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If I were on one side of the room and moved at the speed of light to the other side of the room, to an observer it would appear that I teleported. If time stops at that speed, it would be instantaneous but we know that light is not instantaneous (see light years). So I'm curious what the difference between traveling at the speed of light and teleportation is. I think teleportation has to do with deconstructing objects and then reconstructing them which allows them to travel through things etc., but is there any other noticeable difference?

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i don't think teleportation is a well-defined scientific term. Wikipedia states that is refers to "notions concerning the transfer of matter from one point to another without traversing the physical space between them".. in physical terms this would correspond to disconnected worldlines. maybe more appropriate for scifi.SX. – luksen Sep 29 '11 at 17:52

If you travel at the speed of light (which you can't, nor can any matter or antimatter as far as we know), then time appears to you as though it stops. You notice no passage of time between the point at which you start, and stop, travelling at the speed of light. And similarly, if you start travelling at speeds very close to the speed of light, you will notice very little passage of time between your starting and stopping points at those speeds, although much time may pass for other observers between those points in (space-)time.

As for teleportation: unless you mean the term for communicating the quantum state of a system (usually just a single particle at a time) between distant parties with the aid of classical communication, there is no well-defined meaning for the term. Certainly we don't know how you would actually transmit a physical body across large distances, aside from transporting it bodily. But even in the case of the communication protocol, it cannot be done faster than the speed of light, because it relies on actual communication of measurement results (which is limited by light speed).

So: you can't transport matter at the speed of light; we don't even have a good hypothetical way to teleport matter; and there's no real reason to think that they would be equivalent sorts of things to do.

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