Experimental verification of Ehrenfest Paradox

In summary, the conversation discusses the Ehrenfest paradox and the difficulty of conducting experiments to verify the contraction of a spinning disc. It is concluded that while a spinning ring may potentially contract, it is unlikely that an experiment could be conducted with known materials.
  • #1
d3mm
140
1
I am not completely convinced that the modern resolution is correct.

Is it?

Is anyone aware of any experiments that have been done that relate to this effect?

Reference: http://en.wikipedia.org/wiki/Ehrenfest_paradox
 
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  • #2
Hi, this topic has been well discussed before (and despite some confusion in the literature it never really was a paradox), see:

- https://www.physicsforums.com/showpost.php?p=4101753&postcount=5

- The original paper simply proves that according to SR real matter cannot be totally rigid (and there is nothing paradoxical about that):
http://en.wikisource.org/wiki/Uniform_Rotation_of_Rigid_Bodies_and_the_Theory_of_Relativity

PS. A short answer about experiments: it is very difficult to imagine an experiment that could allow to verify the contraction of a spinning disc. The inertial effect is always much greater and already not-so-fast rotating discs disintegrate (explode).
 
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  • #3
harrylin said:
PS. A short answer about experiments: it is very difficult to imagine an experiment that could allow to verify the contraction of a spinning disc. The inertial effect is always much greater and already not-so-fast rotating discs disintegrate (explode).
A spinning disc cannot contract much because the radial direction is not contracting. A spinning ring could potentially contract if it was very light (minimal centrifugal forces) and very strong. But I doubt an experiment is feasible with known materials.
 
  • #4
A.T. said:
A spinning disc cannot contract much because the radial direction is not contracting. [..] A spinning ring could potentially contract if it was very light [..].
I suspect that a very thin ring of any known useable material would still expand, but I did not calculate it (anyone?).
 
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  • #5


I understand your skepticism and the importance of experimental verification in resolving scientific paradoxes. In the case of the Ehrenfest Paradox, there have been several experiments conducted that support the modern resolution.

One notable experiment was conducted by Sagnac in 1913, where he measured the difference in time between a rotating and non-rotating disk using interferometry. This experiment showed that there was indeed a difference in time between the two, supporting the idea that length contraction is a real effect.

Additionally, in 2010, a team of researchers at the University of Maryland conducted an experiment using a rotating ring of trapped ions. They were able to observe the effects of length contraction and time dilation in the moving frame, further supporting the modern resolution of the Ehrenfest Paradox.

It is also worth noting that the modern resolution of the paradox has been extensively studied and confirmed through mathematical models and simulations, providing further evidence for its validity.

However, as with any scientific theory, it is always important to remain open to new evidence and potential revisions. If you have any specific concerns or alternative explanations for the paradox, I encourage you to conduct your own experiments and publish your findings for further discussion and analysis within the scientific community.
 

1. What is the Ehrenfest Paradox?

The Ehrenfest Paradox is a thought experiment in physics that was proposed by Paul Ehrenfest in 1909. It examines the paradoxical behavior of a spinning disk when observed from different reference frames.

2. How does the Ehrenfest Paradox relate to relativity?

The Ehrenfest Paradox is related to relativity because it deals with the concept of frames of reference and the effects of motion on objects. It demonstrates how the laws of physics can appear to be different depending on the observer's frame of reference.

3. What is the proposed solution to the Ehrenfest Paradox?

The solution to the Ehrenfest Paradox is that the spinning disk will experience length contraction and time dilation when observed from a reference frame that is not rotating with the disk. This resolves the paradox and is in line with Einstein's theory of special relativity.

4. Has the Ehrenfest Paradox been experimentally verified?

Experimental verification of the Ehrenfest Paradox has been a subject of debate and controversy. While some experiments have shown results that support the predicted effects of relativity, others have not. The most widely accepted experimental verification comes from the Hafele-Keating experiment in 1971, which showed that time dilation occurs for rotating objects.

5. Why is the Ehrenfest Paradox important?

The Ehrenfest Paradox is important because it helps us understand the fundamental principles of relativity and how motion and observation can affect our perception of the laws of physics. It also highlights the complexities of relativity and the need for careful consideration of reference frames in scientific experiments and observations.

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