Is einstein about to be dethro
Is einstein about to be dethroA whiff of heresy is in the air. There are very few beliefs in science that have the force of doctrine, but among them is the conviction that the speed of light is fixed. It forms the rock upon which Einstein built one of the 20th century's most enduring monuments, the General Theory of Relativity.
But in science nothing is sacred, and several leading theoretical physicists are now toying with the delicious notion that the speed of light may not be constant after all - but may actually have varied during the 15 billion years the Universe has existed.
To some, it remains anathema. "It took us a year to get the first paper published in Physical Review," says Dr Jo�o Magueijo, a young Portuguese physicist, now a lecturer at Imperial College in London. "The scientists who were asked to comment just couldn't accept it. Finally the editor stepped in and it appeared."
At the age of 11, Dr Magueijo was inspired by The Evolution of Physics, a slim volume by Einstein and Leopold Infeld. A dog-eared copy, in Portuguese, lies on his desk at Imperial College.
"The best book ever written about physics," as he calls it, set him on a course that took him to the University of Lisbon, then Cambridge as a research fellow at St John's, and now London. But if he is right, Einstein's conviction that light travels at a fixed and unalterable speed is about to be dethroned.
Dr Magueijo and colleagues with whom he has worked - Dr Andy Albrecht, of the University of California at Davis, and Professor John Barrow, of Cambridge - were not quite the first to have this idea. Dr John Moffat of the University of Toronto had floated it, but they were unaware of his work until he complained it hadn't been properly acknowledged in the Physical Review.
Of course, nobody would make such a radical suggestion unless there were something amiss with existing cosmological theories. The Big Bang and its offspring, inflation, are extremely well-established. They can explain a lot of what we see when we look into the great beyond. They claim that the Universe began from a single point, and has been expanding outward ever since. Simple as this seems, it raises some puzzling dilemmas. If the speed of light is fixed and not infinite, it means that the Universe always has an edge beyond which we cannot see, simply because light has not had time to reach us from that edge. This "horizon" at present lies some 15 billion light years away.
If we run the expansion backwards to a time soon after the Big Bang, we find that some parts of the Universe which we can now see would then have lain beyond the horizon. This is the puzzle. The Universe we can see is homogenous, the same temperature and density everywhere.
Yet things are only...
To view the complete essay, you be registered.