The Big Bang created the physical universe. Of course life is part of this physical universe, but the immediate building blocks of life are chemicals. Before the Big Bang, words such as “time” had no meaning, but even in the first few minutes there could be no chemistry since there were no atoms. The nuclei of some of the lighter elements formed within minutes, atoms some time later, and elements heavier than lithium were forged in the supernovae of stars. Thus, we are primarily star dust, although the hydrogen atom you drink tonight may be nearly as old as the Big Bang.
But living organisms are more than a collection of atoms. They are a cauldron of molecules in a solvent. For life on earth, that solvent is water. The building blocks of chemical compounds had to form other molecules as well, especially ones based on carbon. Where could these compounds have been formed? Were they formed on earth or transported from elsewhere?
Most stunning are the recent discoveries in astrochemistry showing that the organic compounds that make up life on earth may possibly be THE language of the universe. Stay tuned.
Astrobiology is a new meta-discipline which combines astronomy, biology, chemistry, philosophy, and physics in an effort to study the current state of life in the universe.
In the Stanford Astrobiology Course, lectures follow a, more or less, linear path from the Big Bang all the way to the development of complex life and, finally, space exploration. The course explains how evolutionary principles have operated at the macro, and micro, level ever since the birth of the universe we reside in today.
