4 ms·
Particles are sort of mathematically more poorly defined the shorter their lifetime. But yes, a nanosecond is a long time in this context :)
by tfgg 11y ago
Particles are sort of mathematically more poorly defined the shorter their lifetime. But yes, a nanosecond is a long time in this context :)
- pif 11y ago> Particles are sort of mathematically more poorly defined the shorter their lifetime. This sentence doesn't make any sense to me. Could you please elaborate?
- pc86 11y agoNot the person to whom you're replying, but my lay understanding of it was that it's much more difficult to model mathematically those particles which exist for incredibly small spans of time.
- Benjamin_Dobell 11y agoI know nothing about the mathematics. But I think it's fair to say that in general people tend think of particles as being a _stable_ unit of some sort. So the term "particle" becomes less appropriate the less stable something is, and time is often a factor when thinking about stability. If someone were simply to slam 4 neutrons together, for how long would they need to stay together for this to be deemed a real particle? I think it's for this reason the original commenter quoted the use of the term "particle".
- yk 11y agoNot the person you replied to either, but roughly speaking a resonance is mathematically the same as a particle. However the two concepts differ of course philosophically. So the shorter the lifetime of a particle is, the more one is inclined to call it a resonance rather than a particle.
- yk 11y agoNot the person you replied to either, but roughly speaking a resonance is mathematically the same as a particle. However the two concepts differ of course philosophically. So the shorter the lifetime of a particle is, the more one is inclined to call it a resonance rather than a particle.