Photons are particles of light, or waves, or something like that, right? [Mithuna Yoganathan] explains this conundrum in more detail than you probably got in your high school physics class.
While quantum physics has been around for over a century, it can still be a bit tricky to wrap one’s head around since some of the behaviors of energy and matter at such a small scale aren’t what we’d expect based on our day-to-day experiences. In classical optics, for instance, a brighter light has more energy, and a greater amplitude of its electromagnetic wave. But, when it comes to ejecting an electron from a material via the photoelectric effect, if your wavelength of light is above a certain threshold (bigger wavelengths are less energetic), then nothing happens no matter how bright the light is.
Scientists pondered this for some time until the early 20th Century when Max Planck and Albert Einstein theorized that electromagnetic waves could only release energy in packets of energy, or photons. These quanta can be approximated as particles, but as [Yoganathan] explains, that’s not exactly what’s happening. Despite taking a few classes in quantum mechanics, I still learned something from this video myself. I definitely appreciate her including a failed experiment as anyone who has worked in a lab knows happens all the time. Science is never as tidy as it’s portrayed on TV.
If you want to do some quantum mechanics experiments at home (hopefully with more luck than [Yoganathan]), then how about trying to measure Planck’s Constant with a multimeter or LEGO? If you’re wondering how you might better explain electromagnetism to others, maybe this museum exhibit will be inspiring.
How is a visible light photon inside inside a sealed iron box going to be infinite in extent?
Prove that it’s not.
There is a certain chance the photon tunnels through the iron box, hence the wave function will extend outwards. There is no such thing as a perfectly sealed container.
If the effect of the wall’s response to the photon propagates to just as infinite an extent as the photon, and sums up to effectively be a cancellation when outside the wall, that would be fine.
I don’t know if an empty plastic bottle is best to charge it, I always used a baloon for that. The bottle may have the same property as a dielectric, but the baloon is better perhaps.
There is evidence that light is composed of packets of energy (photons) guided by electromagnetic fields, compatible with the Pilot Wave interpretation of Quantum Mechanics. So light is both a particle and a wave at the same time. This explains all known quantum effects. Here is a link to see how EM theory shows energy is guided EM fields:
https://youtu.be/1wrF_9pxVKI?si=rAo33R-tNKQSgUSa
But Pilot Wave theory violates Relativity, where the real Pilot Wave (EM fields) instantaneously interact with the particles (photons). Another way to say this that Pilot Wave theory requires instantaneous action at a distance.
There is now very strong evidence this is correct. The speed of light is not a constant as once thought, and this has now been proved by Electrodynamic theory and by Experiments done by many independent researchers. The results clearly show that light propagates instantaneously when it is created by a source, and reduces to approximately the speed of light in the farfield, about one wavelength from the source, and never becomes equal to exactly c. This corresponds the phase speed, group speed, and information speed. Any theory assuming the speed of light is a constant, such as Special Relativity and General Relativity are wrong, and it has implications to Quantum theories as well. So this fact about the speed of light affects all of Modern Physics. Often it is stated that Relativity has been verified by so many experiments, how can it be wrong. Well no experiment can prove a theory, and can only provide evidence that a theory is correct. But one experiment can absolutely disprove a theory, and the new speed of light experiments proving the speed of light is not a constant is such a proof. So what does it mean? Well a derivation of Relativity using instantaneous nearfield light yields Galilean Relativity. This can easily seen by inserting c=infinity into the Lorentz Transform, yielding the GalileanTransform, where time is the same in all inertial frames. So a moving object observed with instantaneous nearfield light will yield no Relativistic effects, whereas by changing the frequency of the light such that farfield light is used will observe Relativistic effects. But since time and space are real and independent of the frequency of light used to measure its effects, then one must conclude the effects of Relativity are just an optical illusion.
Since General Relativity is based on Special Relativity, then it has the same problem. A better theory of Gravity is Gravitoelectromagnetism which assumes gravity can be mathematically described by 4 Maxwell equations, similar to to those of electromagnetic theory. It is well known that General Relativity reduces to Gravitoelectromagnetism for weak fields, which is all that we observe. Using this theory, analysis of an oscillating mass yields a wave equation set equal to a source term. Analysis of this equation shows that the phase speed, group speed, and information speed are instantaneous in the nearfield and reduce to the speed of light in the farfield. This theory then accounts for all the observed gravitational effects including instantaneous nearfield and the speed of light farfield. The main difference is that this theory is a field theory, and not a geometrical theory like General Relativity. Because it is a field theory, Gravity can be then be quantized as the Graviton.
Lastly it should be mentioned that this research shows that the Pilot Wave interpretation of Quantum Mechanics can no longer be criticized for requiring instantaneous interaction of the pilot wave, thereby violating Relativity. It should also be noted that nearfield electromagnetic fields can be explained by quantum mechanics using the Pilot Wave interpretation of quantum mechanics and the Heisenberg uncertainty principle (HUP), where Δx and Δp are interpreted as averages, and not the uncertainty in the values as in other interpretations of quantum mechanics. So in HUP: Δx Δp = h, where Δp=mΔv, and m is an effective mass due to momentum, thus HUP becomes: Δx Δv = h/m. In the nearfield where the field is created, Δx=0, therefore Δv=infinity. In the farfield, HUP: Δx Δp = h, where p = h/λ. HUP then becomes: Δx h/λ = h, or Δx=λ. Also in the farfield HUP becomes: λmΔv=h, thus Δv=h/(mλ). Since p=h/λ, then Δv=p/m. Also since p=mc, then Δv=c. So in summary, in the nearfield Δv=infinity, and in the farfield Δv=c, where Δv is the average velocity of the photon according to Pilot Wave theory. Consequently the Pilot wave interpretation should become the preferred interpretation of Quantum Mechanics. It should also be noted that this argument can be applied to all fields, including the graviton. Hence all fields should exhibit instantaneous nearfield and speed c farfield behavior, and this can explain the non-local effects observed in quantum entangled particles.
*YouTube presentation of above arguments: https://www.youtube.com/watch?v=sePdJ7vSQvQ&t=0s
*More extensive paper for the above arguments: William D. Walker and Dag Stranneby, A New Interpretation of Relativity, 2023: http://vixra.org/abs/2309.0145
*Electromagnetic pulse experiment paper: https://www.techrxiv.org/doi/full/10.36227/techrxiv.170862178.82175798/v1
Dr. William Walker – PhD in physics from ETH Zurich, 1997
Sounds like some Miles Mathis level nonsense.
Photons are the fundamental particles of light, carrying energy in discrete packets called quanta. They exhibit both wave-like and particle-like properties, essential to understanding phenomena like the photoelectric effect.
If light is both (electromagnetic) wave-like and (photon) particle-like in nature, can’t the same be said of radio waves? There should exist shortwave photons, for example., but I’ve never heard that acknowledged.
Yep. The mathematics don’t care – it works the same for radio frequencies as for light (or X-rays or gamma rays.) The energy of the photon depends on the frequency (alternatively, on the wavelength.)
https://en.wikipedia.org/wiki/Photon_energy
Photon’s are not ‘particles of light’. Light is wavelike in all its behaviour, but the ENERGY contained within that wave is quantised. Seems like a meaningless difference, but has a big effect on understanding how light behaves and interacts. Huyens Optics has a 3-part series on this, starting here:
https://www.youtube.com/watch?v=dtcq5b0R65w
The fun part is when you figure out that this is what defines a particle. They’re all just quantized waves in some field or other. It might intuitively feel like particles should have mass or exhibit Pauli exclusion or something, but those don’t turn out to be terribly useful working definitions for “particle.” And a lot of what’s passed off as “quantum weirdness” in popular media — notably interference and tunneling — is just wave mechanics showing up in things that feel like they ought to not do that.
“The fun part is when you figure out that this is what defines a particle. They’re all just quantized waves in some field or other.”
Yeah, it’s one of those things where you get confused when people start talking about “particle/wave duality” garbage, thinking “wait, it’s all just waves” and then realize that you never had a definition for “particle” in the first place, and there are plenty of things that are pure “waves” (like a soliton) that would satisfy all your “particle” intuitions anyway.
“And a lot of what’s passed off as “quantum weirdness” in popular media — notably interference and tunneling — is just wave mechanics showing up in things that feel like they ought to not do that.”
I think almost *all* of it is. The part that hurts your brain is realizing that there’s structure to the wave that is undeniably real (its phase) but impossible to measure. Even stuff like entanglement is still weirdo wave mechanics: you have two things that no matter what measurements you do on them *individually* they look identical, but when you combine them correctly, you get an unexpected result. This is just the entire basis of interferometry!
I never really bought into light being a particle. To me it’s always a wave and light’s interactions are quantised giving the appearance of packets of energy.
“To me it’s always a wave and light’s interactions are quantised giving the appearance of packets of energy.”
Try to give a definition of particle that isn’t just the second part of what you said.
Its intrinsic nature is a wave that spreads throughout the universe at once, but functions as a particle with finite speed and quantified energy when observed and measured. Consciousness is what makes the difference.
“Consciousness”, lol.
Yes, consciousness, observer, measurer, whatever you want to call it. Without it, there’s no photon as a “particle”. Prove me wrong or keep laughing in your ignorance.
I’ve read that sci-fi novel – Quarantine by Greg Egan. One of his more interesting pieces, actually.
Thank you for the recommendation: I´m a big fan of Greg Egan. The fact that you need an observer to measure particles is part of another ‘novel’ called Quantum Mechanics which I also recommend you to read.
I know I will regret asking a seemingly simple physics question if I get a typical (maths heavy) answer, but here goes anyway.
I understand that when an atom has an excited electron that drops back down into its lower energy state shell, that a photon is emitted – what *specifically* is going on here? One moment there isn’t a photon, next thing it’s there and going off at the speed of light… are there like intermediate steps involved?
Thanks :-)
Most people would respond “no, there aren’t intermediate steps”, but… actually, there are.
The problem intuitively is thinking about the situation as “electrons and protons and photons” rather than “fields of each and interactions.”
From a classical point of view, the electron (and nucleus) all have electromagnetic fields: even though *at infinity* they’re neutral, they’ve still got structure. So when you shift from “excited mode” to “lower state” the field configuration changes, and that change propagates outward, which is what “generates” the photon. The propagation of the field is what’s limited to the speed of light (via Maxwell’s equations).
Really the only part where the “classical” bit breaks down is that you can *only* have those transitions – plus one other detail. The reason why I said “there kindof are intermediate steps” is that although you know what the “starting mode” looks like and the “ending mode”, that interaction has an *intrinsic spread in time*, which produces an intrinsic spread in the energy of the propagating photon.
This is why when you look at emission and absorption lines, they’re not “infinitely sharp” – they can’t be. The atoms don’t actually emit a photon of an infinitely specific energy, because that’s not possible. (This is called ‘natural line broadening’ in spectroscopy).
Interesting stuff much appreciated, and thank you for sparing me the maths!
So, is the photon emitted in all directions, or one?
Actually that’s something I always wondered, in a mirror I=R but how does the atom “know” which direction to send the photon?
I suspect the answer involves a wave function, but I need simple explanations myself.
Over the years I have occasionally asked physicists a thing I though should have simpleish readon only to get a page of complex equations as an answer… :-)
That’s the classical/quantum difference I was mentioning: if you imagine a situation where an atom “emits” a photon and you later “detect” it, how does it work that the change in the field at the source is detected by *you* and nothing else?
That’s the “how do I interpret this wavefunction thing” issue: the electromagnetic field here’s a “wavefunction” in that whole “how do I interpret this thing” sense.
Note: if it sounds like I’m dodging the answer here a bit, it’s because I am: fundamentally, there’s no way to tell the difference between any of the random interpretations of quantum mechanics, so it all works exactly the same however you want to view it – you want to view it as a weird multiversal bizarro-ness, have fun, but stop imagining you’re going to build a Multiversal Projector or something because the instant they can *interact* that doesn’t work anymore.
I tend to view it as *revealing* things – as in, an interaction later reveals what a certain configuration was. That tends to get confused for a ‘hidden variable’ type thing (which *doesn’t* work) – the difference here is that it’s a *global* situation – you’re not revealing a state of a particle (local), you’re revealing the state of the *field* (global).
If you think about it classically, the radiation gets emitted with some angular distribution which depends on the transition (the states aren’t all the same, although you can think of simple things like an s-shell transition to a lower s-shell transition has to be isotropic because there’s no directionality anywhere).
The “single direction” shows up when the photon interacts with something else later. It’s not like you can “view” the photon without it interacting with something. So it depends on how you want to think about it.
Thanks again for your responses (and dumbing it down for me), they are very helpful. I have put this page on “speed-dial” for future reference.
Switch light on, and it extends immediately all the way to the big bang. It is traversing not space, but space-time. The space-time interval (which is a square) is zero. In 4-dimensions, it hasn’t gone anywhere. Space-time is expanding, so the light is getting redder in frequency. When you see it, you collapse that photon into your eye, you localize it, and its gone, replaced by an electrical signal.
Exactly, it is the act of observation which makes something that is everywhere objectified as a particle.
Photons don’t exist, they are just a virtual particle that only exists when information is transferred between electrons. Prove me wrong, show me a universe without electrons that still has photons.
I’m showing it to you. You can’t see it because no photons. Don’t be a silly goose.