6.2.3 — The Universe

Core

6.2.3.1 — Know that the Milky Way is one of many billions of galaxies; diameter ~100,000 light-years
6.2.3.2 — Describe redshift as an increase in observed wavelength from receding stars and galaxies
6.2.3.3 — Know that light from distant galaxies is redshifted compared to light emitted on Earth
6.2.3.4 — Know that redshift is evidence that the Universe is expanding and supports the Big Bang Theory

6.2.3.5 — Know that microwave radiation of a specific frequency is observed everywhere and is called cosmic microwave background radiation (CMBR)
6.2.3.6 — Explain that CMBR was produced shortly after the Big Bang and was stretched into microwaves as the Universe expanded
6.2.3.7 — Know that speed of a galaxy moving away can be found from redshift data
6.2.3.8 — Know that distance to a far galaxy can be determined using brightness of a supernova
6.2.3.9 — Define the Hubble constant H₀ = v / d and recall/use the equation
6.2.3.10 — Know that the current estimate for H₀ is 2.2 × 10⁻¹⁸ s⁻¹
6.2.3.11 — Know that the equation v/d = 1/H₀ provides an estimate for the age of the Universe and supports that all matter originated at a single point