Time dilation (part two)

[Buffy]

From the same site, there's a great animation of this too. Take a look at:

 

http://www.phys.unsw.edu.au/~jw/twin.html

 

Cheers,

Buffy

[Damo2600]

No buffy.

 

This example is beautiful and I'm really gald you showed it to me. However it does not show 'actual' time dilation at the end of the journey. At the end of the journey everybody meets up and everybody's clocks match. It doesn't show the atomic clock time difference at the end. Janes clock should be slower than Joe's. When Joe's sends his Happy anniversery Jane should recieve it much faster than is being described here and Joe should recieve the return message much later than is being described because her clock is going much slower when they meet up. This fact is being forgoten in this example.

 

This shows from my previous thread that infact negative acceleration = negative time dilation which you told me does not exist.

 

Damien

[Damo2600]

Actually I looked at the example again and it shows no time dilation. All event are happening at the same time however there is a distance growing between the two observers. So if this is moving around a glass earth like I said. The actual time dilation is merely due to the distance growing and receding between the two observers. All time dilation is apparent because of growing distance. The return journey shows that events begin to happen faster.

 

This example has nothing to do with 'actual' time dilation.

 

Damien

[quantum quack]

Damo, are you possibly confusing the superluminal effects with time dilation?

 

If I am not mistaken time dilation and superluminal effects are treated quite separately>>>?

[quantum quack]

I think the symmetry you are looking for is argued as non-existant by SRT due to accelleration of one frame in the twin "paradox" therefore RF's can not be treated equivalently. and one twin will get older than the other and show it as such when they meet.

 

If not for ths accel. arguement both twins would be the same age when they meet.

It is often stated that to solve the twin paradox requires GR to come to the aid of SR. As to exactly how I couldn't say, but maybe some one else would like to enlighten the forum of how GR manages to solve this so called dilation paradox.

[Damo2600]

Yes quantum Quack,

 

I would seriously like someone to show me that too. I hope they can without stating that it is illogical.

 

It is illogical that is why I'm pointing it out.

 

Damien

[Damo2600]

Finally I get it.

 

If I am travelling at 3000km/s how the hell would I see a stationary clock.

 

Time dilation has as much to do with distance as it does speed.

 

Imagine a big clock in the sky. You are stationary away from it a long distance. When it's second ticks over you will not see it for a long time. It's ticking at the same rate your's is however it's evenly ticking behind yours. Someone close to it won't experience time difference. If you move closer to it it will speed up. If you move away from to it it will slow down. Simple.

 

Time dilation over a period of moving at a certain speed will slow down time however you are right Quack it is a completely different concept.

 

There I hope we have all learnt something.

 

Sorry Buffy and Tormod.

 

I certainly am stubourn aren't I?

 

Josephine :circle:

 

How simple if you state it like that!

[Damo2600]

That means if I am moving toward something I won't see it's time to be going slower but faster, and if I may jump forward, it will not be length contraction but length expansion. Anything perpendicular will be going at an equal time and regular length.

 

Why does Einstien make it sound so complicated?

 

Josephine

[quantum quack]

That means if I am moving toward something I won't see it's time to be going slower but faster, and if I may jump forward, it will not be length contraction but length expansion. Anything perpendicular will be going at an equal time and regular length.

 

Why does Einstien make it sound so complicated?

 

Josephine

ha...to him it was relatively easy.

A while ago I was exploring the same issue and I created this table as an excersise:

 

The object would appear to be traveling at 4*c. as it approached you at a v=0.8c

 

Of course this is only true for the object with a vector towards you, and not orthagonal to you.

[IDMclean]

First lets deal with a concept called "Simutania" Imagine, if you will, standing on a street parallel to a row of lights all of which are off.

 

If they were turn on all at the "same time" so that they came on simutaniously relative to each other. you looking at them would see the one closest come on first (for dramatic effect we will imagine being 99% c) then the next two which would be equal distant, then the next two, and so on and so on. even though the event is simutanious you would perceive it as asyncronise.

 

Ok, now for some fun things. "Time dialation" is part of bending spacetime, if a distance gets shorter it takes you less "time" to travel it correct? so if you travel along and accelerate you would notice nothing except for everything rushing in the oppisite direction, you would not notice that your clock is slower than the rest of the universe because you would mearly observe that you have gotten to your destination in a short time, not that your clock went any slower or faster.

 

Now if you observed a clock "at rest" while traveling at high speed it would indeed appear slower, as would everything slower than you, because they would be traveling a longer distance.

[quantum quack]

First lets deal with a concept called "Simutania" Imagine, if you will, standing on a street parallel to a row of lights all of which are off.

 

If they were turn on all at the "same time" so that they came on simutaniously relative to each other. you looking at them would see the one closest come on first (for dramatic effect we will imagine being 99% c) then the next two which would be equal distant, then the next two, and so on and so on. even though the event is simutanious you would perceive it as asyncronise.

 

Ok, now for some fun things. "Time dialation" is part of bending spacetime, if a distance gets shorter it takes you less "time" to travel it correct? so if you travel along and accelerate you would notice nothing except for everything rushing in the oppisite direction, you would not notice that your clock is slower than the rest of the universe because you would mearly observe that you have gotten to your destination in a short time, not that your clock went any slower or faster.

 

Now if you observed a clock "at rest" while traveling at high speed it would indeed appear slower, as would everything slower than you, because they would be traveling a longer distance.

 

I am sorry but I think this is not quite right.

 

From my understanding and I do hope some one will correct me if I am wrong, the rest frame sees the clock with velocity as slow and not the other way round.

 

In SRT the Rest frame always sees the other frame as having the dilation, length contraction and velocity and if we swap frames the now current frame is deemed as at rest and sees the original frame as having the dilation length contraction and velocity.

 

So if you were at velocity and saw a frame at rest to you then they would appear to be faster [not slower] however this is not the usual SRT scenario as the observer always sees himself as at rest and never at velocity.....

 

 

so if we have observer A and B closing at relativistic velocity.

 

Observer A will see B's clock as slow and B will see A's clock as slow.

 

Becasue both obserers will consider them selves as rest when making that observation.

[IDMclean]

It probably is wrong at least in part, I'm a very muddle brained individual but concidering I've spent only a small bit triffling with it before coming to the conclusion that "time" does not exsist. So I don't even worry about it. Except in the case that it makes interstellar travel difficult.

 

With good certainty I can say this. Time Dialation is a derived Equation from Length/Distance contraction. Just take a look at the Lorentz equation. In no example of GR or SR does "time" go faster or slower because time is not a measurement of velocity, it's a measurement of distance. It's all about spacetime geometries.

[C1ay]

Yes quantum Quack....

 

Damien

 

 

Finally I get it.....

 

Josephine :circle:

 

Are you Damien or Josephine or both? Each user needs to have their own account here.

[Tormod]

Are you Damien or Josephine or both? Each user needs to have their own account here.

 

She is both. And she has two accounts, so I'll be closing the first (liliangrn).

[C1ay]

She is both. And she has two accounts, so I'll be closing the first (liliangrn).

So who's Damien?

[Queso]

weird..........

[Tormod]

So who's Damien?

 

A bogus personae, obviously. Sometimes Damian, sometimes Damien.