It would be impossible for ordinary matter to travel at speeds greater than light speed, because the energy required to accelerate anything with mass to c is infinite. However, there are (theoretical) particles that always travel faster than light, and would similarly require an infinite amount of energy to slow down to light speed.

Just google 'Tachyons'

I'll leave it at that because everything beyond that makes my head hurt.

Dark can travel at the speed of light! Everybody seems to miss this part out. :know:

Forces "propagate", too.
Absolute "inelastic" bodies which allow instant force propagation are fictional objects as much as Newton's "point masses" (where all mass of an object is condidered to be confined in a dimentionless point).

In the OP light would reach point B before it felt points A pull.

At least I think it would...

.

The future ? :hmmm:

:doh:

.

For a vibration in the string, the speed depends on the mass and tension on the string (it's a transverse wave). It will be less than c.

For a pull, the string will stretch, and then the wave propagates like sound (longitudinal wave) and will move at the speed of sound in the media.

BTW, doesn't matter if you replace the string with a neutronium rod. Still takes time (more than light) to propagate.

thanks:salute:

Actually you are right. As I understand it Tachyons travel back in time as they travel faster than c.

I know. I was born in 2055. !

:D

.

It should be noted that tachyons themselves are highly speculative, theorized particles.

Of course, but I think the point was that relativity doesn't actually forbid something from going over the speed of light, you just can't accelerate anything to the speed of light in the first place.

But thats not the point, the hypothetical string has no stretch and is completely static. A stick with infinite length, no stretch, and no flex, the moment one end is moved, the other moves too.

Yes, and the term itself derives from the word "tacky," which means both "sticky to the touch" and "tasteless." As tachyons move backwards through time they stick to whatever bits of the past they can find, rendering those items garish and unfashionable to the eyes of the present.

Those of you who are old enough to have a picture of yourself in a plaid polyester leisure suit or gold lamé parachute pants will know what I'm talking about. :yep:

Relativistic length contraction: Link
Or to put simple, in the end, light always wins! :yep:

Until the next theory is discovered ... :hmmm:

,

From your Link:

Since we are dealing with speeds of no more than that of pushing a pencil, lengthwise, across a table, this theory has no application in this scenario.