Schrodinger's Cat

 The Schrodinger's cat is a thought experiment about quantum super-positioning. The cat is put in a box with a poison that has a 50% chance of killing it. Now until we open the box, we would never know if the cat is alive or dead. 

Similarly, there are particles all around that are not always under constant observation. While they are not being observed, they can exist in different states and positions, a phenomenon called Quantum Superpositioning. When we choose to observe them, their state is finalized. 

With the cat too, until we open the box, we won't know if the cat is alive or dead. Hence it is assumed as per quantum physics that it exists in both states. Obviously, common sense says that it is not our observation that is making any difference, but there is no place for common sense in quantum physics. Hence, the cat is both alive and dead at the same time, it is under Quantum Superposition.