Question: What do you know about anti matter?

Marta Varela answered on 15 Mar 2017:

A few things…

Anti-matter is matter with opposite properties (like spin or electric charge) to normal, ordinary matter. Each particle of matter has an anti-matter buddy. If they get close to one another, they can disappear and release all their energy as light!

One of the most common uses of anti-matter is in positron emission technology (PET). It is an imaging technique that can produce beautiful pictures of the inside of the body and that doctors use, for example, to find cancers. (The positron is the anti-matter buddy of the electron, which you must be familiar with.)

In PET, something radioactive is eaten/injected/inhaled by the patient. This releases positrons inside the body, which disappear almost immediately, when they find an electron, and send off a flash of light. You can track this light to make PET images!