Let's have a little story: Three characters are standing on a street corner somewhere in Brooklyn. The tall blonde woman with glasses is a quantum physicist named Mary. Beside her stands a short fellow named Steve who's a social philosopher. And facing them on the other side of his pushcart is a fruit peddler named Mel Brooks with a pushcart piled high with fruit. (My apologies, Mel. I love you.) Mary the Quantum Physicist stands straight and says that at the level of quantum phenomena all reality is merely an arrangement of probabilities. Steve the Social Philosopher sneers and waves a hand and says that since all of science is always an enterprise in a social context, all its conclusions are locally biased. Mel the Fruit Peddler watches them and rubs his jaw. He finally lifts a nectarine from his pushcart and he holds it out to them and says: "Hey, guys, why doesn't someone buy a nectarine? Half a plum, half a peach, it's a hell of a fruit."
There's nothing new here. It's merely a representation of a sophomoric conundrum: There are often several ways to look at the real world, and it's common that more than one way can be both interesting and useful.
Quantum physics is a way of looking at the real world, a view generated by the idea that at very small scales, time, space, and energy are discontinuous. It would be nothing but an entertaining philosophical idea except that when you formulate the idea quantitatively you can use the equations to predict nearly everything that happens on Earth and in the entire Cosmos to a fabulous degree of accuracy.
Which means quantum physics ought to be taken seriously by anyone interested in the real world and how to deal with it. Which in turn underscores the irony that not only does the average Joe or Jane know hardly anything about quantum physics, but the movers and shakers of this crazy planet, the people in politics and finance and industry who ought to at least be curious about the real world for the most part don't give a damn.
History, or course, has its own form of justice. A thousand years from now neither Barack Obama, Mitt Romney, Lady Gaga, Mark Zuckerberg, Bill Gates, or Warren Buffett will be known to anyone. Dust to dust, as the saying goes. If in a thousand years anyone will need to make a list of noteworthy people who have lived in the past hundred years, let's say 1912 to 2012, the list will be short -- almost a joke. Here's my list: Max Planck, Albert Einstein, Erwin Schroedinger, Werner Heisenberg, Paul Dirac, and Richard Feynman. All physicists, all participants in the wondrous human mental migration from counting pebbles to quantum mechanics.
No one else. No politicians, no football jocks, financiers, movie stars, software barnstormers, or druggie blondes with press agents. All dead and gone, reduced to disparate and disconnected atoms behaving according to the laws of what? -- quantum physics.
Everyone who cares about physics has a favorite anecdote about quantum physics. My own favorite is about someone not included in the Magic Six listed above. It's about a Nazi storm-trooper who happened to be a quantum physicist -- not just any quantum physicist but a quantum physicist and mathematician who contributed a heavy dose of his own magic to our understanding of quantum phenomena.
For the past 80 or so years the tendency in professional physics has been to mention Pascual Jordan as little as possible because of his political involvements. I think it's a mistake. I think it's important for people to understand that it's possible for someone who is borderline crazy - -- or even someone on the other side of the sanity border -- to have magical talents and ground-breaking ideas. Yes, Jordan was a despicable Nazi committed to the Nazis and the corrupted Nazi ideology, but there's no need for physicists to be ashamed of his existence. Pascual Jordan is simply a prime example of the complexity of the human brain -- an information network whose parts can produce both brilliant mathematics and serial killers inside the same head.
In the publishing world there's a tendency to groan at the appearance of one more book attempting to explain quantum physics to people who are not physicists. In truth, there are never too many such books, since the awful ignorance of the masses about quantum physics needs to be addressed.
So here's a new book: The Quantum Universe: (And Why Anything That Can Happen, Does). Brian Cox and Jeff Forshaw. Da Capo Press, 2012.
It's a book by two British physicists who talk to you from inside the world of the physicist, a careful and reader savvy exposition that pulls no punches. As the authors say in the final words, "Quantum mechanics, no matter how strange it might seem, is a theory that describes the real world."
Indeed, it does.
If you're interested in the real world and want a worthy introduction to the major achievement of humanity in the past hundred years, get hold of this book, read it slowly, digest it, make it part of your life and your life will change for the better. Never, never can you know too much about where you are.