What is the primary practical difficulty that limits the use of Hubble's law for measuring distances?
A)Redshifts of galaxies are difficult to measure.
B)The recession velocities of distant galaxies are so great that they are hard to measure.
C)We do not know Hubble's constant very accurately yet.
D)Hubble's law is only useful theoretically;it is difficult to use in practice.
E)The motion of Earth relative to the Milky Way is difficult to account for.

Question

Quizplus · Accepted Answer

Hubble's law, which relates the distance of a galaxy to its redshift, is a fundamental tool for measuring cosmic distances. However, its practical application is limited by our imprecise knowledge of Hubble's constant. The value of Hubble's constant is crucial for calculating distances accurately, but despite significant improvements in measurements, there remains a degree of uncertainty in its exact value. This uncertainty directly affects the precision of distance measurements to galaxies and the scale of the universe.

What Is the Primary Practical Difficulty That Limits the Use