Dark Matter – what evidence is there for its existence?
Over 90% of the mass of our universe is in the form of unseen Dark Matter. Determining its nature would solve of the biggest problems in modern cosmology. This workshop will introduce the students to the experimental evidence for its existence. Using real astronomical images students measure the rotational speed of galaxies and hence calculate the mass acting at their centre. They then estimate the mass of the visible stars and calculate the percentage of matter that is visible. Students also estimate the mass of invisible material in clusters of galaxies from arcs of light caused by gravitational lensing of the light from high redshift objects beyond the cluster. The workshop will then consider what form the Dark Matter might take and will draw parallels with the evidence for and acceptance of other theories such as gravitational attraction, the particulate theory of matter, quantum mechanics and relativity.
