Can you solve the famously difficult green-eyed logic puzzle? - Alex Gendler
View full lesson: http://ed.ted.com/lessons/the-famously-difficult-green-eyed-logic-puzzle-alex-gendler One hundred green-eyed logicians have been imprisoned on an island by a mad dictator....
========== Imagine an island where 100 people, all perfect logicians,
are imprisoned by a mad dictator. There's no escape,
except for one strange rule. Any prisoner can approach the guards
at night and ask to leave. If they have green eyes,
they'll be released. If not, they'll be tossed
into the volcano. As it happens,
all 100 prisoners have green eyes, but they've lived there since birth, and the dictator has ensured
they can't learn their own eye color. There are no reflective surfaces, all water is in opaque containers, and most importantly, they're not allowed
to communicate among themselves. Though they do see each other
during each morning's head count. Nevertheless, they all know no one would
ever risk trying to leave withou...