I will try my best to explain this question because I’ve googled multiple times over a decade and have asked a physics PhD and neither could understand what I meant, nor answered the question.
I understand that Photons are wave-particles. The smaller the wavelength, the more frequency. I also know that electromagnetism are 2 of the “same thing”, using the same force particle, a photon.
So what frequency do photons that are a acting as strictly magnetic? Magnetism seems to penetrate a heck of a lot more things than even gamma rays (excluding some metals), so why’s that? What makes them different, if they’re the same particle? Are magnetism photons “straight” or act more as a particle than a wave? Do magnetic photons experience the Doppler Effect? If we can count light photons with special instruments, can we do the same with magnet photons? What causes magnetic photons to “bend” around a magnetic object? Like if there was an MRI machine, does that mean there are just a LOT more magnetic photons or is the amplitude of them greater? Can magnetic photons turn into light photons directly?
In: 1
* So what frequency do photons that are a acting as strictly magnetic?
If you are holding a normal bar magnet, and waving it around, the frequency will; be extremely low. And it won’t be pure magnetism: the movement will generate an electric field, which (because it’s also moving) generates a magnetic field and so on. But the frequency will be ridiculously low.
If you aren’t moving it *at all*, it’s not an electromagnetic wave, it’s just an electromagnetic field with no electrical component.
* Magnetism seems to penetrate a heck of a lot more things than even gamma rays (excluding some metals), so why’s that?
Different frequencies of electromagnetic radiaton penetrate different amounts into different materials. The details depend a lot on the exact type of material. Visible light, for example, can interact with a molecule’s electron cloud, and get scattered. A static magnetic field doesn’t interact very much with anything except (say) ferromagnetic materials such as iron, or with electric currents (eg, in an electromagnet)
* What makes them different, if they’re the same particle?
To interact with matter, a photon often has to have just the right amount of energy for the matter to absorb. Some matter can absorb pretty much any frequency, which is why a metal box will shield radio waves etc, and metal makes a serviceable mirror when polished. Others materials are more “choosy”, eg glass (and carbon dioxide) absorb heat radiation much more readily than they absorb visible light.
The energy of a photon depends on its frequency. So different frequencies of light are absorbed differently by different materials. Our whole sense of colour vision depends on this fact.
* Are magnetism photons “straight” or act more as a particle than a wave?
A static magnetic field acts more like a static field than a photon. You’ll only get photons when you start waving the magnet around. And then, since the frequency of each is so low, each one has such low energy that you get zillions and zillions of them to carry away the tiny amount of electromagnetic energy your waving magnet emits. Sicne there are so many, collectively they act just like a wave.
* Do magnetic photons experience the Doppler Effect?
Yes. If you swing the magnet 1 time per second, someone approaching at a high speed might see an electromagnetic wave with a higher frequency. If they’re approaching fast enough, it might even appear as visible light.
If you have a static magnetic field, someone moving across it at high speed will experience it as a static part magnetic, part electric field. That’s one way to understand why a wire with a current gets affected by a magnetic field – the electrons are moving, so they don’t just see a magnetic field: part of it looks to them like an electric field.
* If we can count light photons with special instruments, can we do the same with magnet photons?
A static magnetic field is better thought of as a field. A photon is what you get when the fields are changing in a way that they keep generating changing fields of the other type. Or, using more technical terms, a photon is an “excitation” of the field.
* What causes magnetic photons to “bend” around a magnetic object?
The field exists in all places (even if it’s zero in some places), so it doesn’t “bend” exactly. However, the *direction it points* might be different at different places, so if we trace “field lines” by tracing the direction the field points, those field lines can bend.
* Like if there was an MRI machine, does that mean there are just a LOT more magnetic photons or is the amplitude of them greater?
A photon doesn’t have an amplitude. To have more electromagnetic energy, you either need (a) higher frequency photons, or (b) more photons.
* Can magnetic photons turn into light photons directly?
I’m getting the impression that what you think of as a “magnetic photon” is actually just the “magnetic field”.
Latest Answers