what is antimatter? Does it exist? How does it matter to us?
In: Physics
Antimatter is normal matter, but with the opposite charge, and it very much does exist.
When it touches normal matter, they annihilate each other and turn into pure energy (usually in the form of light) according to E=mc^2
The easiest example of antimatter is a positron, or anti electron. We can see this come from anything that is radioactive and undergoing β+ decay. Bananas contain potassium, and some of that potassium is potassium-40, which undergoes beta plus decay, which emits positrons.
Another example is a PET scan. PET stands for positron emission tomography. You are given an isotope (carbon-11, nitrogen-13, oxygen-15, or fluorine-18) which undergoes β+ decay, and they use a machine to detect where the positrons are coming from in your body, so they can see what parts of the body are using resources.
Anti protons and anti neutrons have to be made in a lab with a particle accelerator. Basically, we smash together particles with so much energy that we create matter (E=mc^(2)) and it is always created as a matter-antimatter pair. So if we make a proton, we also make an anti proton.
There’s also an entire class of particles made of both matter and antimatter called mesons. Protons and neutrons (baryons), which you’re familiar with, are made of quarks, 3 quarks each. Mesons are made of a quark and antiquark pair.
We have made a few grams of anti hydrogen, and we have just recently used some to prove that antimatter is affected by gravity in the same way as normal matter
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