Why is it predicted that the universe has more matter than antimatter?

Question

The universe at a subatomic has a basic symetry to it (e.g electrons and protons) with equal amounts of each opposite particle (e.g quarks) so why doesn't this apply to matter and antimatter?

Why don't they exist in equal amounts in order to maintain cosmic balance?

If they do exist in equal amounts why didn't they just annihilate each other at the begining of the universe when they were in relatively close proximity?

Answer 1

There are strong evidences that the universe is made of matter with very few antimatter. It is believed that particles and anti-particles were equally numerous in the early universe, but the former came to dominate as the universe cooled. Baryogenesis is the hypothetical physical process, that generated an asymmetry between baryons and anti-baryons in the very early universe.

Soviet physicist (and dissident) Andrei Sakharov pointed out three conditions necessary for the asymmetry to develop:

The universe must be out of equilibrium - This is a natural consequence of the expansion of the universe. In this situation the particles and their corresponding antiparticles do not achieve thermal equilibrium due to rapid expansion decreasing the occurrence of pair-annihilation, and hence allowing a chance for the baryon-asymmetry process to take place.

The conservation of baryon number must be violated - This , too, is inevitable during the epoch of the grand unification of the fundamental forces in the early universe when baryon number was not conserved.

CP symmetry must be violated - Otherwise any process that changes the amount of matter would be balanced by a similar effect for antimatter.

It is observed that only a small asymmetry is required in the early universe, as today we have only one leftover proton for 109 photons (assuming the photons were created by the annihilation of particles and antiparticles).

Dr. H

Answer 2

When particles collide with their anti-particles, the effects are devastating; they both disintegrate into electromagnetic radiation, their energy carried away in neutral particles called photons. In other words, if there were as much antimatter as matter in the universe, we wouldn’t be here to ask grand questions. The universe is somehow unbalanced, biased toward the existence of matter over antimatter. One of the greatest challenges in modern cosmology is to unveil the roots of this cosmic imperfection.

In this hot cosmic furnace, many different types of particles were being cooked, not necessarily the familiar quarks (the constituents of protons and neutrons) or electrons. As the universe expanded and cooled, a sort of selection mechanism not only biased the creation of quarks and electrons over other types of particles, but also generated the excess number of particles over anti-particles. Surviving the annihilation with their antimatter cousins, these excess particles organized themselves into more complex structures, until eventually atoms, mostly hydrogen, were formed when the universe was about 300,000 years old. The mystery, then, is to understand what kind of physics could generate this bias.

Answer 3

The universe has many symmetries and there is one symmetry that is violated that caused more matter than antimatter to be produced when the initial blast of radiation turned to matter. The two annihilated each other leaving the excess matter to stick around.

Answer 4

Well, matter and antimatter cannot be equal amounts because it would be dangerous. If antimatter and matter touched it would create an explosion.

For example if your antimatter version of yourself touched you, both you would blow up as well as about 1/16 of the Earth I think.

So if there were equal amounts life would be more dangerous and explosions would be more common than not.

Answer 5

B is the respond found interior the regularly occurring concept. the certainly clarification is extremely complicated and is composed of debris that existed purely close to the time of the vast Bang. the human beings who choose to maintain an open suggestions could desire to undergo in suggestions there's a differnce between an open suggestions and an empty one.

Answer 6

Because anti matter dumps into a fifth demension(the place where gravity goes). This explains why a paperclip hols on to a magnet and can't be pulled away by the mass of the Earth.