The primary evidence for the expanding universe concept is the
A) slow spreading out of stars in the near neighborhood of the Sun.
B) redshift of light from distant galaxies, which increases with distance of the galaxy from Earth.
C) discovery of black holes in binary stars.
D) slow increase in the Earth-Moon separation-about 4 cm per year-with time.

Question

Quizplus · Accepted Answer

The redshift of light from distant galaxies, which increases with the distance of the galaxy from Earth, is the primary evidence for the expanding universe concept. This phenomenon is explained by the Doppler effect, where light from objects moving away from the observer is shifted to longer wavelengths (redshifted), indicating that galaxies are moving away from us and from each other, thus supporting the idea of an expanding universe.

The Primary Evidence for the Expanding Universe Concept Is the