One hundred years after its birth, quantum mechanics continues to baffle physicists, despite underpinning many of today's technologies. While its equations accurately describe the behaviour of subatomic particles, experts remain deeply divided on what those equations actually reveal about reality.

A recent survey by Nature, involving more than 1,100 physicists, highlighted the lack of consensus within the field. Just over a third supported the Copenhagen interpretation, which claims a particle only assumes a definite state once it is observed.

Others favour alternatives like the many worlds theory, which suggests every possible outcome exists in parallel universes rather than collapsing into a single reality. The concept challenges traditional notions of observation, space and causality.

Physicists also remain split on whether there is a boundary between classical and quantum systems. Only a quarter expressed confidence in their chosen interpretation, with most believing a better theory will eventually replace today's understanding.