All Worldcons pick up some local fannish traditions and the fake track comes from one of the local Chicago conventions. One of the items was Stephen Hawking and Albert Einstein on the Higgs Boson. It's very unfortunate if the descriptions and participants were not enough to convey the joke. As a member I personally regret hearing that some people didn't see it coming and were inconvenienced yet at the same time I am saddened if conventions are not allowed any attempt at humor.