Are there any ways of detecting what happens to particles just left alone? Is magnetic force or gravity faster?
How do you accelerate neutrons with magnets?
I’m not sure who to answer that question in a way that doesn’t sound facetious: particles that are “left alone” do whatever they were doing before you started looking at them.
All forces act at at c.
You cannot. Neutrons do not have an electric charge. There are neutral beam accelerators which function by taking charge (ionic) plasma, accelerating them via electrostatic fields, and the injecting oppositely charged particles to neutralize the resulting plasma.
Stranger
Many of these mystery particles are pretty unstable. For instance, the famous delta particle has a mean lifetime of 5.63 × 10−24 or something like that. So, you do not really have to make an effort to “leave them alone”: they just disappear by themselves and you can detect what’s left via particle detectors, which of course themselves do not leave particles alone but rather try to detect them by exposing then to various fields and observing their interaction with matter; at some point you have to do something…
As for what is “faster”, magnetism or gravity… how fast the particle decays should be related to the mass of the bosons involved… but, since you mention gravity, the first issue is how particles are going to decay via gravitational interactions; this is not the case in run-of-the-mill QFT or the Standard Model, so you probably need some understanding of quantum gravity. Maybe I will let someone else try to address this question, but it seems clear that it would take a while for a proton or an electron to decay via gravity, or at least quantum gravitational effects will not be observable until we get to high (TeV…) energy scales.
As for accelerating neutrons with magnets, that is not really going to work but you can slam a charged particle beam into something to produce some neutrons…
First, the question in the title (which doesn’t appear to be connected with the body of the post): What do you mean by “stop them”? You can, instead of slamming them into beams going the other way, slam them into stationary targets, and this used to be the norm for particle accelerators, because it’s easier to build that way. The catch is that you get lower relative energies. If the physics involved were all Newtonian, you’d get about a quarter of the effective energy from a stationary target as from a head-on collision, and that might be close enough that it’d be worth building them the easier way… but it’s not Newtonian, and with the way that the relativistic equations work out, it’s much, much lower relative energy to use a stationary target, enough so that you couldn’t possibly get the energies you want that way.
Alternately, you might mean instead of crashing them into the target, you feed them into a mirror-imaged “un-accelerator”, which gradually slows them in the same way that the original gradually sped them up. In that case, you’d get the same things happening as happened in the accelerator, i.e., nothing much dramatic.
To the question of whether “magnetic force or gravity is faster”, I think what you mean is not the speed at which changes in those forces propagate (which is c for everything), but which one would produce a greater acceleration on a particle. The answer to that would of course depend on the strengths of the gravitational and magnetic fields, but for almost any realistic scenario, the magnetic field would have a much greater effect. Gravity is really, really weak: When an apple is hanging on a tree, electromagnetic forces in the stem are strong enough to balance out the gravitational force from the entire planet.
I took that to mean capturing them in a magnetic stasis field of some kind so that they are held in place; not impacting something, but not free to keep moving. Effectively at rest relative to its surroundings and suspended there in place, trapped by the magnetic field.
Oh, well that’s easy, then. You (and I and the computer you’re typing on and the desk it’s sitting on and the wires between us) are made of those particles.
Except for the oscillations. This is a really advanced stasis field. Nothing can move, or even vibrate/resonate. Would that mean the baryon was now at absolute zero?
This imperfect question of mine needs a little broadening…
What if an electron is placed by the still proton? Should the electron start spinning around it in no time? Does electrons have negative charge when not moving?
They don’t have a net electric charge, but they’re composite particles that do have an internal distribution of charge, and so they have a magnetic moment. So they can be accelerated a bit with a non-uniform magnetic field.
You can’t accelerate them much, since the charges are so close together. But if you get them cold (slow) enough to start with, you can use magnets to confine them.
What do you mean by “placed” there? Are you imagining a tiny pair of tweezers? Because the tweezers must themselves be made of electrons, protons, and neutrons.
If an electron is in the vicinity of a proton with low enough energy, then it’ll be part of an atom with it (which does not entail anything particularly resembling the electron spinning around the proton). If it has too high an energy, it’ll just zip away. The electron always has the same charge, in any event.
Would an electron fall down due to gravity?
If there are no other forces acting on it, an electron will be drawn towards any other massive object due to gravity.
If you left two neutral particles the mass of electrons in empty space, they would be drawn to eachother. However, given that electrons have charge, the charge that would be repelling them would be a whole bunch (something like 40 or more) orders of magnitude greater than their mutual gravitational attraction.
Theoretically, if you put an electron in a region of no electric fields but with gravity, then yes, it would fall just like anything else. But in practice, it’d be impossible to isolate it sufficiently from electric fields, especially if it’s close enough to any sort of “stuff” to get that gravitational field, because it would only take an incredibly tiny electric field to overwhelm your gravitational field.