Reason, Truth, and History written by Hilary Putnam in 1981 explores the concept of a brain in a vat. The theory concerns notions of perceived reality, for instance picture an evil scientist who captures people and removes their brains. He then keeps the brain in a vat full of nutrients in order to ensure it remains living and hooks it up to a supercomputer to alter its perception, so that the poor victim still thinks he is living his normal life, oblivious to the fact that he is now just a brain in a vat.

The point of the theory? How do you know this didn’t happen to you? Put differently, how do you know the life you are living is real and not just a figment of your or someone else’s  imagination? The premise has been adopted by popular culture in many books and movies, most notably 1999’s The Matrix.

But what has this got to do with the Avatar Forum? Though the forum is for fans to discuss topics around the film by James Cameron, one of the most interesting and amusing discussions on the forum has to be "Ways to cope with the depression of the dream of Pandora being intangible”. Users talk about how they get depressed after watching the movie and later “waking up” to the real world again and realising Pandora isn’t and can’t be real.

Some of the more interesting ideas they've come up with to rid them of this despair include, writing their own Avatar sequel, listening to the original movie soundtrack or living like Neytiri- in touch with nature and not being greedy and wasteful. Anything basically to escape the mundane world and stay immersed in this ‘alternative reality’.

The site is oddly thought provoking, you actually get the impression that some people would prefer it if their brain were trapped in a vat, enjoying the mind altering hallucinations of a scientist named James Cameron.