I am a great believer rather than the popular scientific way of dealing with things that 'Nothing exists unless you can prove it'. I am pretty much the other way that pretty much anything can exist unless you can disprove it.
If you can’t think of an observation that could disprove a theory, that theory simply isn’t scientific.jerry coyne
My own view is that this planet is used as a penal colony, lunatic asylum and dumping ground by a superior civilization , to get rid of the undesirable and unfit. I can't prove it, but you can't disprove it either. It happens to be my view, but it doesn't challenge any of the findings of Darwin or Huxley or Einstein or Hawking .christopher hitchens
There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago.bertrand russell
Unfortunately for Pythagoras, his theorem led at once to the discovery of incommensurables , which appeared to disprove his whole philosophy. So long as no adequate arithmetical theory on incommensurables existed, the method of Euclid was the best that was possible in geometry. When Descartes introduced co-ordinate geometry, thereby again making arithmetic supreme, he [Descartes] assumed the possibility of a solution of the problem of incommensurables, though in his day no such solution had been found.