After the Big Bang

ENERGY & MASS

• The infant Universe was searingly HOT!• It was full of energy of intense radiation.• Albert Einstein’s equation E=mc2 says that

mass and energy are interchangeable. – so one can be turned into the other.

• So in the early Universe Energy was converted into matter (stuff with mass)

the atom

• Basic unit of matter = atom• Consists of:– Central Nucleus • Contains protons and neutrons

– Cloud of Electrons • Bound to nucleus via electromagnetic force

subatomic particles

• Three main Subatomic Particles:– protons (p+)– neutrons (n0)– electrons (e-)

Expansion & Cooling

• After the Big Bang the Universe expanded rapidly.

• As it expanded it cooled.• As it cooled, matter began attracted to each

other and the four forces of the Universe were born.

Four Forces of the Universe

1. Gravity: Mass is attracted to Mass2. Strong Force: the force between the protons and

neutrons of the nucleus of atoms. It holds the nucleus together.

3. Weak Force: An attraction between hydrogen atoms. Causes nuclear fusion between hydrogen atoms, it is the reason the sun burns.

4. Electromagnetism: Attraction between charged particles (e.g.protons & electrons). It is the force that holds atoms together.

Birth of the simple Elements of the periodic table

The first elements

• Hydrogen formed: As the Universe cooled the strong force pulled a proton and neutron together to form hydrogen nuclei.

• Helium forms -- Eventually two protons and two neutrons were attracted to each other via strong force and helium nuclei were formed.

• Lithium forms: Three protons & three neutrons come together become lithium

Helium

Hydrogen

Lithium

Galaxies Form

• Clumps of dark matter attract Hydrogen and Helium gas through the force of gravity

• These clouds form huge clouds will eventually become galaxies.

Stars Form• A star is formed when a large amount of

hydrogen gas starts to collapse on itself due to gravity.

• As the atoms collide the release a lot of heat energy.

• Eventually colliding nuclei hydrogen will fuse and form helium. This nuclear fusion causes a huge release of energy like a nuclear bomb. This nuclear fusion is what causes stars to burn.

Nuclear Fusion – Formation of stars

V.4 Formation of Stars VideoStephen Hawking

http://www.youtube.com/watch?v=9EnBBIx6XkM

Stars Die, Heavier Elements form

• Eventually stars run out of hydrogen gas and this causes the stars to contract and heat up more.

• This increase in heat and pressure causes helium atoms to fusion with other helium and hydrogen atoms.

• This forms heavier elements such as carbon, oxygen • Sometimes large stars will explode when they run out

of hydrogen gas becoming supernovas, this explosion causes the formation of even heavier elements.

V.5 Formation of Elementsof Stars and supernovas in Stephen

Hawking Videohttp://www.youtube.com/watch?v=tXV9mtY1AoI&feature=related

V.6 Formation of our Solar SystemStephen Hawking

http://www.youtube.com/watch?v=Uhy1fucSRQI&feature=relmfu