We will briefly consider the nature of quantum physics. As he has done so many times in our experience, Professor Feynman encapsulates the spirit of quantum
physics in a simple statement: Things behave on a small level much differently than they do on a large level.
Further, Feynman points out that our experience readies us not at all for observing things on a small
level. After all, most of our human experience occurs in the visible, or as a physicist would put it, in the large world.
As you read the final chapter in "Six Easy Pieces," you will find that the last piece is not
easy at all. In fact it is immensely complex. Although delivered almost 40 years ago, Feynman's lectures on quantum physics—then a very young science—are quite mathematical and dense. Although the mathematics are
impressive and of course important, our concern is with the nature of quantum physics.
In quantum physics, early in the last century, some very observant scientists began to observe that the world at a "small"
(subatomic) level is just as complex as it is at a "large" (universal) level. This observation caused them to develop an entirely new theory of physical science, and to design extraordinarily complex means of
discovering this new "small" world.
As Feynman observes, we still know little about quantum physics. Much of what we do "know" is at best theoretical (p. 117). Even its later adaptations, including so-called "Chaos"
science, are still largely theoretical in nature.
"Chaos" science, or nonlinear dynamics, is the branch of physics devoted to exploring "chaotic" or unpredictable behavior in systems. Its central notion is that
within ordered systems there is always evidence of "chaos" or unpredictable differentiation. Likewise, within apparently "chaotic" systems, there is an underlying order.
In Part 6 of "Six Easy Pieces," please do not
be intimidated by the mathematical equations. They are designed for high-level physics students, perhaps even at the graduate level. But please do pay certain attention to the key ideas: the exploration of the unknown
"small" subatomic world, uncertainty, and wave/particle behavior.
Feynman is rare among scientists for his humility. As brilliant as he obviously was, he was unafraid to admit his lack of knowledge. Among those things
about which he admitted to knowing little is the subatomic, quantum world.
It is incredible to think that our world is immensely complex—perhaps even infinitely so—at a level too small for us to observe. It is equally
amazing to think that laws of nature and physics apply consistently to that subatomic level, just as they do on our physical level and, more broadly, to the planets and galaxies of our solar system. But they do.
One
of the promises of quantum physics is that it may unlock the "building blocks" of all creation. It may, as physicist Stephen Hocking has suggested, help us read "the Mind of God."
However, one of the great obstacles
to observation and experiment at the quantum level is the uncertainty principle. More than suggesting the simple universality of uncertainty, the uncertainty principle (or Heisenberg's Uncertainty Principle, as it is
more properly known) suggests that the closer we come to certainty about some aspects of quantum physics (behavior of waves vs. particles, for example), the less certain we can be about others! It is as though the laws
of nature are in conflict at a level beyond our ability to even understand the conflict, let alone the underlying concepts.
Specifically, quantum physics has deeply changed our understanding of some of the "basics" of
classical physics: waves and particles. Given our early understanding of certain physical properties, such as light, scientists concluded that it moves and operates in "waves," washing as it were, over the universe.
With further experiments, scientists have learned that light is actually made up of indescribably small pieces known as photons which are believed to be particles.
Conversely, solid objects (and liquid and gaseous as
well) were understood to be made up of "particles." That is, each "large" object, such as the chair in your living room, was thought to be made up of individual smaller pieces (molecules and atoms). Now, due to an
emerging understanding of quantum concepts, scientists believe that molecules and atoms are constantly in motion. And that motion, put simply, has the characteristics of movement that we used to assign to waves.
So
"waves" actually have the characteristics of particles; and "particles" actually have the characteristics of waves. We think. This is the true drama of "small" physics, or quantum physics, we are still learning about
the universe at the small level; and that understanding is reshaping the way we think about the world at the "large" level as well.
