The Curious World of Quantum Mechanics
History - World Released - Oct 04, 2015
It’s difficult to fathom, but all the matter in the universe once existed as little more than a single object no larger than the point of a pin. Welcome to Quantum Mechanics, the subatomic Alice-in-Wonderland world where, as Alice would say, it gets curiouser and curiouser. But what does Quantum Mechanics have to do with our everyday lives? Quite a bit, actually. The laws of Quantum Mechanics underlie all of the information and communication technologies that have remade our modern world: the computer, the Internet, satellites, cell phones, and all electronics. As important as its practical applications is what Quantum Mechanics is telling us about nature, the universe, and about science.
Today the outer limits of man’s knowledge are defined by Relativity, and the inner limits by Quantum Mechanics. Relativity has shaped our concepts of space, time, gravitation, and all the realities that are too remote and too vast to be perceived. Quantum Mechanics has shaped our concepts of the atom—the basic unit of matter and energy—and the realities that are too elusive, too weird, and too small to be perceived. Believing in the harmony and uniformity of nature, Albert Einstein spent the latter half of his life trying to construct a bridge between the outer and inner worlds, called the Unified Field Theory. What he wanted to show was the link between the gravitational forces of outer space with the electromagnetic forces of inner space, that they are not independent of one another and are, in fact, inseparable. For the most part he failed, but that doesn’t mean he wasn’t right. Many physicists believe the day will come when Einstein’s last great theory will be proved correct. Should that day come (according to the author of THE UNIVERSE AND DR. EINSTEIN, Lincoln Barnett) “all man’s perceptions of the world and all his abstract intuitions of reality will merge into one, and the deep underlying reality of the universe will be laid bare.”
In the meantime, we have the Hubbell Telescope looking deep into outer space and therefore backward in time, as far back as 300 million years after the so-called Big Bang. And we have particle accelerators delving into inner space and unlocking the vast mysteries of the subatomic world. Under closer inspection, both of these worlds—the outer and the inner—are far more bizarre than anyone had imagined.
THE INVISIBLE REALM
In the invisible realm of the Quantum, the classic Newtonian laws of physics do not apply. The world of the Quantum is governed by a completely different set of laws. The last word on Quantum Mechanics was that of a German physicist named Werner Heisenberg, in 1927. While Newton’s world was one of certainties, Heisenberg’s world was one of only probabilities. Forget the classic picture of particles having trajectories or orbits through space. Quantum Mechanics says that objects don’t have precise properties such as position and velocity, and what’s more, if you try to measure them, the more precisely you measure one, the less precisely you can measure the other. In fact, the mere act of observation alters these particles.
As Quantum Mechanics became better understood, it became clear that in the Quantum world there are no certainties, only probabilities—there is no “Yes, this will happen,” only “Any of these things may happen.” “Determinism” lies at the heart of Newtonian science: the idea that one event causes the next, and so on, and that it all can be predicted using mathematics. But Quantum Mechanics tells us that at its heart—on the fundamental level of the atoms and particles of which everything is made—the world is not deterministic, that the present state of the universe doesn’t determine the future (or past) events, but only the probabilities that one of many alternative futures will occur (or pasts have occurred). It was as a reaction to these ideas that Einstein took issue, and made his famous pronouncement that God does not play dice with the universe.
Another of the ideas of which Einstein took exception was the Big Bang Theory. He believed the universe, like God, is eternal, without beginning or end. Yet the evidence of an ever-expanding universe suggests a beginning. Prior to the Big Bang, the universe was an infinitely small, infinitely hot point, called a singularity. From this sprung our universe: 100-billion galaxies, each with a hundred-billion stars. How could so much matter and energy emerge from so small an object? The answer lies with the bizarre world of Quantum Mechanics, which says a subatomic particle can pop in and out of existence.
THE ULTIMATE FREE LUNCH
“It is said that there’s no such thing as a free lunch,” says Alan Guth, a Massachusetts Institute of Technology physicists. “But the universe is the ultimate free lunch.” Guth is author of the “inflationary theory,” which says a particle can pop into existence, expand faster than the speed of light, and create a universe. Indeed, to understand modern physics, you have to put your brain through a U-turn. When you make the turn you come face-to-face with one of the great discoveries of the last 100 years: there is no such thing as nothing. That concept comes from—where else?—the weird science of Quantum Mechanics, which was a crazy idea at first and still seems so to most people. Crazy or not, our limited understanding of it has given us transistors, television, computers, and other wonders of the electronic revolution, as already stated.
Quantum Mechanics says the smallest particles exist or don’t exist by chance. Yet Quantum Mechanics was invented by necessity to account for how atoms did not behave exactly as they were supposed to. Something had to be affecting them. The solution was quantum fluctuation, wherein a particle can pop into existence, bump into an atom or alter some of its properties, and then disappear. It’s now assumed that on Earth as well as so-called empty space, particles are always appearing and quickly vanishing. Physicists at Fermilab in Illinois do that all the time with a giant atom smasher. Colliding particles together at enormously high speeds causes virtual particles—some of gigantic size—to appear in the real world for a brief instant then disappear into the vacuum from whence they came. “When we say the universe came from nothing, what we mean is that nothing—we call it the vacuum, something that has no particles, no net energy—might have some properties that cause things to be created from time to time,” says theoretical astrophysicist Angela Olinto of the University of Chicago. “In quantum mechanics you have particles come out of nowhere. They come out of a vacuum and go back into a vacuum. They exist for a brief moment and then they disappear.”
Such theories may explain how all of the matter and energy of the universe could spring from something as small as a pinpoint, expand rapidly and some 14 billion years later result in the material universe we experience. At the same time, with Einstein, we can question whether or not the universe we experience with our senses is in fact the universe that actually exists. Is there another as yet imperceptible universe from which these particles spring?
“What Quantum physics did was uncover a truth that is ultimately both empowering and profoundly humbling,” says Leonard Mlodinow, in his book THE UPRIGHT THINKERS. “Empowering because Quantum theory demonstrates that we can understand and manipulate an unseen world beyond our experience. And humbling because for millennia, the progress made by scientists and philosophers suggested that our capacity for understanding was infinite, but now nature, speaking through the great discoveries of the Quantum physics, is telling us that there are limits to what we can know, and to what we can control. What’s more, the quantum reminds us that other unseen worlds may exist, that the universe is a place of extraordinary mystery, and that fluttering just beyond the horizon may be further inexplicable phenomena demanding new revolutions in thought and theory.”
Sources: “The Upright Thinkers” by Leonard Mlodinow, Pantheon Books, 2015; “The Universe and Dr. Einstein,” by Lincoln Barnett, Harper & Row, 1948; and “A Cosmic Puzzle,” by Ronald Kotulak, Chicago Tribune, Aug 3, 2003.
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