字幕表 動画を再生する 英語字幕をプリント Yes I hit it! I hit the final note. It's also the name of today's show. Welcome to Michael's Math Magic. I wanna show you a tool today that's very special to me. These are regular old bicycle playing cards that are anything but regular. We here at Vsauce designed these to do something very special. They come in Curiosity Box 12 which many of you already have and some of you it's on it's way to you. When you open the cards up you'll find that you get 52 regular cards with really cool backs. Take a look. It's got Inc on there with some nautical stuff. Some ship wheels some whales and pirate booty as they say in the pirate trade. But I've been playing with these cards for a bit already. They're all shuffled up. I'll shuffle them a few more ties to really convince you that I don't know where any of the cards are. And I'm being really honest at this moment. It doesn't matter what order the cards are in. And then the magic will happen. Alright. Now often a magician will be able to guess a card randomly chosen from a deck. Right? A magician like myself. Not today. No no no. We're gonna go even further. Today the person guessing a card chosen from this deck isn't even in this room. Where are they? Well I will show you. We have taken Jack who works here at Vsauce and locked him away. I'm gonna use my phone camera to show you where he is. Follow me. We gotta leave the studio. Okay. There's Hannah. And let me just carefully walk through the dark, leave the studio, wonderful! Okay now where is Jack. Is he there? No. Where is he? Maybe he's in the refrigerator. Oh no of course he wouldn't be that would not be safe. Sometimes he's up in the loft or he's inside the trash can. Not today though. Nope. Today we have locked him away, not in Testing Room B, but in Testing Room A. Jack are you ready? Yep. Alright let's do this. Okay. So let me make my way back. I want to do this all in real time. No edits. Real magic. Okay going back into the studio. Hannah, I'm back. And it's time for us to use these special cards. Ready? Here we go. I'll give them one more shuffle and then I'm gonna pick a card out of the deck. Now Jack has his phone with him and I'm gonna text him and he's gonna text me and it will be through texts that the magic occurs. Here we go. Let's pick this card right here. I have no idea what this card is and certainly Jack who is not even in this room and is actually as far away as he can be in this office does not know what that card is and I'm going to ask Jack to guess what this card is. Okay. So here we go. Ready? It's time to guess the card Jack. Okay. Let's see what happens! Send. This is what happens when you try to do a trick in real time. There can be some waiting but this is all part of the experience. You can feel the psychic energy between Jack and me and the cards and the phone and Hannah, a little bit. Alright Jack can you do it? I don't know the card. How could he know the card? Locked away in a bathroom. Well perhaps it's not a bathroom. Perhaps it's a throne of magic. King of hearts! Is this the king of hearts? The king of hearts! What?! Excuse me?! Let's try this again. Let's try this again. I have no idea which card is which. I'm gonna pick this one. Okay. I don't know what it is. Jack certainly doesn't know what it is but let's ask him to tell us what it is. Okay. Hello, okay Jack. Can you guess the card? I sent it. I can feel that electricity. Now Jack isn't the only one who can do this and let me reassure you that this is a real, these are real texts. I'm not using some kind of special app. There are no additional cameras in this room besides the ones that are here and here and Jack is not listening to us. He doesn't have any kind of elaborate system of mirrors that allow him to look under the table from inside the bathroom. He really is in there with nothing but his dreams and his phone. And with those tools alone Jack will think about what card this might be and he will be able to miraculously be right. Nine of spades. Is this the nine of spades? There it is! The nine of spades. How the heck is this trick working? Well it's time for me to let you in on a little bit of a secret. Jack knows what card has been chosen because I know what card has been chosen and I tell Jack which card was chosen through code. The special thing about Inq's playing card is that this isn't just a regular deck. It is a marked deck. Which means that by looking at the back of each card you can tell what the card is. If you look at these three cards they all look incredibly similar from the back. Only a trained eye, only someone who knows what to look for can upon close inspection really determine the secret code on the back. What I wanna do is…is there a pencil around here? Or any kind of sharp pointing object? Even, actually Hannah, give me your friend. Thank you very much. Okay take a look at the back of this card. We've got ships wheels. Look at the ship wheel in the upper left hand corner. It doesn't matter which way the card is because the secret code is hidden in the upper left hand corner no matter how you rotate the card. You'll notice that there's a ships wheels with 12 handles. Those 12 handles can be read like a clock. Who you look at them you look to see if a handle is missing. In this case on this particular card no handle is missing which means the card is a king. It's that easy. But what's the suit? Well if you look inside the wheel there's a line and the line is thicker here on the right than it is anywhere else. By following typical CHaSeD order which I introduced in the Si Stebbins video just a bit ago, you can from 12:00 around moving clockwise tell what the suit is by looking at where the thicker line is. If it's thicker at the top you have a card that is a club. If it's thicker on the right it's a heart. Thicker on the bottom it's a spade. Thickest on the left it is a diamond. This ships wheel is thickest on the right hand side which means that this is a club heart. This is a heart. A king of hearts. And it is in fact a king of hearts. Let's look at this card. Now this card is missing a handle right there at the 2:00 position so it's a 2. And the line on the ships wheel is thickest at the bottom which tells us this is a spade. A 2 of spades. Boom. Let's do that one more time. Right here. Perfect. Okay. So looking at this ships wheel we see that the handle is missing at the 10:00 position. So this is a 10 and the line is thickest up at the top. So it's a club. A 10 of clubs. Piece of cake right? Unless you know what to look for though, this is incredibly hard to figure out. Of course when you do a trick with these cards you shouldn't just do it like this. Uhh hey uhh uhh what's uhh what's this card? Oh. Uhh well I can tell you. It's the 4 of diamonds. Hehehe. No because it's too obvious. People will know that there's probably something telling you on the back. So I have today performed for you what I call the bathroom magic trick. And I use a code to convey what I know about the card because of what I can read off of the back since it's a marked deck through text to Jack and here's how I do it. The identity of the card is contained in the tex that I send him. The punctuation at the end of my text tells Jack the suit. If I put no punctuation at the end that tells Jack that the card is a club. If I just put a period at the end of the text that tells us that the card is a heart. A question mark at the end of the text says that the card is a spade. And finally of course an exclamation point tells Jack that it is a diamond. So as you can see the punctuation sort of in my opinion is going up in terms of the amount of emotion in it and that's how I remember CHaSed order club, heart, spade, diamond and the order of the punctuation. Jack actually has a cheat sheet with him hidden in his pocket in the bathroom so he can reference it. I have to memorize this. And it's not actually that hard. You practice a few times. You got it down and the effect is really phenomenal. Okay but Jack wasn't just able to tell us the suit of the card chosen he was also able to tell us the value. And here's how I work that out. If the card is an Ace I begin the card with no salutation. THat's right. The salutation, the greeting in the text is how I tell Jack which three cards the card is. Here's what I mean. If I just begin the text with no hello or hi or anything then the card is an ace. If however I begin the text with the word hi, Jack knows that the card is either a 2, a 3, or a 4. If I begin the text with hey which is a little bit longer he knows that the card is either a 5, a 6, or a 7. If I begin the text with the word hello that tells Jack that the card is either an 8, a 9, or a 10. And if I begin the text with the word ready, that tells him that the card is either a Jack, a Queen, or a King. Here what I think makes this easy to remember is that the greetings just get longer in terms of number of letters the higher the card's value is. But now you may be wondering, alright, fine but even if Jack sees the word hey and knows that there's say an exclamation point at the end all he knows is that there's a diamond and that either it's a 5 6 or 7. How do you tell him which of these three it is? Aha! Well what we're doing is using a little bit more secret tricks. Where I put Jack's name in the text or really any proper name tells him which of these three it is. If right after the greeting I say a proper name, either his or maybe the participants or my own, whatever, he knows that of the three the card is the smallest. So if I said hey Jack he knows right away that it's a 5. If however I put his name or the participant's name at the end, for example, hey guess the card, Jack. Now he knows that it's the last card because his name is at the very end. If his name is anywhere else but the very beginning after the greeting or the very end then he knows that it's the middle number. Hey so, Jack, guess the card. That's a 6. That's how it works. It's that simple. Let's do a couple of examples. In fact let's see if he's still in the bathroom. He should be or else he's fired. Like literally that's what his contract says. Let's just pick a card out of here and we'll do this one together. You can be the magician along with me. Okay. So no one's looked at this card. I haven't. You haven't. Hannah hasn't. Jack hasn't. Let's take a look. So this card is missing a handle at 3:00 position. And the stroke in the inside of the wheel is thickest up there at the top so this is a club, a 3 of clubs. So for the 3 of clubs what should we text Jack? Well we know that the 3 puts us into this category of just using a short greeting, hi. And the 3 is in the middle of the 2, 3, 4, group so we should say hi, so Jack or hi, we're ready Jack. And then finish it with something. So let me just start drafting this out so that we have it written down. And here we go. Hi we're ready Jack. And then…it's a club so no punctuation at the end. Time to guess. Alright. So there's the text. The word hi tells us that it's either a 2, 3, or a 4. The fact that his name, the proper name Jack is somewhere in the middle not the beginning or the end tells him that it's a 3 and the fact there's no punctuation at the end tells him that it's a club, 3 of clubs. I haven't even checked the card that's how much I trust the markings on the back. I hope he's still checking his texts. He may have gotten back to work which is not acceptable. Obviously you can come up with your own code. Use whatever works best for you and your assistant. The more times you do this trick in a row for the same audience the higher the chance will be that they can catch on and go hey every time it's a face card you're saying the word ready. Hmmm. But if you only do the trick once or twice you should really only do it once by the way, for an audience. Three of clubs. He's texted back 3 of clubs and is it the 3 of clubs? The 3 of clubs! Piece of cake. Now these cards are amazing but this show isn't called Michael's Magic. It's called Michael's Math Magic so here in the final few minutes that we have I wanna just show you an awesome magic trick that I like to do because I married a woman from New Zealand. Which is different than Australia but pretty close to Australia and this trick is called the Australian Shuffle also known as the Down Under Deal. Down Under, Australia. Get it? Okay perfect. So a Down Under deal is when you instead of dealing cards like this where each card goes down, you deal down and then under, down under, down under, down under, down under, down under, and so on. Clearly when you deal cards this way, you're dealing them off the pile half as quickly but when you do that technique you will eventually get yourself down to just one card left in your hand. And which card will be left in your hand is something we can know. The card that is left when you've done the Down Under deal over and over again like this, down under, down under, down under, down under, down under, down under, down under, down under, down, the card that you have left will have a known position in the beginning of the pile and it's position will be equal to this equation. This formula. You take the number of cards in the pack you're dealing and you find the closest power of 2 that is not greater than that number. And you find the difference between those two. And then you double that difference. That will be the position in the pack from the top of the card that's left over. So for example how many cards have I pulled out here. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. 10. 10 cards. Okay perfect. So we take 10 and we say what's the nearest power of 2 that isn't greater than 10. 8. What's the difference between 8 and 10. 2. And what is 2, doubled? 4. So the fourth card will be the card I'm left with. The fourth card is the eight of spades. The eight of spades. Down under, down under, down under, down under, down under, down under, down under, down under, down under. Ace of spades. Every time. Beautiful binary sorting. I love it. I've got links below where you can learn more about the math. Could you do it with a down, down under? Would you need to use ternary? I'll leave that as an exercise to you the viewer. And as always, thanks for watching.