Special relativity

 SAS member John Evans gave a fascinating and authoritative talk on Special Relativity, giving the history and people involved in the development of the ideas. The talk was made even more informative by the examples given involving GPS systems, and how the rate decay of muons passing through the atmosphere would mean that none of them would reach the ground even though they are travelling at 98% of the speed of light unless the muon's clock is time dilated, which explains why huge numbers of them do reach the ground. Other example of space contraction in the direction of movement means that the 27km long appears to be only 4m long to a proton that has been accelerated almost to the speed of light. A well received and appreciated talk. Members will look forward to a future talk on General Relativity.