Template Talk

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Big Bangs and Dark Matter
Dr Alan Barr Physics lecturer University of Oxford
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The very BIG
Hubble
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Spectra and redshifts
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Mega parsec 3.26 million light-years 3.1 x
1016 m
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Echos of something big
WMAP satellite
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What was formed matter
Only three elements are formed in the Big Bang
All other elements are formed in stars
Differences between materials are due simply to
the number of protons and electrons in their
atoms.
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The very SMALL (what we see)
x 5
x 10000
cell nucleus 10 µm
dna 2 nm
cells 50 µm
x 5-gt
x 20
x 50000
proton
atom 100 pm
atom nucleus 2 fm
A hundred billion atomic nuclei lined up in a row
would be the width of a human hair
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The whole story?
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The bit we understand Matter Forces
Matter Particles

• ? Components and theory largely understood
  (maths)
• ? Underlie all of physics, astronomy, chemistry,
  life!

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Big questions
What is dark matter made of?
NEED HIGH ENERGY COLLISIONS!
Where has all the anti-matter gone?
Where do the particles get their mass from?
What else is out there?
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Blue Peter guide
? Take some protons Lots of these in
nature! ? Make them move (very fast) ? Bang
them together Its good to stand back
at this point? Photograph the debris
Your camera-phone may not be fast enough!
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http//www.youtube.com/theATLASExperimentp/u/0/Nh
XMXiXOWAA
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Our accelerator
The Large Hadron Collider, CERNGeneva
(Swiss-French boarder)
Electric waves speed particles up
1232 magnets each 8-Tesla bend protons in a circle
Large Hadron Collider
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Note concerning high energy
FOURTEEN THOUSAND BILLION VOLTS

Spark could jump 5000 km in air(radius of The
Earth)
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Our detectors
ATLAS
LHCb
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Big questions
What is dark matter made of?
Where has all the anti-matter gone?
Where do the particles get their mass from?
What else is out there?
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Mass and the Higgs Boson
High energy collisions ought to make Higgs Bosons
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The tentative evidence
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What is Dark Matter?
Normal Made from atoms
Includes stars, planets,
people Dark matter Unknown substance
(not atoms)
May be a fat cousin of
normal light We hope to
make study it at CERN Dark energy Even
weirder!
Need to see the invisible!
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How to see the invisible?
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Useful?
Future discoveries will lead to new technologies
Uses of the electron
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Big Bangs and Dark Matter

• Astronomy ? very large
• (See whats out there)
• Particle physics ? very small
• (Do it at home)
• Both explore the structure, building blocks and
  evolution of the universe
• Complementary information
• New discoveries lead to new technologies

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Source of protons?
Hydrogen molecules
Protons
Electroncloud
Electron gun
Hydrogen gas
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Speed up and bend
Bend
Accelerate
E-field
B-field
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Understanding the elements lets us make
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Discovery of the electron
J.J.Thompson needed just over 13 V to remove
electrons from atoms.
First subatomic particle to be isolated, in 1897