What is the Flash Mind Reader?
The Flash Mind Reader is a clever game credited on its web page to Andy Naughton.
On it you are presented with a matrix of numbers from 99 to 0, each with a distinctive
symbol next to it. There is a limited number of symbols (perhaps 20), which
do not repeat at constant-width intervals. The symbols are taken from the world of religion, astrology, and the
paranormal, working with the suggestion of psychic power to set the mood of the game.
The player is directed to choose a 2-digit number, and to subtract the sum
of its two digits from itself. The player is then to click on a graphic of a
crystal ball, which reveals the symbol associated with the number resulting
from the calculation. If your math is right, the prediction will be correct and impressive. (And accompanied
by the sound of the transporter from the old Star Trek.)
The web page is carefully set up and well thought out. Go try it (http://www.albinoblacksheep.com/flash/mind.php)
and come back for an explanation below (out of spoiler range) if you want it.
How it works.
When subjected to the algorithm, all of the numbers between 99 and 90 always
yield 81; those between 89 and 80 always yield 72; those between 79 and 70 yield
63 and so on, with additional solutions at 54, 45, 36, 27, 18, 9.
While all symbols are changed with each new game, the game associates the same
symbol with each of the numbers which constitute special solutions of the algorithm.
The crystal ball "divines" that symbol which happens to be associated
with all those privileged numbers in each game. The multitude of symbols, plus
the varying numbers and random placement of each (except those in association with the
nine privileged numbers) effectively masks the trick.
Why is this interesting?
On a principle analogous to "all sufficiently advanced technology is indistinguishable
from magic," the Flash Mind Reader offers a thrill until you figure it
out. This trivial game is an amusing and easily soluble riddle which nevertheless points out the danger of assuming paranormal explanations for other, more opaque phenomena. Paranormal solutions should
be grasped at only if extraordinary evidence forces us to.