Quanta, Strings, and James Bond.

I’ll put the disclaimer up front. I’m not a physicist, and I don’t pretend to understand these theories in anything but the smallest, atomic degree; however, that doesn’t mean I’m not fascinated by them.

I was reading a popular magazine the other day, and it said that the newest James Bond movie that would be coming out sometime in the Fall of 2008 is called Quantum of Solace. What a bizarre name, I thought. I’m not the only one because in the article I was reading, the author was complaining about how obtuse the name was. It’s somewhat weird, but I think it’s elegant. It got me thinking about the word “quantum.”

“Quantum” can be a noun or an adjective. It’s an interesting word because it can mean diametrically opposite things. A quantum leap is a massive step, as in—understanding the structure of DNA was a quantum leap in the field of molecular genetics as it helped explain the science of heredity. On the other hand, quantum can also mean extremely miniscule, as in—the size of a quantum of energy can be measured in a billionth of a billionth of a billionth of a unit—in other words, it’s unbelievably tiny.

The field of quantum mechanics is the physics of atomic particles. In other words, it’s the study of the motion of atoms and the particles that make up atoms.

Isaac Newton is one of history's greatest scientists, and he studied many fields including motion, optics, astronomy, theology, and mathematics. He's credited with inventing calculus in order to solve his physics and astronomy questions. The story of popular legend is that Newton first recognized "gravity" when he was sitting under and apple tree, and an apple fell on his head. He's one of the fathers of physics, as his theories described both the motion of everyday objects and stars in mathematical terms.

Now Newton's equations were amazingly accurate, and were enough for modern day scientists and engineers to navigate Earth astronauts to the moon. However, in the 20th century Albert Einstein described that Newton's laws did not fully explain the character and motion of light and space-time. Einstein described space-time as malleable and light existing as particles or quanta of energy. His theory of special relativity posits that space-time is flexible, and that our perception of it can change with the speed we're traveling (the old story of the astronaut who travels for a year at the speed of light and when he returns to Earth, even though he's aged a year, the Earth has aged hundred of years--or something like that).

But even Newton and Einstein didn't explain the whole of physics--the motion of everything in the universe. Why? Well, if you use the equations of Newton and Einstein, they explain very well the motion of everyday objects (cars, apples, birds) and celestial objects (planets, stars, comets), but they cannot explain the motion of atoms and the particles that make up atoms. The laws of physics simply break down when it comes to the very small, or the quantum world.

The quantum world is an extremely bizarre one. It's a world of probability that doesn't seem to make any sense from our view of things. When explaining the motion of a particle (such as an atom or an electron or a quark or muon--there are many of these things, and I don't even pretend to know them all), you can't predict exactly where these things will be in a given moment. It's not like--2 quarks leave the train station going at the speed of light, and how long does it take to reach Pluto, to paraphrase a common physics word problem. You can't say with any surety where the particle is going to be at any one time. All you can do it PREDICT where it will be. And here's the bizarre part--it can be in 2 places at once.

I'm not making this up. The physical laws of our visible world are twisted in the quantum world (and I should point out that we're made up of the quantum world--all the molecules in our body are made up of atoms which are made up of electrons, protons, neutrons, quarks, muons, .......).

Newton's and Einstein's equations just fall apart when trying to describe the motion of these small particles. The field of quantum mechanics was developed to explain the motion of the very tiny. However, the math behind quantum mechanics doesn't do diddly to explain the motion of everyday objects or stars. We don't exist in 2 places at once. I'm sitting in front of my computer now, and no equation is going to predict the probability of me existing both here and in my kitchen at the same time.

So, there is a paradox. If the universe is ordered, how can we there be 2 fields of physics to describe the very small and the very big? There should be some universal theory to explain the motion of everything that would take into account both the big and the small.

Well, there's not an answer, but there is, of course, a theory. (There's always a theory).

A very sexy theory taking physics by storm now is called "string theory." For more on this you can read Brian Greene's great, but somewhat technical book called The Elegant Universe. PBS also made a documentary of it, which is out on DVD, and it's great!

I don't understand the math. But the explanation is that if we describe all the atoms, electrons, neutrons, protons, quarks, muons, etc. as existing not as discrete particles but as strings of energy, then both the motion of big and small can be explained. Think of the strings as violin strings. The identity of the string (be it a electron or proton, etc) is determined by the frequency of how that string vibrates. On a violin, the different strings sound different because they are of different thickness, and so when they are plucked they vibrate on a different frequency. The result is a different sound. Similar to the strings that make up subatomic particles. Their identity is determined by the frequency at which they vibrate.

It's complicated, and I don't understand much more than that, but I still think it's fascinating. There's one problem with the theory in my scientists eye. It's just a theory, and it hasn't been tested. The theory does make predictions that can be tested by experimentation, but the field doesn't have the technology to do those experiments yet. Maybe in the near future, but not now. At the moment, there are lots of physicists doing some extremely complicated math to explain this theory, which is elegant in its simplicity. But until someone can do some experimentation to define it, it's just a theory.