[reappear]

The ramp video is fun, but i don't think it belongs in the same bin as other "optical illusions".

Yes, visual cortex failed, and it failed where a god would succeed (succeed in finding the simplest interpretation and making a sharp bet on that interpretation). But the most surprising optical illusions present a far lower bar which visual cortex then still fails to clear.

Often, they exploit what must be some specific implementation detail of visual cortex.

Often, they feel really weird from the inside. Sometimes they force competing interpretations, sometimes a single interpretation which turns out to be obviously wrong.

So i guess it's probably right to insist that an inference engine's optical illusions be a subset of its koans. At my level, the ramps are no koan, just a (funny and clever) lie.