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F. THE EVENTS OF THE EARLY UNIVERSE
Some 15 billion years ago, a tremendous expansion called the Big Bang
brought our universe into existence.
| TIME |
EVENTS |
| 10-43s |
Temp= 1032K Creation and destruction
of black holes; Superforce separates into the gravitational and Grand Unified
forces; universe begins expanding and cooling |
| 10-35 10-12s |
Temp= 1027K Condensation of matter
and antimatter particles from energy; rapid inflation of universe;
Grand Unified force separates into electroweak and nuclear force; Gravitons
and photons formed; matter and antimatter annihilate each other |
| 10-12 to 10-6 s |
T= 1015K From here on out the universe
expands inertially; electro weak force separates into electromagnetic and
weak nuclear forces; all 4 forces present now; formation electrons and
positrons and neutrinos and anti-neutrinos Gravity begins to slow the inertial
expansion of the universe |
| 10-6s to
1s |
T drops below 1013K
quarks and antiquarks combine into protons and antiprotons and neutrons
and antineutrons which annihilate each other. Because slightly more matter
than antimatter had been created in the beginning, matter is all that remains
to form the present universe. |
| 1s to 15s |
T drops to 1010K
neutrinos cease to interact with other particles |
| 15s to 1 min |
T<3x109 K electrons and positrons
annihilate each other; there is a surplus of electrons |
| 1 min to 5 min |
T drops from 1.6x 109K to 6x108K
Fusion of H nuclei (protons) to He nuclei. Comp of universe:
76%H and 24% He |
| 5 min to 1,000,000 yrs |
T drops from 6x108K to 3x 103K Universe
continues to expand All matter still ionized Universe
is opaque |
| 1,000,000 to one billion years |
T drops from 3000K Electrons combine with nuclei to form
neutral atoms Universe becomes transparent Universe some 107
ly
in size Breakup of universe into primordial clouds |
| 1 billion yrs to now |
T drops to 3K Formation
of galaxies and star systems |
In the first instants there was only pure energy. As this energy expanded,
it cooled, and within the first second, the basic forces and particles
that would later become all the things we see in our universe and how they
interact, condensed from this energy. Within the first five minutes, these
basic particles will have combined to form nuclei, mainly Hydrogen and
Helium, (roughly 75 and 25%). At roughly a million years after the beginning,
this universe has cooled enough for the nuclei to combine with electrons
and to form neutral atoms. This universe contained twice as much matter
as needed to form the 100 billion or so galaxies we see today. As time
went on, about half of this expanding sphere of matter (mostly Hydrogen
and Helium gases) aggregated into components until each of these components
became gravitationally stable and contained enough matter to make a galaxy.
These are called protogalaxies. The other half remains disseminated in
intergalactic space. As stars begin to form in these protogalaxies turning
them into galaxies, the universe begins to take on its present appearance.
In the early stages of galactic formation, many (perhaps even most) of
these are small galaxies, that will collide to form the large galaxies
we see today. This took place perhaps as early as a billion years
after the Big Bang.
One of these immense clouds of Hydrogen and Helium (protogalaxies) would
eventually become our own galaxy, the Milky Way. Over the 10-plus billion
years that the Milky Way has been in existence, stars and solar systems
have been born within it, gone through their lives and died. Some have
died quietly, while others self-destructed in spectacular explosions called
supernovae |
