(a) Estimate the radius of curvature of a horizontally traveling photon at the surface of a 1.4M⊙ neutron star, and compare the result with the 10-km radius of the star. Can general relativity be neglected when studying neutron stars?
(b) If one hour passes at the surface of the neutron star, how much time passes at a great distance? Compare the times obtained from the exact and approximate expressions, Eqs. (17.13) and (17.14), respectively.