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Disappearing Bicyclist – Sam Loyd (1906)

geogebra.org

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Re: Disappearing Bicyclist – Sam Loyd (1906)

#3

Post by bloak »

Unfortunately this doesn't work with banknotes ... unless you can find lots of people who are willing to accept a banknote that appears to have been torn into two pieces and then stuck together again with sticky tape, with the line of the tear being a weird curve that just happens to cross both serial numbers in roughly the same place.

Re: Disappearing Bicyclist – Sam Loyd (1906)

#5

Post by Chinjut »

Put it in the B configuration. There are 12 boys, which can be thought of as 24 halves bundled in pairs: a half on the outside of the circle, and a half on the inside of the circle. (Conveniently, also, each bundled pair of halves includes one half with a flag and one half without a flag). Some of these halves are more substantial looking than others, mind you.

Rotate it to the A configuration: There are still 24 halves, bundled in pairs. But now we count it as 13 boys instead of 12. Why? Because in the bottom left, two of the halves that got paired together are both flag-and-head halves, so even though that was just two halves in our original count, it feels like the two of them bundled together should count as two boys instead of just one now.

(Correspondingly, in the top right, two of the halves that get bundled together in the A configuration are both non-flag halves. But the result still seems sufficient to call one full boy instead of zero boys.)

Re: Disappearing Bicyclist – Sam Loyd (1906)

#6

Post by dane-pgp »

bloak wrote: post #3

Unfortunately this doesn't work with banknotes ... unless you can find lots of people who are willing to accept a banknote that appears to have been torn into two pieces and then stuck together again with sticky tape, with the line of the tear being a weird curve that just happens to cross both serial numbers in roughly the same place.

It does work with chocolate, though...

http://mathandmultimedia.com/2014/07/22/explanation-infinite...

Re: Disappearing Bicyclist – Sam Loyd (1906)

#10

Post by Someone »

bloak wrote: post #3

Unfortunately this doesn't work with banknotes ... unless you can find lots of people who are willing to accept a banknote that appears to have been torn into two pieces and then stuck together again with sticky tape, with the line of the tear being a weird curve that just happens to cross both serial numbers in roughly the same place.

‘Nobody’ looks at banknotes. Also, historically, banknotes were torn and repaired more often. Because of that, you can just cut a 1/10th width strip out of 9 banknotes and glue them together to make a 9/10 width tenth banknote.

Examples: https://books.google.com/books?id=e7QzAQAAMAAJ&pg=PA318&lpg=... (1804)

https://books.google.com/books?id=osjhDwAAQBAJ&pg=PA114&lpg=... (1850s)

A more tricky recent variant replaces the cut-out part with a fake part: https://bc.ctvnews.ca/can-you-spot-the-fake-splice-and-tape-... (why do these criminals take the effort and risk of creating a fake fiver? I would discard the remains of the fiver, and spend all effort on improving the technique for transplanting the hologram to the fake 100)

Of course, this works better with small denominations, if only because people expect larger denominations to look newer.

The risk of getting caught also is fairly large, I think, but a good criminal can feign innocence, claiming to have gotten the note elsewhere.

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