The cosmic microwave background (CMB) radiation detected by Penzias
and Wilson at Bell Labs in 1965 has the spectrum of a blackbody, with an
observed peak at λ = 1 mm. It is believed that when the light was emitted
the spectrum peaked at a wavelength of λ = 1000 nm (close to the peak of
the spectrum of the Sun). The cosmological redshift is directly connected to
the scale factor that we discussed
So, the CMB gives us a picture of the infant universe, when the universe was
just a fraction of its current size. By what factor was the universe smaller
when the CMB was emitted than it is today?
The emission of the CMB occurred when the universe was 389,000 years
old. Its current age is 13.7 billion years. If we compare the universe to a
person of age 80, from what age (in days) do our ‘baby pictures’ come?
2. Z = (lambda_observed - lambda_emitted)/lambda_emitted
a(t) = 1 + z
3. I just got out of my second exam today and I am fairly retarded at the moment. Can someone get me started?