Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 27/11/2012 15:56:38

Title: How long do fundamental particles last?
Post by: thedoc on 27/11/2012 15:56:38
Dear  Dr. Smith,

How long do protons and neutrons survive outside an atom?

Salih
Asked by Salih


                                        Visit the webpage for the podcast in which this question is answered. (http://www.thenakedscientists.com/HTML/podcasts/show/20121125/)

 

Title: How long do fundamental particles last?
Post by: thedoc on 27/11/2012 15:56:38
We answered this question on the show...

Martin -   Protons and electrons, as far as we’re concerned in our lifetime last forever.  
Neutrons last for just under 15 minutes if they're on their own.  To do an experiment, actually the experiments we do with neutron scattering take place where you only need for them to last for less than a second.  So that’s not an issue.  But you can actually capture neutrons, put them in something like a little bottle.  They last for just under 15 minutes.  If you have a neutron that’s actually part of a nucleus then it effectively lasts forever.  But on its own,  just under 15 minutes.
Dave -   So being inside that nucleus is somehow stabilising it, making it last a lifetime.
Martin -   Yes, absolutely.
Title: Re: How long do fundamental particles last?
Post by: syhprum on 27/11/2012 16:22:20
Can Neutrons and Protons be considered Fundamental particles are they not just bundles of Quarks and Gluons that can only be separated at very high energy ?
It is an interesting point that the mass of a proton is much higher than its constituent parts in as much as they can be measured.
Title: Re: How long do fundamental particles last?
Post by: Ethos_ on 27/11/2012 16:43:51
If the neutron lasts for only 15 minutes without the influence of the atomic nucleus, does the neutron exist as such in a neutron star because of the extreme pressures? And if this is so, what about the surface of the neutron star? Are the neutrons also stable at it's surface where pressures are much less than in the interior?