For half a century the Big Bang theory has dominated attempts to explain the origin of the Universe. It is now being discredited by 16 billion year old stars. John Maddox explains the new crisis in cosmologyby John Maddox / February 20, 1996 / Leave a comment
Cosmology seems to have staggered from one crisis to another since Galileo was accused of heresy in 1633. Three decades ago, cosmology was recovering from the great dispute between two Cambridge astronomers, Sir Fred Hoyle and Sir Martin Ryle, on the issue of whether the Universe had a beginning. Then, just a few weeks ago, Professor Stephen Hawking was telling a packed audience at London’s Albert Hall that the ultimate fate of the Universe cannot be foretold. What is cosmology telling us?
The latest crisis has blown up because of the doubt cast on the idea that the Universe, which means Everything, began between 10 and 20 billion years ago. “In the beginning there was the void,” remember? Then suddenly everything appeared in a flash-a huge hot flash whose energy brought with it all the matter now in the world and the momentum that keeps the whole contraption expanding.
This neat echo of Genesis has been the standard view of how our world began. It is known to cosmologists and the world at large as the Big Bang. The theory has been in the public domain since 1946, when George Gamow, a Russian ?migr? to the US, put it forward as an explanation of how the Universe seems to be expanding. Later, with his colleague Herman Alpher, Gamow argued that at all stages in its history the Universe must have had a particular temperature. At the outset, the temperature would have been indistinguishable from infinity-whatever that may mean. Now, despite the temperature at the surface of stars such as the Sun (6,000 degrees) or at their interior (say 15 million degrees), the temperature of the Universe as a whole has fallen to below that of the boiling point of liquid helium, the coldest fixed point of temperature known.
Without Gamow’s Big Bang there would have been no explanation for what remains the most striking feature of the Universe-its apparently continuing expansion. So much had been established by Edwin T. Hubble, the US astronomer, as long ago as 1929. He had trained the then brand new 100-inch Hale telescope in California on some hundreds of the galaxies of stars lying outside the Milky Way, and had found that the light from the fainter (and so presumably more distant) galaxies was redder than it should have been. The classical interpretation is that the reddening of the light arises in much the…