AST201H1 Chapter Notes - Chapter S3: Event Horizon, Gravitational Redshift, Distant Star

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Michael Reid

Document Summary

The general theory of relativity explains gravity as a consequence of the structure of space and time. If you launch two probes in opposite directions from a space station, they will meet as they orbit earth (even though neither fired their engines). Spacetime: the combination of the 3 dimensions of space and the one dimension of time. Einstein"s general theory posits that matter shapes the fabric" of spacetime in a manner somewhat analogous to the way heavy weights distort a taut trampoline: the greater the mass, the greater the distortion of spacetime. Ideas that follow from the general theory: gravity arises from distortions of spacetime. The presence of mass causes the distortions, and the resulting distortions determine how other objects move through spacetime: time runs slowly in gravitational fields. Thought experiment: a and b are in free-float frames in space; a turns on engines and accelerates at 1g=9. 8m/s2.