How To Talk To Aliens

Frederic Friedel writes: "In their efforts to talk to alien civilizations human beings are currently engaged in sending pictures based on a rectangular array of dots, arranged from left to right and top to bottom. But is this stategy sound? For instance what if the aliens do not see in pictures at all, or if they think in vector graphics rather than bitmap? On ChessBase.com grandmaster John Nunn proposes sending them a trading machine instead."