Question: can u go back in time or bend space and time or can you telorport

Martin Archer answered on 15 Mar 2013:

Lots of great questions here.

OK time travel. We have no idea if time travel to the past is possible, some of the greatest minds in Physics argue about this. The problem with time travel are so called paradoxes – things that don’t seem to make sense if time travel is allowed. The Grandfather Paradox is a famous one and science fiction is full of them. Future time travel on the other hand is possible, by travelling fast and then coming back you’re actually going into the future a bit faster than if you were stood still. To have any big effect you need to be going close to the speed of light, but we have measured this effect from jet planes and it’s real!

Space and time get bent due to presence of mass, Einstein said gravity is actually this bending. So the Earth, the Sun even you bend space and time a bit. Of course the extreme version of this bending is a black hole, where space and time are so warped that even light can’t escape beyond the “event horizon”.

We’re not sure if teleportation like in sci fi is possible. The problem is the uncertainty principle which basically says you can’t know precisely everything about an atom. So if you can’t know this, can you really replicate an exact copy in a different place and then destroy the original? However, we can teleport information, though this is in very early stages at the moment.