FORMATION OF THE UNIVERSE THE BIG BANG THEORY

ONCE UPON A TIME, AROUND 14 BILLIONS YEARS AGO… • There was absolutely nothing in the universe • There was not even an universe • Except for an infinitely small, extremely hot point • So small it occupied no space and was nearly infinitely dense • We call it the Singularity • Then it exploded in what we call The Big Bang

BIG BANG THEORY • A theory which describes the process by which our universe originated and evolved. • Proposed in 1927 by Belgian priest Georges Lemaitre • Edwin Hubble found evidence to support Lemaitre’s theory

TIMELINE • The universe begins ~13. 7 Billion years ago as a violent expansion • 0 to 10 -43 seconds • Very little is known about this time period • 10 -43 to 10 -36 seconds • Gravity appears as a separate force • First elementary particles appear (Quarks, Leptons, etc. )

TIMELINE • 10 -36 to 10 -12 seconds • Strong Nuclear Force, Weak Nuclear Force and Electromagnetic Force appear as separate forces • 10 -12 seconds to 3 minutes • Elementary particle fuse to form protons, neutron and electrons • 3 to 400, 000 years • Hydrogen and Helium form

TIMELINE • 400, 000 to billions of years … • Universe slowly cooled • stars and galaxies form • 4. 6 billion years ago (9. 1 billion years after the Big Bang) • Our solar system forms

EVIDENCE FOR THE BIG BANG • Red Shift Analysis • objects in space radiate various forms of energy • If the object is moving away, the wavelength of the light is stretched, so the light is seen as 'shifted' towards the red part of the spectrum • Similar to the Doppler shift for sound Spectrum A shows the spectral pattern in a star or galaxy that is stationary. Spectrum B shows the blue-shifted spectral pattern that indicates the star or galaxy is moving toward Earth. Spectrum C shows the red-shifted spectral pattern that indicates the star or galaxy is moving away from Earth

EVIDENCE FOR THE BIG BANG • Cosmic background radiation • Since the universe is a closed system, the heat generated by the Big Bang does not dissipate. • This heat is distributed throughout the expanding universe and can be detected as Backgound Radiation Blue shows the slightly denser regions of the early universe. These are the areas where galaxies formed as a result of gravity. Red shows the less dense regions that became emptier and emptier as the universe expanded.

EVIDENCE FOR THE BIG BANG • Speed of Light • 300, 000 km/second • 1 light year is the distance light travels in one year • Furthest stars are 10 - 15 billion light years away • We have telescopes that can see further, but there is nothing out there. Hubble Space telescope