- Composition of the universe
- Earth
- Animals
- Plants
- Cosmic rays
- Everthing we see, touch, and feel!
- atomic matter and dark matter
- dark matter makes up about 85% of the matter,
and atomic matter 15% - therefore, dark matter dominates
- atomic matter and dark matter combined only explain 1/4 of the "stuff" of the universe
- only 4% of everything is atoms
- only 22% of everything is dark matter
- what is the remaining 74%? - do we have a matter crisis?
- 74% - dark energy
- the basic unit of all ordinary matter
- nucleus
- protons and neutrons
- protons and neutrons are
made of quarks (up and down type)
- electrons
- up, down, charm, strange, bottom, top
- six types of "leptons"
- electron, electron-neutrino,
muon, muon-neutrino, tau, tau-neutrino
These "quarks" and "leptons" have been discovered
in high energy cosmic rays and
at high energy accelerators - electron, electron-neutrino,
- Today we recognize
- Gravity - weakest force
- Electroweak - unified electromagnetism and weak nuclear force
- Strong nuclear force - holds nucleus together
- History of understanding forces (developing theories)
- 17th century
- Newton unified celestial and terrestrial gravity
- gravity on surface of earth same as gravity in space
- Law of Universal Gravitation
- 19th Century
- Maxwell unified electricity and magnetism (electromagnetism)
- led to understanding of light and EM radiation
- two forces known then (gravity and electromagnetism)
- Maxwell unified electricity and magnetism (electromagnetism)
- 20th Century
- nuclear forces are discovered
- 4 forces in nature
- gravity
- weak nuclear force
- electromagnetism
- strong nuclear force
- nuclear forces explained source of Sun's energy
- along with Einstein's relativity &rarr E=mc2
- electroweak theory unifies two forces (weak and electromagnetism)
- 17th century
- J.J. Thomson
- Cathode rays
- discovery of electron - 1897
- 1934 - Thomson comments on remarkable practical impact
- Stanford
- electron accelerator
- discovery of quarks - 1969
- Fermilab - near Chicago
- proton and anti-proton collider
- discovery of top quark (the heaviest quark) - 1995
- expect it to be discovered as new form of exotic subatomic particle
- theories predict such particles
- eg. SuperString theory (unconfirmed)
- hypothesizes that fundamental particle are very small vibrating strings
- predicts super-particles
- a new particle for every known particle
- similar to prediction of anti-matter in 20th Century
- eg. SuperString theory (unconfirmed)
- Large Hadron Collider
- Geneva, Switzerland
- collides high energy protons
- the proton is a hadron
- searching for production of dark matter particles
- Linear Collider
- next generation electron collider
- under development
- could study dark matter produce in collisions
- All the matter of our earthly experience is made of atoms
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- Matter crisis
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- Atoms
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- So - common matter today is composed of atoms made
of up quarks, down quarks, and electrons
- "Atomic matter" in the early universe
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- Fundamental Forces
- Particle discoveries and accelerators
- Dark Matter