Wave-Particle Duality: What is it?

There are many well-educated people out there. I'm not saying that's a problem. But there are a hell of a lot of only partially-educated people, too. Partial education can be dangerous; someone thinks they understand a topic, while the fully-educated person will know that they can never understand an interest fully. Sometimes this becomes a problem if those partially-educated people become politicians, law-makers, or people who make decisions in general.

But those problems are far out of the field of my expertise. I only venture to correct one of the many scientific misgivings I hear so very often: that of "wave-particle duality." You've heard of it, almost certainly. And you've also almost certainly heard someone tell you: "a photon, the stuff that light is made of, is both a wave and a particle. That's called wave-particle duality."

Sigh.

You've been misled. Your high school teachers have had you think this whole time that photons are both a particle and a wave, simultaneously. Wrong!

The simple truth is that photons are neither particle, nor wave. They're something totally different. The argument that a photon is a particle and a wave is akin to someone saying: "Apples are both crunchy and sweet, so they're both a potato and a melon."

The apple thing is totally absurd. We all know that. Well, now you know that the photon thing is absurd too. Obviously, an apple has traits of both a potato (texture) and melons (sweetness).. but the truth is we all know that apples are something totally different.

The problem is that we're all familiar with apples. We have the appropriate concepts to define apples. This isn't the case for photons. When the photon was discovered, we had never seen anything like it. Light very obviously has a wavelength, as proven by the spectrum of visible color, as well as the standard "double slit interference" experiment in optics. But we also know that photons come as discrete particles. While it's not possible to have just one constituent piece of a sound wave, we can have just one photon.

So where does that leave us? Enter the entire study of quantum mechanics. We'll leave that for another discussion.

For now, just take for granted that photons are neither particles nor waves, but some totally different animal.

Until next time,
an engineer.

Science in Plain English

Why is science so hard?

It's probably because nobody has explained it to you the right way before. The thing to remember is that science is easy -- maybe not in practice, but at least in concept.

The universe works in a certain way. You may not grasp it because you don't understand the mathematical proofs behind Schrodinger's equation or Maxwell's laws.. but you still live and work and play in this universe. It can't be that hard to understand.

So, here we are. Topic by topic, we'll learn about how the universe works. I make no assumptions on the readers' behalf. You may need to know the basic laws of the universe, but you don't need to be a mathematician.

Hopefully, in this way, we can all understand a little more.

Happy reading,
an engineer.