1. Theory on the Formation of the Universe

2. Popular Theories
Steady State Theory - theory suggesting that the universe & everything within it is unchanging. Elastic Theory - the universe acts like a rubber band, expanding & contracting over time (currently it is expanding) Big Bang Theory - most widely accepted theory by scientists today

3. What is a Theory?
Theories are an explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many observations, experiments and laws.
Theories are:
Based on evidence
Tested
Effective in problem solving
The explanation of HOW

4. Origin of the Universe Big Bang Theory
occurred approx. 14 billion years ago
model for the beginning of the universe

5. Building a Universe
Infinitely dense point not governed by our physical laws or time
All matter and energy contained in one point the size of a pinhead.
The temperature was so great that atoms could not exist
Einstein’s theory of relativity predicts this “smaller than a proton” time=0 state

6. Building a Universe Instantaneous filling of space with all matter.
Universe came into existence at one moment in time and then expanded rapidly
Instantaneous filling of space with all matter.
Not an explosion, but rather an expansion of space itself, with all its matter and energy

7. After the Bang
Ever since the big bang, the universe has been expanding and cooling.
10-43 seconds after the Big Bang…
(that’s seconds)
The four fundamental forces were created:
Gravity,
Electromagnetic,
Weak Nuclear,
Strong Nuclear

8. After the Bang 3-20 minutes after the Big Bang…
Nucleosynthesis = creating new nuclei from existing nuclei (two H’s make one He)
It took billions of years for the universe to cool down enough to allow stars and planets to form.

9. Today All the matter and energy in the universe is still expanding.
And has been expanding for the last billion years.
Summarizing, “A cosmological theory theory that the universe originated approximately 13.7 billion years ago from the violent explosion of a very small point of matter of extremely high density and temperature.”
The Size of the Universe

10. Edwin Hubble found… Universe is continuously expanding
Galaxy’s velocity is proportional to
its distance (galaxies that are twice
as far from us move twice as fast)
Taken every galaxy the
same amount of time to
move from a common
starting position
to its current position
Edwin P. Hubble ( )
Hubble's Law

11. Wave compression or stretching due to velocity
Hubble’s Evidence of an Expanding Universe Doppler shift - wavelength emitted by something moving away from us is shifted to a lower frequency
Sound of a fire truck siren - pitch of the siren is higher as the fire truck moves towards you, and lower as it moves away from you
Wave compression or stretching due to velocity
Works with sound or light (electromagnetic waves), but…velocity changes have to be comparable to their speed to some degree.
Sound m/s Light m/s

12. Visible Light

13. Visible wavelengths emitted by objects moving away from us are shifted towards the red part of the visible spectrum The faster they move away from us, the more they are red-shifted. Thus, red-shift is a reasonable way to measure the speed of an object

14. When we observe the red-shift of galaxies.
The galaxy appears to be moving away from us –
universe is expanding.
Expanding Demo

15. Red Shift - moving away since the wavelength is getting longer and the frequency shorter
Blue Shift - moving closer since the wavelength is getting shorter and the frequency higher

16. Evidence for Big Bang
Red shift - as light from distant galaxies approach earth there is an increase of space between earth and the galaxy, which leads to wavelengths being stretched
Cosmic Microwave Background radiation (CMB) left over from the Big Bang shows that as the universe expands the wavelength of its energy wave expand, stretch and cool
An abundance of hydrogen and helium in the far reaches of the universe - consistent with the Big Bang theory that a mixture of hydrogen and helium was created at the beginning of the universe

17. Working timeline since the Big Bang