In this much acclaimed book, first published in 2011, Adam Frank charts the changing perception of time and shows how man’s experience of time in social and cultural life shapes his understanding of the cosmos. Much discussion centres around the nature of the Big Bang and the supposed beginning of time, with astrophysicists arguing about numerous hidden dimensions and huge quantities of invisible ‘black matter’ needed to satisfy their complex mathematical speculations. The Big Bang, itself so long part of popular scientific understanding, is now called into question. And perhaps most surprising of all for the lay reader is to discover that physicists still ague about the nature of time, to the extent that some even doubt its existence.

Since their discovery, Newton’s laws, treating time as a fourth dimension, have been applied with so much success that they guided the Apollo missions to the moon. Einstein had already shown that time varies with the speed of the observer, slowing to zero at the speed of light, but the effect was negligible at the relatively modest speed of a Saturn rocket. The same cannot be said of astronomical bodies, galaxies and stars, which move much faster and at speeds at which the effect on time cannot be ignored. There is no doubt that the universe is expanding, and at an increasing rate, the question still unanswered is how did it all begin? Is time tied to the physical dimensions of the universe, starting at the same instant in the Big Bang, or does it have an independent existence? Was there a before our present universe and will there be an after?

Some physicists reasoned that the Big Bang was just one of a series of repeating universes. Teachers used to tell their students that only one physical law was certain: the second law of thermodynamics. This law, simply stated as entropy tends to increase, implies that order will degenerate into disorder and temperature differences will disappear leaving everything at a uniform low temperature. When applied to the possibility of repeated cycles of expanding universes the second law has the effect of increasing the duration of each successive cycle. Going back, the cycle length reduces to zero, so as Frank says, ‘entropy forces a beginning for even a cyclic universe.’

In spite of much thought, manipulation of equations and introduction of hidden dimensions, physicists have not been able to find a full explanation for a beginning of the universe. Some theories suggest multiple universes coexisting, each with different physical laws, our universe happening to have just the right conditions to support life. That our universe exists is certain, and that is the conclusion of Frank’s argument: ‘Always and again we have been the co-creators of a time and a cosmos that exist together with us.’ For Frank, it is the process of discovery that matters not its imagined end and that is likely to continue for a long time.



Source by John Powell

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