Length Contraction: Measuring Circumference of Moving Circle

[unchained1978]

As I understand it, there is no length contraction in the direction perpendicular to the motion being described. So if I were to observe a circle moving along a line (not rostating) and I were to measure the radius in te direction parallel to the motion, I would observe a contracted radius, and therefore calculate a smaller circumference. But if I were to measure the radius in the direction perpendicular to motion, I would observe the inertial radius and therefore the inertial circumference. Does this mean that to calculate the circumference of a moving circle, I would need to treat it as an ellipse?

 

[Dale]

Yes, that is correct.

 

[DaveC426913]

A spherical object will compress along its axis of travel into a disclike shape (an oblate spheroid).