For one thing, the universe has been around forever.
This means if any antimattter out there hasn't collided with matter yet, it's probably not going to collide with it tomorrow either.
Some of it got away, it was no big thing, same ole same ole.
It doesn't all come at once in one universal energy decay event, the universe is too big for that, there's no limit to the universe, it's infinite with infinite energy. Energy is always conserved that way.
This means if any antimattter out there hasn't collided with matter yet, it's probably not going to collide with it tomorrow either.
How long has the universe existed? How long, to the best of your knowledge, has plutonium existed? See a pattern here? Of course not, that was a leading question. I seen on TV show some of top nucular science wizards in manhattan were worried that a a u-bomb might actually set fire to the atmosphere. Boy that would suck, eh?
How long has the universe existed? How long, to the best of your knowledge, has plutonium existed? See a pattern here? Of course not, that was a leading question.
LOL.
I 'figured' all this out once I decided gravity has a static or standing wavelength relative to its source and the waves have both negative (antigravity) and positive phases. I'll call it 'bipolar' quantum gravity. Seems there could be different wavelengths of gravity too. The basic bipolar gravity wave idea could explain at least some dark energy and dark matter, I suppose.
Anti-matter has much to do with the Dirac sea, where the surface is empty space. If the sea is regular I suppose the probed surface must have some of the event qualities of a space lattice made of particles and their anti-particle twins. Maybe space is like a matter-antimatter checkerboard, and matter is like a white-square bishop. If so, maybe dark matter and energy come from anti- matter. This further suggests that maybe gravity from antimatter starts out in opposite phase relative to matter's gravity, which for example would cause gravitational repulsion between matter and antimatter when both gravities predominate and are positioned within the relevant gravitational wavelengths, as with sufficiently large paired masses of the two forms.
I've always thought of matter/antimatter as almost godlike magnets, fiercely quarrelsome and unwilling to meet. It's no wonder most people prefer to worship the relatively weak magnet.
The idea lends itself to that sort of visualization where bodies of both type interact gravitationally in a bipolar way, just like with magnetic N and S. There's also a slight suggestion within the idea, along that vein, to suppose the cutoff of minimum gravity wavelength is the maximum electromagnetic wavelength, where the force particle energy is large enough to have its own significant gravitational interaction with space, as a separate gravitational entity. Perhaps thus electromagnetic force particle phase is not of the static or standing variety except for gravitationally, relative to the particle. The electromagnetic particle is I suppose skating over the Dirac sea, not pushing (probing) into it, up to a further energy threshold, where it begins to behave as a spinning charged matter-antimatter pair, apparently by the way it interacts with the Dirac sea.
When matter and antimatter particles have opposite charges they attract electrostatically, but when either has no charge apparent to the other I suppose (for the sake of this theory) they only gravitationally repel. This is one way of thinking about how a proton can produce a positron and a neutron, and how antimatter and matter can seemingly be mixed together in one particle.
Here's something more conventional, the source is easy to look up:
Why is mass of neutron greater than mass of proton?
This is a very complicated question with no simple "hand-waving" answer. In energy units (using E = mc^2), the masses are: Proton: 938.272 MeV, neutron: 939.566 MeV, mass difference = 1.293 MeV, electron: 0.511 Mev.
It is tempting to say that a neutron consists of a proton plus an electron; the mass of the electron would make up 40% of the mass difference. This argument is totally invalid. It would be equally valid to say that a proton consists of a neutron plus a positron (a positron has exactly the same mass as an electron, but is positively charged). The validity of using this argument in both directions is strengthened by the fact that neutrons in neutron rich nuclei beta decay into an electron and a neutrino while protons in proton rich nuclei beta decay into a positron and a neutrino. For example a N13 (nitrogen 13) nucleus decays into C13 (carbon 13), a positron, and a neutrino with the release of 2.221 MeV.
The charge of the proton adds some electromagnetic energy to the proton mass, but the magnitude of that effect is not only impossible to calculate, but works in the wrong direction.
Quarks give the best chance to explain the proton-neutron mass difference by "hand-waving". A proton consists (mainly) of two up quarks and one down quark. A neutron consists (mainly) of one up quark and two down quarks. Current estimates are that the up quark has a mass in the range 2-8 Mev and the down quark 5-15 MeV. So replacing one up quark in the proton by a down quark would increase the mass by something between -3 MeV and +13 MeV. Clearly this is not a precise calculation, but it is (mostly) in the right direction and could overcome the electromagnetic contribution and produce the correct answer. There are other known contributions to these masses including interactions with the weak and strong interactions, but this is probably already more than you want to know about this subject!