ENVR 1200 Study Guide - Midterm Guide: Continental Drift, Chemical Formula, Homo Sapiens

• School: Northeastern University
• Department: Earth & Environmental Sciences
• Course: ENVR 1200
• Professor: Daniel C.Douglass

Document Summary

Nebula: when stars die and explode, they form a nebula. Everything spreads out, but gravity pulls it back together again. Most material winds up in the middle mass concentration/protostar/protosun. More mass = more gravitational attraction=pull more stuff in=more mass. All stuff that doesn"t have a lot of velocity gets pulled to the middle. Momentum wants to travel in straight line, but gravitational attraction pulls it towards the center so the object goes around in a circle. Intersecting orbits: objects wind up at same place at same time. Collision: elliptical orbits collide with objects with circular orbits. Inner 4: small and rocky, planets are closer together and to the sun. Outer 4: big and gassy, planets are far apart. Collect data through experiments, observations, and models/ simulations. If yes, retest again. conduct more experiments, tweak experiments. Theories are very well tested hypotheses that are probably correct. If something can"t be tested, it"s not science.