“Of course, quantum mechanics is tinged with this kind of solipsism, because there is a sense in which an electron doesn’t really have any properties until you measure it. There is a subjective aspect to quantum mechanics. Some experts like Eugene Wigner were convinced the universe wouldn’t exist if it didn’t have observers in it. He argued that, without a conscious mind observing the quantum events, the events don’t really exist, which I think is a crazy point of view. But it is defended by a number of quantum mechanics experts.”