ORIGINS 2B03 Lecture : Lecture 26
9 Feb 2012
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Document Summary
Galaxies do not rotate as if all their mass were in the visible stars (left) but instead rotate at almost a constant rate no matter the distance from their centres (right) 90% of the mass in galaxies, clusters, etc. is dark matter. Dm goes beyond the galaxies shown by spiral galaxy rotation curves, and gravitational lensing. Modes of things connected by filaments to other nodes (high density and low density) 90% of the mass in the large scale of the universe is dark matter. Wmap to the network is due to time and gravity. 3 independent lines of evidence that mass in luminous material is a small fraction of the total mass! In other words, mass in stuff we can see is way less than the mass implied by gravity. Without dark matter cbr fluctuations would be different, large scale structure would look different. We can also estimate the amount of dm by looking at large scale structure.
