Time Travel

[Wiccan_Child]

They said it would take half the energy in the whole universe. WE know that time is relative. You have to get mass to travel at the speed of light and that would take a huge amount of energy.

It would take an infinite amount of energy to accelerate something to lightspeed - that's why it's impossible to do so. But tachyons present an intriguing possibility: though you need infeasible amounts of energy to accelerate to lightspeed, you could theoretically get particles that always travel at lightspeed (as, indeed, light itself does). Tachyons are particles that naturally travel at faster-than-light speeds, so should by all rights travel backwards through time. Science fiction always throws the word 'tachyon' around when time travel gets involved

 

[Lion Hearted Man]

It would take an infinite amount of energy to accelerate something to lightspeed - that's why it's impossible to do so. But tachyons present an intriguing possibility: though you need infeasible amounts of energy to accelerate to lightspeed, you could theoretically get particles that always travel at lightspeed (as, indeed, light itself does). Tachyons are particles that naturally travel at faster-than-light speeds, so should by all rights travel backwards through time. Science fiction always throws the word 'tachyon' around when time travel gets involved

Tachyons be blockin' my ability to see the future!