The Big Bang!

“To make an apple pie from scratch, you must first invent the universe”

Carl Sagan 1980

Why Must We Create The Universe?

• The original atoms and elements were created seconds after the Big Bang

What Was The Big Bang?

• The Big Bang Theory States that the universe began as a point and has been expanding ever since– All of the matter and energy in the universe was

contained in this point

Big Bang Timeline

What was it like during the Big Bang?

• Matter as we know it did not exist due to the extremely hot temperatures and incredible density

• Temperature was 1023 K (This is really hot)

• You must realize the big bang was not an explosion but a rapid expansion

4 Forces of Nature

• At the time of the Big Bang, these forces could not be distinguished!!!!!

1. 10-43 – 10-36 second gravity split from the other 3 forces

2. 10-36 – 10-12 second the strong force separates from the electromagnetic and weak force

3. 10-12 – 10-6 the electromagnetic and weak forces separate

What Happened Next?

• 1 second after the Big Bang the temperature dropped to 1011 K or 100 Billion K– At this temperature protons, neutrons and

electrons form

• As seconds go by the temperature continues to drop– Atoms cannot form due to the subatomic particles

having too much energy

At about 100 seconds

• Temperature drops to 109 K or 1 Billion K– At this temperature protons and neutrons form

the first atomic nuclei • Deuterium is formed.

– Deuterium is an isotope of hydrogen with an extra neutron– Important to remember that not all atoms were formed at

this point– Sometimes when deuterium nuclei collided with each other at

great speeds helium nuclei formed

As the expansion continues

• Temperatures continue to fall• More nuclei are formed• After a couple of minutes the universe has

three elements– Hydrogen (95%)– Helium (5%)– Lithium (Trace Amounts)