Transcript Big Bang Theory - West Jefferson Local Schools Home

Big Bang Theory
Theoretical Origins of the
Universe
- most widely accepted among
scientists at the present
Nobody alive was there
to see this.
• You are under no
obligation to believe this
theory. It is simply one
possible explanation
among many possible
explanations for the
origins of the universe.
Big Bang Theory
• Main Premise:
 the universe began with a gigantic
explosion 10-29 billion years ago
 nothing existed before this  NO
time, NO space
 out of nothingness came everything in
the universe and it started to expand
Where is Theory found?
 Authored and thought of by
several scientists based on
work of Hubble’s red shift
Timeline:
• What we see around us (according
to the Big Bang theory) fig. 16-10,
pg. 533
1. Dime sized densely packed piece
of matter (containing all the
matter in the universe) appeared
out of the nothingness and
exploded
Timeline:
2. Expansion of the universe
during the first few seconds
after the big bang, cooled the
created matter enough for
protons, neutrons, and
electrons to form as free
particles, but not to
become stable atoms
Timeline:
3. After ~1million years  the
expansion and cooling allowed
hydrogen to form
- now hydrogen is the most
abundant element in the known
universe
Timeline:
4. This allowed the formation of
other elements, then stars,
planets, etc.
Timeline:
5. Eventually life evolved from
non-living precursors, and
eventually into the life
we see on Earth.
Timeline:
6. Maybe life evolved on other
planets in our galaxy or other
galaxies as well?
Timeline:
7. The future of the universe
- still expanding but for how long?
- gravity from all existing objects pulls against this
expansion
- 3 possible outcomes
1. Universe expands forever
2. Expansion will gradually slow down until a size limit is
reached
3. Expansion will stop and the universe will begin to
contract and fall in on itself  Big Crunch
** Depends on the amount of matter in the
universe (and the mass)
Evidence:
 Cosmic background radiation is
evidence used in support of the
theory
- faint radiation left over from the
explosion itself
 Red shift of wavelengths of light
from distant galaxies
 Expansion implies smaller in past
Problems / Issues /
Flaws with theory:
There was nothing, then there
was something. From where did it
come?
 All matter in the universe in a
dime sized package
 Outcomes? Which will happen?