Down at the level of atoms and electrons, quantum physics describes the behavior of the very smallest objects. Solar panels, LED lights, your mobile phone and MRI scanners in hospitals: all of these rely on quantum behavior. It is one of the best-tested theories of physics, and we use it all the time.
On the face of it, however, the quantum realm is extraordinary: Within it, quantum objects can be “in two places at once”; they can move through barriers; and share a connection no matter how far apart they are. Compared to what you would expect of, say, a tennis ball, their properties are certainly weird and counterintuitive.
But don’t let this scare you off! Much of quantum physics’ odd behavior becomes a lot less surprising if you stop thinking of atoms and electrons as minuscule tennis balls, and instead imagine any “quantum object” as something like a wave you create by pushing your hand through water. You could say that, at small scales, everything is made of waves.
To read more, click here.