time dilation

[ydoaPs]

is time considered a vector in SR? does dilation occur in direction of motion or in all directions?

[CPL.Luke]

well I can't see time being dilated more in one direction than anouther. So I would say that it just dilates relative to you.

 

however if the object moved at a angle to you, then you would have to solve out for its velocity relative to you at all times.

[ecoli]

I thought time was more like a property of the universe, like a dimension.

[ydoaPs]

aren't dimensions vectors? ie. unit vectors used to define other vectors?

[ecoli]

not sure...its hard to image 3-dimensional space as a vector.

 

edit: unless your not talking in terms of a single vector

[ydoaPs]

take a vector in a three dimensional space: [math]\vec{v}=a_1{\vec{i}}+a_2{\vec{j}}+a_3{\vec{k}}[/math] where i, j, and k are the unit vectors for x, y, and z, respectively

[swansont]

No. Time and time dilation are not vectors. All that is necessary is relative motion, and the direction of motion is not a factor.

[J.C.MacSwell]

No. Time and time dilation are not vectors. All that is necessary is relative motion, and the direction of motion is not a factor.

 

I'm not sure how this bears on the topic, but the direction of acceleration is a factor.

 

Edit: or is it? It (direction) will not effect the present rate of flow of time although it will effect the future rate.

 

Whereas the rate of acceleration will effect both.

[timo]

is time considered a vector in SR?

No. There are two different "times" in SR. Eigentime, which is a scalar (=a real number which remains invariant under coordinate transformations) and coordinate time which is the first entry of a four-vector (also a real number but not invariant under coordinate transformations).

[swansont]

I'm not sure how this bears on the topic' date=' but the direction of acceleration is a factor.

 

Edit: or is it? It (direction) will not effect the present rate of flow of time although it will effect the future rate.

 

Whereas the rate of acceleration will effect both.[/quote']

 

 

Acceleration means it's not strictly SR, but I don't think the direction matters

[ydoaPs]

so, time dilates in response to relative speed and instead of relative velocity?

[5614]

Correct... it is the speed between two bodies that counts.

 

If me and you are both travelling north, but you are traveling at c-1 and I'm travelling at c/100 time dilation will occur although we both are travelling in the same direction, whereas if we are travelling in opposite directions but with the same relative speed as in the previous example the dilation effect will be the same.

[ydoaPs]

what about if our motions are perpendicular to each other?

[swansont]

what about if our motions are perpendicular to each other?

 

The speed is with respect to your frame of reference. e.g. the dilation of a clock on a satellite is given by the orbital speed, which is perpendicular.