CERN Accelerating science

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ACCELERATORS

You know what happens when your dad "accelerate" while driving: the car goes faster and faster!
Well, an accelerator does the same thing to particles (or antiparticles): they speed up to very high speeds and that means they gain higher energy!
An accelerator is usually a ring shaped tunnel, but it can also have different shapes. Particles moves through the middle of the tunnel, around and around, over and over again. At each turn their speed increases a little, and as they go round they gain all the energy needed for various experiments.
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CHARGE

"Charge" is what we call a fundamental property of particles. You are a boy or a girl - this is one of your fundamental properties!
Any particle has either a positive charge, or a negative charge, or zero charge.
Charge is one of the things that determines how particles behave when they get close to each other:
- if they have the same charge they repel each other (positive-positive, negative-negative);
- if they have opposite charge they attract each other (positive-negative);
- zero-charge particles are neutral and can get close to anyone!
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CONCENTRATED ENERGY

It's hard to picture "concentrated energy"!
But imagine what happens with the sun's rays and a lens.
Rays from the sun warm your skin (thermal energy). But a lens can concentrate (or focus) the rays down to a small point. The same amount of energy is in a much smaller space and now the sun's rays can burn you!
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PAUL DIRAC

Paul Adrien Maurice Dirac was born on 8th August, 1902, in Bristol, England. He studied electrical engineering and mathematics, and at the age of 25 became a teacher at Bristol University.
He is best known for the famous "Dirac equation" which describes various properties of the electron and predicts the existence of the positron. When this prediction was confirmed, Dirac was awarded a Nobel Prize in Physics (1933).
He was a very shy man and when informed that he had just won the Nobel Prize told his boss that he did not want to accept it because he disliked the publicity! (of course, his boss told him that refusing the prize would bring him even more publicity!)

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ENERGY

Energy is everywhere. The sun gives us energy as light and heat. Fuels provide energy to power our cars and planes and to heat our homes. Food gives you the energy you need to run and play.
It's all different forms of the same thing: energy.
You cannot create or destroy energy, it's always there. But you can transform it into the type you prefer - electrical energy to power your TV, thermal energy to heat things up, mechanical energy to work your bicycle,�
And as energy can be transformed in so many different ways, no wonder it can also transform into matter!

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WHAT'S A PHYSICIST?

A physicist is a scientist who try to understand the way nature works.
If you gave a physicist a marble, the physicist will wonder, what is it is made of? Why, if you drop the marble, does it fall not fly? How does it roll down a hill and how long will it take to get to the bottom?
He usually describes how things behave (move, fall, fly,�) with mathematical formula.
A physicist can be a man or a woman, but always a very curious person! There are different kinds of physicist too: some of them concentrate on stars and planets (astrophysicists), some of them on rocks and mountains on the Earth (geophysicists).
The one we are talking about here study the very basic constituents of matter, which they call "particles", and their interactions at high energies: they are called "particle physicists" or "high energy physicists".
You'll discover more about what they do by reading these pages!

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THE AD

The Antiproton Decelerator is a new tool of CERN's physicists. It looks a lot like an accelerator (ring shaped tunnel) but in fact it... decelerate antiprotons, i.e. it slows them down! This way, their energy gets smaller, and physicists can do many different kind of studies, including the assembly of antimatter's atoms.