NATS 1585 Lecture Notes - Lecture 4: Gravitational Lens, Energy Economics, Nuclear Power
5 Mar 2016
School
Department
Course
Professor
Document Summary
Special relativity showed that space and time are not absolute. Instead, they are inextricably linked in a four dimension. Travelers going in opposite directions in straight lines will eventually meet. General relativity says this happens because space-time is curved. Gravity can cause space probes moving around earth to meet. Heavier weights cause a greater distortion of the rubber sheet. The universe may have no boundaries and no center but still have finite volume. Rapid changes in the motion of large masses can cause gravitational waves. Einstein preserved the idea that all motion is relative by pointing out that the effects of acceleration are exactly equivalent to those of gravity. Someone who feels a force may be hovering in a gravitational field. Someone who feels weightless may be in free-fall. Black holes can exist" universe may be finite. Effects of gravity are exactly equivalent to the effects of acceleration einstein"s equivalence principle.
