Schrödinger's cat of Light

Factual Questions
21

Are you complaining that particle physics is hard to understand? And that this is somehow the fault of physicists?

Yes, it would be awesome if physicists could come up with theories about the fundamental forces of the universe that were easy to understand and matched our intuitions about how the universe should work.

Unfortunately the universe works the way it works. Physicists try to understand how it works, and explain what they’ve figured out to the rest of us. If you insist that a photon can’t act like both a particle and a wave because that doesn’t make sense, then welcome to the club. There are lots of people who insisted the same thing. The only problem with this is that every experiment we’ve been able to do shows that photons really do act both like particles and waves.

And there’s never going to be an experiment that reveals once and for all that all the particle talk was nonsense, or all the wave talk was nonsense, because that would throw out all the experiments we’ve actually done over the last 100 years that show the fundamental particleness and fundamental waviness of photons.

If you can come up with an explanation for the two slit experiment that shows that a single photon creates an interference pattern, and your explanation doesn’t require that a photon be both a particle and a wave at the same time, then I hear Stockholm is nice this time of year.

The experimental evidence is that “particle” and “wave” are ways that our human minds try to understand photons, but those explanations are just analogies, and photons are not actually particles or waves. They act the way they act. “Photon” is just a word that humans use to describe certain types of interactions.

Now, we know quite a bit about those interactions. Those interactions are kind of weird, but they are consistent. It’s not like one guy running an experiment finds out that photons are particles, and another guy running the exact same experiment finds out that photons are waves, and then those two guys have to fight a duel to see who’s right. No, different guys running the same experiments see the same results, it’s just that the same guy running different experiments might see different results.

Run one experiment, and see results that confirm that photons act like particles. Run a different experiment and see results that confirm that photons act like waves. So which one is right? Both are right, because photons act like particles and they act like waves. If you don’t like that, the only defense I can offer is that this has been confirmed by thousands of different experiments. And so if your explanation is that all the experiments are wrong, you’ll have to explain in detail exactly how they went wrong, and then sit home and wait for your invitation to Stockholm.

22

The idea that a photon/electron behaves as both a wave and particle is a key idea of the old quantum theory, but in quantum mechanics the explanation as to why quantum particles exhibit both similarities with classical particles and classical waves relies on more basic principles which can vary between interpretations. For example in Copenhagen-like interpretations wave-particle duality emerges from the complementarity of different properties of the particle, but in Bohmian mechanics there is a particle and a pilot wave, which are physical and distinct entities.

23

This didn’t come out right.

First, it’s post hoc ergo propter hoc.

Second, its premises are wrong to begin with based on historical evidence. Consider the propter, and always remember this current spiffy OP (nunc) always becomes somebody’s propter.

Other scientific “systems actually done over 100’s of] years” which show the natures of “the fundamental” x and its necessary relationship to "the fundamental " y–and that relationship itself exemplifying the correctness of the entire program–are encountered frequently, arguably by definition.

Yes “throwing out all the experiments [and their data and mathematical approach]” is sometimes the case when their supporting and thought-to-be-consistent systems of experimental method and mathematical rigor–eg those on the buoyancy of witches or on the music of the spheres --have been re-evaluated to be what is called “batshit.”

Other propter investigations predicated on consistent systems have been re-evaluated and been subsumed in our current (consistent) experimental and mathematical standards of proof. Investigations of the Aether are as valid as those predicated on a system dealing with dropped apples and their fundamental relation to dropped feathers.

24

Cx: delete word: “… when their supporting [del]and[/del] thought-to-be-consistent systems of experimental method and mathematical rigor…”

25

Dude, did you just “they laughed at Columbus when he said the Earth was round” at me?

Of course the experiments on the properties of Aether were good experiments. That’s the whole point.

Those guys were all “Hey, light is like a wave. Well, waves are disturbances in a medium, and light is a wave, and so light is a disturbance in a medium…let’s call it “Aether”. Now, what is this Aether stuff, anyway?”

And so they did all sorts of experiments, but the experiments didn’t make much sense. And eventually the experimental evidence mounted up that there could not be any such thing as Aether. But…but…but…how can light be a wave then?

So go back and read this little story again: Luminiferous aether - Wikipedia

Obviously, one experiment by Michelson and Morley didn’t kill the Aether theory. Because, you know, one experiment can be messed up in any number of ways. But every time people tried to prove that they got it wrong, they couldn’t do so.

So yeah, go ahead with your “maybe you’re wrong, dude” about the wave and particle nature of light. It could be true that all of modern physics for the last 100 years is just bullshit. That would be kind of odd though, what with the lasers and nuclear bombs, but maybe it’s all a big coincidence and lasers don’t really work?

The point is, if you think all of modern physics for the last 100 years is wrong, feel free to point out the errors. Don’t forget to show your work. Then lean all the way back in your easy chair and await that invitation to Stockholm, because you’ll have earned it.

But you have to, you know, show your work. “Maybe you’re wrong,” isn’t good enough. Because we’ve got lasers and space telescopes and shit, so maybe explain how a laser can work when all of modern physics for the last 100 years is wrong. Again, the Nobel Committee is just waiting.

And the first step in showing that all of physics is wrong is getting down in the weeds and figuring out what those lying scientist motherfuckers are actually saying. Oh, you cracked open a physics textbook and didn’t understand it, and that means it’s all bullshit? Is that it?

Because that’s not it. You can’t dismiss it without understanding it. If you wanna overturn modern physics you can’t just wave your arms, you’ve gotta come up with theories that explain everything better than the bullshit that the current crop of scrubs is coming out with. So what’s your experiment that’s going to show that light is just a particle, not a wave even a little bit? What’s your experiment that’s going to show that light is a wave, and not a particle even a little bit?

But if you crack open a physics textbook and your eyes glaze over every time you see some equations and you just skip over that part, well, good luck with overturning physics then.

26

Beware: If you take this reasoning too far, this is a logical fallacy up with which we shall not put.

(I don’t think you’re committing the fallacy, Lemur866, but others have in the past.)

Like the guy who kicked the rock, you’re close to committing a fallacy of trying to invert something which cannot be inverted: The theories are very good descriptions of reality, therefore we get those results. True. But you’re trying to say that, since we have the results, those theories are very good descriptions of reality. That’s wrong, and you can see it using light: The luminiferous aether predicts the result of light diffracting through a grating perfectly well, but we can’t use the diffraction of light as proof that the aether exists after all.

It’s better to say that good theories are true at least to a point: Aether is good for describing some aspects of light, Newtonian mechanics is great for describing some aspects of gravity, and even phlogiston has its good days. However, all of those theories break down in scenarios we know how to construct, or are over-complicated and don’t integrate very well with other knowledge we now have, so we no longer regard them as the best current models.

The difficulty some people have with this basic notion comes back to something which isn’t even a fallacy, but a psychological deficit: All-or-nothingism, or the inability to see gray areas. A theory is entirely correct or it’s useless and we must throw it out entirely, yea, even unto forgetting experiments we ran a few years ago prompted by the old theory. Us changing our minds about how we model the Universe changes history, apparently, because no theory can ever be competent within a specific domain. Nope, it must be the final word or it’s nothing at all.

So the most your inversion (“Results, therefore theory has value.”) can be used to show is that the theory isn’t completely hopeless. But the fact matches burn doesn’t mean we currently think match heads are full of phlogiston, even if matches were initially invented in the phlogiston era.

This, however, is entirely correct.

I think you have hit on the very nub of how physics and mathematics cranks think: They’re morally opposed to the idea that the world could possibly be so complex they’d need actual effort to understand it.

27

I think it’s a little more complicated like that. One problem is that it’s hard to see how theories that posit non-existent entities (like the aether) can actually get anything right about the world; therefore, a standard position in the philosophy of science is that there must be something that the theoretical terms of the theory correspond to, otherwise its accuracy would literally be miraculous (this is also known as the ‘no miracles’ argument).

This runs right into the pessimistic meta-induction: our old theories turned out to be wrong about how the world works; therefore, our current theories, most likely, will turn out to be wrong, as well. So we should probably reject their ontological claims. Nevertheless, they must get something right about the world, otherwise, again, it’s just a miracle that they work at all. But if there’s no aether, then what is it that makes it such that predictions on the basis that there is an aether come out right in very many cases?

A prime candidate for that stuff is structure, leading to a position called ‘structural realism’—the structure of aether is such that it can ‘substitute’ for the actual stuff (whatever it may be) some putative final theory posits at least in certain cases. But this comes with problems, as well: structure is fully explicated in terms of relations; but the mere set of relations doesn’t suffice to nail down what it is that actually stands in those relations—in fact, given some set of relations, the most you can do is put a lower bound on the number of things that must exist (the cardinality of the ‘smallest’ set that can support the structure). This is Newman’s objection. But it seems that science tells us more about the world than that there are at least n things out there!

So, we have a puzzle: either we admit that the stuff our best current theories tell us is out there, actually is out there. Then, we get into trouble once our best current theories are shown to be wrong. Or, we don’t admit that stuff as real. Then, we have difficulties explaining why our theories work at all. Finally, we may hold that the stuff our theories posit at least partially shares those properties with the stuff that’s really out there that explain the success of our theories. But the best candidate for these shared properties doesn’t really seem to support the sort of knowledge we seem to have about the world, being able to only answer questions of cardinality.

So a ‘theory true to a point’ isn’t really an easy notion to define precisely.

28

…how a Photon becomes a frequency? And what part of an electron exits?

29

Photons have a frequency as a consequence of their existence.
The whole electron exits, whatever that means for an effectively 0 dimensional object.

30

Makes no sense at all

31

It is very upsetting that physics on the subatomic scale doesn’t work very much like how we expect things to work. We expect electrons to be little balls that orbit around the nucleus, and then get upset when our experimental results don’t match that model.

But the problem is that electrons are not little balls, and they don’t orbit around the nucleus of an atom like a little solar system. Neither a photons little balls. Photons are like nothing else in our experience except photons, and electrons are like nothing else in our experience except electrons.

We can describe the behavior of electrons and photons very precisely. These are the results that our theories have to explain. It can really help if we develop a mental picture of what a photon should act like. Then we can check to see if the photon really does act the way we predict. If it turns out that the photon does not act the way we predict, then we have to change our prediction.

So I’m not really sure what exactly the question is. We have lots of mathematical formulas that precisely describe how light behaves, and we use these formulas every day to make useful objects like telephones and lasers and so on. If the formulas are merely an approximation that describe reality but don’t explain it, that’s fine. Your challenge, should you chose to accept it, is to explain exactly how and why the formulas don’t match reality, and present a better representation that more completely matches reality. Good luck.

32

Have you ever thought all without particles - only waves and wavefronts (that act)

33

That’s fine - the universe doesn’t care if you don’t get it. Honestly though your question is poorly formed and can almost be classed as not even wrong.

A photon has a frequency driven by its energy. A zero energy photon would have a zero frequency … it would also not exist. There’s no “becoming” with a photon. It’s either there or it’s not.

As for electrons, they appear to be fundamental and are not made up of smaller parts as hadrons (e.g. proton) are. There’s nothing there that, if it wasn’t there, would allow the electron to continue to exist.

34

How 'bout “There’s nothing there there that if it weren’t/wasn’t there, there would wouldn’t have been a there to begin with.”

Or something. :slight_smile:

35

There is so much of …
I’ll just have to wait for Chronos who will Save this thread! No relatives included

36

We evolved ( were created with if you prefer) capabilities that were useful to us for survival. When you hear a bump in the night you assume it is a bear or a burglar because the cost of assuming it is something unimportant is potentially a lot more expensive than assuming it is something serious.

The same needs and concerns and experiences are what causes our intuition and assumptions, and in general they have served us very well.

But when we talk about items way past the domain of our non-technologically assisted perception there was very little need to develop an innate understanding and some times things work in ways that do not mirror how things work at our scale.

Unfortunately our assumptions and daily experiences do not prepare us for how things work when scales get really small like the quantum world.

If you quantum mechanics to “make sense” without a concerted effort to abandon your assumptions in favor of empirical tests this will be a frustrating experience. And there will be some aspects that you may never gain an intuitive understanding of but the particle/wave duality model is within your reach.

You have to use and trust tools like science which was developed to get around limitations in human cognition and faulty intuition.

While this may sound absurd, but as you personally stated a limited background in physics if you think you have an intuitive understanding of quantum mechanics you are almost certainly wrong.

This is true even for professional scientists on many topics, so realize that our understanding of the world has grown past our innate intuition, and that in itself is truly amazing. We use terms like particle and wave as tools to work within these domains, but the answer is that a photon and an electron are both at the same time. It is important to point out that there is a vast difference between intuition and understanding. We can calculate and predict events and behaviors to amazing levels of precision but they will be counter intuitive.

As an example, gold is the color it is because of how the probability clouds are structured in the atom, and the fact that the electrons are moving fast enough that the relativistic effects move the absorption band, which for most metals is outside of our visible range into an area that is within our visual range. If this board had good math support, and you would understand the math I could demonstrate this to you quite clearly, but I cannot do so with a million words and analogies.

We have very accurate models that predict this effect and describe it’s behavior, but you nor I will ever have the ability to visualize a 4D curved spacetime to intuitively understand why.

To be clear, we can understand why, but expecting it to make intuitive sense based on our normal interactions of the world won’t happen; it is just beyond our abilities as humans.

37

Try this:

You’re not alone with your objection that light should be treated as a wave. During the 19th century the wave nature of light was regarded as a settled question. The only problem with this theory is that if light is a wave, what is the medium that the wave propagates in? And so the search began for this mysterious substance, which was given the name Aether.

At the same time, research into the nature of matter seemed to absolutely confirm the particulate nature of matter. They figured out that all elements were composed of atoms, and then discovered that the misnamed atoms themselves could be disintegrated into parts.

So which view was correct? Did light have a particle nature, like matter, or was it a wave propagating through some unknown mysterious medium? And the answer is that there is no medium for light waves to propagate through, and light has a definite particulate nature. We can fine tune experimental apparatus to emit single photons and study them. Except, whoops, those single particles also mysteriously act as waves, and a single particle can interfere with itself, just like waves can.

There is no satisfactory intuitive interpretation of these experimental results. All we can do is point to the experimental results and say that light acts as a wave, and it acts as a particle, just as Einstein said in the quote above. Lots of people tried to figure out ways to improve our understanding of these results, but nobody was able to. And modern physicists no longer spend a lot of effort trying to prove that light solely has a wave nature or solely a particle nature, because the experimental results that show both are so well established over the last 100 years. And our mathematical models of the behavior of light are so accurate that it seems pretty much impossible that we’ll discover that we were wrong all along.

The simplest explanation for the paradox is that matter and energy in the universe has both wavelike and particlelike behavior, and this is a fundamental physical fact. That this view is confusing is no longer regarded as a problem to be solved, but a fact to be accepted.

38

It may surprise you to learn that we, in fact, understand light better than we understand anything else in the Universe. We can make predictions about electromagnetism, and then make measurements corresponding to those predictions which are good to 20 decimal places, and even to hat insane level of precision, our experimental results match our predictions. And electromagnetism has been the best-understood area of physics for well over a century, even before the modern quantum field theories: For instance, our understanding of it conformed to Einstein’s special theory of relativity decades before Einstein even published.

Now, if you want something that we really don’t understand very well, try protons and neutrons. They’re about 99.95% of the mass of everything we perceive, and yet we can only vaguely even say why they exist at all.

Scroll up to Lemur866’s post 14, and follow the link. Among the many things we don’t actually understand very well is understanding itself. We tend to say that we understand something, when really what we mean is just that we’re familiar with it. We’re familiar with springs, and we’re not as familiar with electromagnetism, and so we try to explain electromagnetism in terms of springs… but if we do that, we don’t actually understand springs. We should be explaining springs in terms of electromagnetism, not the other way around.

39

Light is a wave. This “wave-particle duality” stuff is nonsense. Do a google scholar search for the 1968 paper “The photoelectric effect without photons” by Lamb and Scully for a simple 15 page explanation. Yeah, it was first explained to an impressive degree assuming light is a particle, but so what? That’s just a calculational trick. And sure, students can do calculations assuming a particle here and a wave there and get good answers, but so what? That doesn’t make light a particle. Do you have to empty the photons out of your camera after taking a bunch of pictures? I think quantum field theory, where a photon is described as a disturbance in a field is getting back to waves in an ether. So I think the cognocenti in physics have actually abandoned wave-particle duality.

40

That paper only covers one effect of wave-particle duality, and does not fully describe all of the partical like behaviors, which would be required to abandon the idea.

Note that we also now have experimental data that has simultaneously observed both wavelike and particle like behavior.

https://www.nature.com/articles/ncomms7407