Timeline of the Big Bang - Ep.1
Timeline of the Big Bang
Just thought I would summarize the Big Bang timeline as the brit brat about it on LowYatNet is going on. As usual the human mind to place everything in compartments and labeling everything in chronological order has brought us to a timeline of the birth of the Universe as we know it today. Pretty gory stuff especially the annihilation between ‘forces’ that would put most tragic Norse/Greek epics to shame. If this Universe was brought forth by such turbulent ‘forces’ is it possible that the living beings that inhibit it
inherited such characteristics?
According to the Big Bang theory, a sequence of events described below is believed to have taken place starting 13.7 ± 0.2 x 109 years ago, a time at which in general relativity there is a gravitational singularity (a point of infinite space-time curvature). The problem with the big bang is that general relativity and therefore classical physics itself, cannot describe the universe at this time, because there is no time and space before the Big Bang. The theory gives infinite values for the temperature and
density of the universe. Such predictions require a theory of quantum gravity/Grand Unified Theory/TOE (when such a theory is completed). Nevertheless, the time at which general relativity predicts a singularity makes a convenient starting point to begin the timeline, whether there was such a singularity or not.
Planck Epoch - 10-43to 10-35 seconds after the Big Bang
Science tells us nothing about what happened from the time of the Big Bang until 10-43 seconds, a concept known as Planck time. After this, the time is grouped into epochs. At first, these are very short periods; of the seven epochs described below, the first five together last for three minute. The temperature during this epoch is estimated to decrease from 1032 K to 1027 K.
10-43 seconds
At this point, the force of gravity separated from the other three electronuclear force.
10-36 seconds
Separation of the strong force from the electronuclear force, leaving three forces: gravity, strong, and electroweak forces.
Grand Unification Epoch - 10-35 to 10-12 seconds after the Big Bang.
10-35 seconds
This period is where the postulating of the existence of inflation solves a number of problems that were described in cosmic inflation. This period is also very important for the existence of matter in the universe.
Individually, the strong and the electroweak forces behave exactly the same way toward matter and antimatter meaning that there is no opportunity after this time for more matter to be created than antimatter. The strong and the electroweak forces are mixed and act as a single force. Grand unification theories suggest that when this is the case, it may be possible to have particle reactions which create more matter than antimatter.
10-33 seconds
The Quark-Antiquark freezeout begins and lasts until 10-5 seconds. Quarks are able to condense out at these temps but it is still too hot for protons and neutrons to exist (temp approximately 1025 kelvins). Quarks and anti-quarks annihilate each other to create photons, but quarks are created at a ratio of approximately 109 (1 billion) anti-quarks to 109 plus 1 (a billion and one) quarks, resulting in one quark per billion matter-antimatter interactions. The mechanism causing this asymmetry, is called baryogenesis. Here free quarks multiply rapidly.
Electroweak Epoch - 10-12to 10-6 seconds after the Big Bang
10-12 seconds
The diameter of the observable universe increases to approximately 10-13 meters. The weak force, which involves massive particles, condenses and separates from the electromagnetic force, which
involves a massless particle, leaving us with the four separate forces we know today.
Hadron Epoch - 10-6 seconds to 1 second after the Big Bang
Electrons and positrons turn kamizake and annihilate each other.
10-5 seconds
Quarks combine to form protons and neutrons. The lowering temperature allows quark/anti-quark pairs to combine into mesons. After this period quarks and anti-quarks can no longer exist as free particles.
10-4 seconds
The existence of antimatter is cancelled out, as lepton/anti-lepton pairs are annihilated by existing photons. Neutrinos break free and exist on their own.
Lepton Epoch - From 1 second to 3 minutes after the Big Bang.
1 second after the Big Bang
The Formation of hydrogen nuclei (the fuel of suns), the first atomic nuclei. Nuclear fusion begins to occur as the universe is now cool enough for atomic nuclei to form and still hot enough for them to collide to
form heavier elements.
Epoch of Nucleosynthesis - 3 minutes to 300K years after the Big Bang.
3 minutes after the Big Bang
Three minutes after the Big Bang, the universe is too cool for nuclear activity to occur, and these reactions stop. At this point the universe consists of about 75% hydrogen, 25% helium and trace amounts of deuterium, lithium, beryllium, and boron. Elements heavier than this do not have time to form before nuclear reactions stop. By looking at conditions between 1 second and 3 minutes after the Big Bang, one can predict the elemental abundance of the Universe. These predictions are broadly in agreement with observations.
300K years after the Big Bang
The temperature of the Universe is approximately 3K kelvins. At this temperature hydrogen nuclei capture electrons to form stable atoms. This event is known as recombination and is particularly significant because free electrons are effective at scattering light. This implies that this is the time at which space becomes transparent to light, since photons no longer interact strongly with atoms. This means that what we normally think of as matter and what we normally think of as energy become separate. The light from the moment at which the universe became transparent has been redshifted to radio waves and makes up the cosmic microwave background.
Epoch of Galaxies
A major event of this epoch is reionization. We see astronomical objects as they were some time ago. The greater the time since the object was as we see it now, the greater the redshift in the electromagnetic radiation we get from it. In the following table, the variable z is a measure of redshift of objects in which, if we were to observe them, we might see the listed events taking place.
z = 1500 - cosmic microwave background generated 300,000 years after Big Bang
z = 15 - First reionization
z = 6 - Oldest quasars
z = 5 - Reionization ends
z = 1 - Youngest quasars
Next up The Death Of The Universe.Woot! Episode 2 and finale
