HW Ch-24

The first detection of gravitational waves involved the merger of two black holes in a galaxy 1.3 billion light-years away. If the gravitational waves spread out from this event isotropically (the same in all directions) and just reached us, how large a volume have the gravitational waves traveled through? Give your answer in cubic light-years.

Volume = 9.203 X 10^27 LY^3

In 1959, Pound and Rebka did an experiment to test the prediction of Einstein's general theory of relativity about the relationship between the pace of time and the strength of gravity. They did this by measuring the frequency of emitted gamma rays at the top and bottom of a laboratory tower, where the frequency acted like a "clock". When these two 'clocks' were compared,

the "clock" on the ground floor ran a tiny bit slower

The equivalence principle (principle of equivalence) says that

the effects of gravity are equivalent to the effects of acceleration

In the first direct detection of gravitational waves by LIGO in 2015, the waves came from

the merger of two black holes

According to Einstein's general theory of relativity, the stronger a star's gravity,

the slower time runs near it