Unit conversions and collected numbers in cosmology
  This note collects together useful unit conversions and numerical values from
early universe cosmology. It is a quick reference that can be used to make easy
order-of-magnitude estimates. Included are tables for unit conversions, the
thermal history of the universe, and collected properties of astronomical
objects. The note also introduces a modifiable Mathematica package NaturalUnits
(newest version 2.0), which makes it easy to convert between natural and
physical units.
