Hard Science Fiction

That is, science fiction that bases itself more in realism than fantasy, is very difficult to find.  We all seem to favor escapism over a story that presents an actual possible future.  In a time as fascinating as 2012, with all our knowledge of the world around us, why does our sci-fi revolve around space wizards and magic zombies?  Why do space lasers still go 'pew-pew!'?
Sci-fi makers, no one is asking you to hire Steven Hawking as a science adviser to the sound department- but, come on.  Realism in a fantastic situation can be very powerful!