AST201H1 Lecture Notes - Lecture 24: Dark Energy, Future Of An Expanding Universe, Big Crunch

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Bryan Gaensler

Document Summary

The more mass in the universe, the slower it expands due to more gravity. The larger a galaxy"s redshit, the more space between it and us has expanded it doesn"t mater when this expansion occurred, so long as the expansion happened, the redshit will not change. If the universe expansion is gradually slowing down, its redshit would appear to be higher-than-it- should-be. In 1998, measurements of the redshits of distant type la supernovae showed hubble"s law incorrect that the universe was actually expanding faster with ime. We call the driver of this acceleraion dark energy nb: this has nothing to do with dark mater. Dark energy makes up about 70% of the contents of the universe as you can convert energy to mass. We know what dark energy does (accelerate the expansion of the universe), but we have litle idea what it is.