I could probably divide people who read this title into 3 groups. One group has no idea what I’m talking about and the other is going “well obviously” - because they know that everything in quantum. That’s just how the universe is.
The third group is more clever than me and already knows what I want to talk about.
Computers (yes, classical computers) rely on a interesting quantum effect. In fact we couldn’t have made modern computers without the science of quantum mechanics.
A fundamental part modern computers is the transistor. It is effectively a electronic off/on switch. It allows the flow of electricity in a wire to be controlled by another wire. This allows for logic gates to be created and is so useful to computing that Silicon Valley was named after the semiconductor material used to make it.
Semiconductors are so called because they have properties between those of conductors and insulators.
Disclaimer: I have no idea what I’m talking about from here on.
For most materials the electrons can either freely move between atoms (conductors) or are stuck orbiting just one (insulators). Semiconductor electrons need a bit of energy to leave there orbits but they can do it. This makes them a bit like chameleons, able to behave like either type of material.
Semiconductors also have something called (apparently) a energy bandgap. This means that you need to give the material a bit of energy to transform it from a insulator to a conductor. This is because of something called the Pauli Exclusion principle. This is a quantum thing that says that no 2 electrons can have the same quantum state (i.e. energy). This makes the semiconductor ‘jump’ from insulator to conductor mode, rather than smoothly changing. This makes them useful for computers which work with binary - which only uses 1s and 0s.
So that’s how quantum mechanics helped create modern computers.
Credit: The guy who was talking at the York Uni open day who got me thinking about this (sorry I don’t know your name)
Dr. Alan Doolittle from the university of Georgia Tech for this slideshow I found online to make sure I got something a bit right. If you actually want to know about this (why wouldn’t you), read that.