How Does the Twin Paradox Challenge Our Understanding of Time Dilation?

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    Paradox Twin paradox
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Discussion Overview

The discussion revolves around the twin paradox, a thought experiment in special relativity that examines the effects of time dilation on two twins, one of whom travels at relativistic speeds while the other remains stationary. Participants explore the implications of time dilation from different reference frames and the conditions under which each twin ages differently.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants assert that only the twin who travels (Twin B) will age slower due to their high velocity relative to Twin A, while others question this by suggesting that both twins experience time dilation relative to each other.
  • A participant mentions that the concept of simultaneity changes between reference frames, leading to different perceptions of aging when comparing the twins' ages.
  • There is a discussion about the necessity of a physical turnaround for Twin B to return to Earth, which affects the aging process compared to Twin A.
  • Some participants express confusion over the phrasing of time dilation, suggesting that it is important to clarify that a moving observer's proper time does not change, but rather the time measured in different frames does.
  • One participant provides an analogy involving two men walking at angles to illustrate how each perceives the other's progress through time, drawing parallels to the twin paradox.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of the twin paradox. There are competing views on how time dilation affects each twin and whether their experiences can be reconciled. The discussion remains unresolved with multiple interpretations presented.

Contextual Notes

Participants express uncertainty regarding the definitions of motion and time dilation, and the discussion highlights the complexity of simultaneity in special relativity. There are references to external resources for further clarification, indicating that the topic may require more foundational understanding.

  • #31
newTonn said:
it seems the clock which is ahead is ahead in time in contradiction with your explanation.

Draw a diagram, with A at the left side and A2 at the right. If B moves to the right in A's and A2's frame, then A and A2 move to the left in B's frame, with A "ahead" of A2.

A2's clock reads a later time than A's clock does, in B's frame, so A2's clock is "ahead."
 
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  • #32
newTonn said:
Time dilation is caused due to the relative motion(between two inertial frames) isn't it?.In this case One of the frame is accelerating.So the equation for time dilation is not apllicale to both frames.or if there is any equation of time dilation between one inertial frame and one accelerating frame,it is applicable to both in the same manner.
So when traveller turns around and accelerate,whatever equation applicable for traveller,is true for the men at rest also.

Finally both will give the same result of same ages for both twins.Am i correct?
Observation for such case should be done from an inertial frame. Since B returns (thus accelerats & it is only felt by B). its frame reference can't be selected. So u can choose A's reference Or any other inertial frame. U'll find that twin who returns, is younger.
 
  • #33
ratn_kumbh said:
Observation for such case should be done from an inertial frame. Since B returns (thus accelerats & it is only felt by B). its frame reference can't be selected. So u can choose A's reference Or any other inertial frame. U'll find that twin who returns, is younger.
Time dilation equation is applicable from one frame to another frame which is moving with a uniform velocity with respect to the first frame.So it is not possible from any frame (at rest or uniform motion),to apply time dilation equation for calculation of time in an accelerating frame(here B).
So somebody has to find an equation for that.The equation contains v(not a),which is the relative velocity(not acceleration)
 
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  • #34
newTonn said:
Time dilation equation is applicable from one frame to another frame which is moving with a uniform velocity with respect to the first frame.So it is not possible from any frame (at rest or uniform motion),to apply time dilation equation for calculation of time in an accelerating frame(here B).
So somebody has to find an equation for that.The equation contains v(not a),which is the relative velocity(not acceleration)


They already exist:
t = \frac{c}{a} sinh \left( \frac{aT}{c} \right)

T = \frac{c}{a} sinh^{-1} \left( \frac{at}{c} \right)

They are derived from the standard Relativity equations.
 
  • #35
Janus said:
They already exist:
t = \frac{c}{a} sinh \left( \frac{aT}{c} \right)

T = \frac{c}{a} sinh^{-1} \left( \frac{at}{c} \right)

They are derived from the standard Relativity equations.
Could you please give me an explanation of notations used and if possible,a link to derivations.
And please explain me how somebody knows,who is accelerating?
 
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  • #36
newTonn said:
Could you please give me an explanation of notations used and if possible,a link to derivations.
The notation is explained on the http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html page, not sure where you'd find a derivation.
newTonn said:
And please explain me how somebody knows,who is accelerating?
In flat spacetime (no sources of gravity), the accelerating individual will feel G-forces in the direction of acceleration, the inertial individual will feel weightless.
 
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