A good obituary in The Economist this morning, with an excellent synthesis of the "brain in a vat" thought experiment and an interesting reference to The Matrix:
“A related example of the tension between knowledge and reality came with another thought experiment: a sceptic might wonder whether she were no more than a brain in a vat, artificially nourished, and stimulated with a bogus but utterly convincing version of the real world. How could one prove that this is not so? The answer is that our brains are more than just perception machines, and meaning depends on what other people think too. So a brain in a vat might exist, but it could not meaningfully say that it was merely a brain in a vat. Philosophers would call that epistemological externalism: factors outside the mind are crucial to what it can be said to “know” and “think”.
Many saw parallels between that controversy and “The Matrix”, a successful Hollywood film which bridged science fiction and philosophy. It portrayed a dystopia in which machines have subdued humans by trapping them in a simulated reality while their bodies languish in vats.
Mr Putnam was surprised and flattered by the film-makers’ interest. ”
Although I knew the thought experiment (a long time ago) and enjoyed the original film when it came out in 1999, I hadn't made the connection with Putnam - who as the obituary also hints was far from being a populariser.