(full essay posted at 3QD)
Writers at this site have discussed the "Uncanny Valley" before. Put simply, it's that point along the curve from "clearly artificial" to "almost lifelike" at which most people get ... well, creeped out.
While the term is new (a Japanese roboticist coined it in 1970), the idea may be as old as myth: Ugly things - things that look very different from us - are repulsive. But so are things that look almost like us - or things that could be us, but aren't.
Isn't that why vampires fascinate us? "I thought she or he was safe, trustworthy, one of us ... until I saw no reflection in the mirror ..."
No reflection in the mirror = no confirmation of humanity, either theirs or ours. If they don't cast a reflection than they don't reflect us.
So a monster that's human-like is scary for different reasons than an obviously grotesque one. In the dark that face seemed almost human. But when I turned on the light ...
Anybody want to insert a Joan Rivers joke here? Go right ahead. Plastic surgery falls into the Uncanny Valley sometimes. We allowed ourselves to adjust as famous people gradually began reconstructing themselves more and more.
Imagine if someone with a heavily reconstructed face - Michael Jackson, let's say - were sent back in time 100 years. It wouldn't be a joke. People would run away in horror.
"Monster: From the root of the Latin monere, to warn - as of something terrible or portentous." That's what the Encyclopedia Britannica says.
"Monster ... not one with the blowing clover or the falling rain." That's what Ralph Waldo Emerson says.
So let's call Uncanny Valley monstrosity a warning: That thing you thought might be human ... isn't.
And what does John Lennon have to do with all of this? Surprisingly, nobody's built any animatronic Beatles yet. I have seen Beatles cover bands in about five different countries, including Japan, Portugal, and India. Moptops, collarless suits, bobbing heads ... the whole deal. But, while the late Mr. Lennon has escaped robotic reproduction (which could leave him looking like the overly humanized "actroid" on the right), he lives on in at least two back roads of the Uncanny Valley.