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I know nothing about physics as it is not my domain. So I don't know if what you're saying is true or not. But if it is, I find that notion somewhat poetic. Fo

I know nothing about physics as it is not my domain. So I don't know if what you're saying is true or not. But if it is, I find that notion somewhat poetic. For the sake of my own edification, I'd like to follow this up with a few somewhat seemingly dumb questions if you dont mind: Is it the case that a given particle is trying to settle into a "lowest energy state" possible? I am not using physics terms here. More like conceptually, are these particles, due to the number of options available to them, decaying into the lightest stable variant allowed by the laws of physics? if that is the case, then could we perhaps find ways to engineer structures within which these particles last for a whole lot longer than they should (on a human timescale)? And what is stopping us from doing that? is it the energy cost associated with such a structure/device or is there a more fundamental reason we cant do that?

samstave 4y ago
(I' in the exact same boat as you) --- >>trying to settle into a "lowest energy state" possible? What if its actually the reverse: Its attempting and succeeding to be the most it can be given the eddy of forces around it - the particle is "becoming" - not "falling apart"
sethhovestol 4y ago
It is the case that particles always try to settle into the lowest energy, and the more options they have the faster. We may be able to engineer places where they're stable, like in the example from my grandparent of a neutron. They are unstable since their mass is greater than the mass of a proton and an electron combined, but they're stable in all common elements we're used to. So much so that we think of radioactive elements as the exception, but (mostly) all that's happening there (in beta decay) is a neutron decaying. I'm not an expert, but I'd imagine making a stable situation for a heavier particle much harder than just making an atom, and the fine grained control is even hard still.
lisper 4y ago
These are great questions! > Is it the case that a given particle is trying to settle into a "lowest energy state" possible? Not exactly. Energy is conserved during these decays. In fact, energy is conserved during all physical processes, so the "lowest energy state possible" is a little bit of a white lie. What makes it a white lie is that it is a very good approximation to the truth for thermodynamic systems, i.e. systems consisting of large numbers of particles. But for quantum systems, it is no longer a good approximation. In quantum systems, what happens is that you have a wave function that describes all of the possible states a system can be in. The more mass the system contains, the more possible states there are in its wave function, and so the more likely it is to end up in some state other than the one it started out in. It is even possible for the process of decay to reverse itself, and for the constituent particles to come back together and reconstruct the original, but for that to happen all the constituents have to be brought back together, so as a practical matter this never happens spontaneously in nature. In fact, that is the whole reason for building the LHC -- to make particles (protons) come together and make high-mass systems which then decay in interesting ways. > are these particles, due to the number of options available to them, decaying into the lightest stable variant allowed by the laws of physics? Not the lightest stable variant, just to one of the possibilities described by that particle's wave function. These will always be subject to the constraints of conservation laws, so the decay products will always be lighter than the original. But which particular set of possible decay products is actually produced in any given decay event is fundamentally random. > if that is the case, then could we perhaps find ways to engineer structures within which these particles last for a whole lot longer than they should (on a human timescale)? No. The wave functions for particles are fixed by nature. They are what give particles their identities. They cannot be engineered. The only thing that we can engineer is the arrangement of particles. Particles are like Lego bricks. You can stick them together in lots of different ways, but you can't change the shape of a given brick. Sometimes quantum Lego bricks fall apart spontaneously, but there is no way to control that.
- dotopotoro 4y ago
  If neutron is likely to decay into. Why protons dont decay while being part of an atom? (Wouldn’t this be example of a structure that prevents decaying?)
  - at_a_remove 4y ago
    No. Protons weigh less than neutrons. What will your proton decay into? Be careful to remember your conservation of baryon number when listing your options!
    - dotopotoro 4y ago
      Edit: If neutron is likely to decay into. Why *neutrons* dont decay while being part of an atom? (Wouldn’t this be example of a structure that prevents decaying?)
      - lisper 4y ago
        https://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/the-energy-that-holds-things-together/neutron-stability-in-atomic-nuclei/ https://profmattstrassler.com/articles-and-posts/particle-ph...
  - davrosthedalek 4y ago
    Neutrons don't decay while being part of a stable atom, because the atom has actually less energy than the sum of the constituents -- the difference is the binding energy. Look at deuterium, for example. It has a mass of 2.0141 u. A proton alone is 1.0073 u, and a neutron is 1.0087 u. Deuterium is lighter than the mass of proton + neutron. It's also slightly lighter than two protons, so the neutron cannot decay without external energy input.
    - DiggyJohnson 4y ago
      This comment caps off an exceedingly educational thread of questions and answers.
at_a_remove 4y ago
More or less. Sometimes they will have intermediates, which then decay, and then those products decay, and so on. That's quite common. Eventually they just ... fall apart. The more options, the faster. The greater the energy stepdown, the faster, by which I mean "can it release a gamma? Or fall apart into some much smaller things?" However, it is independent of "nearby" structure, where nearby is any distance larger than the nucleus. So, no, we cannot contain these particles within anything to prevent their decay, it is like trying to build a bouncy castle around a hand grenade in hopes that it won't go off. Note that there is an apparent delay in decay, from our perspective, when particles are moving very fast, like a relativistic muon lasting longer (although still a very brief period of time by our standards) than expected, simply due to special relativity. But here this also would not help. Things fall apart, the center cannot hold, and so on.
- wesammikhail 4y ago
  > However, it is independent of "nearby" structure, where nearby is any distance larger than the nucleus. That puts it in perspective. Thanks for the reply and for taking the time!
holmium 4y ago
As another not-physicist who is interested in physics, I've found the articles/explainers at Of Particular Significance very helpful. There are a few on particle decay, and I think that these two provide a longer answer to your questions: Most Particles Decay — But Why? https://profmattstrassler.com/articles-and-posts/particle-physics-basics/why-do-particles-decay/most-particles-decay-why/ https://profmattstrassler.com/articles-and-posts/particle-ph... Most Particles Decay — Yet Some Don’t! https://profmattstrassler.com/articles-and-posts/particle-physics-basics/why-do-particles-decay/most-particles-decay-yet-some-dont/ https://profmattstrassler.com/articles-and-posts/particle-ph... Neutron Stability in Atomic Nuclei https://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/the-energy-that-holds-things-together/neutron-stability-in-atomic-nuclei/ https://profmattstrassler.com/articles-and-posts/particle-ph...
chriswarbo 4y ago
> Is it the case that a given particle is trying to settle into a "lowest energy state" possible? It's more accurate to think of the energy "spreading out" (remember that mass is a form of energy too, since E=mc^2). The energy can rearrange (subject to conservation laws), between being one massive particle, or several lighter ones (in fact there's a superposition of possibilities, because quantum). In principle the probability of switching back-and-forth is equal, e.g. the probability of particle A decaying into a B+C pair, is identical to the probability of a B+C collision producing an A. However, most of the directions those light particles can take will result in them flying apart rather than colliding; that spreads out the energy, so it can no longer switch back into the massive particle configuration. Note that this is essentially the first and second laws of thermodynamics (energy is conserved, and concentrations tend to "spread out" over time)
- wesammikhail 4y ago
  That makes sense. Thanks for putting it in simple terms. Much appreciated :)
snissn 4y ago
an interesting analog is if you have a house of cards on a table, it's in a way "trying to settle" into the lowest energy state possible which is post collapse all the cards on the table! But it's also not "trying" to do anything, it's just vibing / vibrating and what ever happens to it happens to it :)
- wesammikhail 4y ago
  Haha lovely analogy. Will make sure to remember it.

samstave 4y ago

(I' in the exact same boat as you) --- >>trying to settle into a "lowest energy state" possible? What if its actually the reverse: Its attempting and succeeding to be the most it can be given the eddy of forces around it - the particle is "becoming" - not "falling apart"

sethhovestol 4y ago

It is the case that particles always try to settle into the lowest energy, and the more options they have the faster. We may be able to engineer places where they're stable, like in the example from my grandparent of a neutron. They are unstable since their mass is greater than the mass of a proton and an electron combined, but they're stable in all common elements we're used to. So much so that we think of radioactive elements as the exception, but (mostly) all that's happening there (in beta decay) is a neutron decaying. I'm not an expert, but I'd imagine making a stable situation for a heavier particle much harder than just making an atom, and the fine grained control is even hard still.

lisper 4y ago

These are great questions! > Is it the case that a given particle is trying to settle into a "lowest energy state" possible? Not exactly. Energy is conserved during these decays. In fact, energy is conserved during all physical processes, so the "lowest energy state possible" is a little bit of a white lie. What makes it a white lie is that it is a very good approximation to the truth for thermodynamic systems, i.e. systems consisting of large numbers of particles. But for quantum systems, it is no longer a good approximation. In quantum systems, what happens is that you have a wave function that describes all of the possible states a system can be in. The more mass the system contains, the more possible states there are in its wave function, and so the more likely it is to end up in some state other than the one it started out in. It is even possible for the process of decay to reverse itself, and for the constituent particles to come back together and reconstruct the original, but for that to happen all the constituents have to be brought back together, so as a practical matter this never happens spontaneously in nature. In fact, that is the whole reason for building the LHC -- to make particles (protons) come together and make high-mass systems which then decay in interesting ways. > are these particles, due to the number of options available to them, decaying into the lightest stable variant allowed by the laws of physics? Not the lightest stable variant, just to one of the possibilities described by that particle's wave function. These will always be subject to the constraints of conservation laws, so the decay products will always be lighter than the original. But which particular set of possible decay products is actually produced in any given decay event is fundamentally random. > if that is the case, then could we perhaps find ways to engineer structures within which these particles last for a whole lot longer than they should (on a human timescale)? No. The wave functions for particles are fixed by nature. They are what give particles their identities. They cannot be engineered. The only thing that we can engineer is the arrangement of particles. Particles are like Lego bricks. You can stick them together in lots of different ways, but you can't change the shape of a given brick. Sometimes quantum Lego bricks fall apart spontaneously, but there is no way to control that.

dotopotoro 4y ago
If neutron is likely to decay into. Why protons dont decay while being part of an atom? (Wouldn’t this be example of a structure that prevents decaying?)
- at_a_remove 4y ago
  No. Protons weigh less than neutrons. What will your proton decay into? Be careful to remember your conservation of baryon number when listing your options!
  - dotopotoro 4y ago
    Edit: If neutron is likely to decay into. Why *neutrons* dont decay while being part of an atom? (Wouldn’t this be example of a structure that prevents decaying?)
    - lisper 4y ago
      https://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/the-energy-that-holds-things-together/neutron-stability-in-atomic-nuclei/ https://profmattstrassler.com/articles-and-posts/particle-ph...
- davrosthedalek 4y ago
  Neutrons don't decay while being part of a stable atom, because the atom has actually less energy than the sum of the constituents -- the difference is the binding energy. Look at deuterium, for example. It has a mass of 2.0141 u. A proton alone is 1.0073 u, and a neutron is 1.0087 u. Deuterium is lighter than the mass of proton + neutron. It's also slightly lighter than two protons, so the neutron cannot decay without external energy input.
  - DiggyJohnson 4y ago
    This comment caps off an exceedingly educational thread of questions and answers.

at_a_remove 4y ago

More or less. Sometimes they will have intermediates, which then decay, and then those products decay, and so on. That's quite common. Eventually they just ... fall apart. The more options, the faster. The greater the energy stepdown, the faster, by which I mean "can it release a gamma? Or fall apart into some much smaller things?" However, it is independent of "nearby" structure, where nearby is any distance larger than the nucleus. So, no, we cannot contain these particles within anything to prevent their decay, it is like trying to build a bouncy castle around a hand grenade in hopes that it won't go off. Note that there is an apparent delay in decay, from our perspective, when particles are moving very fast, like a relativistic muon lasting longer (although still a very brief period of time by our standards) than expected, simply due to special relativity. But here this also would not help. Things fall apart, the center cannot hold, and so on.

wesammikhail 4y ago
> However, it is independent of "nearby" structure, where nearby is any distance larger than the nucleus. That puts it in perspective. Thanks for the reply and for taking the time!

holmium 4y ago

As another not-physicist who is interested in physics, I've found the articles/explainers at Of Particular Significance very helpful. There are a few on particle decay, and I think that these two provide a longer answer to your questions: Most Particles Decay — But Why? https://profmattstrassler.com/articles-and-posts/particle-physics-basics/why-do-particles-decay/most-particles-decay-why/ https://profmattstrassler.com/articles-and-posts/particle-ph... Most Particles Decay — Yet Some Don’t! https://profmattstrassler.com/articles-and-posts/particle-physics-basics/why-do-particles-decay/most-particles-decay-yet-some-dont/ https://profmattstrassler.com/articles-and-posts/particle-ph... Neutron Stability in Atomic Nuclei https://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/the-energy-that-holds-things-together/neutron-stability-in-atomic-nuclei/ https://profmattstrassler.com/articles-and-posts/particle-ph...

chriswarbo 4y ago

> Is it the case that a given particle is trying to settle into a "lowest energy state" possible? It's more accurate to think of the energy "spreading out" (remember that mass is a form of energy too, since E=mc^2). The energy can rearrange (subject to conservation laws), between being one massive particle, or several lighter ones (in fact there's a superposition of possibilities, because quantum). In principle the probability of switching back-and-forth is equal, e.g. the probability of particle A decaying into a B+C pair, is identical to the probability of a B+C collision producing an A. However, most of the directions those light particles can take will result in them flying apart rather than colliding; that spreads out the energy, so it can no longer switch back into the massive particle configuration. Note that this is essentially the first and second laws of thermodynamics (energy is conserved, and concentrations tend to "spread out" over time)

wesammikhail 4y ago
That makes sense. Thanks for putting it in simple terms. Much appreciated :)

snissn 4y ago

an interesting analog is if you have a house of cards on a table, it's in a way "trying to settle" into the lowest energy state possible which is post collapse all the cards on the table! But it's also not "trying" to do anything, it's just vibing / vibrating and what ever happens to it happens to it :)

wesammikhail 4y ago
Haha lovely analogy. Will make sure to remember it.