The Big Bang
This is a quick summary of the standard model for the Big Bang. It may help if you read my pages on Quantum Mechanics and Particle Physics before reading this.
I am not going to deal here with what occurred before the Big Bang, that is outside the scope of this essay. If you want to argue that a supernatural cause must have started the Big Bang, I will go along with that for the sake of argument. Here is the supernatural version that I would subscribe to:
From the Rig Veda
The non-existent was not; the existent was not at that time. The atmosphere was not nor the heavens which are beyond. What was concealed? Where? In whose protection? Was it water? An unfathomable abyss?
There was neither death nor immortality then. There was not distinction of day or night. That alone breathed windless by its own power. Other than that there was not anything else.
Darkness was hidden by darkness in the beginning. All this was an indistinguishable sea. That which becomes, that which was enveloped by the void, that alone was born through the power of heat.
Upon that desire arose in the beginning. This was the first discharge of thought. Sages discovered this link of the existent to the non-existent, having searched in the heart with wisdom.
Their line [of vision] was extended across; what was below, what was above? There were impregnators, there were powers: inherent power below, impulses above.
Who knows truly? Who here will declare whence it arose, whence this creation? The gods are subsequent to the creation of this. Who, then, knows whence it has come into being?
Whence this creation has come into being; whether it was made or not; he in the highest heaven is its surveyor. Surely he knows, or perhaps he knows not.
Now that before the Big Bang has been dealt with, I will start the story backwards.
We live in a universe that is expanding. We know this because if we look at distant galaxies, they are nearly all moving away from us. We can tell this by the red shift of the light we receive. Theis redshift is caused by the Doppler effect. If we go backwards in time, the galaxies start moving towards each other, and the light we receive gets 'blue shifted'. Light moving towards the blue end of the spectrum increases in energy, and if we push things together and increase the pressure then the temperature increases.
Another way of knowing that the universe is expanding is Relativity theory. When Einstein developed general relativity he was noticed that the equations showed an expanding universe. At that time (1915) it was believed that the universe was static, so Einstein put in a constant to prevent his equations from showing an expanding universe. When Hubble showed the universe really was expanding, Einstein admitted the constant was "The biggest mistake I ever made". Relativity, which has been proven so many times shows an expanding universe.
So, as we get closer to the start of the universe, the temperature and pressure increases. Keep pushing backwards and we eventually reach a point where the whole universe is compacted into a tiny point. This is a difficult concept, because time and space were also contained inside that very small point. That is the Big Bang. The following is a description of the mathematics that describe the Big Bang. A lot of the concepts in this have been experimentally confirmed.
Now, we can go forward again. I will start at a point 10-2 seconds after the Big bang. At this time the temperature of the universe was 100 Billion K. This is such a high temperature that all the radiation in the universe could create matter and matter could make radiation freely, according to the ideas behind relativity.
From 10-4 to 10-1 seconds the following nuclear reactions could occur:
A photon could change into an electron and a positron. This was because the energy of the photons was greater than the energy of an electron-Positron pair.
An antineutrino could combine with a proton to form a positron and a neutron
A neutrino and a neutron could combine to form a an electron and a proton.
All of these were reversible. There was enough energy to do this until the temperature went below 30 Billion K.
This is where the Protons and Neutrons that formed all the elements came from. After this point, Prorons and Neutrons couldn't be created any more, the temperature was too low.
A neutron will spontaneously change into a proton and an electron. This happens very rapidly. They are only stable inside a nucleus. This means that in the early universe, when there was too much energy for nuclei to be stable, but not enough for there creation, neutrons started decaying.
At 0.2 Seconds after the Big Bang there was a ratio of neutrons: protons of 38:62
At 1.1 seconds after the Big Bang when the temperature had dropped to 10 Billion K the density of the universe dropped sufficiently for neutrinos to "decouple" as they no longer got caught up in the creation of the nuclear particles. They could go their separate ways to the rest of matter/radiation.
After 2 Seconds, the temperature was 109 K and the neutron: proton ratio was down to 24:76
After 13.8 Seconds, there was no longer enough energy in the photons to produce electron-positron pairs.
After 3 minutes He4 Nuclei became stable. At this point the neutron: proton ratio was 14:86. This meant that the total amount of helium in the universe, by mass was 28%. This is what is observed today in the universe, an excellent confirmation of the processes that went on.
So, the elements that came out of the Big Bang were Hydrogen and Helium. By the time that helium was stable, the density was too low to produce any heavier elements.
One other time, early in universal times. That is 300,000 years after the Big Bang. It was then that the temperature of the universe dropped enough for electrons to get caught up in atoms. This meant that photons could "decouple" like the neutrino's did. From that point on the radiation continued travelling across the universe, and that is the background radiation that can still be picked up today.
These are some tentative notes about the origin of the Big Bang. This is still to be worked on
There are mathematical proofs that show that in a closed universe the Gravity MUST counterbalance the other forces, leaving the total amount of energy in the universe as zero.
This is possible, because gravity is at zero when the matter in the universe is at infinity (according to Einsteins relativity). Bringing the matter together makes the gravity negative (the position we are in now). The mathematics of N=11 gravity (the 11 is the number of dimensions that are used to describe the equations) show that the gravity must balance the other forces.
Now according to Heisenbergs uncertainty theory, a virtual thing can appear for a limited time, based on the amount of energy it has, the more energy, the less time. Now, with a closed universe this means that the total energy is zero (seen from the outside) so the amount of time it can exist for is infinity. Nothing is "borrowed" from uncertainty so nothing needs to be returned.
Hawking has also shown using N=8 gravity (superstring) that there need not be a singularity at the start of the universe. This is dealing with 8 dimensions, so an analogy needs to cut them down a little.
You are on a globe, you go to the North pole. Now, within the dimensions of that sphere what is north of that? The question has no meaningful answer. The same is true with the Big Bang, all the dimensions can be screwed up tight within themselves, needing nothing to create the universe. This includes the fourth dimension of time, so time and space started at the same point, and to ask 'What was before it?' is a pointless question, because there was no 'before' Time.
This was first said by Hawking in 1981 to the Vatican, at the same conference that the Pope said that Scientists can discuss what happened after the Big Bang, but cannot discuss the moment of creation itself.
All this taken from 'In search of the Big Bang' by John Gribbon.
