So many people wrote in to say how hard it is to get their minds around retrocausation – the idea that present thoughts can influence past actions - that I thought I’d share an even more mind-warping experiment.
This was simple experiment carried out by the Oxford University physicist Vlatko Vedral who decided to use Bell’s inequality, the famous test of non-locality – that spooky entanglement between quantum particles. Bell demonstrated that two quantum subatomic particles can remotely influence each other, even over vast distances, which completely ‘violates’ our Newtonian view of separation in space.
Could this same test be used to show that limits governing time can also be violated, they wondered? Brukner enlisted one of his colleagues at the University of Vienna, Caslav Brukner, to design a thought experiment (an experiment essentially just carried out mathematically).