From home.CERN
In some strange way could a light particle remain a wave when observed? Could dark matter have a property that prevents wave function collapse, by not interacting with EMF?Unlike normal matter, dark matter does not interact with the electromagnetic force. This means it does not absorb, reflect or emit light, making it extremely hard to spot. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter.