Weird science question?

So today in cl my physics teacher told us of this theory that was the product of a scientist using lsd. And that it says the whole universe and everything is like a collective conscience/imagination from everyone? I'm probably butchering what it really is but the topic is not so typical so anything remotely to it is probably related. He also said it could be mathematically proven. I was wondering where I could find more info on this it sounded pretty interesting. Btw he even said himself that he didn't believe it once he heard it but as he read and researched the topic he became more and more convinced (although he believes in a single god).