On Thu, Oct 24, 2013 at 01:15:53PM -0600, Robert J. Cordingley wrote: > From the BBC at > http://www.bbc.co.uk/news/science-environment-24637890 (today) > > /Because it takes light so long to travel from the outer edge of the > Universe to us, the galaxy appears as it was 13.1 billion years ago > (its distance from Earth of 30 billion light-years is because the > Universe is expanding)./ > > Robert C
It implicitly assumes a universal "now" at which the galaxy is located 30 billion light years away. Such a "now" is actually not meaningful, according to relativity. Of course the universe was only 13.1 billion light years away when the photons departed it that we're seeing now. -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
