Today’s Wonder of the Day was inspired by Connor. Connor Wonders, “what is antimatter ” Thanks for WONDERing with us, Connor!
You've probably come across the prefix "anti-" in other contexts. For example, protesters who don't like war are often called antiwar protesters. Antifreeze is a fluid you put in a vehicle's engine to keep fluids from freezing. Antibacterial soap fights against harmful bacteria.
If you're a fan of science, you might have run across another "anti-" word: antimatter. This may puzzle you if you're familiar with the meaning of the "anti-" prefix. Could there really be something in the universe that's the opposite of the matter that makes up us and everything around us?
That's exactly what antimatter is! It's the opposite of regular matter. Regular matter is made up of regular atoms. Regular atoms are composed of regular subatomic particles, such as protons, neutrons, and electrons.
Antimatter, on the other hand, is composed of subatomic particles that have the opposite charge and spin of regular subatomic particles. For example, anti-electrons, also known as positrons, behave just like electrons, except they have a positive charge. Likewise, antiprotons have a negative charge but act like protons.
We come across regular matter everyday, but where is antimatter? Scientists believe it was created alongside regular matter just after the beginning of the universe. However, it's rare in the modern universe and scientists don't know why.
Antimatter can be created by scientists today. Using particle accelerators, such as the Large Hadron Collider in Europe, scientists can cause collisions between atoms at extremely high speeds, resulting in the creation of particles of antimatter. Particle decelerators can also be used to capture and slow down antimatter particles for in-depth study by scientists.
Tiny bits of antimatter are around us much of the time. For example, cosmic rays from outer space bring antimatter particles into Earth's atmosphere on a regular, ongoing basis.
There are also a couple of other sources of occasional positrons: bananas and you! Both bananas and human beings contain minute quantities of potassium-40, which is a naturally-occurring isotope of potassium. As it decays, it emits a positron every once in a while.
If you're eating a banana, is it likely you'd see a positron occasionally? Nope! First of all, subatomic antimatter particles are way too small for our eyes to see.
The other primary reason is that antimatter particles have an extremely short life span. As soon as an antimatter particle encounters a particle of regular matter, the two particles annihilate each other and release energy.
Science fiction works have used this property of antimatter to suggest that future spacecraft could be powered by antimatter, since its combination with regular matter could produce huge amounts of energy. For example, a gram of antimatter could cause an explosion similar to a nuclear bomb.
Are antimatter-powered spacecraft just a fantasy? Maybe not! Scientists are studying possible ways to harness and use energy created by antimatter. The problem today is that antimatter is extremely expensive to produce, and to date scientists have only been able to create a tiny amount of antimatter.
Scientists estimate creating and storing a gram of antimatter would cost in excess of a million billion dollars and require about 25 million billion kilowatt-hours of energy. So far, all the antimatter created in all the particle accelerators on Earth wouldn't be enough to boil a cup of water.