Undergrad Measuring Star Radii with General Relativity

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Measuring the radii of stars using general relativity involves understanding the curvature of spacetime rather than just space. Stars do have a well-defined radius in the context of general relativity, but the definition can vary based on the method used. The discussion emphasizes that gravity is a result of spacetime curvature, which complicates straightforward measurements. Different approaches to defining a star's radius can yield varying results. Overall, general relativity provides a framework for understanding stellar radii, but the complexities of spacetime must be considered.
Natchanon
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Hi, I'm wondering if it is possible to measure radii of stars using general relativity, given its explanation of gravity as curvature of space.

Thank you
 
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How would you do this?
 
Natchanon said:
given its explanation of gravity as curvature of space.

Curvature of spacetime, not space.
 
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Natchanon said:
Hi, I'm wondering if it is possible to measure radii of stars using general relativity, given its explanation of gravity as curvature of space.
Are you asking if stars have a well-defined radius in GR? Yes, although you will get different answers depending on how you define radius.

As weirdoguy notes, it's curvature of spacetime, not space. You can't explain gravity just through curvature of space.
 
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Thread 'EPR revisited'

In an inertial frame of reference (IFR), there are two fixed points, A and B, which share an entangled state $$ \frac{1}{\sqrt{2}}(|0>_A|1>_B+|1>_A|0>_B) $$ At point A, a measurement is made. The state then collapses to $$ |a>_A|b>_B, \{a,b\}=\{0,1\} $$ We assume that A has the state ##|a>_A## and B has ##|b>_B## simultaneously, i.e., when their synchronized clocks both read time T However, in other inertial frames, due to the relativity of simultaneity, the moment when B has ##|b>_B##...
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