Why don’t electrons crash into protons?
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Discuss In ForumsHelp us find a better explanation than “because Quantum Mechanics says so.”
The question was summarized on physicsforums:
- Why doesn’t the Electron crash into the proton?
- We know in an H atom the e- is attracted to the + charge of the proton.
- And it wants to get down to the “0 level” orbit.
- But what makes that level zero – or why does e- stop going down?
- Is there another force that counteracts the force of charge trying to pull them together?
Responses included “Quantum Mechanics” and dismissal, as well as comparisons to gravitation (as a metaphor). A summary here:
- An attractive force between two particles can result in a circular orbit, with the particles keeping the same distance apart, rather than the particles rushing togther (Newtonian Gravity)
- If the particles are electromagnetically charged then classical electromagnetism says that they will emit electromagnetic waves, lose energy and hence approach each other until they join.
- Quantum theory says that energy can only be lost in discrete amounts, and in particular there is a minimum energy a system can have, so that electrons do not fall into the nucleus as predicted by 2)
- General relativity says that a body orbiting a star will lose energy by gravitational radiation, and so suffer the same fate as in (2). However, for the earth-sun system this effect is too slow to be of importance
#3 “Quantum theory says”. Perhaps the verb should be “observes” and “describes”. Is this a descriptive theory without a why? Is the “why” only comprehensible to those who can do the math?
Help us find a clear explanation on this as we populate the “Learning Center”.
Thanks!
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Swedish researcher Bengt Nyman has an interesting website outlining his ideas about dipolar interactions and how quarks work inside [a very limited palette of] subatomic particles to explain a few more steps about what causes the phenomena we observe as gravity and electromagnetic interactions, and the formation of helium and hydrogen atoms.
It’s not extremely advanced math, but his YouTube simulations are rather interesting.
http://dipole.se.
Jjohnson
Wow, thanks for the link! If Nyman is correct, and if I understand him correctly, his composite dipole hypothesis could have profound implications for fusion research:
*The magnetic confinement people tell us extremely high temperatures are necessary for fusion.
*The inertial electrostatic confinement people tell us extremely high ion velocities are necessary for fusion.
*Nyman appears to be telling us that extremely precise ion attitudes are necessary for fusion.
If that’s so, it makes most fusion devices built so far (and in particular those of the magnetic confinement type) look rather brute force indeed. Of course, the problem then becomes how you control ion attitude with precision while achieving a high fusion rate. Sounds like a non-trivial problem to me.
Note: It seems to me that a corollary of Nyman’s hypothesis is that the cold fusion folks might just be on to something.
Does this mean that alignment of the atom with respect to the application of a proton results in an easier fusion of the two?
Like a door on a sphere that once found and opened would allow a proton to enter easily.
Sounds like a small magnetic coil might help in alignment.
Later discussion interested me in adding high energy electrons to neutrons to produce a proton. What would a neutron star become when bombarded with an electron beam?
Think of the electron as a wave instead of a particle: at the zero-level “orbit”, the wave reinforces itself as the electron orbits (i.e., it’s constructive interference). This is also why electrons orbit in shells: at any other energy levels, the wave would exhibit destructive interference with itself. But the zero-level is the lowest possible level for constructive interference, because it’s exactly one wavelength long. The electron can’t go lower ... down to the nucleus, say ... because it would interfere with itself and cease to exist.
I really don’t know if this is any better than “just because” ... but it might help some people.
And the other answer, of course, is that sometimes electrons DO collide with protons. If the collision has sufficient energy, a neutron can be produced. This is essentially the opposite of beta decay.
It would help to have a context. Most of the above answers presume the question relates to the stability of electrons in atoms. But if the context is within a plasma (where the free electrons and ions are flying around at extremely high energies), I think the answer is: because they’re so darned small! Even though they have an attractive force, they’re moving so fast that they usually miss. Kinda like why the Earth isn’t hit by comets or asteroids very often. Sure they’re attracted gravitationally towards each other, but the size and speed make collisions unlikely.
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