Which is not a piece of evidence that most scientists use to prove the origin of our universe? a. Movement of the galaxies
b. cosmic microwave background radiation
c. presence of hydrogen and helium in the correct percentages
d. The contraction of objects in space

The speed of light can be used to measure the

Gabby calls her cousin who lives in a different state and tells her to turn her radio to channel 98.7 so they can listen to their favorite song that is playing. her cousin turns her radio to 98.7, but does not hear the same song gabby hears. which most likely explains why?

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?