Matter and anti-matter are identical except they have opposite electrical charges.
They are anti-particles.

Einstein's equation reduces to its most famous form E = mc². In the 1930's physicists
discovered the equation worked in both directions. That is, if enough energy exists
in a given area, mass in the form of a pair of particles (electron and positron )
would be created, travel a short distance, then collide and annihilate each other
with 100% of their mass would ending up as energy (E). This process takes an extremely
short time; about 0.000000000000000001 of a second.

Astronomers tell us that when the big bang occurred there was an equal amount of matter
and anti-matter created. Now, however, the anti-matter is missing.

What if just prior to the big bang the only thing in existence was an enormous energy
field and the universe is just an example of pair production writ large? Would the ratio
of the combined masses of the pair to the time taken to complete the process be the same
for the electron/positron pair as for the matter/anti-matter universe?

The mass for an electron/positron pair is ≈ 1.8 X 10 ^ -30 Kg.

The time span for an electron/positron pair from inception to destruction
is ≈ 10 ^ -18 Sec

Estimates for the mass of the universe range from 1.4 X 10 ^ 53 Kg to 8 X 10 ^ 52 Kg.
X 2 to account for the anti-matter universe.

The ratio for the election/positron pair is

1.8 X 10 ^ -30 Kg
------------------- ≈ 1.8 X 10 ^ -12
1 X 10 ^ -18 Sec

Hence, the ratio for the matter/anti-matter universes is

2.8 X 10 ^ 53 Kg
------------------- ≈ 1.8 x 10 ^ -12
1.6 X 10 ^ 65 Sec

And

1.6 X 10 ^ 65 Sec ≈ 5.1 X 10 ^ 57 years

Would be the time it will take for the matter/anti-matter universes to collide and
disappear back into the energy field.

Therefore, the universe has a beginning and an end, the missing anti-matter is
accounted for, and simplicity is elegant.