Antimatter annihilates with matter!
It’s difficult to make antimatter, and even harder to store it
|One reason is that when antimatter and matter come into contact, they annihilate. In other words, if any particle and its antiparticle come together, nothing is left of the original particles. Instead, their entire mass is converted into energy.|
Mass turns into energy
Einstein’s most famous equation shows how matter can be converted into energy.
- E is the energy that will be released, in joules
- m is the mass of the two particles, in kilograms
- c is the speed of light, in metres per second
Annihilation can be useful
When an electron and its antiparticle (a positron) come together and annihilate, they are both entirely converted into energy, in the form of two gamma rays. The gamma rays are always given off in opposite directions, and they always have an energy of 511 thousand electron volts each.
When we make use of antimatter, we can rely on this fact, and it’s a useful thing to know: it means that when we detect a pair of matching gamma rays we can trace them back, and tell exactly when and where a positron and electron ran into each other.
If we want to put antimatter to practical use, we have to find a way to keep it safe, until we’re ready to use it.
We have to keep it away from all of the ordinary, positive matter which surrounds it. If antimatter comes into contact with the air, or even the walls of its container, it will annihilate and be lost.