The document summarizes Edwin Hubble's early 20th century findings that helped establish the Big Bang theory of the universe's origin. Hubble observed that galaxies were moving away from Earth at speeds proportional to their distance, indicating an expanding universe. This led astronomers to propose that the universe began as a single point that expanded over billions of years, explaining the observed red shifts and increasing distances between galaxies. Subsequent evidence like the cosmic microwave background radiation further supported the Big Bang model of the origin and evolution of the universe.

1. 10.1 THE EARLY UNIVERSE

2. EARLY IDEAS ABOUT SPACE
• Until about 100 years ago
astronomers thought that
outer space was
unchanging.
• 1918-1929 Telescope
technology improved and
allowed astronomers to
observe many celestial
bodies that had never
been seen before.

3. EDWIN HUBBLE

4. • First astronomer to identify galaxies other than
our own (Milky Way)
• By 1929 Hubble had identified and estimated
distances of 46 galaxies
• He noted that the galaxies were not staying still,
but were moving away from each other

5. HUBBLE’S PROPOSAL
• Universe is expanding in all directions
• More distant galaxies are moving away faster
than near by galaxies
• Expansion is accelerating
• Path of expansion can be traced backwards and
galaxies appear to originate from the same
location
• Hubble based his proposal on evidence from red
shift analysis

6. RED SHIFT ANALYSIS
• Electromagnetic Radiation:
• Energy that is carried in the form of waves.
• Includes: Visable light, X-rays, radio waves, UV
radiation etc.
• Stars and galaxies emit different types of
electromagnetic radiation

7. SPECTRAL PATTERNS
• White light spits into bands of rainbow colours
when it passes through a prism
• The pattern of colours is called a spectrum
• Each colour of the spectrum represents a
specific wavelength
• A spectroscope is an instrument that allows the
observer to see the pattern of spectral lines

8. • Galaxies and stars emit characteristic spectral
patterns created by the elements they contain

9. COSMOLOGICAL RED SHIFT
• Hubble noticed that the spectrum from distant
galaxies appeared to have shifted toward the red
end of the spectrum.
• This change is due to a lengthening of
wavelengths as the galaxy move away from the
observer.

10. BIG BANG THEORY
• Hubble’s observations about galaxies
moving apart led astronomers to
hypothesize what the beginning of that
process must have been
• In 1927 Georges Lemaître proposed a
theory that stated the universe was
formed in a single dramatic moment of
expansion
• His theory was ridiculed and
sarcastically nicknamed the big bang
theory
• Evidence has since been collected to
support this theory and the name
stuck.

11. • Big Bang Theory: 13.7 billion years ago, a tiny
volume of space quickly expanded to a very
large size. In a short time, all matter and energy
were formed.

12. THE BIG BANG THEORY EXPLAINED
• http://youtu.be/DmUiCweDic4

13. EVIDENCE FOR THE BIG BANG THEORY
• Cosmic Background Radiation:
• Astronomers in the 60’s monitoring microwave
radiation in space picked up background noise or
interference. They concluded this was the left over
cosmic energy from the big bang
• Radiation: the transmission of energy in waves.
• As particles of gas were created in the early
universe, heat was produced in the form of
microwave radiation.

14. • Data gathered by the Cosmic Background Explorer
(COBE) and the Wilkinson Microwave Anistropy
Probe (WMAP) has helped corroborate the Big Bang
Theory.

15. WHAT WE KNOW SO FAR
• http://youtu.be/17jymDn0W6U