Blog Archives

The Wacky World(s) of Quantum Theory

by Howard Shirley, Teen Department

“If you’re not shocked by quantum theory, you haven’t understood it.”—Niels Bohr, winner of the 1922 Nobel Prize in Physics.

“I think I can safely say nobody understands quantum mechanics.”—Richard Feynman, winner of the 1965 Nobel Prize in Physics

The Universe is weird. And the closer you look, the weirder it gets.

How weird you say?

Well according to quantum theory:

  • We know stuff cannot appear out of nothing (The Law of Conservation of Matter and Energy), but stuff appears out of nothing all the time, but disappears before there is any time for it to be here, so it doesn’t violate the previous law.
  • A pure vacuum, empty of all matter, isn’t actually empty (see the above).
  • A thing in one place can be changed, and it instantly changes an identical thing in another place, no matter how far apart they are.
  • Things can move from one location to another without going through the space in between.
  • Things don’t exist as things in specific places but as the possibility of things in different places at once, until you look at them.

Now, all of that is about things that are very, very tiny (add a lot more “very, veries” to that). Things like electrons and photons and all the things that make up all the matter and energy in our Universe. But it’s also therefore about all the big things too—like stars and planets and black holes and even you and me.

Which means that all that little weirdness has some weird implications for the big things, like:

  • We might be living in a massive simulation, like a virtual world in a computer (don’t take the red pill!).
  • Nothing might exist unless someone observes it.
  • OR, everything might exist in all possible combinations of all possible events, all at the same time, but we only experience (and observe) one progression of these (while, presumably, infinite other “us”-es experience all the other versions).
  • We (and everything else) are all just parts of one big energy field that “ripples” back and forth through time.
  • We could exist alongside a completely invisible, undetectable world with invisible, undetectable living beings, all made out of “dark matter” and “dark energy.”

And none of the above is just another over-the-top Hollywood movie. It’s serious science, all stemming from the basics of quantum theory. And, yes, quantum theory isn’t just wild speculation, but one of the most robustly established concepts in modern science, going back to 1900, proven again and again by experimentation and practical application (you’re looking at one of those applications right now as you use an electronic device to read this blog; if quantum theory were wrong, your electronic device wouldn’t work).

Light photographed as both a particle and a wave by Fabrizio Carbone.

Quantum theory is based on the concept that energy, like matter, is divisible and isolatable into definable, self-contained bits, or quanta. Think of it as a long band of light, seen from a distance. The light looks like one continuous bar. But as you get closer, you can see that the bar is instead made of individual lights separated by gaps. We will call these lights “photons.” Each light in our analogy represents a single “packet” or “quanta” of energy, which cannot be any smaller, but is very much separated from each of the other photons, like particles. That may not be confusing, but what is confusing is that these photons behave both as if they each are individual particles and as if they each are also a continuous wave of energy, like our distant band of light. And if you observe them in one way, they will appear to be particles and not waves, and if you observe them in another way, they will appear to be waves and not particles. They are neither, and they are both, at the same time. And it is from this bit of weirdness that all the other weirdness of the quantum world arises.

It’s heady stuff, but it’s also a lot of fun. If you’re intrigued, come in and search for some of our titles on quantum physics. And don’t worry—they’re written for the layman to understand. So you don’t have to be either Niels Bohr or Richard Feynman to appreciate all that weirdness (but you probably will still be shocked).

*Howard Shirley is the Teen Library Assistant. And no, he doesn’t claim to understand quantum theory, but still enjoys being shocked by it.*

Sources:

  • Rocket Science for the Rest of Us by Ben Gilliland (YA 520 GIL)
  • Quantifying Matter by Joseph A. Angelo, Jr. (YA 530 ANG)
  • The New Encyclopedia of Science: 1 Matter and Energy by John O.E. Clark (YA 503 NEW vol.1)
Advertisements
%d bloggers like this: