The Large Hadron Collider

• The coldest and emptiest place in the solar system

• The highest energies ever created

• Cameras the size of cathedrals

• A machine 27km long

LHC Overview [CERN]

• The biggest machine in the world to study the smallest particles in the universe

• Based in a 27km circular ring 100m underground

• Protons and neutrons are examples of hadrons, which are made of quarks: fundamental particles that aren’t made of anything smaller

• How can you study particles that are too small to see with light?

• This microscope can’t resolve anything smaller than 1 micrometer across (0.000001m)

The XY table and microscope[CERN]

• Shorter wavelength reveals details down to the size of molecules…

• It’s as small as we can look by shining a beam of electromagnetic radiation

• You just can’t “see” what’s inside atoms - it needs a different approach

• Particle accelerators can give us clues about what is inside atoms themselves

• The LHC accelerates particles to nearly the speed of light, and collides them with incredible energy inside huge detectors

• Studying the results lets us test our ideas about the very smallest units of matter and energy, far smaller than the atom

LHC Tube in Tunnel[CERN]

• Our picture of these basic units and the interactions between them is called the standard model

• It explains a lot, but there are holes in it

• It doesn’t include gravity, or explain what gives particles mass, for example

• Scientists expect the missing pieces of the jigsaw to appear when they create very high energies in the LHC

The Standard Model[CERN]

• Einstein showed that matter and energy are interchangeable: matter is like “concentrated energy”

• On a tiny scale, the LHC recreates the incredibly hot, dense conditions close to when the universe began

• Hadrons smash together with so much energy that some energy turns into mass, briefly creating particles that haven’t existed since the Big Bang

http://commons.wikimedia.org/wiki/Image:Albert_Einstein_1947.jpg

• The LHC lets us glimpse the conditions 1/100th of a billionth of a second after the Big Bang: the hot beginning of the universe before it cooled enough for normal matter to exist

• It might reveal what the mysterious dark matter and dark energy, that make up 96% of the universe today, actually are

• And explain the mystery of what happened to all the antimatter that was made when the universe began but has since vanished…

• Or raise completely new questionsBig Bang[CERN]

• 4 gigantic detectors use sensors to measure the direction, charge, mass and energy of the particles as they zip through

• Scientists then piece together what happened in each collision

CMS endcap being lowered into position

[CERN]

• 1232 superconducting magnets at -271.3C (1.9K), colder than outer space

• Ultrahigh vacuum, the emptiest place in the solar system

Dipole magnet schematic [CERN]

• Proton bunches circle the 27km ring 11,000 times a second

• At 99.9999991% the speed of light!

Simulated collision of two protons in ATLAS[CERN]

• A new view of the building blocks of the universe and the laws that make the universe the way it is

Simulated lead-lead collision in ALICE [CERN]

• Log on to LHC UK website to find out more