Zero - Charles Seife [81]
Astronomers have begun to measure the change in the universe’s expansion. A certain type of supernova (exploding star), called a type Ia, is a standard candle like Hubble’s Cepheid stars. The Ia supernovas explode in roughly the same way and with the same brightness. But unlike Hubble’s dim Cepheids, supernovas are visible halfway across the universe.
In late 1997 astronomers announced that they had used these supernovas to measure the distance to some very dim and ancient galaxies. The distance of the galaxy yields its age—and its Doppler shift yields its velocity. By comparing how fast galaxies were receding at different eras in the past, the astronomers were able to track how fast space-time was expanding. The answer they got was an odd one.
The expansion of the universe isn’t slowing down. It might even be speeding up. The supernova data imply that the universe is getting bigger and bigger, faster and faster. If this is the case, there is little chance of a big crunch, because something is opposing the force of gravity. Once again physicists are talking about the cosmological constant—the mysterious term that Einstein added to his equations to balance the push of gravity. Einstein’s biggest blunder might not have been a blunder after all.
The mysterious force, once again, might be the force of the vacuum. The tiny particles that seethe through space-time exert a gentle outward push, stretching the fabric of space-time imperceptibly. Over billions of years, that stretch adds up, and the universe inflates faster and faster. The fate of our universe will not be a big crunch but an eternal expansion, cooling, and heat death, thanks to the zero-point energy, a zero in the equations of quantum mechanics that imbues the vacuum with an infinity of particles.
Astronomers are still cautious. These supernova results are preliminary, but they are getting more solid with each observation. Other studies, which analyze plumes of gas or the number of gravitational lenses in a given field of view, also support the supernova results, implying that the cosmos will expand forever. The universe will die a cold death, not a hot one.
The answer is ice, not fire, thanks to the power of zero.
To Infinity and Beyond
However, if we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason—for we would know the mind of God.
—STEPHEN HAWKING
Zero is behind all of the big puzzles in physics. The infinite density of the black hole is a division by zero. The big bang creation from the void is a division by zero. The infinite energy of the vacuum is a division by zero. Yet dividing by zero destroys the fabric of mathematics and the framework of logic—and threatens to undermine the very basis of science.
In Pythagoras’s day, before the age of zero, pure logic reigned supreme. The universe was predictable and orderly. It was built upon rational numbers and implied the existence of God. Zeno’s troubling paradox was explained away by banishing infinity and zero from the realm of numbers.
With the scientific revolution, the purely logical world gave way to an empirical one, based upon observation rather than philosophy. For Newton to explain the laws of the universe, he had to ignore the illogic within his calculus—an illogic caused by a division by zero.
Just as mathematicians and physicists managed to overcome the divison-by-zero problem in the calculus and set it once more upon a logical framework, zero returned in the equations of quantum mechanics and general relativity and, once again, tainted science with the infinite. At the zeros