- #1
Stephanus
- 1,316
- 104
Dear PF Forum,
I have read a link about big bang time line. Started from time zero, then Baryogenesis, lepto genesis, Planck time then on...
http://www.physicsoftheuniverse.com/topics_bigbang_timeline.html
The mass of the universe is: 1053Kg.
Schwarzschild radius: 1.486 x 1026
So at T+20 minutes after big bag, the radius of the universe is: 1.8 x 107Km
All these mass is packed at that radius, defintely below Schwarzshild Radius.
How can all that mass continued to spread out much less for millions of year.
What triggered that expansion?
And if I imagine what sphere is 20 minutes light year with that mass compared to Neutron Star.
A 2 solar mass neutron star is about 10 km in diameter, this is very roughly.
In 20 minutes light speed, the sphere could be packed by... (1.8 x 107/5)3 = 4.66 x 1019 neutron stars.
And the number of stars in the universe if a galaxy has roughly 100 billions stars in 100 billions galaxy is 1022. So the sphere is much denser than neutron star?
I have read a link about big bang time line. Started from time zero, then Baryogenesis, lepto genesis, Planck time then on...
http://www.physicsoftheuniverse.com/topics_bigbang_timeline.html
I try to make a simple calculation here with Schwarzschild calculator.
- Nucleosynthesis, from 3 minutes to 20 minutes:
The temperature of the universe falls to the point (about a billion degrees) where atomic nucleican begin to form as protons and neutrons combine through nuclear fusion to form the nuclei of the simple elements of hydrogen, helium and lithium. After about 20 minutes, the temperature and density of the universe has fallen to the point where nuclear fusion cannot continue.
The mass of the universe is: 1053Kg.
Schwarzschild radius: 1.486 x 1026
So at T+20 minutes after big bag, the radius of the universe is: 1.8 x 107Km
All these mass is packed at that radius, defintely below Schwarzshild Radius.
How can all that mass continued to spread out much less for millions of year.
What triggered that expansion?
And if I imagine what sphere is 20 minutes light year with that mass compared to Neutron Star.
A 2 solar mass neutron star is about 10 km in diameter, this is very roughly.
In 20 minutes light speed, the sphere could be packed by... (1.8 x 107/5)3 = 4.66 x 1019 neutron stars.
And the number of stars in the universe if a galaxy has roughly 100 billions stars in 100 billions galaxy is 1022. So the sphere is much denser than neutron star?