To start off the New Year a reason to be thankful...
When I was in high school I came across one of those factoids that both amazed and bothered me. One of those things that forces you to dive in deeper so you can sleep. It turns out the neutron is radioactive ... it decays to three particles - a proton, electron and neutrino with a half life of 611 seconds.1 If this suddenly happened all of the neutrons in the universe would be gone in a couple of days. Forget carbon, oxygen and the other building blocks of life, everything other than hydrogen would be gone. Fusion couldn't take place and stars wouldn't have ignited. Sort of bad news for a budding universe. So what gives?
A neutron is very slightly more massive than a proton. In fact a little more more massive than a proton, electron and neutrino. The decay is allowed ... the sum of the decay products is less than the neutron we started with. But that isn't happening.
When a neutron is bound to the nucleus it loses a bit of energy. Think about it. You let a neutron fall into a friendly nucleus it is bound to the nucleus. It takes energy to pull it out, so the bound neutron has less energy than it did when it was free. Einstein showed the equivalence of mass and energy with E = mc2, so the bound neutron has effectively lost a little mass. Now the neutron has less mass than the sum of the proton, electron and antineutrino and there are no other paths it could use to decay. Conservation of energy keeps it stable.
If the neutron was a bit more massive - anything more than about a tenth of a percent - it would have enough energy to decay even though it was bound. Had that happened the universe would have been a boring place.
Mass is cause for celebration not to mention existance. By special relatively a massless particle, a light photon for example, moves at the speed of light. If all particles were is only partly true. It gives electrons mass but only about 0.03% of your mass comes from electrons - 21 grams for the average 70 kilogram person. The Higgs field also gives mass to the quarks, but if you add it up your quark mass is only about one percent of the total ... about seven-tenths of a kilo for the average person.2
The rest of it can be readily explained it gets a little technical. If anyone's interested I'll work on a high level description. Underlying this is a remarkable story. The period from 1960 to 1975 was one of the most revolutionary in physics -- in all of science for that matter. It's not very well known, but few real revolutions are.
1 99.9% of free neutrons decay to proton, electron and anti-electron neutrino. About 0.1% decay to proton, electron, anti-electron neutrino and a gamma ray. There is an obscure mode that occurs even more rarely
2 If someone asks your weight you can fool with them and give them your electron or your quark mass.
Nothing specific other than noting juice cleanses and dietary detoxes are pseudoscience ranging from ineffective to sometimes dangerous. A healthy diet is the better way to start a new year..