If they somehow actually achieved light speed, they would be incapable of doing anything because they'd functionally be in permanent stasis. If they got very very close to it then they could take an action, but the handful of seconds required to perform the action could take thousands of years depending on how close to that speed they are. So that's what I mean about time dilation impacting the ability to slow down.Slenn said:I'm not sure how time dilation prevents a ship from slowing down. Time dilation makes it so that events that are happening aboard a ship happen at a slower rate relative to the observers on Earth. We don't see any change in the ship's speed due to time dilation.Lightknight said:So if time dilation prevents a ship from being able to slow itself down. Would it be possible for us to use quantum entanglement so that we as the observers could interact with the ship spontaneously? Perhaps it could perform actions instantaneously and side step the fact that there is no time on board the ship?
Then again, maybe even if we ever figured out how to go light speed we should only maintain speeds at a relative dilation that would allow for appropriate reaction times. I mean, near light speed still has clear advantages considering nearby solar systems and preventing the crew from losing too much of their youth.
Hmm, I thought the whole point of quantum entanglement was that the entangled particles could potentially be across the universe and still be entangled and ergo allow instantaneous transmission of information. Are you telling me that while space may not be an issue for entanglement, relative time could be? Wouldn't that make it no longer instantaneous like they claim? See... this is why I need to get more physicist friends...The catch with special relativity is that events that are simultaneous in one frame are no longer simultaneous in another. I would not expect that the electrons that are being controlled through quantum entanglement would act simultaneously on a ship moving close to the speed of light. It could be that in some abstract frame of reference, the two electrons feel a simultaneous force acting on them, but to an observer on Earth the events don't appear to be simultaneous. I could be wrong.
Looks like the lower boundary on the speed of entanglement communication is at least 10,000 times the speed of light if these physicists are to be believed:
http://www.gizmag.com/quantum-entanglement-speed-10000-faster-light/26587/
They were not able to rule out that the action is actually instantaneous, just that they know it's at least 10,000 times the speed of light or faster.
Ok, so if a ship is traveling at .9 v/c instead of .5 v/c in the example you gave and fired off a projectile itself heading .9 v/c then an observer wouldn't see that as 1 v/c or more even though the two things aren't really going that way. I'd be fascinated to see how the math works on that but I'm certainly not going to eat up your time on this when you've been so helpful on my dilation questions.There is no such scenario. No matter what happens during any calculation with special relativity, you'll never end up with a speed that's equal to or faster than the speed of light. If you do, it's usually because someone didn't do their math properly. In laboratory settings, scientists have observed no such speeds.