RTT’s mind boggling Time Dilation Paradox

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Discussion Overview

The discussion revolves around the concept of time dilation as it relates to a hypothetical scenario involving a train and a rocket moving at high speeds relative to Earth. Participants explore the implications of special relativity on clock rates and synchronization, raising questions about the nature of time in different reference frames.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that if a train moves at high speed, its clock slows down relative to Earth, and a rocket moving in the opposite direction also experiences time dilation.
  • Others argue that the rocket is stationary in the Earth's frame, suggesting that the train's time dilation does not create a paradox.
  • A participant questions how the direction of travel affects clock rates, asking which direction allows a clock to run the fastest without an absolute rest frame.
  • Some participants discuss the addition of velocities in special relativity, noting that simple addition does not apply and referencing the formula for relativistic velocity addition.
  • There are claims that misunderstandings exist regarding which frame of reference is being used to analyze the scenario, with some suggesting that the original poster lacks clarity on this aspect.
  • A participant introduces an alien observer scenario, questioning the synchronization of clocks and the implications of viewing time from different frames.
  • Another participant raises concerns about the lack of information regarding the synchronization of clocks and the conditions under which they were set, emphasizing the need for clarity in the discussion.
  • There is mention of a "triplet paradox," with a request for an explanation without mathematical references, leading to a humorous commentary on geometric paradoxes.

Areas of Agreement / Disagreement

The discussion contains multiple competing views and remains unresolved regarding the implications of time dilation and the interpretation of the scenario presented. Participants express differing opinions on the nature of the paradox and the correct application of relativistic principles.

Contextual Notes

Limitations include potential misunderstandings about reference frames, the synchronization of clocks, and the conditions under which the scenario is analyzed. Participants have not reached a consensus on these points.

RawThinkTank
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A train is moving relative to Earth at such a high speed that the clock on the train slows down to half rate compared to clocks on earth. A rocket is launched in the opposite direction train is moving to such a high speed that the clock on the rocket slows down to half rate compared to the clock on train.

The rate of clock ticks on rocket compared to that of clocks on Earth should be 1/4. So what do U think, Or Can U ?
 
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Did you realize that this rocket is actually stationary in the Earth's frame? The rocket is an irrelevant part of this story.

If the Earth sees the train's clocks slow down by a factor of 2, the train will see Earth's clocks slow down by a factor of 2. This may be surprising, but it's not a paradox.

You seem to be new here, so you probably don't know that there are lots of threads about this already. I suggest you use the search feature to find some of them and read them. You can e.g. search for "twin paradox", "time dilation" or "simultaneity".
 
I think this is a very good question.

If you go back in the direction of Earth does you clock go faster and tick at the same rate as the clocks on Earth or slower? Which direction can you go to have your clock run the fastest? How can this be if there is no absolute rest frame?
 
In any inertial reference frame, stationary clocks run the fastest, relative to the time coordinate of the frame.
 
RawThinkTank said:
A train is moving relative to Earth at such a high speed that the clock on the train slows down to half rate compared to clocks on earth. A rocket is launched in the opposite direction train is moving to such a high speed that the clock on the rocket slows down to half rate compared to the clock on train.

The rate of clock ticks on rocket compared to that of clocks on Earth should be 1/4. So what do U think, Or Can U ?

I don't see how this is a paradox, the rocket would simply be stationary to earth, or at least I think. :eek:
 
RawThinkTank said:
A train is moving relative to Earth at such a high speed that the clock on the train slows down to half rate compared to clocks on earth. A rocket is launched in the opposite direction train is moving to such a high speed that the clock on the rocket slows down to half rate compared to the clock on train.

The rate of clock ticks on rocket compared to that of clocks on Earth should be 1/4. So what do U think, Or Can U ?
When you suggest this question(or paradox in your opinion) did you think about the relative speed between the Earth, the rocket and the train.In SR, i don't think it is right when you just simply add the relative speed of the rocket to the train and the relative speed of the train to the Earth to find the speed of the relative speed of the rocket to the Earth.
you know, it is not right when 2 things move toward each other with the speed of c, the speed will be 2c.That's ridiculous.
 
RawThinkTank
like fredrik suggested, i think you should find some threads that have the similar question like you.I myself found it's very interesting and useful in "is age relative" or "paradoxes".we have a lot of discussions and problems there
 
AVNguyen said:
In SR, i don't think it is right when you just simply add the relative speed of the rocket to the train and the relative speed of the train to the Earth to find the speed of the relative speed of the rocket to the Earth.

But in this case it works out OK. Using w = (u + v)/(1 + uv/c^2) to add velocities, if v=-u then the answer comes out at zero.
 
  • #10
chronon said:
But in this case it works out OK. Using w = (u + v)/(1 + uv/c^2) to add velocities, if v=-u then the answer comes out at zero.
Mind you, we are talking about the case when the racket move so fast that the clock on the rocket slow down to the half rate compared with the clock on the train.therefore lvl>lUl, and even when v=-u, they can be equal to c.
 
  • #11
I think I misunderstood the post that started this thread. When I wrote my reply I thought that RTT meant that in the train's frame the clock on the rocket slows down to half the rate of a clock on the train, but I realize now that he probably meant that this this happens in the earth's frame.
 
  • #12
Fredrik said:
I think I misunderstood the post that started this thread. When I wrote my reply I thought that RTT meant that in the train's frame the clock on the rocket slows down to half the rate of a clock on the train, but I realize now that he probably meant that this this happens in the earth's frame.

Actually, having run into this poster (RTT) before, I don't think that he even grasps the fact that there is a difference depending on which frame you choose. That's why he doesn't specify which frame. It is also part of the reason he believes this to be such a "mind boggling" paradox.
 
  • #13
RawThinkTank said:
A train is moving relative to Earth at such a high speed that the clock on the train slows down to half rate compared to clocks on earth. A rocket is launched in the opposite direction train is moving to such a high speed that the clock on the rocket slows down to half rate compared to the clock on train. ...

The alien inside this train has two powerful telescopes; One for the rocket and one for the earth, He has shown me that the clock on the rocket has struck only 2:00 and Clock on Earth has struck 4:00 simultaneously. I was shocked and ever since I have been posting this question on the internet in hope that my mind bogledness will be over.
 
  • #14
RawThinkTank said:
The alien inside this train has two powerful telescopes; One for the rocket and one for the earth, He has shown me that the clock on the rocket has struck only 2:00 and Clock on Earth has struck 4:00 simultaneously.
You see,rtt.that's why Janus said you don't understand.Both of the alien's telecopes are in the rocket'stime frame.how can you expect them to be different.
 
  • #15
AVNguyen said:
You see,rtt.that's why Janus said you don't understand.Both of the alien's telecopes are in the rocket'stime frame.how can you expect them to be different.

The real problem here is that he doesn't provide enough information.
When and How were the Clocks originally synchronized?
What did they read when they were?
Did the train move with respect to the Earth between the time the rocket was launched and the clocks were synchronized?
If so, how far(or for how long) and as measured from which frame?
 
  • #16
so is there anybody here beyond human intellect ?

If so can anybody tell me in words without numbers

" What is the TRIPLET PARADOX ? "
 
Last edited:
  • #17
RawThinkTank said:
so is there anybody here beyond human intellect ?

no

If so can anybody tell me in words without numbers

" What is the TRIPLET PARADOX ? "
[/quote]

[insert tongue in cheek]

Oh, this is probably just the triangle paradox. The triangle paradox is the paradox that the sum of any two sides of a triangle is (given some assumptions about the underlying geometry), always longer than the third side. So if you go from a to b, then from b to c, you travel a longer distance than if you went from a to c.

Mind boggling, isn't it?

Note that this is totally different from clocks - with clocks, when you go from a to b, and from b to c, they always read a shorter time than if you go directly from a to c in a straight line.

Rulers are sure weird, why can't they behave simply like clocks?

[remove tounge frome cheek]
 

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