4 ms·

Whenever two objects are in relative motion to one another, they each perceive a time dilation taking place at the other object. The flow of time is directly li

by Udo 12y ago

Whenever two objects are in relative motion to one another, they each perceive a time dilation taking place at the other object. The flow of time is directly linked to the relative speed of an object. On an object that moves at the speed of light, time stands still. For more information on the mathematics, I refer you to the Lorentz transformation (http://en.wikipedia.org/wiki/Lorentz_transformation http://en.wikipedia.org/wiki/Lorentz_transformation), but it's actually enough if you imagine that increases in speed are causing a decrease in the flow of time, the limit of that process has to be the velocity at which the flow of time is zero.

Ono-Sendai 12y ago
Ok. When you say 'how fast an object moves through time', you mean 'how fast time passes for a moving object, as seen from the inertial reference frame of another object'. I regard objects as moving at the same speed through time - 1 second per second.
- Udo 12y ago
  It's of course a matter of taste what expression sounds more fitting to you, precisely because time is such a fluid concept. Personally, when I think about a neutrino for example, I'd say that neutrinos go crazy fast, and they experience time unimaginably slowly, so it feels more natural for me to think that velocity and time are tradeoff values of each other.
  - joshuahutt 12y ago
    Wouldn't it be more accurate to say that neutrinos experience time normally, but observe everything else to be unimaginably slow?
tjradcliffe 12y ago
> Whenever two objects are in relative motion to one another, they each perceive a time dilation taking place at the other object. This is true. >The flow of time is directly linked to the relative speed of an object. I'm not sure this is even a coherent statement. "Flow of time" along what? Consider for comparison: what would the "Flow of latitude" refer to on a planet's surface? Any coherent statement about the "Flow of time" should also make sense when applied to the "Flow of latitude", and I can't think of any way of conceptualizing the "flow of latitude" that makes sense. Maybe I'm not understanding what you mean by "flow", but in relativity dimensions do not "flow" in any conventional sense, and the notion that "increases in speed are causing a decrease in the flow of time" makes no sense: to an observer on an object clocks continue to run at a constant rate, and the whole point of relativity is that observers on objects are just as good as observers anywhere else. The laws of physics are the same for everyone (this is the principle of relativity) so since an observer on an object does not observe co-moving clocks slowing down, any talk of "a decrease in the flow of time" requires a violation of the principle of relativity.
- Udo 12y ago
  > but in relativity dimensions do not "flow" in any conventional sense That is not really the point. You are concentrating on the word flow, and maybe I chose that foolishly, so bear in mind that I'm of course not a native speaker. If we discard for a moment things that move at the speed of light, that leaves us with objects for which time does not stand still. Whether or not you agree with the word "flow", is it really that objectionable to characterize the experience of time as a movement through a fourth dimension? My entire point in this regard was really that relative velocity and time dilation are linked. Which they are. It's right there in the math. Maybe my mistake was to use "flow" conversationally, but if you could see past that it would probably a more productive discussion for both of us. > "a decrease in the flow of time" requires a violation of the principle of relativity You misunderstood what I was trying to say, in a colossal way. I apologize for not being clearer. At no point was I suggesting a global "flow of time". In fact, I made a special effort to talk about individual reference frames.

by Udo 12y ago

Ono-Sendai 12y ago

Ok. When you say 'how fast an object moves through time', you mean 'how fast time passes for a moving object, as seen from the inertial reference frame of another object'. I regard objects as moving at the same speed through time - 1 second per second.

Udo 12y ago
It's of course a matter of taste what expression sounds more fitting to you, precisely because time is such a fluid concept. Personally, when I think about a neutrino for example, I'd say that neutrinos go crazy fast, and they experience time unimaginably slowly, so it feels more natural for me to think that velocity and time are tradeoff values of each other.
- joshuahutt 12y ago
  Wouldn't it be more accurate to say that neutrinos experience time normally, but observe everything else to be unimaginably slow?

tjradcliffe 12y ago

> Whenever two objects are in relative motion to one another, they each perceive a time dilation taking place at the other object. This is true. >The flow of time is directly linked to the relative speed of an object. I'm not sure this is even a coherent statement. "Flow of time" along what? Consider for comparison: what would the "Flow of latitude" refer to on a planet's surface? Any coherent statement about the "Flow of time" should also make sense when applied to the "Flow of latitude", and I can't think of any way of conceptualizing the "flow of latitude" that makes sense. Maybe I'm not understanding what you mean by "flow", but in relativity dimensions do not "flow" in any conventional sense, and the notion that "increases in speed are causing a decrease in the flow of time" makes no sense: to an observer on an object clocks continue to run at a constant rate, and the whole point of relativity is that observers on objects are just as good as observers anywhere else. The laws of physics are the same for everyone (this is the principle of relativity) so since an observer on an object does not observe co-moving clocks slowing down, any talk of "a decrease in the flow of time" requires a violation of the principle of relativity.

Udo 12y ago
> but in relativity dimensions do not "flow" in any conventional sense That is not really the point. You are concentrating on the word flow, and maybe I chose that foolishly, so bear in mind that I'm of course not a native speaker. If we discard for a moment things that move at the speed of light, that leaves us with objects for which time does not stand still. Whether or not you agree with the word "flow", is it really that objectionable to characterize the experience of time as a movement through a fourth dimension? My entire point in this regard was really that relative velocity and time dilation are linked. Which they are. It's right there in the math. Maybe my mistake was to use "flow" conversationally, but if you could see past that it would probably a more productive discussion for both of us. > "a decrease in the flow of time" requires a violation of the principle of relativity You misunderstood what I was trying to say, in a colossal way. I apologize for not being clearer. At no point was I suggesting a global "flow of time". In fact, I made a special effort to talk about individual reference frames.