Can something be in 2 places at the same time? Yes - in our Quantum world

 

 Objects can be in two places at once

Erwin Schrödinger used the idea of a cat in a box to simplify superposition. (Image credit: Mopic / Alamy Stock Photo)

Wave-particle duality is an example of superposition. That is, a quantum object existing in multiple states at once. An electron, for example, is both ‘here’ and ‘there’ simultaneously. It’s only once we do an experiment to find out where it is that it settles down into one or the other. 

This makes quantum physics all about probabilities. We can only say which state an object is most likely to be in once we look. These odds are encapsulated into a mathematical entity called the wave function. Making an observation is said to ‘collapse’ the wave function, destroying the superposition and forcing the object into just one of its many possible states.

This idea is behind the famous Schrödinger’s cat thought experiment. A cat in a sealed box has its fate linked to a quantum device. As the device exists in both states until a measurement is made, the cat is simultaneously alive and dead until we look.