What is the cosmic background radiation?
A. Photons that have always existed, even before the start of the big bang.
B. Photons from the very start of the big bang.
C. Photons from about 400,000 years after the start of the big bang.
D. Photons from the end of gravitational deceleration (start of dark energy acceleration).
Answer:C
What is the cosmic background radiation?
A. Photons that have always existed, even before the start of the big bang. B. Photons from the very start of the big bang. C. Photons from about 400,000 years after the start of the big bang. D. Photons from the end of gravitational deceleration (start of dark energy acceleration).