A big pie, rotating in the sky, should have apparently shorter circumference than a non-rotating one, and both with the same radii.
I can’t swallow this. Not because it is weird, but because it is inconsistent.
There is no inconsistency. In one case you are measuring the circumference with moving rulers, while in the other case you are measuring the circumference with stationary rulers. It’s not inconsistent for these two different measurements to give different results.
No. I am measuring from here, from the centre with some measuring device.
First I measure stationary pie, then I measure the rotating one. Those red-white stripes are either constant, either they shrink. If they are shrinking, they should multiply as well. If they are not shrinking, what happened with Mr. Lorentz’s contraction?
If you measure a wheel with a ruler, and the wheel is moving relative to the ruler, then your measurement assumes that both ends of a piece of the wheel line up with both ends of a piece of the ruler at the same time. Whether these events happen at the same time, and therefore whether this is a measurement of the wheel, are different depending on the frame of reference.
There is no inconsistency. In one case you are measuring the circumference with moving rulers, while in the other case you are measuring the circumference with stationary rulers. It’s not inconsistent for these two different measurements to give different results.
No. I am measuring from here, from the centre with some measuring device.
First I measure stationary pie, then I measure the rotating one. Those red-white stripes are either constant, either they shrink. If they are shrinking, they should multiply as well. If they are not shrinking, what happened with Mr. Lorentz’s contraction?
If you measure a wheel with a ruler, and the wheel is moving relative to the ruler, then your measurement assumes that both ends of a piece of the wheel line up with both ends of a piece of the ruler at the same time. Whether these events happen at the same time, and therefore whether this is a measurement of the wheel, are different depending on the frame of reference.