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Do contracting objects show red shift? 
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#19
May214, 08:11 PM

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If the distance between me and the central point of the contracting object is ##R## and at some moment the radius of the contracting object is ##r##, then the points on the edge of the disk of the object will be at a distance ##\sqrt{R^2+r^2}## from me, and this will become smaller (the point is moving towards me) as ##r## diminishes with the contraction. Of course this effect is well and thoroughly negligible if ##R\gt\gt{r}##, whereas the effect on the points that are directly on the line between the two centers is independent of ##R##. 


#20
May214, 10:28 PM

P: 145




#21
May214, 10:54 PM

Mentor
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#22
May214, 11:08 PM

P: 1,857

lets try this your observer C on earth, take the image you posted on post number 9. with a and b. Now that circle you posted is 3D, a planet. So as B moves towards point A on that 3D image. the distance between B and C decreases, hence its moving towards you=blueshift.



#23
May214, 11:12 PM

P: 1,857

In Drakkiths example observer A is the center of a circle, B is a point on the surface. As the surface contracts B moves towards A =blueshift



#24
May214, 11:24 PM

Sci Advisor
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It depends on the observer. I remain convinced there is no privileged observer in the universe.



#25
May214, 11:27 PM

P: 1,857

"It depends on the observer" 100% correct "I remain convinced there is no privileged observer in the universe" 100% unrelated to the context and examples in this thread 


#26
May314, 06:53 AM

P: 145

@Mordred That's exactly what I was thinking. I din't know you were talking about rotating objects. Got it now.



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