A proof that 12=13. Just look at the picture and count the people. (pic) | Hacker News Reader

A proof that 12=13. Just look at the picture and count the people. (pic)

tamu-commerce.edu

27 pointsnickb17 comments

This is driving me crazy. Time to break out an image editor.

edit: if you can't let this go either, save yourself a few minutes: http://tlrobinson.net/misc/illuuusions.png

Some time ago I found this picture and worked on it until I could generate similar animations on my own. It's tricky: the guy that disappears is gone not because it's divided in two parts and both are made into different guys; but because lots of little parts are made into different guys, so making a disappearing complete guy. That is: lots of different parts in different guys disappear in a very obvious way, and if you sum all of them, they complete a single guy (it's not easy to explain, but there is not a single disappearing guy, but a lot of tiny parts of different guys disappearing at once).

Try to make it work on paper to understand how it works. Notice that the upper half of the "paper" should be cut in two halves, and those two halves _have_ to be of a different size.

Ingenious. Made my (early) morning. Reminds me of this proof: "The less you know, the more you make" http://tinyurl.com/yu2swe

I don't have time to look at this carefully, but this has to be a dissection fallacy like the ol' "64=65" one.

For geometric examples, see http://mathworld.wolfram.com/DissectionFallacy.html .

No, it's not the dissection fallacy, it's a different trick. I gave some details on another post on this thread...

The guy on the far left counts as an extra person after the shift (and the loss of the top of his head).

This guy is right! Im amazed I thought you all here were smart, it took me 60 seconds to figure it. And im a dumb arse who uses LAMP.

Wow, I definitely stared at that for 15 minutes. I know it's trickery, but it's still pretty brain-twistingly cool.

So it cuts a line out of like seven people and makes a thirteenth dude, right?

Wasn't this puzzle originally invented by Henry Dudeney like 100 years ago?

No one's seen the disappearing square trick in math class?

I didn't... How does it work?

http://everything2.com/index.pl?node_id=810090

Same sort of idea - makes use of deviations in the picture that are hard to pick out.

Ah, but it's not it. The one in the animation is not a geometric problem, it's more subtle (I solved two years ago, see my other comment).

This is insanely cool, but...

optical illusion != proof

Not an optical illusion. Twelve guys really become thirteen. But they have to pay a price for that: they're somewhat shorter, their heads are slightly smashed in, etc. Basically the same as what happened when hunter-gatherers switched to agriculture: more people but less healthy.

This is worse than the stuff that ends up on the reddit front-page. Please, let's try to keep this stuff away from yc.

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