"Boltzmann's Brain", a scientific version of solipsism:
Big Brain Theory: Have Cosmologists Lost Theirs? - New York Times: "If true, it would mean that you yourself reading this article are more likely to be some momentary fluctuation in a field of matter and energy out in space than a person with a real past born through billions of years of evolution in an orderly star-spangled cosmos. Your memories and the world you think you see around you are illusions."It's an interesting idea, basically given random fluctuations and cycles of creations in a multiverse, it's more likely that what we perceive as an entire universe is just an illusion than that an entire universe exists.