Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Don't let the catchy name distract you, says Philip Ball: the questions inspired by this arguably misnamed phenomenon go to the heart of quantum theory.