Which of the following methods used to determine the mass of a cluster does not depend on Newton's laws of gravity?
A)measuring the orbital velocities of galaxies in a cluster
B)measuring the temperature of X-ray gas in the intracluster medium
C)measuring the amount of distortion caused by a gravitational lens
D)none of the above

Question

Quizplus · Accepted Answer

Methods A and B rely on Newton's laws of gravity to infer mass based on the motion of galaxies and the temperature of gas, which is influenced by the gravitational potential of the cluster. Method C, gravitational lensing, although it involves gravity, does not depend on Newton's laws but rather on the general theory of relativity by Einstein, which describes how mass warps space-time, causing the bending of light from distant objects.

Which of the Following Methods Used to Determine the Mass