Introduction

Abstract

When looking at events with a geological perspective a “moment” might be a very long period of time. The events discussed here range in absolute time from seconds or days to as long as tens of millions of years. The geologic record is very sparse for extremely old events on Earth, and virtually non-existent for times before the solar system formed. The earliest events, such as the Big Bang origin of the Universe, production of heavy elements in stars, and the formation of the Sun and Solar System can only be understood by general principles of physics, with observation of the current state and activity on astrophysical scales. This early (astro)physical viewpoint shifts to considerations of chemistry and biochemistry even before we arrive at the point where there is a geological record preserved in rocks. Past that point we can describe several important transition points where life turned a corner, and subsequent history of the planet and life entered a new phase. There were bursts of biological innovation and maybe extinction events before we arrived at our current state. What the future holds may well depend on how we apply what we have been able to learn about the past, and how life has responded to changed conditions.