Quantum

A Note to the Reader

Johann Wolff’s vision of tiny, one-dimensional loops — filaments whose vibrations and oscillations define both matter and energy — is not the product of my imagination. String theory is a very real scientific frontier, one being explored by a handful of physicists in search of a better way to describe how the universe works. I am not ashamed to admit to possessing only a layman’s understanding of string theory. Fewer than a thousand scientists have waded into the depths of this young theory to explore its mysteries, and what they’ve found so far is both frighteningly complex and extraordinarily beautiful.

To understand string theory, you need a little background. Isaac Newton observed apples falling and planets orbiting and set out to write a mathematical description of these actions. He didn’t have a clue how gravity worked, but he realized that it always worked the same way. The rules of gravity were too much for the math of Newton’s day, so he developed new techniques and laid the foundations for modern calculus.

Newton’s description worked just fine until the 1800s, when scientists working with electricity and magnetism, both of which move very fast, discovered some problems. This troubling situation festered until the early 1900s, when Albert Einstein wrote a better theory of how gravity worked. In Einstein’s description, time could go fast or slow, the curved space of the universe was expanding, and energy and matter were intimately connected (E=mc²).

Einstein’s description (general relativity) works very well for studying the big stuff: stars, galaxies, black holes, and the entire universe itself. Where it’s not so useful is where things get really small, deep inside the atom.

Split an atom and you’ll find it’s made of protons, neutrons, and electrons. Smashing these particles yields a collection of quarks, muons, and neutrinos. The rules for how these particles interact, forming what we experience as matter and energy, were painstakingly revealed by many physicists during the twentieth century. Collectively, these rules are known as quantum mechanics.

Nearly all of the predictions made by general relativity and quantum mechanics have been proven with startling accuracy. The breakneck pace of technological advances during the past fifty years is, in part, a testament to the value of these two theories. There’s just one problem: as they are currently written, general relativity and quantum mechanics don’t mesh.

In Hollywood, when movie moguls find a problem with the script, they call for a rewrite. The same is true in physics. String theory is a rewrite that seamlessly incorporates the rules of the big stuff and the small in a way that changes our understanding of how the universe works. And like the two systems it hopes to replace, string theory reveals some unexpected surprises.

One facet of string theory that seems really out there is the idea that we live in an eleven-dimensional universe. We are accustomed to four dimensions: height, width, depth, and time. The rest of these dimensions are bundled in tightly with the strings, invisible to us yet the very cornerstone of everything. It is in these coiled dimensions that we may finally learn how the universe really works.

Like Newton, the physicists pursuing string theory are pushing mathematics in new directions. Solving problems with three or four variables is tough enough for most of us — eleven variables is downright frightening. Exploring the unknown has never been easy.

In the next few decades, I am certain that several Nobel Prizes in physics and mathematics will be awarded for work tied to string theory. And once we develop a better understanding of how the universe works, the engineers will come in and begin applying this knowledge in new and innovative ways. For better or worse, discovery and exploitation go hand in hand — and that’s what Quantum is really all about.

Tom Grace