If the wavelength of the background radiation peaked at 1 $\mu$m at the time of recombination, how old was the universe then compared to its age today?
A) 1/10th as old
B) 1/100th as old
C) 1/1,000th as old
D) 1/10,000th as old
E) 1/100,000 as old

Question

Quizplus · Accepted Answer

The peak wavelength of the cosmic microwave background radiation is inversely proportional to the temperature of the universe. At recombination, the universe was about 1,000 times hotter than it is today, indicating it was 1/1,000th of its current age.

If the Wavelength of the Background Radiation Peaked at 1 μ\muμ

If the Wavelength of the Background Radiation Peaked at 1 $\mu$