|
Stage |
|
Time after Zero |
|
State |
|
Inherent Entropy |
|
Homogeneity through Time |
|
|
The Beginning |
|
Time zero |
|
kernel of energy of infinitely small magnitude |
|
open to discussion |
|
no time (or space) |
|
|
Stage I |
|
10-32 sec |
|
plasma of primary or fundamental particles, quarks, leptons, antimatter, formed by explosion of the kernel |
|
absolute minimum |
|
homogeneous (as a gas cloud) |
|
|
Stage II |
|
10-4 sec |
|
plasma of secondary particles e.g. protons and neutrons formed by combination of the primary fundamental particles. The transition occurred because the Universe cooled. |
|
step increase to a state of entropy which was very low (because of a decrease of temperature sufficient to allow particle agglomeration) |
|
homogeneous (as a gas cloud) still |
|
|
Stage III |
|
3x105 years |
|
atoms of hydrogen and helium form by condensation of secondary particles, Universe becomes more transparent. |
|
further step increase to state of low entropy (gas cloud) |
|
homogeneous (as a gas cloud) |
|
|
Stage IV |
|
109 years |
|
clouds of hydrogen condense to form stars |
|
increase in entropy |
|
no longer homogeneous |
|
|
Stage IVa |
|
>109 years |
|
stars form galaxies and clusters of galaxies |
|
further increase in entropy |
|
not homogeneous |
|
|
Stage IVb |
|
>109 years |
|
some stars begin to make heavier nuclei by fusion |
|
increase in entropy |
|
not homogeneous
| |
|
Stage IVc |
|
>109 years |
|
some stars collapse at the end of their lives, and explode in supernovae explosions, producing even heavier atoms and dispersing them |
|
increase in entropy from manufacture of heavy elements and dispersion |
|
not homogeneous
| |
|
Stage V |
|
15 x 109 years i.e. today |
|
all processes continue. Add black holes e.g. at the centre of galaxies, as in Milky Way. Add dark matter, which forms a large part of the Universe. |
|
ever increasing, as the Universe cools down |
|
not homogeneous
| |
|
The Future |
|
for ever, from today |
|
endless expansion. Increasing separation of component parts until they eventually lose touch. No stars in the sky. |
|
entropy ever increasing to a maximum |
|
not homogeneous |
|