Superconducting quantum interference device

Okay kiddo, so you know how some things conduct electricity, like wires? Well there are special materials called superconductors that can conduct electricity with no resistance at all.

Now, a superconducting quantum interference device (or SQUID for short) is a really cool little tool that uses this superconductive ability to help scientists and doctors measure very tiny magnetic fields.

Think of your own magnetic field as a little invisible bubble around your body. Well, all things with atoms inside of them (which is everything) have their own magnetic fields too, no matter how small.

With a SQUID, scientists can measure these tiny magnetic fields from things like the human brain, to study how different areas of the brain work together.

The device has two tiny superconducting loops that are connected by some special wires. One of these loops is slightly smaller than the other one, so when you send a current through them, the current flows a little faster in the smaller loop.

Now this is where it gets really interesting - when a magnetic field hits the loops, it messes with the flow of the current between them, changing the amount of electricity in each loop. This creates an overall electrical signal that scientists can measure, and they use it to figure out how strong the magnetic field was.

So using this little device, scientists can measure magnetic fields so tiny that they're even smaller than the magnetic fields produced by the neurons in your brain as they communicate with each other! This helps them learn more about how the brain works, and maybe even develop new treatments for brain diseases.

Pretty neat stuff, huh?