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Paul
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Re: Card Flip

May 3rd, 2017, 6:04 pm

And this is without even going into quantum effects.

What was the original source of this version of this question? Most versions I've seen are more tightly worded than this one.
 
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Traden4Alpha
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Re: Card Flip

May 3rd, 2017, 6:54 pm

And what if the "green" card has this on the other side?
Image
We assume all observers have identical visual sensitivity.

Or what if the other side is cyanotype paper that turns blue after exposure to UV light? We assume the color or pattern on the card is time-invariant and not photosensitive.
 
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outrun
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Re: Card Flip

May 3rd, 2017, 7:39 pm

I can't remember where I found it, but I know i didn't alter the wording.
Adding 5 pages of definitions will probably only make things worse, people will start to look for weaknesses and there is going to be 5 pages of them!

Lots of discussions end up being about the physiology of science: what theory is your observation build on? You can't observe without a theory about the instrument, reality, but is that theory true?
 
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Traden4Alpha
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Re: Card Flip

May 3rd, 2017, 7:52 pm

Quite so! 5 pages begets 5^2 pages begets ..... Pretty soon there's e^5 pages!

But aren't brainteasers as much about brains as about teasers?

Moreover, isn't there a difference in how one is expected to approach a textbook problem in the Student forum versus a brainteaser problem in this forum?

Besides, life would be boring without the occasional arctangential digression!
 
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katastrofa
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Re: Card Flip

May 4th, 2017, 12:22 am

This question discriminates against donkeys; they cannot see the blue colour (source: "Shrek" part I). They can write numerical code on paper, though.

Image
Last edited by katastrofa on May 4th, 2017, 9:34 am, edited 1 time in total.
 
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Paul
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Joined: July 20th, 2001, 3:28 pm

Re: Card Flip

May 4th, 2017, 6:41 am

Moreover, isn't there a difference in how one is expected to approach a textbook problem in the Student forum versus a brainteaser problem in this forum?

Besides, life would be boring without the occasional arctangential digression!
Normally I'd agree with you. But in this example it's too easy to come up with not very interesting "approaches." (Although bringing in lawyers was a novel angle!)

Also the original question is just too clever and thought-provoking to be beaten.
 
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Traden4Alpha
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Re: Card Flip

May 4th, 2017, 1:46 pm

Moreover, isn't there a difference in how one is expected to approach a textbook problem in the Student forum versus a brainteaser problem in this forum?

Besides, life would be boring without the occasional arctangential digression!
Normally I'd agree with you. But in this example it's too easy to come up with not very interesting "approaches." (Although bringing in lawyers was a novel angle!)

Also the original question is just too clever and thought-provoking to be beaten.
Interesting!

So you're saying that some brainteasers are intrinsically clever enough not to require (or desire) clever (mis)interpretations of the problem statement?

I wonder if it is possible to create a taxonomy or parameter space for the O(1690) brainteasers on this forum that segment them by where the cleverness lies in the chain between problem statement and solution set.
 
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Paul
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Re: Card Flip

May 4th, 2017, 3:30 pm

Arctan, and its ancestor, Square Root, near one extreme and Card Flip near the other.
 
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Traden4Alpha
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Re: Card Flip

May 5th, 2017, 1:59 am

I see four stopping conditions for brainteasers on this forum

1) no answer.
2) a single correct answer that is acknowledged as best.
3) a series of potentially correct alternative answers accepted based on alternative interpretations of the question.
4) a series of potentially correct alternative answers sparking bitter disagreement.

Card Flip seems to be case #2 (or a little way toward #3).

But cases 3 and 4 seem to reflect two dimensions of difference from case 2: A) the postulation of alternative interpretations and B) the acceptance/rejection of those alternatives.

(Note: some brainteasers don't really stop. e^5 has taken on a life of it's own and may become sentient.)
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