Distinctness

Distinguishability means that with two objects you can determine which of the two objects you are looking at.

Distinctness is always based on one or more features. So z. B. to distinguish between real money and counterfeit money certain distinguishing features (security features) are used, which are very difficult to copy.

In information theory , distinguishability is a prerequisite for the existence of information . The information content is measured by how many differentiation options there are.

In physics (especially quantum mechanics ) the indistinguishability of elementary particles plays a decisive role: particles of the same type (e.g. two electrons or two protons ) are indistinguishable. This indistinguishability affects the properties of the particles. For example, indistinguishable fermions cannot be in the same state ( Pauli principle ), while this is not a problem for distinguishable particles (e.g. an electron and a muon ). This fact is decisive for the stability and properties of matter.

Indistinguishable bosons, on the other hand, are preferably in the same state, this is the basis of the laser , superfluidity and Bose-Einstein condensation .