Research reveals a surprising topological reversal in quantum systems
Favicon 
phys.org

Research reveals a surprising topological reversal in quantum systems

In principle‚ one shouldn't compare apples to oranges. However‚ in topology‚ which is a branch of mathematics‚ one must do just that. Apples and oranges‚ it turns out‚ are said to be topologically the same since they both lack a hole—in contrast to doughnuts or coffee cups‚ for instance‚ which both have one (the handle in the case of the cup)‚ and thus are topologically equal.