2011-01-13
Explanation
This comic is titled "Do-It-Yourself Machines: The Skeptic Confuser" and presents step-by-step instructions for building a prank device. The instructions are: (1) find an old computer case, (2) fill it with cards that all say "This is Bullshit," (3) cut a slit through which cards can be extracted, and (4) present it to someone as a mind-reading machine.
The humor lies in the fact that a skeptic's natural response to any claim of a mind-reading machine would be "this is bullshit" -- which is exactly what the card says. So when the skeptic asks the machine what they are thinking and pulls out a card, it appears to have correctly read their mind. The prank creates an ironic paradox: the skeptic's very skepticism becomes the thing that makes the fake machine appear to work, momentarily undermining their rational worldview with their own predictable reaction.