The Number Illusion You Won't Believe
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- čas přidán 25. 02. 2020
- Sometimes math is so beautifully tricky, and presented in such a subtle way, that it’s virtually indistinguishable from magic. Welcome to The Kruskal Count.
David Copperfield is probably the most famous living magician/illusionist, and he’s made use of the Kruskal Count to convince millions of people worldwide that he harbors amazing predictive powers. Does he? Well… yes and no.
At the core of his mathematical mind reading is physicist Martin Kruskal’s discovery that certain counting games are really a sequence of chains that can intersect and eventually become one single chain. Using that knowledge of well-concealed probability, it’s easy to perform a mind-blowing demonstration that appears to be pure magic.
But it doesn’t always work, because that’s the way probability goes. Sometimes it’s perfect, sometimes it isn’t. By examining the Kruskal Count as a magic trick and also through its original card-based format, we’ll see that magic can be math… and math can be magic.
Play “The Kruskal Count Card Trick” simulator by Alex Frieden and Ravi Montenegro: faculty.uml.edu/rmontenegro/re...
** SOURCES **
David Copperfield Vacation Destination Trick: • Magic of David Copperf...
“The Kruskal Count,” Lavarius, Rains, Vanderbei, October 2001. arxiv.org/pdf/math/0110143.pdf
Mathematical Card Tricks: “It’s probably magic,” American Mathematical Society: www.ams.org/publicoutreach/fea...
“How Long Does It Take To Catch A Wild Kangaroo?” by Ravi Montenegro and Prasad Tetali:
arxiv.org/pdf/0812.0789.pdf
** LINKS **
Vsauce2:
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Hosted and Produced by Kevin Lieber
Instagram: / kevlieber
Twitter: / kevinlieber
Podcast: / thecreateunknown
Research And Writing by Matthew Tabor
/ tabortcu
Editing by John Swan
/ @johnswanyt
Huge Thanks To Paula Lieber
www.etsy.com/shop/Craftality
Select Music By Jake Chudnow: / jakechudnow
Get Vsauce's favorite science and math toys delivered to your door!
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#learning #education #vsauce2
Two Things:
ONE. Thanks again to NordVPN for sponsoring this video and supporting my fake wizard beard addiction. Get 70% off NordVPN plus and additional month free: nordvpn.com/vsauce2 and use coupon code: vsauce2
TWO: Something WEIRD happened in my first Kruskal Count card game. Did you notice? TELL ME NOW. Also, don't eat cat food. Bye.
Heeeeey
Yeah how
You never drank your choccy milk
All of the sequences in the first card trick lead to the same 9
I got 6 on the first card one.
Jokes on you, apparently I can't spell nor count.
Yeah buddy go
Apparently i can't either lol
I started at twelve and got to 3, ELIMINATED
you cna count
Same I was on the 5
Well I'm convinced Kevin is a psychic. You didn't even need to predict my number you already knew I was thinking about memes and pizza rolls.
TierZoo hi
Lol what tierzoo
Time to rank all of Kevin's "characters" and their abilities
Hahaha
tierzoo upload more pleeasee
-are you on 8?
-yes
-NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
An interesting thing you should've brought up is how if we changed the face card's value from 5 to say, 1 or 2, it'd improve the odds for chains to intersect because of the smaller jumps
"If your secret number is 7..."
We don't even need to proceed with the trick, you already guessed it before it even began...
God damnit...
I always pick 2 numbers when they say that to throw them off.
He got me there to. He got 7 11.
@@phoenixstormjr.1018 Same bruh
Happened to me also, twice. On 11 and then on 6
Rubens Cavalcanti same
Same
Vsauce: eats a donut taken out from the toilet.
Vsauce2: eats cat food.
It's Jake's turn now
Vsauce 3 JoJo part 5 addition.
Kevin has also eaten slightly under cooked cow brain, and has drunk water from a toilet.
Eat your cereal
Except it was never in a toilet
The card trick works (usually) because the face cards are assigned a value of 5, which is the average of the number cards, aside from 10, which is simply double 5. On average, you move 5 spaces, and the longer the sequence, the closer you converge on this average.
There's an old board game named Bonkers that has chains like this. You build the board as you play and you learn pretty quickly that you can link anywhere into the chain to get to its endpoint.
The best magic trick: Pick a number, then multiply that number by 0.
Your number is 0.
this is how most equation tricks go but their just longer equations
Kira Apprentice Are you dumb?
Oh shoot this works! I thought it was fake!
oH MY GOD HOW DId YOu GUESS ThaT
What are you a magician
“If your secret number is 7”
Me: *panik*
“Then you move 5 times”
Me: *kalm*
Ngl it was exactly my reaction lol
Same Xd
Same
so u spell "calm" with a "k"
Same lol
Maybe it is because I am a physicist that minored in math but this trick seemed instantly obvious as soon as you started setting it up. Cool that the numbers happened to work out that way though.
When a magic trick starts to feel more like homework 😆
Kevin: "Let's say your number was 7"
Me: *gasps* "The beard is magical"
welp mine was seven so yea
Me too
Same
MINE WAS 7
seven gang
Kevin: "Do you live in a country?"
Me: "Yes."
Kevin: "WRONG!!!"
hahahahah XDDD!!!
Oh no he found out about us aliens we must hide
I'm living in the ranch
I live in a priso-I mean house!
You actually live on an ARCHIPELAGO!
Or an ISLAND!
In computer science, this forms a forest graph. A forest graph consists of multiple tree graphs. The trick always works if and only if the starting numbers are all on the same tree.
Yeah, I remember watching David Copperfield's show where he did this on tv as kid. Was super wowed that young.
The longer Michael’s beard is the crazier he is.
Kevin has done the same
"I'm in my mom's basement" reminded me of "I'm in my parents basement"
Lol
“I will guess your number”
“Psh yeah right”
*explaining the rules, very first example* “if you picked seven, for instance.”
Damn he’s good
if i remember correctly from 1 to 10 7 will get chosed the most
Sameeeee
I picked 2 numbers to throw him off. He got me. He really is psychic and doesnt know it.
In5aNeGuY Yes i know to never pick 7 when someone’s doing the guessing thing lolol
I originally was gonna choose six, then five, but I thought that they were too obvious and went with seven. Big mistake.
I had already done the math on the first one to realize how fast they would line up once. Although at first I thought it was going to be counting based on where our number started which made me think it would take more time.
12:15 Nope; Not this guy!
I'm still chuckling over the original "weiner...dog" joke...lol
Vsauce: So you're at... SIX!
Me at 8⅝: *confused screaming*
I think I messed up I was at 3
I was at the 7. Because I spelled in German. He didn't say not to do that😌
Me at 4 1/8: *confused confusion*
@@ethanb2698 me 2
me 10
"If you picked seven"
Not even 10 seconds into the trick and he knows my number...
Seven is the best number tbh
@@usernametaken017 yep
Lol first thing i pick os seven too
Same
Me too
Problems with such tricks is that you attempt to do at the beggining, that them are language dependent, but you could calculate chain for different languages and improve trick to guess viewer language/country
"but i do know, that you are not on the 2"
Anyone who landed on that: YIPPEE
*Stops on eight*
"I guess I have done everything correctly"
"You are SURELY not on the number eight!"
"Now hold on..."
this happened to me too 😪
Go back to 1:29 and pay attention.
same
@@markconigliaro Dude, there are 4 letters in four. That puts you back at 4. Using the number of letters in the "new number" that puts you at 8.
@@yaroslavsky yes, but then he says do it *again* , which puts you then to 1, which is, as he explained, the magic number
Him: YOURE ON THE 6
Me, on the 7: Welp what did I do wrong now...
Same happened to me😅...
Meet too
Me too
Sike that's the wrong number
"""Oooooohhhhhhhhhoohohhohoohoh""""
You simply have more value in numbers
I remember one of Copperfield's TV specials, when I was a kid, and doing this trick. I was freaked out!
Vsauce2: "you dident land on the 12."
me, who got 12: *WRONG!*
1:37 "if your secret number is 7"
*starts sweating*
same dude, he's just too good
@@danielchoucinofigueiras1733 same.
Same, i picked 7 too
I also picked 7...
Bro doesn’t need to even do his trick fully
"If you picked eleven"
Me (picked 11): he's doing the job for me. How nice.
I'm the 69th liker of your comment... N I C E :-)
i picked seven haha
but if u start at four it's doing this :
3 then
8 but he remove 8, so if you want to do at 7 now. You land on the 3
and I have no idea what im doing wrong here
That was creepy!!
@@samymehni1382 dont count the 12, he said start from 12 not with 12.. put your finger at 12 and start moving to 1 2 3 . . and if you picked 4(f o u r) you go from 1(f) 2(o) 3(u) 4(r)..... dont count at 12... start count when you are at 1 ok
0:12 - Is this a glass with "Gojira" (French Metal music group) logo on it?
9:06 who else thought he was gonna bring out a hot dog? 😂
Him: choose a number
Me: seven is my lucky number
Him: for example, if you choose seven
i started on 4 and ended up on 12
That is why I did not choose seven
I debated about choosing seven or five I chose seven he used that as an example then landed on five WTF
dude i chose 7 too!!!
He didn’t have my lucky 13
"Pick one"
Me: ok *picks 1*
Богдан Седин lol same
Lol
Samee
Same
lol :p
So, when you first did the deck of dog cards, ALL (100%) of the first 10 cards lead to the same 9 on the last row. While mathematically, only 85% will lead to the same final card on average, this particular set was just right for every single one of the first 10 to match up.
Cards 1 and 5 go to card 10, which then go to card 11 (King on second row) along with cards 3 ajd 6, which all go to card 16 (10 on second row). Card 2 goes to 7, which goes to 10 and links up with cards 1 and 5. 4 goes to 8 which goes to 13 (first 6 on second row) and then to card 19 (3 on second row) along with card 9 (10 on first row). So, by now, everyone is on card 16 (10 on second row) or 19 (3 on second row). 16 goes to 26 while 19 goes to 22, which goes to 24, which goes to 30, so now everyone is on the third row at 8 (card 26) or 4 (card 30). Next step for both chains leads to card 34 (a 9 in the 4th row) which leads to card 43 (first 5 on last row) which leads to that final 9 (card 48).
When your ten parallel universes ahead, because you spelled your letter in a different language
What is unverse ahead? You only know one you are in.
"If you're on 3.."
*Sweating*
relatable moment xd lol
i was on 4
Me too and this didn't work for me..
I was on 3
@@Suran107 then you probably can't count lol
Vsause: you are on the three? No no no, you are not on the three
Me: just looking at my number being thrown out of the number group
Signar Mikkelsen You didn't pass math did you
@@werrywit maybe they passed in another language
@@hugofontes5708 And the Chinese only has to move one space at a time. Nice.
I thought pi, I WIN
SAME
I've seen these so many times that I don't even try to work around the system anymore lol.
I want to say a few things, no matter what number you pick at the start, you will land on 3, 4, 5, or 6. 3 goes to 8 , 4 goes to 8, 5 goes to 9, and 6 goes to 9
so after the second round you will be on 8 or 9, but after the 3rd round you will only be on 1. Then to 4, but removes it. I'm not sure if that was going to happen but, it did, how many people now see this?
Ok, I did something wrong or did it 4 times instead of 3 or something
“If your secret number is seven...”
*Breathing intensifies*
exactly my thought too
He got us
Lol
I always pick 7 for things, so this time I picked 3...... coincidence ?
same
Me: picks 7
Him: If you're secret number is seven, let's say
Ne: visibly freaked out
Same
Sane here
We all suffered the same fate
Your*
Aron Fekete same
Why am I yelling at my phone saying “ITS TWOOO”
Merlin's beard that's bloody brilliant!
Kevin: "If you picked 7"
Me: *panicked hyperventilating*
to be fair people tend to pick 7 more often than other numbers
@@Melecie are there studies or something?
@@soullessangel207 ah thank you for the reply. I havent watched that lad in years so also thanks for reminding me about him.
7 is a holy number that we all subconciously love. Thats why slot machines have triple 7's give the biggest payout.
I try to respect others beliefs, but 7 being a "holy number" definitely wasnt an answer I was looking for.
Me: Clicks play
Merlin: “I know everything about what you do and think”
Me: *takes hearty swig of chocolate milk*
Merlin: “…with my chocolate milk”
Me: *closing computer* “well this video has been fun”
You were way off I started with the 5
@@daletaylor330 .
@@daletaylor330 what
Haha
Lmao
4:25 Jokes on you, I was on the three
KEVIN: Pick a card, any card.
ME: Alright, Stan Musial.
"Do you live in a country? Yes. You do."
People in Antarctica: "Am I a joke to you?"
Arthur Uppiano you can’t actually permanently live in Antarctica.
Sure, maybe science, but not actually reside there.
Antarctica is a country and continent right.... well so it Australia so I don’t get it? What’s the argument here???
Technically Antarctica was separated in to pieces due to colonization
"Magic works 100% of the time"
Hear that DM? Vsauce Kevin guarantees it! now stop asking me to roll spell casts.
Too bad
Make a concentration check
"I'm lounging by the pool drinking chocolate milk right now"
Actually, in my mind, you won't find chocolate of any sort unless it's in the "to be removed from existence" area
Oh wow. SO impressive. Three point three got me on the ten.
Just spell the numbers in any language other than english...
Mind size: *MEGA*
When I pick 1 and u say that and I think of french so uno
Wait a minute
@@williammartin8873 **laughing emoji**
i know this is a joke buuuuuuuut not quite, for example "nine" has four letters and in german it's "neun" which also has four letters and also in french where it is "neuf". Same with "six" and "sechs" wait a minute-
@@SentientPotato3 well, "nine" has four letters and in russian it's "девять", which has six letters; "eight" has five letters and in russian it's "восемь", which has six letters; "seven" has five letters and in russian it's "семь", which has 4 letters... So if you spell the numbers in russian, you'll always end up on a different number than in english.
"If you picked seven..."
WELL uh i get called out like this ? Before the magic trick starts ? Well damn.
Everybody was on 1 when you started removing numbers. The trick is simple: all the numbers 1-12 consist of 3-6 letters, so after the first step, everybody is in 3-6. With your next step, we have 3->8, 4->8, 5->9, 6->9, so now everybody is on 8 or 9. Finally, with your third push, everybody is on 1, so the final step of the trick follows smoothly as long as the user didn't make a mistake.
Edit: I guess you explained it but I enjoyed explaining it first. :-P
Nice taste in music! I noticed the Gojira logo on that cup.
Everyone saying they beat him:
Me actually getting 6: what
I got 7 lol
You always get 6 unless you did the math wrong.
@@ItsLogic Every number you choose at the start has 3-5 letters, those three outcomes all lead back to the one in the end, everybody then takes the same steps and ends up on 6.
I got 6
Nelson Lantican ik
Merlin: You aren't on 10.....
me: but I am o-
Merlin: *You aren't on 10.....*
Same
You can't count then~
Same!
Bose-Einstein You are being mean
Same
0:11 that Gojira glass didn't escape my attention. 👀
I started with the number 7. The trick is so cool!
“you're not on three”
Its either I am on thre or I forgot how to count
U chosed 10?
11
Replys are dumb. See how he wrote 3.(I actually can't spell 3)
Same
Same i got it
“If your secret number is seven”
Me: *Sweats nervously*
i also picked seven first and it lands on 5 *and 75 is my favorite number*
Same
XD same happened here
7 is most popular number
I picked seven than 11 and he guessed those to first
I feel like people saying "he removed the number I was on" were doing it wrong
12:16 It might only work five in six times on average, but I think that means five times out of six, no matter which card you pick, you all agree. That certainly was the case here; everyone lands on the six of hearts in the third row and from there itʼs the same.
Me: picks number 7
Kevin: "Suppose you pick number 7....."
Me: aaaaaaaaaaa
Same
Same
That awkward moment when he takes your number away
That awkward moment when you realise you messed up, but dont know where TwT
When you realize you can't count?
when you realise that you cannot spell XD
Oof
if you start with 6 it doesnt work
Haha Vsauce you did count for my brain to be off when you where telling the rules
This is amazing 😁😍👏❤
For those who have difficulty spelling
1. One
2. Two
3. Three
4. Four
5. Five
6. Six
7. Seven
8. Eight
9. Nine
10. Ten
11. Eleven
12. Twelve
is this the reason why spelling bee is still a real contest
Thx
Спасибо
Thanks this is so helpful!
My faith in humanity is disappearing.
“ i know that you’re not on the 2 either... or the 4... or the 8”
Me being on the 8: 😔
Also me on 4
I choose 6, and was on 4 too
I chose 8 And ended on three
Joan me to
I was in the 8 too
Pretty cool. Now next time try to actually guess the number i had in mind ;)
eventually you land on a handful of numbers and as the specific cards are removed, they all point to the same one
Okay, Vsauce2 is a professional wizard now. I am proud of him.
Doesn't do what's on the tin.
Never once guessed the number *I picked.* Just sent me along to another number and told me that one.
Vsauce2: "If you picked seven, for instance, you would move..."
Me: Oh, guess I won't need to count this one
I picked 7 aswell
@@jgperes me too then l picked 4
Me too
The first time, I cheated and didn't follow the rules...
I don't know how, but he still got me.
Mind blown.
You : you chosed the 6 ! Me : I didn't know i chosed the 6 .
Joke's on you - I spelled in an other language.
Me too
Me too
What language did you count in?
I did in norwegian and ended on 12
@@arketim7938 French personally
great minds think alike
Showing this to my family members is easier than explain the trick.
absolutely😂
@Emily Moore 🤣
Why on earth would you want to explain the trick. I'm going to use this in D&D puzzles for my players and blow their minds
this is really the featured comment?
Just say "it's magic"
He doesn’t realize the only thing I thought of this whole time was bananas
Nice force, well disguised
"Now clear your mind of its usual thoughts. Memes, pizza rolls, energy drinks."
OK WOW YOU DIDN'T HAVE TO MAKE IT PERSONAL
Official vsauces:
Michael
Jake
Kevin
Ethan and Hila
Merlin
And Ian
Aren't Ethan and hola from h3h3
I'm not a vsauce
Although I am ethan
Good job
I was on three and you removed that number, i was like: I thought you are a genius wizard or something but im wrong, i guess ima just choose another random number on that point
"Spell the number"
Me, a non-English viewer: *Giorno's theme plays*
"8 okay lets count: S-E-K-İ-Z now I am on 5 lets count: B-E-Ş now I am on 8 lets count: S-E-K-İ-Z now I am on 1" The random number I choose joins the chain where english chain joins 1. If I try this with Turkish when I spin third time I would end up in 1 if I choose 4,6,7,8,9,11 or 12. 1,2,3,5 and 10 would end up in 8 and chains would perfectly follow each other with one move lag.
Can you make the same type of game work in your native language
@@umbraemilitos Maybe with another number as the final number? I'd have to check
@@Mauripsu You may need more or less than 12.
1 = B-İ-R
2 = İ-K-İ
3 = ü-Ç
4 = D-Ö-R-T
5 = B-E-Ş
6 = A-L-T-I
7 = Y-E-D-İ
8 = S-E-K-İ-Z
9 = D-O-K-U-Z
10 = O-N
11 = O-N-B-İ-R
12 = O-N-İ-K-İ
these are the spellings of the numbers do the math yourself.
Kevin: Do you have friends?
Me: Yes
Kevin: WRONG!!!
Me: how did you know ;-;
Always good to see Aaron Paul do Science.
At 2:31 If you on the 3 move 5 spaces, it puts you on the 7 not the 8.
I have never felt such power as being able to tell where the trick was going after step one
ikr
Yeeeee same :D
Me: **lands on the 2**
Him: **removes the 2**
I guess doing it in my mother-tongue is like cheating lol
I chose 2 also and he pulled it off the board.
i landed on 4
@@dejyyz same
I landed on 3 then he removed it
landed on 9
So far on the clock one and trying to find out the trick as you do it, commenting at about 3:00 and I found out that at this step it always goes to one
Edit: this was my method, realized step one lands you in the 3-6 range, then step 2 lands you on 8 or 9, then step three can only land you on 1, the final step lands you on 6 :)
When he took my number away: Welp today I learned that i cannot count or spell.
I picked seven to start with and then the example of seven being used made my eyes widen.
me too smoge
Same
WHY DID ALL OF US CHOOSE SEVEN
True why did we
me too
"Spell your number"
Laughs not in english
Same😂
O-N-E
Spanish: Uno
French: Un
Chinese: e
Bfb_Pencil Finnish: yksi
@@jarkki1017 German: Eins
Love the Gojira glass!
that gojira cup at the start made me strangely happy
Me spelling the numbers in German:
Magic doesn’t work on me 😏
I spelled the numbers in russian and it didn't work on me either
Edit: I also did that on purpose because I've seen a few videos on the same thing and I knew what he was going to do
yeah same in polish
A German, a Russian and a Pole walk into a bar...
Spanish here... xD
Same with Dutch lmaoo
Me: ends on 12
He : I know everything about you..... continues removing 12
(None can understand me 🥺😢)
Yup, sadly thus trick doesn't work in other languages rather than English
Me: choose 4 and land on 4
LOL
Same i was on 12 too
@@areeshakhalid4629 😂😂😂😂🤣🤣🤣
Same dude i ended on 8 and he removed it 😂
Bro became santa claus teaching magic