PHYS 183 Lecture Notes - Baryon, Gravitational Lens, Bullet Cluster
Document Summary
Phys 183 the milky way inside and out tracy webb. General relativity: space is curved by the presence of mass. You can therefore see multiple images of what is really a single galaxy. Existence of dark matter we know it exists on large scales. We think we understand gravity well, so we choose option 1, which is occam"s razor. The bullet cluster is 2 different clusters merging together. We still do not know what dark matter is. Baryonic matter is a fancy word for regular matter, it is normal stuff that makes everything up. We thought that dark matter was baryonic matter, just very faint. But we found that it cannot be normal matter, because the normal matter would still have to give gravitational lensing. Micro lensing events: a way to detect dark objects in our galaxy. Weakly interacting massive particles (wimps) is the current best guess for what dark matter is (non-baryonic matter)
