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An Odd Card Trick

chalkdustmagazine.com

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Re: An Odd Card Trick

#21

Post by cyounkins »

fenomas wrote: post #10
wellpast wrote: post #2

Just performed this trick for my partner and she was very underwhelmed. There’s probably a good delivery to figure out.

TFA explains the trick somewhat oddly, to make the math angle more obvious. Here's a (random) video of someone doing it a more usual presentation of the effect: https://www.youtube.com/watch?v=Xau8Ng4aQ6Y Not the world's greatest magic trick or anything, but I don't think it's as transparently obvious to figure out as several commenters are suggesting.

The article describes a fixed number of cards to the performer and spectator, but the video has him split the deck behind his back. Is he counting by touch to have the correct number of cards?

Re: An Odd Card Trick

#22

Post by d--b »

alasdair_ wrote: post #19

The wine and water explanation doesn’t make sense to me. Wine and water have different molar masses and combining a liter of water and a liter of wine doesn’t give exactly two liters of the new substance, in the same way as a liter of ping pong balls and a liter of sand doesn’t produce two liters of ping pong sand when mixed together - some of the molecules are bigger than some of the others. Once you pour a liter of…

No, it’s not like ping pong balls and sand. A liter of water and a liter of wine definitely make 2 liters of liquid…

Re: An Odd Card Trick

#23

Post by gus_massa »

alasdair_ wrote: post #19

The wine and water explanation doesn’t make sense to me. Wine and water have different molar masses and combining a liter of water and a liter of wine doesn’t give exactly two liters of the new substance, in the same way as a liter of ping pong balls and a liter of sand doesn’t produce two liters of ping pong sand when mixed together - some of the molecules are bigger than some of the others. Once you pour a liter of…

The article is about mathematical water and mathematical wine. They have additive volumes.

Real water and real wine are more complicates. More generally, after mixing some water and some ethanol the volume of the mix is smaller than the sum of the volumes. And this is not only a theoretical result, it's possible to measure the difference experimentally https://en.wikipedia.org/wiki/Alcohol_by_volume#Volume_chang...

Re: An Odd Card Trick

#24

Post by asxd »

ummonk wrote: post #5

https://web.archive.org/web/20211122214741/https://chalkdust... since it has the Hacker News hug of death. This is such a ridiculously obvious trick I'm surprised any audience is impressed by it. But that happens for me with a lot of magic tricks... I guess a lot of people just choose to shut off basic thinking (and in this case don't have an intuitive understanding of conserved quantities).

This is often called "suspension of disbelief" and is an integral part of becoming immersed in some forms of art. When you watch a movie, for instance, you know that none of it every really happened. You probably can guess the tricks they used to create the visuals. But constantly reminding yourself of that fact tends to ruin the illusion and the fun.

Re: An Odd Card Trick

#25

Post by dreamcompiler »

alasdair_ wrote: post #19

The wine and water explanation doesn’t make sense to me. Wine and water have different molar masses and combining a liter of water and a liter of wine doesn’t give exactly two liters of the new substance, in the same way as a liter of ping pong balls and a liter of sand doesn’t produce two liters of ping pong sand when mixed together - some of the molecules are bigger than some of the others. Once you pour a liter of…

If you mix 1 liter of pure alcohol with 1 liter of pure water, you'll end up with less than 2 liters of liquid. But wine is a little bit of alcohol already mixed with a lot of water, so the "interstitial molecular crowding" will have already happened. So 1L of wine + 1L of water produces 2L total.

Re: An Odd Card Trick

#26

Post by GoldenGateBRDG »

alasdair_ wrote: post #19

The wine and water explanation doesn’t make sense to me. Wine and water have different molar masses and combining a liter of water and a liter of wine doesn’t give exactly two liters of the new substance, in the same way as a liter of ping pong balls and a liter of sand doesn’t produce two liters of ping pong sand when mixed together - some of the molecules are bigger than some of the others. Once you pour a liter of…

https://de.wikipedia.org/wiki/Mischungskreuz

Re: An Odd Card Trick

#27

Post by nickpeterson »

rnoorda wrote: post #16
wellpast wrote: post #2

Just performed this trick for my partner and she was very underwhelmed. There’s probably a good delivery to figure out.

Having dabbled in magic some, I can confirm that the delivery is far more important than I originally thought. Several times I have had my mind absolutely blown by a card trick, then found out it's a trick I have done myself! But they had put in so much more effort on honing the delivery, presentation, and patter to the point it became a different trick.

This is so important in most fields. Marketing works.

Re: An Odd Card Trick

#28

Post by anamexis »

d--b wrote: post #22
alasdair_ wrote: post #19

The wine and water explanation doesn’t make sense to me. Wine and water have different molar masses and combining a liter of water and a liter of wine doesn’t give exactly two liters of the new substance, in the same way as a liter of ping pong balls and a liter of sand doesn’t produce two liters of ping pong sand when mixed together - some of the molecules are bigger than some of the others. Once you pour a liter of…

No, it’s not like ping pong balls and sand. A liter of water and a liter of wine definitely make 2 liters of liquid…

Not quite. Mixing alcohol and water results in a different total volume than the sum of the two before mixing.

https://en.wikipedia.org/wiki/Alcohol_by_volume#Volume_chang...

Re: An Odd Card Trick

#29

Post by daveFNbuck »

graup wrote: post #20
alasdair_ wrote: post #19

The wine and water explanation doesn’t make sense to me. Wine and water have different molar masses and combining a liter of water and a liter of wine doesn’t give exactly two liters of the new substance, in the same way as a liter of ping pong balls and a liter of sand doesn’t produce two liters of ping pong sand when mixed together - some of the molecules are bigger than some of the others. Once you pour a liter of…

I think you made the same mistake that I made when I first read it. The question isn't "what contains more wine?" but "compare the amount of water in A to the amount of wine in B." Step 1: A with 10 L wine; B with 10 L water Step 2: A with 9 L wine; B with 11 L liquid (10 L water and 1 L wine => 10/11 water, 1/11 wine) Step 3: A with 10/11 * 1/11 = 10/11^2 L water; B with 1/11 * 10/11 = 10/11^2 L wine. 10 / 11*2 wate…

You're misunderstanding the objection. They're saying that if you move 1L of wine to the water side, the side you poured into will have fewer than 11L and when you pour 1L back the two sides won't have equal volume.

Re: An Odd Card Trick

#30

Post by rawoke083600 »

Lol cool. I wonder if some of these types of card-tricks methods - based on "math and shuffle-rounds etc" to get a desired "result/order", can be used in a type of DB-Indexing ?

There must a 100+ of these types of tricks or algo's

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