Reference no: EM133296843

1. The cosmological principle says that

a. observers on Earth occupy a special, preferred location unlike other locations in the Universe.

b. the Universe is homogeneous and isotropic when averaged over large scales.

c. when viewed on very large scales, the Universe is heterogeneous and anisotropic.

d. quasars are powered by accretion onto black holes.

Dark matter appears to dominate the mass of the Universe.

2. Which are ways that astronomers have detected dark matter?

a. Gravitational lensing, when light from a distant source is bent by a nearer large mass, points to the existence of dark matter.

b. Dark matter can be seen directly using telescopes above the atmosphere such as the Hubble Space Telescope.

c. The orbits of stars within the Milky Way indicate the presence of dark matter.

d. The way solar activity increases and decreases every eleven years indicates the existence of dark matter.