The days are gone when observable quantities are known only to within a factor of ten or so. Ask the same questions today that cosmologists of yore had struggled to answer, and any cosmologist can rattle off the answers as quickly and confidently as a schoolchild who has mastered his multiplication tables.
How quickly are galaxies receding from each other? 70.4 kilometres per second per megaparsec, plus or minus 1.8 per cent.
How old is our observable universe? 13.75 billion years, plus or minus 0.8 per cent.
How much matter and energy fills the universe? If one includes the weird and unwelcome dark energy in the tally, the total weighs in at precisely the razor-edge critical value, give or take 0.7 per cent, meaning that the universe should continue expanding for ever.
How quickly are galaxies receding from each other? 70.4 kilometres per second per megaparsec, plus or minus 1.8 per cent.
How old is our observable universe? 13.75 billion years, plus or minus 0.8 per cent.
How much matter and energy fills the universe? If one includes the weird and unwelcome dark energy in the tally, the total weighs in at precisely the razor-edge critical value, give or take 0.7 per cent, meaning that the universe should continue expanding for ever.
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