Date: Wednesday 5th June 2002
Title: Can one check on a non-zero Cosmological Constant using our own galaxy? : Cosmogony at red shift zero
Speaker: Professor George Isaak (Birmingham)
In 1998 it was discovered that the expansion of the Universe is accelerating if type Ia supernovae are assumed to be standard candles and there is no unusual extinction in space. This is, if true, a remarkable result as previously one expected a slowing down due to gravity of matter and this claim brought back the cosmological constant, Einstein's biggest mistake (or greatest insight ?). Extraordinary findings require extraordinarily good evidence, preferably from many sources. It seems possible to calibrate stellar ages using an extension of solar seismology to suitable old stars in our vicinity and thereby overcome many problems ( or at least change the systematic errors). The stellar eigenfrequencies measure the mean molecular weight in the stellar core and thereby the helium NOW, and subtracting the primordial helium and dividing by the mean stellar luminosity provides a DIRECT AEON GLASS. A zero cosmological constant demands ages of just under 10 Gyears, whereas the currently favoured value demands an age of just under 14 Gyears.