Select all of the answers that apply. Which statements are true regarding the scientific evidence supporting the big bang theory?
1)Researchers found cosmic microwave background radiation, which is a heat imprint left over from the big bang.
2)Quasars have been observed exploding and expanding from a single, hot, dense singularity.
3)A primordial form of helium gas was found by the Endeavor space shuttle.
4)A redshift of light emitted by stars and galaxies indicates the universe is expanding.
5)Redshift and blueshift of light emitted by stars and galaxies indicate that universe is expanding and contracting.