Dark Energy and Dark Matter

Week 6 Theories 2 There is, as yet, no clear consensus on a theory that explains the existence of dark matter. Describe an alternative theory, in as much detail as you can. Comment on the strength of the evidence for this theory. Remember to quote sources for your information - 3 sources would be a good number.

Week 5 Theories 1 Describe the difference between baryonic and non-baryonic matter. Explain for each type of matter how it could contribute to dark matter. Evaluate the strength of the arguments for whether dark matter is likely to be composed of baryonic or non baryonic matter

Week 4 - the rate of rotation of galaxies. Another major piece of evidence is the fact the inner and outer parts of galaxies appear to rotate at the same rate. This does not make sense, on the basis of calculations of the gravitational force from the stars and dust clouds that are visible in galaxies. Use your understanding of circular motion to show how angular velocity of a star, around the centre of a galaxy, should depend on the distance from the centre of the galaxy. (Assume that the mass of the galaxy acts as if concentrated at the centre). Post your conclusions, together with comments on what distribution of matter would explain observations.