1 00:00:16,399 --> 00:00:17,300 Why does this matter? 2 00:00:17,300 --> 00:00:19,336 I'm going to give you a brief "why this matters." 3 00:00:19,336 --> 00:00:22,572 And we've been talking about the quantum nature of things, 4 00:00:22,572 --> 00:00:23,340 right? 5 00:00:23,340 --> 00:00:24,841 Quantum is this. 6 00:00:24,841 --> 00:00:26,543 Quantum are these differences. 7 00:00:26,543 --> 00:00:27,978 It's this probability. 8 00:00:27,978 --> 00:00:30,714 It's quantization of energies. 9 00:00:30,714 --> 00:00:32,415 What does that mean, right? 10 00:00:32,415 --> 00:00:35,819 Well, last time I told you that by electrons 11 00:00:35,819 --> 00:00:38,288 being quantum, and having wave-like character-- 12 00:00:38,288 --> 00:00:40,490 we're able to use them to see things, 13 00:00:40,490 --> 00:00:42,859 and it started the nanotechnology revolution 14 00:00:42,859 --> 00:00:44,160 about 30 years ago. 15 00:00:44,160 --> 00:00:46,296 And today I want to give you an example of that 16 00:00:46,296 --> 00:00:48,999 in my "why this matters." 17 00:00:48,999 --> 00:00:52,702 And it has to do with quantum domination, which should be 18 00:00:52,702 --> 00:00:56,506 the title of a movie or a book. 19 00:00:56,506 --> 00:00:59,075 And here's the example-- take a piece of bulk material. 20 00:00:59,075 --> 00:01:01,044 Take a piece of silicon, OK? 21 00:01:01,044 --> 00:01:02,712 And if you look at the silicon, it's 22 00:01:02,712 --> 00:01:04,346 kind of boring to look at optically. 23 00:01:04,346 --> 00:01:05,749 It's not very interesting. 24 00:01:05,749 --> 00:01:07,450 You know, don't tell that to your iPhone, 25 00:01:07,450 --> 00:01:10,987 which has a lot of it in there, but it's boring. 26 00:01:10,987 --> 00:01:14,657 But now, take out your little nano ice cream scooper, 27 00:01:14,657 --> 00:01:15,558 which you all have. 28 00:01:15,558 --> 00:01:17,527 And you take a little tiny piece of it. 29 00:01:17,527 --> 00:01:20,096 We call that a quantum dot. 30 00:01:20,096 --> 00:01:20,797 Why? 31 00:01:20,797 --> 00:01:23,333 We call it a quantum dot because it kind of looks 32 00:01:23,333 --> 00:01:25,969 like a dot-- its smallish. 33 00:01:25,969 --> 00:01:28,571 But we call it that because quantum mechanics 34 00:01:28,571 --> 00:01:30,373 takes over the properties. 35 00:01:30,373 --> 00:01:33,743 Here's an example-- shine light on this thing, 36 00:01:33,743 --> 00:01:35,878 or have it glow, and all of a sudden instead 37 00:01:35,878 --> 00:01:39,848 of being boring it can be any color you want. 38 00:01:39,848 --> 00:01:40,616 Why? 39 00:01:40,616 --> 00:01:42,352 Because if I shine light-- and here is 40 00:01:42,352 --> 00:01:46,056 a very sophisticated picture of a laser, which you can tell 41 00:01:46,056 --> 00:01:48,491 I had trouble making transparent. 42 00:01:48,491 --> 00:01:51,795 And so you shine a laser on this piece-- 43 00:01:51,795 --> 00:01:56,332 we know already, light excites charge in an atom. 44 00:01:56,332 --> 00:01:57,634 It does the same in solids. 45 00:01:57,634 --> 00:02:00,737 So here's my piece of silicon, and what that does 46 00:02:00,737 --> 00:02:03,873 is it sends an electron up in energy levels. 47 00:02:03,873 --> 00:02:05,642 But the electron is up in an energy level, 48 00:02:05,642 --> 00:02:07,444 and it left behind a hole. 49 00:02:07,444 --> 00:02:09,378 Which is something we'll talk about later when 50 00:02:09,378 --> 00:02:11,281 we talk about semiconductors. 51 00:02:11,281 --> 00:02:14,117 A hole is just a positive charge. 52 00:02:14,117 --> 00:02:16,920 And it turns out that that electron and that hole 53 00:02:16,920 --> 00:02:21,357 are attracted to each other, but not-- they can't get too close. 54 00:02:21,357 --> 00:02:23,927 But they want to kind of hang out at a certain distance. 55 00:02:23,927 --> 00:02:24,427 Where? 56 00:02:24,427 --> 00:02:25,628 How far? 57 00:02:25,628 --> 00:02:28,198 Yeah-- quantum mechanics. 58 00:02:28,198 --> 00:02:31,134 N 2, 3, 4 tells us. 59 00:02:31,134 --> 00:02:34,637 It tells us how far, right? 60 00:02:34,637 --> 00:02:35,605 They want to hang out-- 61 00:02:35,605 --> 00:02:38,074 and now all of a sudden, I've nano-scooped them out, 62 00:02:38,074 --> 00:02:39,242 and I've made a quantum dot. 63 00:02:39,242 --> 00:02:41,144 But if I try to do the same thing there, 64 00:02:41,144 --> 00:02:43,046 that's how far they wanted to be. 65 00:02:43,046 --> 00:02:43,980 And they can't be. 66 00:02:43,980 --> 00:02:47,016 They literally ran out of real estate. 67 00:02:47,016 --> 00:02:48,985 They ran out of atoms. 68 00:02:48,985 --> 00:02:51,788 They cannot be out here, because there's no stuff out here. 69 00:02:51,788 --> 00:02:53,790 So they get squeezed. 70 00:02:53,790 --> 00:02:56,459 I am squeezing these quantum mechanical objects, 71 00:02:56,459 --> 00:02:58,161 this electron and this hole. 72 00:02:58,161 --> 00:03:02,532 And by squeezing them, I'm changing the way 73 00:03:02,532 --> 00:03:03,867 they interact with light. 74 00:03:03,867 --> 00:03:07,670 I'm changing the color, right? 75 00:03:07,670 --> 00:03:08,571 Oh. 76 00:03:08,571 --> 00:03:11,174 It's all stuff we've learned that explains 77 00:03:11,174 --> 00:03:13,776 something revolutionary. 78 00:03:13,776 --> 00:03:17,147 By the way, if you buy a QLED TV, is it as good as OLED? 79 00:03:17,147 --> 00:03:18,081 No. 80 00:03:18,081 --> 00:03:19,849 But is it better than LED? 81 00:03:19,849 --> 00:03:20,984 Yeah, a little bit. 82 00:03:20,984 --> 00:03:22,085 That's what they-- QLED-- 83 00:03:22,085 --> 00:03:24,187 quantum is quantum dots. 84 00:03:24,187 --> 00:03:27,957 They have coated the LED emitters with quantum dots 85 00:03:27,957 --> 00:03:30,393 to give you better color. 86 00:03:30,393 --> 00:03:34,430 Now what this means, why this matters, 87 00:03:34,430 --> 00:03:37,100 is nothing less than the periodic table itself. 88 00:03:37,100 --> 00:03:39,668 Because I think I showed you this-- 89 00:03:39,668 --> 00:03:41,905 we're living in these different ages, which I love. 90 00:03:41,905 --> 00:03:44,007 We have the periodic table that has-- 91 00:03:44,007 --> 00:03:46,509 the ability to work with it is what's brought us 92 00:03:46,509 --> 00:03:49,679 to the age of materials design. 93 00:03:49,679 --> 00:03:54,751 But see, now I've literally just told you that by changing 94 00:03:54,751 --> 00:03:57,086 the size-- nothing more than the size-- 95 00:03:57,086 --> 00:04:00,089 I can tune a property because of quantum mechanics. 96 00:04:00,089 --> 00:04:02,792 Because I'm changing its quantum mechanical interactions. 97 00:04:02,792 --> 00:04:06,262 It would be like saying, I can take a piece of this table-- 98 00:04:06,262 --> 00:04:07,730 I can break a piece of this table, 99 00:04:07,730 --> 00:04:10,099 and it's now going to be red. 100 00:04:10,099 --> 00:04:13,436 That's exactly what we're doing, but at a very tiny size. 101 00:04:13,436 --> 00:04:16,805 That is as if we are taking this periodic table 102 00:04:16,805 --> 00:04:19,809 and giving it a whole other dimension. 103 00:04:19,809 --> 00:04:24,280 Every element can do more things than we thought possible 104 00:04:24,280 --> 00:04:27,417 because we can tune these properties related 105 00:04:27,417 --> 00:04:29,452 to quantum mechanics. 106 00:04:29,452 --> 00:04:30,920 So that's a big deal. 107 00:04:30,920 --> 00:04:31,888 That's a very big deal.