In the intense heat of the Big Bang, particles of matter were forged out of pure energy. But for every particle of matter created, a 'twin' was also born - an 'antiparticle' identical in mass but with opposite electric charge.

For the first few instants of its existence the Universe was balanced, with matter and antimatter created in equal abundance. Then just one second after the Big Bang, the antimatter had all but disappeared, together with almost all the matter, leaving a minute amount of matter alone to form everything that we see around us – from the stars and galaxies, to the Earth and all life that it supports.

Antimatter: a mirror image of matter

Our world is made of matter, which consists of three types of particles called electrons, protons and neutrons. Each particle has a specific mass and electric charge. For example, the electron has a negative charge, and the proton a positive charge.

Antimatter particles have the same mass as the particles that make up our world, but carry the opposite charge. For example, the electron, which has a negative charge, has an antimatter 'twin' with the same mass but the opposite charge; we call the 'anti-electron' a positron.

Particles and antiparticles go together. Imagine sitting on a sandy beach. When you dig a hole, you also create a pile of sand. One cannot be made without making the other: they are complementary - just like particles and antiparticles.

Antimatter and matter were created in equal amounts in the Big Bang, but we don't see antimatter around us today.

The fundamental particles

Protons, neutrons and many other particles consist of combinations of 12
fundamental particles, called quarks, which also have antiparticles with
opposite charges. The antiquarks that make up antiprotons, for example,
carry opposite charges to the quarks that make up protons.

There are 12 fundamental particles that make up all matter - each one of these has an antimatter 'twin'

E = mc²

Einstein’s famous formula means that 'mass is condensed energy'. Since 'c' is the speed of light, which is a very large number, the equation tells us that a small amount of mass contains an enormous amount of energy. It is like exchanging money between different currencies, with a huge exchange rate.

A mass of 1 kg contains an energy of 90 million gigajoules, equivalent to worldwide energy consumption over 90 minutes.

Highly volatile

When antiparticles and particles meet, they destroy each other. This process, called 'annihilation', liberates all the energy that is stored in their mass. Annihilation can create gamma-rays or even new particle-antiparticle pairs.

CERN scientists are exploring big mysteries such as: if matter and antimatter were created in equal amounts during the Big Bang, and matter and antimatter annihilate, then why is all this matter left-over to form our Universe?