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)
Abstract
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.