It is true that we do not *know* that QED is the ultimate truth on the subject. But that’s not the point. The point is that QED doesn’t describe light as being a “wave” or a “particle”. It describes light as behaving in accordance with certain equations. In extreme cases, these equations predict particle-like behavior; in other extreme cases, they predict wave-like behavior. But the equations, taken as a whole, are what QED says; “particle” and “wave” are just metaphors, and not to be taken too literally.

No problem with that **John W. Kennedy**.

(Just an aside, I once had a long argument with someone that taught post-grad applied math. He seemed to believe that the “ultimate truth” lay in the equations, and not in the physical universe. I wrongly suspected that you were in that camp. I can see a benefit in forcing students to focus on the equations rather than “real world analogies”, as long as they come out of the process understanding that the math is just a better analogy.)

**JWK** I see your argument and it makes sense. But I’m not sure we can reduce physics to math. I’d like to see *interpretation*. I’d like to understand the two-slit experiment. I don’t think this needs math, in broad terms and I believe it is possible. But not in classical terms of course. Maybe when we go a level deeper than QED we will look back and say, of course, that is why the electron behaves so-and-so. A lot of maybes.

How does a photon behave “in between” a particle and a wave by the way? I have no idea. I had thought of a reasonable analogy to make my point with a theory of conservation using momentum and energy without understanding friction but since I don’t know QED it’s just speculation.

To the limits of our present knowledge, the only sensible answer to that is, “as in the QED equations” – which describe a sort of behavior that simply doesn’t exist (at least, to our perception) in the macrocosmic world of which we are aware – a behavior we can no more visualize than we can visualize a tesseract, something else that can be accurately described only with equations. Just as we can approximately visualize a tesseract as a cube nested within a larger cube, with line segments connecting the corresponding vertices, so we can approximately visualize a photon as a particle or as a wave. But a tesseract is not a smaller cube nested within a larger cube, and a photon is neither a particle nor a wave. It is what it is, and if we cannot understand it, that’s not the photon’s problem.

Okay. It has been Proven that light is a particle. It has also been Proven that light is a wave.

So, what caused the problem?

Not the nature of light, but the word “is”. It implies that there is one absolute view of reality on a quantum level, a view that is truly and incontroverably correct, when this simply isn’t the case.

It would be far more useful to say that, DEPENDANT UPON THE OBSERVER, light can be modeled as either a wave or a particle.

See? the parodox dissapears, all from removing that one little word “is”.

A hijack, but imaginary numbers “exist”, even in straightforward physical terms, just as well as real numbers or any other numbers do, names notwithstanding. I’ll repost what I’ve said here before:

Let’s think about sticks. Sticks have lengths. And we can scale these lengths; we can make a stick twice as big, or three times as big, or half as big, or 5.8 times as big, and so on. And it’s in terms of these length ratios that we actually give our measurements; we say “John is 5.8 feet tall” to mean “John is 5.8 times as big as a ruler; i.e., if you scaled a ruler by a factor of 5.8, it’d be as large as John”. And this shows us how to interpret certain numbers as actually about real-world quantities, and life is good. We might even say this shows that 5.8 “exists”, if you want to talk that way, but I’d really rather you didn’t.

And we can interpret addition and multiplication within this framework as well: multiplication means “chain the scalings one after another”: 7 * 5 = 35 because making something 7 times as large, and then making the result 5 times as large has the net effect of making what you started with 35 times as large. Addition means “carry out both scalings, then place the one stick after the other and see where you end up”" 7 + 5 = 12 because something 7 times as large as a ruler laid end to end with something 5 times as large as a ruler ends up at the same place as something 12 times as large as a ruler. So life is really good. We know perfectly well what arithmetic means now.

But wait… we’re missing something. We haven’t accounted for negative numbers. It wouldn’t seem like it means something to scale by a negative factor, so how can we make sense of them? Well, as you are probably familiar, there is a natural convention to adopt. Instead of focusing solely on lengths, we’ll now look at what direction our sticks are pointing in as well; in addition to scaling sticks up or down in size, we’ll also talk about flipping them 180 degrees around to point the other way. So, for example, -1 will mean “Turn your stick 180 degrees”, and -5 will mean “Make your stick 5 times as big and turn it 180 degrees”. But we’ll interpret addition and multiplication exactly the same way as before: -7 * 5 = -35 because “Make it 7 times as large and turn it 180 degrees” followed by “Make it 5 times as large” has the same net effect as “Make it 35 times as large and turn it 180 degrees”. And -7 + 5 = -2 because if I make two copies of my ruler, one 7 times as large but turned around, and the other 5 times as large and unturned, and place the one after the other, the ending point’s location is the same as if I’d just made a copy of my ruler which was twice as large and turned around. So life is super. Looks like negative numbers “exist” as well (but, please, don’t talk that way).

But, hell, once we’ve started talking about turning sticks, why limit ourselves to full half-circle turns? Why not look at quarter-turns, eight-turns, 23.4 degree turns, and so on?

Why not indeed. Once we toss these in, we get… the complex numbers. All that mysterious i means is “Make a 90 degree turn”. We still interpret addition and multiplication exactly the same way as before; multiplication is still “Do these in sequence” and addition is still “Do these in parallel, lay the results one after another, and see where you end up.” In particular, as far as multiplication goes, since “Turn your stick 90 degrees. Now turn it 90 degrees again.” has the same net effect as “Turn your stick a full 180 degrees”, we see that i * i = -1. That’s it; it’s extraordinarily simple. Life is fantastic. Complex numbers “exist” every bit as much as real numbers; it’s just that the complex numbers express scaling with arbitrary rotation, while real numbers are limited to scaling with half-turn-increment rotation. [And non-negative real numbers express scaling with no rotation at all.]

Positive real numbers, non-negative real numbers, arbitrary real numbers, arbitrary complex numbers, positive integers, natural numbers, arbitrary integers, whatever; they all “exist” to the same extent. Some just happen to be applicable in wider or more narrow generality than others.

If it wasn’t for the fossilized ignorance of those damned names “imaginary” and “real”, there would probably be much less confusion on this point.

So it depends on what your definition of “is” is? Clinton must be smarter than I thought.

Seems to me we just need a new name for an object that has the properties of a particle and a wave. I nominate Waticle. There problem solved. Light is a Waticle.

OK, I really don’t understand most of the arguments put forth. Physics isn’t my strong point, but isn’t the problem it does not match up 100% with waves or particles? Why don’t they just make up a new classification? My waticle. Remember you heard it here first. Does the math that we use now to explain this only allow waves or particles?

-Otanx

I’m afraid you didn’t read the whole thread. The math does not “only allow waves or particles”. It says that a quantum object behaves exactly like a wave or exactly like a particle depending upon conditions, but that you can never observe and measure both properties simultaneously. Physicists don’t use a separate name for this quantum behavior, because this property is true for all matter. It is a property of the universe, not an individual particle. It’s true it can be investigated most easily in photons, but can also be observed in electrons or even atoms.

It has the same fundamental status as mass (or, better, momentum). We don’t have a name for “a momentum” because it’s a property rather than a thing. Same for wave/particle duality.

What prompted the zombification?

Oh, Jesus. I have no idea. I can’t remember how I got to this thread. Someone must’ve linked it somewhere, I suppose, and I didn’t realize.

My apologies; mods, feel free to lock this down.

ETA: Ah, I remember how I got here now: I saw **xcalibre** posting in “Do lawyers tend liberal? Why?”, thought to myself “I wonder if there’s any relation between them and the erstwhile **Excalibre**”, ran a search on their posts, and ended up here. And then forgot to check the dates. Whoops!

Only if you promise to post the above explanation whenever someone claims something in the ‘imaginary numbers aren’t real anyway’-spectrum. Really, that’s just nicely done.

Thanks. I think I can adhere to that promise.

Actually, I recall that for a time (I’m thinking it was late '50s or early '60s, but my memory might be faulty) the term “wavicle” (pronounced with a long A) was used. I’m not sure why it fell into disuse. It can’t be because it sounds silly; if physicists are content to talk about “superstrings” and “quarks” with “charm”, surely the word “wavicle” wouldn’t cause them any problems.

The first dictionary I picked up gives eleven definitions for “is”, and that doesn’t even include the problems caused by the ongoing replacement of the present tense in English by the present progressive, as the present slowly evolves into a null tense.

“Wavicle” was coined to take that position long ago, probably before you were born.

They have: “quantum”. But laypeople can’t visualize a quantum; they want something nice and cozy that they can visualize, and that always leads back to “wave” and “particle”, while actual scientists bang their heads against the wall, shouting “Why?!”

All of this, and nobody has pointed out the typo in the first sentence yet?

That should be “thought”.

Since it’s been dug up, I’ll respond to a previous question.

**xcalibre** said:

Whether or not I (or anyone else) know it exists is independent of whether or not it exists. Awareness of the event is not causation of the event.

It is if all “reality” exists only in my mind.