The following might be totally obvious or easily dismissed by the average undergrad physics student, but it is something that occurred to me and I can not come up with an answer one way or another through Google searches.
My understanding is that there is no known mechanism that causes an atomic nucleus to decay. It is just something that happens and it is impossible to predict for a specific atom. What we can know is how likely a nucleus is to decay over a certain period of time, usually expressed in terms of the half-life of large groupings of similar atoms.
Some theories surmise that at the smallest levels the universe is a “Quantum Foam” where “phenomena” quickly come into existence and vanish. Like atomic decay, it is impossible to predict when a phenomenon will occur at a certain point in space or what the magnitude of that phenomenon will be.
I don’t have a grasp about what quantum foam theories say about phenomena occurring in or near an atomic nucleus. Layman-level articles on the subject usually discuss how quantum foam creates energy in an empty vacuum.
Could it be possible that quantum foam phenomena in or near atomic nuclei cause nuclear decay?
Would it be reasonable to measure quantum foam phenomena by their capability to cause an atom to decay? E.g., a phenomenon sufficient to decay U239 (qfU239) would be much weaker then a phenomenon sufficient to decay U238 (qfU238). The half-life of U238 would be a measure of how likely it is for a phenomenon of qfU238 or higher to occur within the volume of space occupied by (or near to) the U238 nucleus.
If you brush after meals, floss daily, avoid between meal sweets and see your physicist every six months you should be able to drink as much quantom foam as you like without worrying about nuclear decay.
Needless to say, I haven’t a friggin’ clue about physics. I do wish you luck in finding someone who can truly help with your query.
My understanding is that it’s very difficult to measure quantum foam phenomena. On the other hand, nuclear decay is certainly caused by quantum interactions of some kind. So I’m going to answer your question “yes”, although I’d wait for someone more qualified to come along.
You might say that the same thing (if anything) causes quantum foam and nuclear decay. There’s not really much to measure about the foam: On any scale at which we can possibly look at it, all we’re going to see is an average, and we already know most of what there is to know (not much) about its average behavior.
I’m fairly sure that the OP measurement system wouldn’t work. I’m sitting here thinking through a couple situations and here’s the thought experiment i came up with.
Given that half-life is the time for half of the sample to decay, and given that the model that the actual decay for a particular atom can occur any time during the half-life.
Now, imagine a group of atoms created in a particle accelerator, they all start at age 0. Under a ‘they take this long to decay’ model, they would all decay at the same time and thus the half-life model wouldn’t work. IIRC reports on new atom discoveries include an estimate of half-life, so this must not apply. So the first answer I was gonna post kinda died on the keyboard.
Not real familiar with quantum foam, but what i can gather from the posts below the idea is that at a quantum level there might be spikes in energy in one location and deficits in a another, while all we can detect is a smooth average. This is a reasonably hypothesis about how atoms decay, since it seems to apply to all situations, as well as explaining why some atoms last longer than others (some require a higher spike to decay).
Problem is, as a measuring tool, this theory is useless. We can’t measure the spikes, so we can’t issue an exact value for the decay tolerance of atoms with this method. All we can do is say if atom A decays easier than atom B, which we could tell far more easily by using the half-lifes.
On a somewhat different note, anyone with recent physics experience know if half-life varies by backround energy, (i.e. temp)?
Okay, let me try to explain. I’m not an expert, so I may muck something up, but I think I’ll get the gist right.
Now then, nuclei are of course made up of protons and neutrons. These things are held together by the strong force, as are the quarks that make up any individual proton or neutron. What can happen at times is that a neutron, which is slightly heavier than a proton, can decay into a proton, an electron, and an anti-neutrino (so called [sym]b[/sym] decay). This is really, as erl noted, a manifestation of the weak force. We can predict things of this type, since we know how the weak force works. Unfortunately, any corrections that might have to be made due to the presence of the other quarks are hard to do, because the strong force is not something we can readily calculate with yet.
Because of relativity, you have to give the decay rate in a specific frame of reference, usually taken to be the rest frame of the nucleus. We, of course, would measure these things in the laboratory frame. I suppose that with a higher temperature, the nuclei would move faster and we’d see time dilation affecting them in principle, but I suspect that this is a totally insignificant effect at standard temperatures.
To clarify a bit of confusion, the half-life is the time it takes for half the nuclei in a large sample to decay. Any individual nucleus might decay in 1/10 of a half-life, or in 100000 half-lives, or never, or any other time.
Lastly, quantum foam is a phenomenon that takes place on the Planck scales, which are truly insignificant in comparison to nuclei, so we don’t have to worry about it.
Quantum foam is scale dependent. In other words, as Chronos implied, it doesn’t in actuality exist at any scale above the Planck length. It therefore could not be the cause of particle decay. As far as anyone knows particle decay is strictly a stochastic phenomenon.
Even though I could not find any mention of the cosmic foam having anything to do with nuclear decay. It is possible to observe the effects of Quatum Foam at the atomic scale.
Right. First, Zot has correctly pointed out that virtual particles popping in and out of the vacuum does have an effect that can even be seen in atoms, and is certainly important for particle physics. This isn’t, as I understand it, what is meant by quantum foam, though. I always thought quantum foam is the same sort of phenomenon except that rather than virtual particles, it’s virtual changes in the shape of spacetime, which DOES occur on the Planck scale. I could be misinterpreting the term…
For erl, the problem is not that we don’t think we know how the strong force works, it’s that we can’t calculate with it very accurately. Here’s why.
[slightly technical aside]
In quantum field theory, we have this little problem that you can’t solve the problem exactly because it’s too complicated. What is ordinarily done (and works marvelously in QED, for example) is something called a perturbation expansion. This comes down to calculating that part of the answer that we can easily calculate and then adding quantum corrections on top of it. These quantum corrections are, in fact, the effects of the virtual particles that Zot was mentioning.
Now, the problem is that unlike in QED, where these corrections are typically fairly small (so that the series converges rapidly), these corrections are large in QCD. So perturbative calculations aren’t really feasible for QCD except on really really short length scales (where they’re okay). So we have to try numerical solutions, and these are pretty hard to do. Currently, accuracy to about 10% is what can be expected for QCD lattice calculations, and obviously, this isn’t enough to get the fine details right.
[end of technical aside]
I have no idea if a glueball has been seen or not; I don’t keep up much with experimental particle physics. I suspect someone has seen one, but it’s not like you can just shoot a couple of protons at each other and do so in a way that produces only glueballs. Whatever happens happens, and then it’s up to a lot of people who are brighter than me to interpret it.
I have always heard it in the way you interpret it. Virtual particle pairs are still to large. Quantum foam is the state of size at which length and time no longer have any meaning.
Nobody’s created a glueball yet, but CERN did manage to produce a quark-gluon plasma about a year ago. I imagine that particle physicists did learn a good bit about it, but it certainly isn’t the Ultimate Answer to All Questions, or anything like that.
