassional bit of dust and once in a "blue moon" a tiny sand pebble.

At half the speed of light you begin to realize that space can also be viewed as a thin but very significant gas. Striking a grain of sand at half the speed of light would be disasterous.

If you completely ignore relativity and figure the force of the impact in Newtonian terms you can see the problem:

F = 1/2 * mv^2. A 1mg grain of sand becomes an extremely high velocity armor piercing round.