This week we discuss the geologic time scale, meteorites, and fitness trackers!
Pittsburgh Fireball Feb. 17, 2015
Geologic Time-it’s really big (and deep)
How do we begin to define Geologic time?
- International Commission on Stratigraphy: “ International Geologic Time Scale; thus setting global standards for the fundamental scale for expressing the history of the Earth”
- We have to have a baseline so that we can all talk about the “same” rocks across the world
- Many techniques, and the actual dates between our epochs change all the time as our age-dating techniques evolve
- Many periods/eras/epochs are marked by “catastrophic” occurrences, hence making them natural boundaries, but the dates change.
- 5 major extinction events
Time as an arrow v. time as a cycle
- Catastrophism vs. uniformitarianism and gradualism
- Constantly evolving and vastly interesting
- Thinking about the definitions of time and how we as humans try to grasp the enormity of geologic time in particular is humbling.
Fun Paper Friday