What the bleep do we know?

Long time ago, I had watched the movie named "What the bleep do we know?"

It was actually a documentary type movie about how the quantum physics changed the way we perceive and interpret the seemingly real world we live in.

Now as I am reading Descartes' meditations, I cannot avoid, but think that modern philosophers do not apreciate as much Descartes' starting point by questioning the existence of anything as they should in the light of quantum theory's recent findings. 

Anyway, as Simon Blackburn says:

"Perhaps the most unsettling thought many of us have, often quite early on in childhood, is that the whole world might be a dream; that the ordinary scenes and objects of everyday life might be fantasies. The reality we live in may be a virtual reality, spun out of our own minds, or perhaps injected into our minds by some sinister Other. Of course, such thought come, and then go. Most of us shake them off. But why are we right to do so? How can we know that the world as we take it to be, is the world as it is? How do we begin to think about the relation between appearance and reality: things as we take them to be, as opposed to things as they are?" (Think, pp. 15, Simon Blackburn)