3 ms·

Eh, this was never about instantaneous travel, this was about a slight increase in speed. The thing you need to understand about relativity is that travelling

Eh, this was never about instantaneous travel, this was about a slight increase in speed. The thing you need to understand about relativity is that travelling even slightly faster than the speed of light in any frame of reference is instantaneous communication, in some other frame of reference. If I send a signal from point A and it arrives at point B just infinitesimally faster than the speed of light, then according to an observer in some other reference frame the transmission from A and arrival at B happened simultaneously, and according to some other observer the arrival actually happened before the transmission. It's also important to note that once you have any FTL travel you automatically have time travel (or at least, backwards-in-time communication). But I'd have to draw a diagram to explain why.

patdennis 14y ago
I think you misunderstand >travelling even slightly faster than the speed of light in any frame of reference is instantaneous communication, in some other frame of reference. Even traveling at the speed of light is instantaneous communication... from the photon's frame of reference. If neutrinos were traveling at 3.7 miles per second faster than light it would indicate that we simply don't understand how the universe works. Let me put it this way: Given our current understanding of the universe going faster than the speed of light should violate causality. It should be impossible to travel 3.7 miles per second faster than light without arriving before you left. But that doesn't mean that if these neutrinos were traveling 3.7 miles per second faster than light that it would enable instantaneous communication. C + 3.7 miles per second would still take a long time to travel interstellar distances.
- planetguy 14y ago
  >Even traveling at the speed of light is instantaneous communication... from the photon's frame of reference. Photons don't have a frame of reference. It makes no sense, in relativity, to talk about a frame in which a photon is at rest, and trying to talk about them only leads to nonsense. I say this not to nitpick, but because the fact that you're trying to use the concept suggests to me that your grasp on relativity might not be that strong. >But that doesn't mean that if these neutrinos were traveling 3.7 miles per second faster than light that it would enable instantaneous communication. C + 3.7 miles per second would still take a long time to travel interstellar distances. An object travelling at c+3.7mps in your reference frame is travelling at infinity miles per second in some other (sensible, subluminal) reference frame, that's the point. This is all undergrad-level stuff.

patdennis 14y ago

I think you misunderstand >travelling even slightly faster than the speed of light in any frame of reference is instantaneous communication, in some other frame of reference. Even traveling at the speed of light is instantaneous communication... from the photon's frame of reference. If neutrinos were traveling at 3.7 miles per second faster than light it would indicate that we simply don't understand how the universe works. Let me put it this way: Given our current understanding of the universe going faster than the speed of light should violate causality. It should be impossible to travel 3.7 miles per second faster than light without arriving before you left. But that doesn't mean that if these neutrinos were traveling 3.7 miles per second faster than light that it would enable instantaneous communication. C + 3.7 miles per second would still take a long time to travel interstellar distances.

planetguy 14y ago
>Even traveling at the speed of light is instantaneous communication... from the photon's frame of reference. Photons don't have a frame of reference. It makes no sense, in relativity, to talk about a frame in which a photon is at rest, and trying to talk about them only leads to nonsense. I say this not to nitpick, but because the fact that you're trying to use the concept suggests to me that your grasp on relativity might not be that strong. >But that doesn't mean that if these neutrinos were traveling 3.7 miles per second faster than light that it would enable instantaneous communication. C + 3.7 miles per second would still take a long time to travel interstellar distances. An object travelling at c+3.7mps in your reference frame is travelling at infinity miles per second in some other (sensible, subluminal) reference frame, that's the point. This is all undergrad-level stuff.