Twin Paradox: Understanding Who Ages Less

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Discussion Overview

The discussion revolves around the twin paradox in the context of special relativity, specifically addressing the aging difference between twins when one travels in space while the other remains on Earth. Participants explore the implications of acceleration, relative motion, and the nature of time dilation, questioning how these factors determine which twin ages less.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant questions how to determine which twin ages less if absolute motion cannot be defined, suggesting that both twins should perceive each other's clocks as running slow.
  • Another participant asserts that the symmetry is broken by the acceleration of the traveling twin, leading to less proper time experienced by that twin.
  • Some participants argue that the accelerating twin perceives the Earth as being in uniform motion, raising questions about the relativity of acceleration.
  • There is a discussion about the effects of acceleration and how the twin on Earth remains in an inertial frame while the traveling twin does not.
  • One participant proposes a hypothetical scenario where the traveling twin does not operate the spaceship and questions how time dilation would apply in that case.
  • Another participant emphasizes that the twin on Earth does not feel any effects during the traveling twin's acceleration, which is relevant to their experience of time.
  • Participants discuss the implications of forces experienced during acceleration and how they relate to time dilation in both special and general relativity.
  • There is a distinction made between measuring clock rates during the journey versus comparing clocks after the traveling twin returns.

Areas of Agreement / Disagreement

Participants express differing views on the nature of acceleration and its implications for time dilation, with no consensus reached on how to reconcile the perspectives of the two twins during the journey.

Contextual Notes

Participants highlight the complexity of the twin paradox, noting the importance of distinguishing between different frames of reference and the effects of acceleration, which complicate the understanding of time dilation.

  • #121
MeJennifer said:
The metric of spacetime defines the distance between two events. This metric is well defined (ignoring for the moment if this space is actually Hausdorff) for both flat (Minkowski) and curved (Lorentzian) spacetimes.

http://en.wikipedia.org/wiki/Metric_(mathematics )
First off, you've cited the definition of the wrong word: see Metric tensor. Secondly, see proper length and proper time.
 
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  • #122
Every serious book on relativity writes about distances between events in spacetime.

What I write seems to fall on deaf ears, so I won't respond anymore to this.
 
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  • #123
matheinste said:
Hello Al68.

I think you are wrong. However i would rather let someone decide this for us rather than continue disagreeing.

It's 4AM here so i will be disappearg soon.

Matheinste.

I don't understand why there's a disagreement. In the twins paradox, the ship's twin measures the distance traveled to be less than that measured by the Earth twin. If I'm right, that would mean that the ship's twin would age less. I thought we all agreed on which twin aged less. I thought the only disagreement was why.

Al
 
  • #124
Hello Al68.

I have no disagreement about which twin ages less. I only disagree about the spactime distance. Tomorrow i will consult my textbooks and then can hopefully quote some relevant passages.

Matheinste.
 
  • #125
matheinste said:
Hello Al68.

I have no disagreement about which twin ages less. I only disagree about the spactime distance. Tomorrow i will consult my textbooks and then can hopefully quote some relevant passages.

Matheinste.

Well, there's the problem, I was referring to spatial distance, not spacetime length.

Al
 

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