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By Michael Hanlon
Do we live in a Universe that is old, or young? Leaving aside the possibility that we do in fact live in a Multiverse –a vast assemblage of Universes and concentrating only on the galaxies that we can observe – this seems a daft question. The Universe (or our bit of the Multiverse anyway) is estimated to be 13.7 billion years old. That is the time it would take to rewind the expansion of the galaxies back to where they were all in the same place – the Big Bang. And 13.7bn years is rather a long time.
It is three times the age of the Earth, for instance. Probably twice as old as our galaxy – both objects of great antiquity. And yet many cosmologists have wondered if we are in fact living in the mere birth pangs of the Cosmos, what University of Michigan Cosmologist Fred Adams calls the ‘Stelliferous Era’, a time when space is still rich in abundant supplies of hydrogen, when great stars can be born and die. .....
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