Does a Rod's Size Change When Rotating at the Speed of Light?

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SUMMARY

The discussion centers on the behavior of a rotating rod moving at relativistic speeds, specifically near the speed of light. It concludes that the rod cannot be treated as a rigid body due to relativistic effects, leading to changes in its perceived length and width as observed from an external frame. The endpoints of the rod cannot exceed the speed of light, resulting in a bending appearance. The concept of angular momentum and torque is also addressed, indicating that these factors are influenced by the rod's motion.

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  • Understanding of special relativity principles
  • Familiarity with angular momentum concepts
  • Knowledge of rigid body dynamics
  • Basic comprehension of relativistic effects on length contraction
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  • Research the implications of special relativity on rigid body motion
  • Study the concept of length contraction in relativistic physics
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Physicists, students of relativity, and anyone interested in the effects of high-speed motion on physical objects will benefit from this discussion.

captain
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if a rod is moving close to the speed of light in its linear velocity and rotating at some angular velocity will the rod's length and width change as it rotates making it look all funky or will it do something else because it can't be treated as a rigid body? If it does do what i mentioned above then its angular momentum is changing and that means there is torque.
 
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Because its endpoints cannot move faster than the speed of light, relative to some external observer (You say it is "moving close to the speed of light". You mean, of course, relative to this observer.) it will appear to bend. As has been said here many times, there is no such thing as a "rigid body" in relativity.
 
captain said:
making it look all funky
Depends, do you call http://commons.wikimedia.org/wiki/Image:Relativistic_Rolling_Wheel.png" "funky"?

PS I cannot vouch for the accuracy of these pictures, it is a wikipedia link after all, but they seem about right.
 
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