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UCftwRNsjfRo08xYE31tkiyw
|
https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
|
Neuroscientist Explains One Concept in 5 Levels of Difficulty | WIRED
|
opqIa5Jiwuw
| 583
|
[
{
"end_time": 36,
"start_time": 0,
"title": "Intro"
},
{
"end_time": 95,
"start_time": 36,
"title": "What is the Connectome"
},
{
"end_time": 161,
"start_time": 95,
"title": "Brain Cells"
},
{
"end_time": 272,
"start_time": 161,
"title": "Connectome"
},
{
"end_time": 583,
"start_time": 272,
"title": "Wiring Map"
}
] |
[
{
"text": " Hi, I'm Jim Carosa.",
"timestamp": [
0,
1.64
]
},
{
"text": " I'm a professor at the University of Massachusetts at Amherst.",
"timestamp": [
1.64,
4.92
]
},
{
"text": " And I've been challenged to describe the internet",
"timestamp": [
4.92,
7.44
]
},
{
"text": " in five levels of increasing difficulty.",
"timestamp": [
7.44,
10.28
]
},
{
"text": " The internet is the most technically complex system",
"timestamp": [
10.28,
13.64
]
},
{
"text": " that humanity has ever built. The internet",
"timestamp": [
13.64,
16.52
]
},
{
"text": " is a network of networks.",
"timestamp": [
16.52,
18.04
]
},
{
"text": " It's a platform on which all of the internet applications",
"timestamp": [
18.04,
21.92
]
},
{
"text": " that you've heard of can be built. Hi, it's really, really nice to meet you.",
"timestamp": [
21.92,
28.16
]
},
{
"text": " What's your name?",
"timestamp": [
28.16,
29.16
]
},
{
"text": " My name is Skylar.",
"timestamp": [
29.16,
30.16
]
},
{
"text": " Skylar, we're here to talk about the internet, and I bet you must use the internet a lot,",
"timestamp": [
30.16,
33.6
]
},
{
"text": " right?",
"timestamp": [
33.6,
34.6
]
},
{
"text": " Yeah.",
"timestamp": [
34.6,
35.6
]
},
{
"text": " What's your conception about what the internet is?",
"timestamp": [
35.6,
36.6
]
},
{
"text": " The internet, for me, it's just something to use when I need to search up something",
"timestamp": [
36.6,
42.64
]
},
{
"text": " or watch videos.",
"timestamp": [
42.64,
45
]
},
{
"text": " The internet is physically these computers",
"timestamp": [
45.68,
49.52
]
},
{
"text": " that all talk to each other,",
"timestamp": [
49.52,
50.8
]
},
{
"text": " billions of computers in the case of the internet.",
"timestamp": [
50.8,
53.2
]
},
{
"text": " The internet allows us to do a lot of",
"timestamp": [
53.2,
56.8
]
},
{
"text": " really, really interesting, what we call applications.",
"timestamp": [
56.8,
59.8
]
},
{
"text": " You ever think about how that video",
"timestamp": [
59.8,
61.84
]
},
{
"text": " gets to you over the internet?",
"timestamp": [
61.84,
63.64
]
},
{
"text": " Yeah, I have no idea.",
"timestamp": [
63.64,
64.48
]
},
{
"text": " Got a favorite movie?",
"timestamp": [
64.48,
65.74
]
},
{
"text": " Matilda.",
"timestamp": [
65.74,
66.58
]
},
{
"text": " Matilda, all right.",
"timestamp": [
66.58,
67.66
]
},
{
"text": " We're gonna actually build an internet.",
"timestamp": [
67.66,
69.02
]
},
{
"text": " I've got a couple of things here that I wanna show you,",
"timestamp": [
69.02,
72.48
]
},
{
"text": " or a couple of toys, actually.",
"timestamp": [
72.48,
74.1
]
},
{
"text": " Okay, let's pretend that these round balls are computers,",
"timestamp": [
74.1,
77.38
]
},
{
"text": " and the internet is something that connects them.",
"timestamp": [
77.38,
79.7
]
},
{
"text": " And right now, the internet is just one communication link,",
"timestamp": [
79.7,
83.74
]
},
{
"text": " and Matilda is sent over the internet from this computer to your computer.",
"timestamp": [
83.74,
89.72
]
},
{
"text": " So the internet is a network for carrying information from one computer to another.",
"timestamp": [
89.72,
95.24
]
},
{
"text": " Now this network here looks pretty simple, doesn't it?",
"timestamp": [
95.24,
98.24
]
},
{
"text": " It's just one thing.",
"timestamp": [
98.24,
99.24
]
},
{
"text": " Should we add some more friends in?",
"timestamp": [
99.24,
100.92
]
},
{
"text": " Yeah.",
"timestamp": [
100.92,
101.92
]
},
{
"text": " Let's say we want to get a video from here over to here.",
"timestamp": [
101.92,
105.76
]
},
{
"text": " How do you think that video would sort of travel through this network? Maybe it could go to here, to here, to here, to here. That's right. So that's pretty cool. There are actually",
"timestamp": [
111.44,
116.16
]
},
{
"text": " lots of different ways to actually go through the internet to get from what we call a source,",
"timestamp": [
116.16,
123.12
]
},
{
"text": " the place that's sending the information to the source, the place that's sending the information,",
"timestamp": [
123.76,
126
]
},
{
"text": " to the receiver, the place that's actually gathering the information together.",
"timestamp": [
126,
130.2
]
},
{
"text": " And that's something we actually call routing.",
"timestamp": [
130.2,
132.2
]
},
{
"text": " Huh. But wouldn't it just be easier for it to go from here to here,",
"timestamp": [
132.2,
136.7
]
},
{
"text": " instead of going from here to here to here to here?",
"timestamp": [
136.7,
139.9
]
},
{
"text": " Yeah. So that's a really good observation.",
"timestamp": [
139.9,
143.4
]
},
{
"text": " In most pieces of the Internet, that's exactly what would happen.",
"timestamp": [
143.4,
146.6
]
},
{
"text": " We want to take what's called a shortest path.",
"timestamp": [
146.6,
149.44
]
},
{
"text": " But still, there are multiple paths.",
"timestamp": [
149.44,
151.68
]
},
{
"text": " Why do you think that might be valuable?",
"timestamp": [
151.68,
153.52
]
},
{
"text": " Maybe one way like messed up or broken so you can't go away?",
"timestamp": [
153.52,
157.12
]
},
{
"text": " Yeah. Exactly. So Skylar,",
"timestamp": [
157.12,
159.72
]
},
{
"text": " that was a great discussion about what we just built.",
"timestamp": [
159.72,
163.2
]
},
{
"text": " I wanted to talk to you about, or ask you about maybe one other",
"timestamp": [
163.2,
167.1
]
},
{
"text": " really important part about networks.",
"timestamp": [
167.1,
169.64
]
},
{
"text": " And it's not so much the thing itself,",
"timestamp": [
169.64,
172.82
]
},
{
"text": " the physical thing, but more about the rules",
"timestamp": [
172.82,
176.46
]
},
{
"text": " about communication.",
"timestamp": [
176.46,
178.12
]
},
{
"text": " That's governed by something that are called protocols.",
"timestamp": [
178.12,
181.74
]
},
{
"text": " Are you up for one?",
"timestamp": [
181.74,
182.58
]
},
{
"text": " Yeah.",
"timestamp": [
182.58,
183.42
]
},
{
"text": " Knock, knock.",
"timestamp": [
183.42,
184.24
]
},
{
"text": " Who's there? Lettuce. Lett for one? Yeah. Knock, knock. Who's there?",
"timestamp": [
184.24,
185.06
]
},
{
"text": " Lettuce.",
"timestamp": [
185.06,
185.9
]
},
{
"text": " Lettuce who?",
"timestamp": [
185.9,
186.72
]
},
{
"text": " Lettuce go on.",
"timestamp": [
186.72,
187.56
]
},
{
"text": " A knock-knock joke is an example of a protocol, right?",
"timestamp": [
187.56,
191.44
]
},
{
"text": " The computer that you're using, say, makes a request.",
"timestamp": [
191.44,
194.68
]
},
{
"text": " You ask for something, you get something in return.",
"timestamp": [
194.68,
197.28
]
},
{
"text": " In the internet, there are protocols everywhere.",
"timestamp": [
197.28,
199.76
]
},
{
"text": " So that two computers that have never talked",
"timestamp": [
199.76,
201.84
]
},
{
"text": " to each other before know the rules for talking to each other.",
"timestamp": [
201.84,
206.48
]
},
{
"text": " This global internet with billions of people using it",
"timestamp": [
206.48,
210.36
]
},
{
"text": " are just lots of smaller networks",
"timestamp": [
210.36,
212.88
]
},
{
"text": " that are all hooked together to each other.",
"timestamp": [
212.88,
215.24
]
},
{
"text": " But also what the internet allows",
"timestamp": [
215.24,
218.48
]
},
{
"text": " are all of these what we call applications,",
"timestamp": [
218.48,
221.92
]
},
{
"text": " Zoom, video playing services,",
"timestamp": [
221.92,
224.72
]
},
{
"text": " can all run on top of the same Internet.",
"timestamp": [
224.72,
227.34
]
},
{
"text": " Yes, there's one Internet for all of them.",
"timestamp": [
227.34,
229.4
]
},
{
"text": " Exactly. There's one Internet and",
"timestamp": [
229.4,
231.88
]
},
{
"text": " lots and lots and lots of",
"timestamp": [
231.88,
233.38
]
},
{
"text": " things that you can do on top of it.",
"timestamp": [
233.38,
235.24
]
},
{
"text": " So you're a student in high school, is that right?",
"timestamp": [
235.24,
241.12
]
},
{
"text": " Yes, I'm a sophomore.",
"timestamp": [
241.12,
242.44
]
},
{
"text": " Well, we're going to be talking about computers here today, and we're going to be talking",
"timestamp": [
242.44,
245.64
]
},
{
"text": " about the internet.",
"timestamp": [
245.64,
246.8
]
},
{
"text": " I always like to think of the internet by analogy to, say, road systems, for example,",
"timestamp": [
246.8,
251.84
]
},
{
"text": " where you have roads in your neighborhood, you have state roads, you have the interstate",
"timestamp": [
251.84,
255.76
]
},
{
"text": " highway system.",
"timestamp": [
255.76,
256.76
]
},
{
"text": " And so the internet is a lot like that.",
"timestamp": [
256.76,
258.56
]
},
{
"text": " It's an interconnection of local roads, local networks, like the network in your house,",
"timestamp": [
258.56,
264.48
]
},
{
"text": " for example.",
"timestamp": [
264.48,
265.4
]
},
{
"text": " How does all of the networks in my house connect to all the city networks?",
"timestamp": [
265.4,
270.76
]
},
{
"text": " Wow, great question.",
"timestamp": [
270.76,
273.08
]
},
{
"text": " Often it's a little blue wire called an Ethernet cable.",
"timestamp": [
273.08,
276.48
]
},
{
"text": " So that cable is able to bring bits of information up into your apartment at, say, a billion",
"timestamp": [
276.48,
282.76
]
},
{
"text": " bits per second.",
"timestamp": [
282.76,
284
]
},
{
"text": " That's pretty fast, right?",
"timestamp": [
284,
285.8
]
},
{
"text": " Literally a wire that goes between a box in your apartment,",
"timestamp": [
285.8,
290.42
]
},
{
"text": " sometimes called a router, or a modem in your apartment",
"timestamp": [
290.42,
293.9
]
},
{
"text": " that comes from an internet service provider,",
"timestamp": [
293.9,
295.8
]
},
{
"text": " come into this first network,",
"timestamp": [
295.8,
297.68
]
},
{
"text": " and then that network connects to another network,",
"timestamp": [
297.68,
299.84
]
},
{
"text": " connects to another network, connects to another network.",
"timestamp": [
299.84,
302
]
},
{
"text": " You could FaceTime somebody who's like in Australia.",
"timestamp": [
302,
306.08
]
},
{
"text": " You can talk to them at the same time and like you're reaching the same signals.",
"timestamp": [
306.08,
309.52
]
},
{
"text": " So how is it that it gets there so fast?",
"timestamp": [
309.52,
311.52
]
},
{
"text": " We could talk about that by analogy to a road system.",
"timestamp": [
311.52,
314.88
]
},
{
"text": " It's not just one big super highway.",
"timestamp": [
314.88,
318.16
]
},
{
"text": " It's a lot of smaller super highways that are all interconnected.",
"timestamp": [
318.8,
322.8
]
},
{
"text": " And those interchanges are what are called routers.",
"timestamp": [
322.8,
325.4
]
},
{
"text": " That's where the links come together.",
"timestamp": [
325.4,
327.04
]
},
{
"text": " We're talking about talking to a friend in Australia.",
"timestamp": [
327.04,
329.16
]
},
{
"text": " So, oh, it's coming in from the East Coast",
"timestamp": [
329.16,
330.92
]
},
{
"text": " of the United States to this router,",
"timestamp": [
330.92,
332.8
]
},
{
"text": " and it's going out, say that router's in San Francisco,",
"timestamp": [
332.8,
335.56
]
},
{
"text": " it's going out on an underseas cable over to Australia,",
"timestamp": [
335.56,
339.64
]
},
{
"text": " rather than in this direction up to Japan.",
"timestamp": [
339.64,
341.56
]
},
{
"text": " So there is an underseas cable.",
"timestamp": [
341.56,
343.44
]
},
{
"text": " The underseas cables are so cool.",
"timestamp": [
343.44,
345.56
]
},
{
"text": " They're these big cables that are laid down by switches.",
"timestamp": [
345.56,
348.98
]
},
{
"text": " They cross both the Atlantic, the Pacific, the Indian Ocean.",
"timestamp": [
348.98,
352
]
},
{
"text": " So the underseas cables are how the networks in Europe, the United States, Asia are all",
"timestamp": [
352,
358.52
]
},
{
"text": " connected together.",
"timestamp": [
358.52,
359.6
]
},
{
"text": " How do you connect like wirelessly?",
"timestamp": [
359.6,
361.52
]
},
{
"text": " That's really what we call the first hop.",
"timestamp": [
361.52,
364.16
]
},
{
"text": " It's like from your phone, from your tablet,",
"timestamp": [
364.16,
366.48
]
},
{
"text": " from the computer that you're on.",
"timestamp": [
366.48,
368.16
]
},
{
"text": " There's no cables coming in.",
"timestamp": [
368.16,
369.52
]
},
{
"text": " You go over a wireless connection.",
"timestamp": [
369.52,
371.48
]
},
{
"text": " Wi-Fi is the protocol that allows your computer",
"timestamp": [
371.48,
374.28
]
},
{
"text": " to talk to that first hop router",
"timestamp": [
374.28,
376.32
]
},
{
"text": " over a wireless communication link.",
"timestamp": [
376.32,
378.64
]
},
{
"text": " And I was wondering like how there's so many different",
"timestamp": [
378.64,
381.44
]
},
{
"text": " movies or TV shows that you can download",
"timestamp": [
381.44,
383.48
]
},
{
"text": " and that they're all there.",
"timestamp": [
383.48,
384.92
]
},
{
"text": " And like, if you just play it, it just knows what to play.",
"timestamp": [
384.92,
388.12
]
},
{
"text": " But they're all in one spot.",
"timestamp": [
388.12,
389.4
]
},
{
"text": " Ah, you said they're all in one spot.",
"timestamp": [
389.4,
392.22
]
},
{
"text": " In fact, they're in lots of spots in Netflix.",
"timestamp": [
392.22,
395.4
]
},
{
"text": " And so most applications would like to connect you",
"timestamp": [
395.4,
398.28
]
},
{
"text": " with a server that's close to you.",
"timestamp": [
398.28,
400.36
]
},
{
"text": " Server's really just a big computer with a lot of memory,",
"timestamp": [
400.36,
403.56
]
},
{
"text": " a lot of disks that store all the Netflix movies.",
"timestamp": [
403.56,
407.28
]
},
{
"text": " And also so that you don't have to cross over",
"timestamp": [
407.28,
409.66
]
},
{
"text": " too many internet links to get from where the server is",
"timestamp": [
409.66,
413.18
]
},
{
"text": " to the TV or the device in your home.",
"timestamp": [
413.18,
415.84
]
},
{
"text": " So when I'm watching Vampire Diaries in my house,",
"timestamp": [
415.84,
418.48
]
},
{
"text": " how does it know exactly what to do",
"timestamp": [
418.48,
420.52
]
},
{
"text": " without getting scrambled up?",
"timestamp": [
420.52,
421.72
]
},
{
"text": " Ah, another great question.",
"timestamp": [
421.72,
423.68
]
},
{
"text": " There's a couple of things",
"timestamp": [
423.68,
425.22
]
},
{
"text": " that could happen inside the Internet.",
"timestamp": [
425.22,
427.12
]
},
{
"text": " Information is sent in these little packets of",
"timestamp": [
427.12,
429.54
]
},
{
"text": " information from the Netflix server to your display device.",
"timestamp": [
429.54,
434.16
]
},
{
"text": " Literally, each packet that arrives says,",
"timestamp": [
434.16,
436.84
]
},
{
"text": " this is the first packet for Jenna,",
"timestamp": [
436.84,
438.48
]
},
{
"text": " this is the second, this is the third,",
"timestamp": [
438.48,
440.26
]
},
{
"text": " this is the fifth, this is the fourth,",
"timestamp": [
440.26,
442.58
]
},
{
"text": " and they're reordered for you.",
"timestamp": [
442.58,
444.46
]
},
{
"text": " Matter of fact, your computer will say using the TCP protocol to the fifth, this is the fourth. And they're reordered for you. As a matter of fact, your computer will say,",
"timestamp": [
444.46,
446.24
]
},
{
"text": " using the TCP protocol to the server,",
"timestamp": [
446.24,
448.24
]
},
{
"text": " hey, I didn't get packet four, can you resend it again?",
"timestamp": [
448.24,
451.48
]
},
{
"text": " And again, the Netflix server is very happy",
"timestamp": [
451.48,
453.56
]
},
{
"text": " to send you packet four again.",
"timestamp": [
453.56,
455.08
]
},
{
"text": " The other is the internet protocol.",
"timestamp": [
455.08,
457.28
]
},
{
"text": " If you think about sending letters",
"timestamp": [
457.28,
459.24
]
},
{
"text": " through the US Postal Service,",
"timestamp": [
459.24,
461.48
]
},
{
"text": " how you've got an address on it.",
"timestamp": [
461.48,
462.98
]
},
{
"text": " So every packet that flows from the Netflix server to you has an address on it.",
"timestamp": [
462.98,
467.26
]
},
{
"text": " So this is going to Jenna.",
"timestamp": [
467.26,
468.72
]
},
{
"text": " It's going to what's called",
"timestamp": [
468.72,
470.08
]
},
{
"text": " the Internet Protocol address of your device.",
"timestamp": [
470.08,
473.18
]
},
{
"text": " Think of all the range of",
"timestamp": [
473.18,
475
]
},
{
"text": " devices that are hooked up to the Internet.",
"timestamp": [
475,
476.52
]
},
{
"text": " It's totally amazing.",
"timestamp": [
476.52,
477.92
]
},
{
"text": " Every single one of them has one thing in common,",
"timestamp": [
477.92,
480.94
]
},
{
"text": " and that is they speak the IP protocol,",
"timestamp": [
480.94,
483.6
]
},
{
"text": " the Internet Protocol. That was a great question.",
"timestamp": [
483.6,
486
]
},
{
"text": " So tell me a little bit about yourself.",
"timestamp": [
486,
490.56
]
},
{
"text": " I am a senior at New York University.",
"timestamp": [
490.56,
493.4
]
},
{
"text": " I study computer science.",
"timestamp": [
493.4,
494.84
]
},
{
"text": " Have you taken any courses on the Internet or studied it at all?",
"timestamp": [
494.84,
497.96
]
},
{
"text": " I've taken applied Internet technology.",
"timestamp": [
497.96,
499.92
]
},
{
"text": " So we've talked about back-end,",
"timestamp": [
499.92,
502.4
]
},
{
"text": " slash front-end frameworks and libraries, things like that.",
"timestamp": [
502.4,
506.72
]
},
{
"text": " So really at the application level.",
"timestamp": [
506.72,
508.24
]
},
{
"text": " At the application level, for sure.",
"timestamp": [
508.24,
509.24
]
},
{
"text": " I wanted to ask you a little bit about what you know about the history of the Internet.",
"timestamp": [
509.24,
513.84
]
},
{
"text": " Have you heard of ARPANET, for example?",
"timestamp": [
513.84,
515.68
]
},
{
"text": " I have not heard of ARPANET.",
"timestamp": [
515.68,
518.34
]
},
{
"text": " Back into the 1960s, there was a research agency in the United States called DARPA,",
"timestamp": [
518.34,
523.2
]
},
{
"text": " the Defense Advanced Research Projects Agency.",
"timestamp": [
523.2,
525.84
]
},
{
"text": " Actually, it was called ARPA at the time.",
"timestamp": [
525.84,
528.04
]
},
{
"text": " They wanted to build this notion of a packet switching network, not a circuit switch network",
"timestamp": [
528.04,
533.72
]
},
{
"text": " like a phone network where you get a dedicated path and a dedicated set of bandwidth and",
"timestamp": [
533.72,
538.66
]
},
{
"text": " links from source to destination.",
"timestamp": [
538.66,
540.6
]
},
{
"text": " So what would packet switching enable?",
"timestamp": [
540.6,
542.84
]
},
{
"text": " I'm sure there's something big here for sure.",
"timestamp": [
542.84,
545
]
},
{
"text": " There's a lot big, right?",
"timestamp": [
545,
547
]
},
{
"text": " And so remember this was a Department of Defense.",
"timestamp": [
547,
549
]
},
{
"text": " They wanted to have forms of communication that were very robust, that were survivable.",
"timestamp": [
549,
555
]
},
{
"text": " Packets could all find their own ways, be routed differently through the network.",
"timestamp": [
555,
559
]
},
{
"text": " So if parts of the network failed, you could route around failures.",
"timestamp": [
559,
562
]
},
{
"text": " Sounds like the reason for a request response type of structure.",
"timestamp": [
562,
569.26
]
},
{
"text": " So you can see how the network architecture that wasn't designed to be",
"timestamp": [
569.26,
575.08
]
},
{
"text": " 100 percent reliable inside the core of the network and had",
"timestamp": [
575.08,
578.5
]
},
{
"text": " that complexity built into the edges of the network.",
"timestamp": [
578.5,
582.26
]
},
{
"text": " To me, the really cool thing is you put this infrastructure in place,",
"timestamp": [
582.26,
586.84
]
},
{
"text": " and then all these super creative people think",
"timestamp": [
586.84,
589.6
]
},
{
"text": " about amazing things to build on top of it.",
"timestamp": [
589.6,
593.28
]
},
{
"text": " You see this proliferation of amazing applications.",
"timestamp": [
593.28,
596.84
]
},
{
"text": " Abstraction, I think it's the reason why everything.",
"timestamp": [
596.84,
600.72
]
},
{
"text": " Spoken like a real computer scientist.",
"timestamp": [
600.72,
602.84
]
},
{
"text": " Right.",
"timestamp": [
602.84,
603.36
]
},
{
"text": " You're a computer scientist, I'm a computer scientist. We talk about APIs, Application Programming Inter computer scientist. Right. Your computer scientists, I'm a computer scientist.",
"timestamp": [
603.36,
605.24
]
},
{
"text": " We talk about APIs,",
"timestamp": [
605.24,
606.52
]
},
{
"text": " Application Programming Interfaces.",
"timestamp": [
606.52,
608.56
]
},
{
"text": " The API for the Internet is something called a socket.",
"timestamp": [
608.56,
613.16
]
},
{
"text": " A socket simply says,",
"timestamp": [
613.16,
614.96
]
},
{
"text": " I can communicate if I know your Internet address,",
"timestamp": [
614.96,
618.08
]
},
{
"text": " 128.119.40.186, that number is",
"timestamp": [
618.08,
622.44
]
},
{
"text": " the IP address of my server,",
"timestamp": [
622.44,
624.2
]
},
{
"text": " the University of Massachusetts.",
"timestamp": [
624.2,
625.68
]
},
{
"text": " If you know that,",
"timestamp": [
625.68,
627.12
]
},
{
"text": " you can write a program anywhere in the world and send",
"timestamp": [
627.12,
630.14
]
},
{
"text": " a message and it'll pop out at my end.",
"timestamp": [
630.14,
633.04
]
},
{
"text": " I will be remembering that.",
"timestamp": [
633.04,
635.16
]
},
{
"text": " I've heard that there are seven keys to the Internet,",
"timestamp": [
635.16,
640
]
},
{
"text": " something like that.",
"timestamp": [
640,
641.08
]
},
{
"text": " Okay. Well, I don't know about the number seven,",
"timestamp": [
641.08,
644.52
]
},
{
"text": " but there's something in the Internet that's similar to that. Okay, well, I don't know about the number seven, but there's something in the internet",
"timestamp": [
644.52,
647.32
]
},
{
"text": " that's sort of similar to that.",
"timestamp": [
647.32,
649.48
]
},
{
"text": " It's called the domain name system.",
"timestamp": [
649.48,
651.48
]
},
{
"text": " The DNS's role is to translate names,",
"timestamp": [
651.48,
655.52
]
},
{
"text": " like gaia.cs.ums.edu or ibm.com or facebook.com",
"timestamp": [
655.52,
660.24
]
},
{
"text": " to an IP address so that your application",
"timestamp": [
660.24,
663.64
]
},
{
"text": " can actually send a message to that name, to that named service.",
"timestamp": [
663.64,
668
]
},
{
"text": " This whatever quantity of people is able to have some form of control.",
"timestamp": [
668,
673
]
},
{
"text": " So that's a great question. Who do you think controls the Internet?",
"timestamp": [
673,
676
]
},
{
"text": " I'm pretty sure the Internet is fairly decentralized.",
"timestamp": [
676,
680
]
},
{
"text": " Okay. What does that mean?",
"timestamp": [
680,
681
]
},
{
"text": " No one authority holds control over any sort of decisions or destinations.",
"timestamp": [
681,
688.36
]
},
{
"text": " So that's 98% true, right?",
"timestamp": [
688.36,
692.56
]
},
{
"text": " And if you own a network like your AT&T.com or your Verizon.com, you can do within that",
"timestamp": [
692.56,
699.32
]
},
{
"text": " network, you can do what you want, right?",
"timestamp": [
699.32,
701.92
]
},
{
"text": " So in that sense, the internet is very decentralized, that the control",
"timestamp": [
701.92,
705.92
]
},
{
"text": " of the network is up to whoever owns the network. The 2% where you said there's nobody in control,",
"timestamp": [
705.92,
712.48
]
},
{
"text": " there's a little bit of centralized control. There's an organization called the Internet",
"timestamp": [
712.48,
716.8
]
},
{
"text": " Corporation for Assigned Names and Numbers. Its responsibility is to handle, as the name",
"timestamp": [
716.8,
722.48
]
},
{
"text": " I can suggest, names and numbers.",
"timestamp": [
722.48,
725.24
]
},
{
"text": " It's that little bit of centralization,",
"timestamp": [
725.24,
728
]
},
{
"text": " central authority that you need.",
"timestamp": [
728,
729.8
]
},
{
"text": " When can we see the next tenfold increase in Wi-Fi speed?",
"timestamp": [
729.8,
734.8
]
},
{
"text": " You know, in terms of tenfold speeds of increases,",
"timestamp": [
735.12,
738.7
]
},
{
"text": " depending on what device you're using right now,",
"timestamp": [
738.7,
741
]
},
{
"text": " it's available, all you need to do is upgrade, right?",
"timestamp": [
741,
743.46
]
},
{
"text": " So the Wi-Fi protocol is called 802.11.",
"timestamp": [
743.46,
746.92
]
},
{
"text": " And this is sometimes a source of confusion for people.",
"timestamp": [
746.92,
749.68
]
},
{
"text": " How can it be that I've got a connection",
"timestamp": [
749.68,
752.24
]
},
{
"text": " at 100 megabits per second from our TV into our router,",
"timestamp": [
752.24,
756.4
]
},
{
"text": " 100 megabits per second, not enough?",
"timestamp": [
756.4,
759.04
]
},
{
"text": " Packets dropping.",
"timestamp": [
759.04,
760.44
]
},
{
"text": " Where do they get dropped, do you think?",
"timestamp": [
760.44,
763.2
]
},
{
"text": " Somewhere in their travel process.",
"timestamp": [
763.2,
764.96
]
},
{
"text": " Exactly, right? And maybe they're dropped, do you think? Somewhere in their travel process.",
"timestamp": [
764.96,
765.08
]
},
{
"text": " Exactly, right? And maybe they're dropped in your apartment, but much more likely",
"timestamp": [
765.2,
769.24
]
},
{
"text": " they're dropped because of congestion somewhere between",
"timestamp": [
769.6,
772.4
]
},
{
"text": " the Hulu or the Netflix or the Disney server if you're watching a video and your home. So even though you've got",
"timestamp": [
772.84,
778.96
]
},
{
"text": " 200 megabits per second on that last hop, you don't have 200 megabits per second from the server",
"timestamp": [
779.96,
785.76
]
},
{
"text": " into your apartment. I see. I'm curious, has our conversation sort of changed your view or",
"timestamp": [
786.32,
793.36
]
},
{
"text": " sort of taught you new things about the internet? I think that I've sort of realized that it's a,",
"timestamp": [
793.36,
798.64
]
},
{
"text": " the internet is a technology that's dependent upon so many other factors, some more in our control, some less.",
"timestamp": [
799.36,
806.32
]
},
{
"text": " Tell us a little bit about yourself.",
"timestamp": [
809.44,
810.88
]
},
{
"text": " I'm Casper Lant.",
"timestamp": [
810.88,
812.08
]
},
{
"text": " I'm a PhD student at Columbia University",
"timestamp": [
812.08,
814.24
]
},
{
"text": " under Henning Schulze-Rinne's tutelage.",
"timestamp": [
814.24,
816.32
]
},
{
"text": " Oh, good pronunciation.",
"timestamp": [
816.32,
817.68
]
},
{
"text": " Thank you.",
"timestamp": [
817.68,
818
]
},
{
"text": " I'm interested in networking, IoT,",
"timestamp": [
818.56,
820.96
]
},
{
"text": " and sort of what kind of data science you can use",
"timestamp": [
820.96,
823.36
]
},
{
"text": " with the data sets that",
"timestamp": [
823.36,
825.28
]
},
{
"text": " you get from such devices.",
"timestamp": [
825.28,
826.8
]
},
{
"text": " One of the things that I designed before starting my PhD with heading was a IoT pill dispenser,",
"timestamp": [
826.8,
833.52
]
},
{
"text": " essentially, which pairs with your smartphone, which does facial detection and other computer",
"timestamp": [
833.52,
838
]
},
{
"text": " vision controls and can basically tell who's taking some sensitive medication and make",
"timestamp": [
838,
843.72
]
},
{
"text": " sure that they've taken it correctly.",
"timestamp": [
843.72,
845.4
]
},
{
"text": " We have these low power devices,",
"timestamp": [
845.4,
846.76
]
},
{
"text": " they're sort of at the edge.",
"timestamp": [
846.76,
848.56
]
},
{
"text": " Is it just connecting them in across a wireless device,",
"timestamp": [
848.56,
851.6
]
},
{
"text": " across a wireless link, is that the primary challenge or?",
"timestamp": [
851.6,
854.74
]
},
{
"text": " Well, I think the primary challenge is that for sure,",
"timestamp": [
854.74,
857.64
]
},
{
"text": " but then an additional challenge is",
"timestamp": [
857.64,
859.92
]
},
{
"text": " keeping everything configured in the way",
"timestamp": [
859.92,
861.52
]
},
{
"text": " that you expect it to be configured.",
"timestamp": [
861.52,
863.6
]
},
{
"text": " So for example, most IoT devices require you, when you're configuring them,",
"timestamp": [
863.6,
867.84
]
},
{
"text": " for you to enter some kind of captive login portal,",
"timestamp": [
867.84,
871.6
]
},
{
"text": " where you connect to a local network that the IoT device produces,",
"timestamp": [
871.6,
876.04
]
},
{
"text": " and then you can input your Wi-Fi SSID and password.",
"timestamp": [
876.04,
879.76
]
},
{
"text": " But then say if you were to change the password or the name of your Wi-Fi network,",
"timestamp": [
879.76,
884.04
]
},
{
"text": " or you move to a new place, then suddenly everything needs to be reconfigured.",
"timestamp": [
884.04,
888.28
]
},
{
"text": " That's a problem that scales linearly. Right, that you don't want the",
"timestamp": [
888.28,
892.2
]
},
{
"text": " complexity of managing them to go up linearly with that. You'd like it to",
"timestamp": [
892.2,
896.92
]
},
{
"text": " stay pretty flat as you start adding. Right, exactly. I mean the good thing",
"timestamp": [
896.92,
900.6
]
},
{
"text": " about IoT devices is that they tend to transmit very, very small amounts of data.",
"timestamp": [
900.6,
905.4
]
},
{
"text": " We're used to Ethernet cables that can handle",
"timestamp": [
905.4,
907.62
]
},
{
"text": " many hundreds of gigabits per second over a wired device.",
"timestamp": [
907.62,
911.1
]
},
{
"text": " What are the typical data rates for IoT devices?",
"timestamp": [
911.1,
914.4
]
},
{
"text": " I mean, not hundreds of gigabits, for example.",
"timestamp": [
914.4,
916
]
},
{
"text": " No, I mean, I would imagine upper bound KB per second.",
"timestamp": [
916,
920.6
]
},
{
"text": " Lower bound, you could see bytes per second,",
"timestamp": [
920.6,
922.46
]
},
{
"text": " just on average.",
"timestamp": [
922.46,
923.48
]
},
{
"text": " But I mean, say that you have a temperature sensor",
"timestamp": [
923.48,
927.12
]
},
{
"text": " running off of your Arduino that's reporting",
"timestamp": [
927.12,
929.12
]
},
{
"text": " the temperature in your house every minute,",
"timestamp": [
929.12,
931.6
]
},
{
"text": " that's going to be far less than",
"timestamp": [
931.6,
933.16
]
},
{
"text": " kilobytes per second on average.",
"timestamp": [
933.16,
934.68
]
},
{
"text": " My sense is you're spot on,",
"timestamp": [
934.68,
936.84
]
},
{
"text": " but they'll produce over time a lot of data",
"timestamp": [
936.84,
940.24
]
},
{
"text": " and that a lot of IoT is about computing on that data.",
"timestamp": [
940.24,
943.84
]
},
{
"text": " That computation happened mostly at the edge or somehow a combination",
"timestamp": [
943.84,
947.64
]
},
{
"text": " between the edge and something happening in a faraway data center?",
"timestamp": [
947.64,
952
]
},
{
"text": " Well, my sense is right now that all that data tends to be centralized",
"timestamp": [
952,
955
]
},
{
"text": " because IoT devices are usually the commercial products of companies.",
"timestamp": [
955,
959.16
]
},
{
"text": " Do you think they'll share it?",
"timestamp": [
959.16,
960.24
]
},
{
"text": " Not without some persuasion,",
"timestamp": [
960.24,
962.46
]
},
{
"text": " but I agree that these data have massive, massive research value.",
"timestamp": [
962.46,
966.6
]
},
{
"text": " Something I'm interested in with my research is collaborating with people who manage these distributed sensor devices",
"timestamp": [
966.6,
973.3
]
},
{
"text": " and then taking advantage of those data sets and comparing them to, say,",
"timestamp": [
973.3,
978.6
]
},
{
"text": " say you were interested in doing a research project on how daily rush hour traffic impacts the acoustic landscape",
"timestamp": [
978.6,
985.16
]
},
{
"text": " of New York City. Figuring out, look this street next to this school is causing",
"timestamp": [
985.16,
990.26
]
},
{
"text": " decimal ratings above what we mandate and so there needs to be an intervention.",
"timestamp": [
990.26,
994.68
]
},
{
"text": " I think for a long time the internet hasn't grappled with but now has with",
"timestamp": [
994.68,
999.2
]
},
{
"text": " IOT and also with cellular networks generally is the question of mobility. Do",
"timestamp": [
999.2,
1003.8
]
},
{
"text": " you imagine in the future that it might be possible",
"timestamp": [
1003.8,
1006.44
]
},
{
"text": " for mobile devices not to always have to connect",
"timestamp": [
1006.44,
1009.48
]
},
{
"text": " through the same provider to go from one network to another?",
"timestamp": [
1009.48,
1012.32
]
},
{
"text": " Definitely.",
"timestamp": [
1012.32,
1012.82
]
},
{
"text": " I mean, we're already seeing long-range networks",
"timestamp": [
1012.82,
1015.02
]
},
{
"text": " like LoRa that can, first of all,",
"timestamp": [
1015.02,
1017.16
]
},
{
"text": " provide access over a much larger coverage area,",
"timestamp": [
1017.16,
1019.68
]
},
{
"text": " but then also look the same because they're",
"timestamp": [
1019.68,
1022.04
]
},
{
"text": " set up to the same specification regardless of where",
"timestamp": [
1022.04,
1024.68
]
},
{
"text": " the individual gateway is.",
"timestamp": [
1024.68,
1026
]
},
{
"text": " Hey Jen, it's great to see you again.",
"timestamp": [
1026,
1030.44
]
},
{
"text": " Good to see you, Jim.",
"timestamp": [
1030.44,
1031.2
]
},
{
"text": " We're in level five now,",
"timestamp": [
1031.2,
1032.96
]
},
{
"text": " so you're the expert expert.",
"timestamp": [
1032.96,
1035.12
]
},
{
"text": " I'm a huge fan of the work that you did in RCP,",
"timestamp": [
1035.12,
1038.36
]
},
{
"text": " the routing control platform being a precursor to software-defined networking,",
"timestamp": [
1038.36,
1043.56
]
},
{
"text": " and the notion that rather than having protocols",
"timestamp": [
1043.56,
1046.36
]
},
{
"text": " actually always compute things,",
"timestamp": [
1046.36,
1047.88
]
},
{
"text": " that we could compute things in data centers.",
"timestamp": [
1047.88,
1051.08
]
},
{
"text": " I'd be interested if you could sort of just reflect back",
"timestamp": [
1051.08,
1053.52
]
},
{
"text": " on that time and sort of the beginnings of SDN",
"timestamp": [
1053.52,
1056.12
]
},
{
"text": " and where it's come since then.",
"timestamp": [
1056.12,
1057.48
]
},
{
"text": " Yeah, and when we were at AT&T,",
"timestamp": [
1057.48,
1059.2
]
},
{
"text": " the thing we found most frustrating",
"timestamp": [
1059.2,
1060.64
]
},
{
"text": " is AT&T would buy routers",
"timestamp": [
1060.64,
1062.16
]
},
{
"text": " and they would come pre-baked with a set of protocols,",
"timestamp": [
1062.16,
1065.48
]
},
{
"text": " a set of knobs that you could turn if you wanted to influence how the traffic flowed,",
"timestamp": [
1065.48,
1069.36
]
},
{
"text": " and a set of dials you could read to understand what was going on inside the network.",
"timestamp": [
1069.36,
1073.16
]
},
{
"text": " Right, you couldn't directly do what you wanted to do.",
"timestamp": [
1073.16,
1075.88
]
},
{
"text": " Exactly.",
"timestamp": [
1075.88,
1076.88
]
},
{
"text": " And so we started thinking about earlier work that was done in the telephony network, the",
"timestamp": [
1076.88,
1079.56
]
},
{
"text": " old telephone network, and there they had the same problem.",
"timestamp": [
1079.56,
1082.12
]
},
{
"text": " And they had the idea of having a computer running a program tell a distributed set of telephony switches what to do. But",
"timestamp": [
1082.12,
1089.24
]
},
{
"text": " the idea was like, wow, it was kind of a revelation. Like, what would that look like if we did",
"timestamp": [
1089.24,
1092.34
]
},
{
"text": " that? Not for the whole internet, but at least AT&T is part of the internet. So in other",
"timestamp": [
1092.34,
1096.08
]
},
{
"text": " words, use software instead of distributed protocols to tell the network what to do.",
"timestamp": [
1096.08,
1100.56
]
},
{
"text": " Yeah. Do you see the softwareization of the internet",
"timestamp": [
1100.56,
1103.16
]
},
{
"text": " as a whole happening? So, So far it hasn't very much.",
"timestamp": [
1103.16,
1106.52
]
},
{
"text": " I mean, basically software-defined networking exists, let's say, within a single provider",
"timestamp": [
1106.52,
1110.16
]
},
{
"text": " backbone or a single cloud provider's network or a single campus.",
"timestamp": [
1110.16,
1114.48
]
},
{
"text": " There's been some work on doing it at the juncture points between a pair of networks.",
"timestamp": [
1114.48,
1118
]
},
{
"text": " But one other trend that's happening that makes it more possible is it used to be that",
"timestamp": [
1118,
1121.56
]
},
{
"text": " to get from one end of the internet to the other, you have access networks getting much closer",
"timestamp": [
1121.56,
1126.72
]
},
{
"text": " to say Google or Microsoft or other large cloud providers,",
"timestamp": [
1126.72,
1130.62
]
},
{
"text": " where even you might only go through two networks.",
"timestamp": [
1130.62,
1133.3
]
},
{
"text": " Right, so some people have called that",
"timestamp": [
1133.3,
1134.54
]
},
{
"text": " the flattening of the internet, right?",
"timestamp": [
1134.54,
1136.24
]
},
{
"text": " So I think it used to be on average,",
"timestamp": [
1136.24,
1137.6
]
},
{
"text": " you would go through 10 different networks",
"timestamp": [
1137.6,
1140.26
]
},
{
"text": " to get from a source to a destination.",
"timestamp": [
1140.26,
1142.24
]
},
{
"text": " Exactly, and if you take that even further,",
"timestamp": [
1142.24,
1144.04
]
},
{
"text": " there's starting to be more edge computing",
"timestamp": [
1144.04,
1145.56
]
},
{
"text": " where you might imagine you might have a cell tower",
"timestamp": [
1145.56,
1148.16
]
},
{
"text": " connected to a small number of routers",
"timestamp": [
1148.16,
1149.76
]
},
{
"text": " connected directly to a server",
"timestamp": [
1149.76,
1151.2
]
},
{
"text": " that's gonna be running the application.",
"timestamp": [
1151.2,
1153.12
]
},
{
"text": " In that case, the entire infrastructure",
"timestamp": [
1153.12,
1154.92
]
},
{
"text": " might be controlled by a single party.",
"timestamp": [
1154.92,
1156.32
]
},
{
"text": " It's totally fascinating to me",
"timestamp": [
1156.32,
1157.6
]
},
{
"text": " that we have such an important global infrastructure,",
"timestamp": [
1157.6,
1162.56
]
},
{
"text": " and yet the laws that govern it tend to be very, very local.",
"timestamp": [
1162.56,
1168
]
},
{
"text": " There are tens of thousands of separately administered networks, and of course in hundreds",
"timestamp": [
1168,
1172.2
]
},
{
"text": " of countries, and the fact that it even holds together at all is kind of a miracle.",
"timestamp": [
1172.2,
1176
]
},
{
"text": " Right.",
"timestamp": [
1176,
1177
]
},
{
"text": " Well, it holds together because we have standards and we have protocols that you mentioned.",
"timestamp": [
1177,
1180.4
]
},
{
"text": " Exactly, the protocol standards for how the equipment talks to one another, and increasingly",
"timestamp": [
1180.4,
1184.38
]
},
{
"text": " certificate authorities that help bootstrap the secure, encrypted communication between",
"timestamp": [
1184.38,
1189.52
]
},
{
"text": " end hosts.",
"timestamp": [
1189.52,
1190.52
]
},
{
"text": " So there are a few of these sort of centrally kind of agreed upon kinds of infrastructure,",
"timestamp": [
1190.52,
1194.8
]
},
{
"text": " but for the most part, each network runs itself.",
"timestamp": [
1194.8,
1197.36
]
},
{
"text": " And certainly we've heard about some countries that impose firewalls that don't let certain",
"timestamp": [
1197.36,
1201.64
]
},
{
"text": " kinds of traffic out or certain kinds of traffic in.",
"timestamp": [
1201.64,
1205.52
]
},
{
"text": " So there's no global body that is regulating that.",
"timestamp": [
1205.52,
1208.88
]
},
{
"text": " Not really, because each country really can have its own laws, its own norms.",
"timestamp": [
1208.88,
1212.64
]
},
{
"text": " And so they can decide, like the Great Firewall of China can decide,",
"timestamp": [
1212.64,
1216.24
]
},
{
"text": " they don't want to let certain content be accessed by the citizens inside that country.",
"timestamp": [
1216.24,
1220
]
},
{
"text": " So if a country decides they don't want to answer requests for a particular domain name,",
"timestamp": [
1220,
1223.44
]
},
{
"text": " they say, hey, I don't want to let someone know the IP address of this website.",
"timestamp": [
1223.44,
1226.64
]
},
{
"text": " They can decide not to let those answers be delivered inside their country.",
"timestamp": [
1226.64,
1230.44
]
},
{
"text": " And so encryption plays a role in helping people keep their privacy or prevent surveillance,",
"timestamp": [
1230.44,
1236.16
]
},
{
"text": " but it's not perfect.",
"timestamp": [
1236.16,
1237.16
]
},
{
"text": " It's often possible still to know a fair amount about what people are doing, even if you can't",
"timestamp": [
1237.16,
1241.92
]
},
{
"text": " look inside the envelope at the letter that's written.",
"timestamp": [
1241.92,
1244.56
]
},
{
"text": " Right. I mean, even you could just tell that two people are doing, even if you can't look inside the envelope at the letter that's written. Right, I mean, even you could just tell",
"timestamp": [
1244.56,
1246.08
]
},
{
"text": " that two people are communicating,",
"timestamp": [
1246.08,
1247.52
]
},
{
"text": " even though the traffic itself is encrypted.",
"timestamp": [
1247.52,
1249.96
]
},
{
"text": " So you don't know what they're saying,",
"timestamp": [
1249.96,
1251.48
]
},
{
"text": " just even knowing two devices are communicating.",
"timestamp": [
1251.48,
1254.24
]
},
{
"text": " Exactly, and in fact, if you look at, say,",
"timestamp": [
1254.24,
1256.52
]
},
{
"text": " the sizes of the transfers that they're doing,",
"timestamp": [
1256.52,
1258.84
]
},
{
"text": " you may know, hey, I'm talking to Netflix,",
"timestamp": [
1258.84,
1260.56
]
},
{
"text": " and by the way, this is the length of the movie I watched,",
"timestamp": [
1260.56,
1263.36
]
},
{
"text": " and this is the size of each of the frames.",
"timestamp": [
1263.36,
1264.2
]
},
{
"text": " Right, so you can infer or guess a lot of things. Exactly. You're one of the most",
"timestamp": [
1264.2,
1267.92
]
},
{
"text": " awesome networking researchers that I know. I'm curious, just to pick your brain, what do you",
"timestamp": [
1267.92,
1271.76
]
},
{
"text": " think are some of the hot topics in networking research? Where do you think the field is heading?",
"timestamp": [
1271.76,
1276.16
]
},
{
"text": " Yeah, I'm excited about the convergence of wireless communications, cellular networks,",
"timestamp": [
1276.16,
1281.04
]
},
{
"text": " Wi-Fi, with networking and cloud computing. And in particular, we're seeing in edge computing a convergence of all three, where you might",
"timestamp": [
1281.04,
1288.52
]
},
{
"text": " have a mobile phone or a drone or some other kind of device connecting over the wireless",
"timestamp": [
1288.52,
1293.2
]
},
{
"text": " medium directly to a network that connects you directly to the server that might run",
"timestamp": [
1293.2,
1297.24
]
},
{
"text": " your application.",
"timestamp": [
1297.24,
1298.24
]
},
{
"text": " So you want the computation close to where the end point is.",
"timestamp": [
1298.24,
1302.6
]
},
{
"text": " Exactly.",
"timestamp": [
1302.6,
1303.6
]
},
{
"text": " And I think that what's now exciting about that",
"timestamp": [
1303.6,
1305.34
]
},
{
"text": " is all three of these technologies,",
"timestamp": [
1305.34,
1306.86
]
},
{
"text": " wireless, networking, and cloud,",
"timestamp": [
1306.86,
1308.46
]
},
{
"text": " which are normally three different communities,",
"timestamp": [
1308.46,
1310.32
]
},
{
"text": " three different sets of technologies,",
"timestamp": [
1310.32,
1312.06
]
},
{
"text": " three different sets of standards or practices,",
"timestamp": [
1312.06,
1314.26
]
},
{
"text": " now have to work together in close harmony",
"timestamp": [
1314.26,
1317.1
]
},
{
"text": " to be able to service applications that are really critical",
"timestamp": [
1317.1,
1320.3
]
},
{
"text": " and that might be interacting with the physical world",
"timestamp": [
1320.3,
1322.36
]
},
{
"text": " in ways where safety is a potential concern.",
"timestamp": [
1322.36,
1324.94
]
},
{
"text": " You know, we've had cellular networks now for 20, 30 years.",
"timestamp": [
1324.94,
1329.4
]
},
{
"text": " So when we hear about 5G, what's trumpeted the most",
"timestamp": [
1329.4,
1332
]
},
{
"text": " is the fact that, oh, super high bandwidth, right?",
"timestamp": [
1332,
1334.6
]
},
{
"text": " But I sense that the exciting things are more",
"timestamp": [
1334.6,
1337.08
]
},
{
"text": " than just the network being faster.",
"timestamp": [
1337.08,
1340.16
]
},
{
"text": " I agree.",
"timestamp": [
1340.16,
1341
]
},
{
"text": " It's both the high bandwidth, it's the low delay",
"timestamp": [
1341,
1343.04
]
},
{
"text": " so that you can have these applications that interact with the physical world and need answers in real time. It's about having",
"timestamp": [
1343.04,
1349.44
]
},
{
"text": " the compute really close so that you can integrate computation and communication. It's about having",
"timestamp": [
1349.44,
1355.28
]
},
{
"text": " more coverage. Coming back again to the softwareization, SDN and softwareization is",
"timestamp": [
1355.28,
1360.4
]
},
{
"text": " maybe a little bit behind the covers that you wouldn't normally see it as a user",
"timestamp": [
1361.12,
1365.98
]
},
{
"text": " going from 3G to 4G to 5G,",
"timestamp": [
1365.98,
1368.58
]
},
{
"text": " you just see an increase in speed.",
"timestamp": [
1368.58,
1370.18
]
},
{
"text": " But yet, the way the network is now being managed again,",
"timestamp": [
1370.18,
1374.14
]
},
{
"text": " I think, is bringing the cellular networking world",
"timestamp": [
1374.14,
1376.62
]
},
{
"text": " sort of into the internet world",
"timestamp": [
1376.62,
1378.08
]
},
{
"text": " in terms of the softwareization of all the management.",
"timestamp": [
1378.08,
1381.42
]
},
{
"text": " And I think the bringing in of compute and storage",
"timestamp": [
1381.42,
1383.38
]
},
{
"text": " is important too.",
"timestamp": [
1383.38,
1384.22
]
},
{
"text": " I think when you think just about networking,",
"timestamp": [
1384.22,
1386.46
]
},
{
"text": " it really is often just one part of the IT,",
"timestamp": [
1386.46,
1389.34
]
},
{
"text": " you know, the information technology ecosystem",
"timestamp": [
1389.34,
1391.54
]
},
{
"text": " as there's often compute and storage as well.",
"timestamp": [
1391.54,
1394.82
]
},
{
"text": " And so I think now there's an opportunity",
"timestamp": [
1394.82,
1396.54
]
},
{
"text": " to have all of those parts of the infrastructure",
"timestamp": [
1396.54,
1398.7
]
},
{
"text": " work together towards an even higher level goal.",
"timestamp": [
1398.7,
1401.1
]
},
{
"text": " And so I think it's a really exciting time",
"timestamp": [
1401.1,
1403.34
]
},
{
"text": " to be in the field",
"timestamp": [
1403.34,
1404.34
]
},
{
"text": " because now the plumbing is getting close to the application in a way that it wasn't before.",
"timestamp": [
1404.34,
1408.8
]
},
{
"text": " So I really hope you've enjoyed this video and I hope you've also understood",
"timestamp": [
1411.36,
1415.04
]
},
{
"text": " the internet is part of the worldwide global communication fabric.",
"timestamp": [
1415.04,
1420.32
]
},
{
"text": " Absolutely fascinating how it works.",
"timestamp": [
1420.32,
1426.72
]
}
] |
[
[
"Intro",
" Hi, I'm Jim Carosa. I'm a professor at the University of Massachusetts at Amherst. And I've been challenged to describe the internet in five levels of increasing difficulty. The internet is the most technically complex system that humanity has ever built. The internet is a network of networks. It's a platform on which all of the internet applications that you've heard of can be built. Hi, it's really, really nice to meet you. What's your name? My name is Skylar. Skylar, we're here to talk about the internet, and I bet you must use the internet a lot, right? Yeah. What's your conception about what the internet is?"
],
[
"What is the Connectome",
" The internet, for me, it's just something to use when I need to search up something or watch videos. The internet is physically these computers that all talk to each other, billions of computers in the case of the internet. The internet allows us to do a lot of really, really interesting, what we call applications. You ever think about how that video gets to you over the internet? Yeah, I have no idea. Got a favorite movie? Matilda. Matilda, all right. We're gonna actually build an internet. I've got a couple of things here that I wanna show you, or a couple of toys, actually. Okay, let's pretend that these round balls are computers, and the internet is something that connects them. And right now, the internet is just one communication link, and Matilda is sent over the internet from this computer to your computer. So the internet is a network for carrying information from one computer to another."
],
[
"Brain Cells",
" Now this network here looks pretty simple, doesn't it? It's just one thing. Should we add some more friends in? Yeah. Let's say we want to get a video from here over to here. How do you think that video would sort of travel through this network? Maybe it could go to here, to here, to here, to here. That's right. So that's pretty cool. There are actually lots of different ways to actually go through the internet to get from what we call a source, the place that's sending the information to the source, the place that's sending the information, to the receiver, the place that's actually gathering the information together. And that's something we actually call routing. Huh. But wouldn't it just be easier for it to go from here to here, instead of going from here to here to here to here? Yeah. So that's a really good observation. In most pieces of the Internet, that's exactly what would happen. We want to take what's called a shortest path. But still, there are multiple paths. Why do you think that might be valuable? Maybe one way like messed up or broken so you can't go away? Yeah. Exactly. So Skylar, that was a great discussion about what we just built."
],
[
"Connectome",
" I wanted to talk to you about, or ask you about maybe one other really important part about networks. And it's not so much the thing itself, the physical thing, but more about the rules about communication. That's governed by something that are called protocols. Are you up for one? Yeah. Knock, knock. Who's there? Lettuce. Lett for one? Yeah. Knock, knock. Who's there? Lettuce. Lettuce who? Lettuce go on. A knock-knock joke is an example of a protocol, right? The computer that you're using, say, makes a request. You ask for something, you get something in return. In the internet, there are protocols everywhere. So that two computers that have never talked to each other before know the rules for talking to each other. This global internet with billions of people using it are just lots of smaller networks that are all hooked together to each other. But also what the internet allows are all of these what we call applications, Zoom, video playing services, can all run on top of the same Internet. Yes, there's one Internet for all of them. Exactly. There's one Internet and lots and lots and lots of things that you can do on top of it. So you're a student in high school, is that right? Yes, I'm a sophomore. Well, we're going to be talking about computers here today, and we're going to be talking about the internet. I always like to think of the internet by analogy to, say, road systems, for example, where you have roads in your neighborhood, you have state roads, you have the interstate highway system. And so the internet is a lot like that. It's an interconnection of local roads, local networks, like the network in your house, for example. How does all of the networks in my house connect to all the city networks? Wow, great question."
],
[
"Wiring Map",
" Often it's a little blue wire called an Ethernet cable. So that cable is able to bring bits of information up into your apartment at, say, a billion bits per second. That's pretty fast, right? Literally a wire that goes between a box in your apartment, sometimes called a router, or a modem in your apartment that comes from an internet service provider, come into this first network, and then that network connects to another network, connects to another network, connects to another network. You could FaceTime somebody who's like in Australia. You can talk to them at the same time and like you're reaching the same signals. So how is it that it gets there so fast? We could talk about that by analogy to a road system. It's not just one big super highway. It's a lot of smaller super highways that are all interconnected. And those interchanges are what are called routers. That's where the links come together. We're talking about talking to a friend in Australia. So, oh, it's coming in from the East Coast of the United States to this router, and it's going out, say that router's in San Francisco, it's going out on an underseas cable over to Australia, rather than in this direction up to Japan. So there is an underseas cable. The underseas cables are so cool. They're these big cables that are laid down by switches. They cross both the Atlantic, the Pacific, the Indian Ocean. So the underseas cables are how the networks in Europe, the United States, Asia are all connected together. How do you connect like wirelessly? That's really what we call the first hop. It's like from your phone, from your tablet, from the computer that you're on. There's no cables coming in. You go over a wireless connection. Wi-Fi is the protocol that allows your computer to talk to that first hop router over a wireless communication link. And I was wondering like how there's so many different movies or TV shows that you can download and that they're all there. And like, if you just play it, it just knows what to play. But they're all in one spot. Ah, you said they're all in one spot. In fact, they're in lots of spots in Netflix. And so most applications would like to connect you with a server that's close to you. Server's really just a big computer with a lot of memory, a lot of disks that store all the Netflix movies. And also so that you don't have to cross over too many internet links to get from where the server is to the TV or the device in your home. So when I'm watching Vampire Diaries in my house, how does it know exactly what to do without getting scrambled up? Ah, another great question. There's a couple of things that could happen inside the Internet. Information is sent in these little packets of information from the Netflix server to your display device. Literally, each packet that arrives says, this is the first packet for Jenna, this is the second, this is the third, this is the fifth, this is the fourth, and they're reordered for you. Matter of fact, your computer will say using the TCP protocol to the fifth, this is the fourth. And they're reordered for you. As a matter of fact, your computer will say, using the TCP protocol to the server, hey, I didn't get packet four, can you resend it again? And again, the Netflix server is very happy to send you packet four again. The other is the internet protocol. If you think about sending letters through the US Postal Service, how you've got an address on it. So every packet that flows from the Netflix server to you has an address on it. So this is going to Jenna. It's going to what's called the Internet Protocol address of your device. Think of all the range of devices that are hooked up to the Internet. It's totally amazing. Every single one of them has one thing in common, and that is they speak the IP protocol, the Internet Protocol. That was a great question. So tell me a little bit about yourself. I am a senior at New York University. I study computer science. Have you taken any courses on the Internet or studied it at all? I've taken applied Internet technology. So we've talked about back-end, slash front-end frameworks and libraries, things like that. So really at the application level. At the application level, for sure. I wanted to ask you a little bit about what you know about the history of the Internet. Have you heard of ARPANET, for example? I have not heard of ARPANET. Back into the 1960s, there was a research agency in the United States called DARPA, the Defense Advanced Research Projects Agency. Actually, it was called ARPA at the time. They wanted to build this notion of a packet switching network, not a circuit switch network like a phone network where you get a dedicated path and a dedicated set of bandwidth and links from source to destination. So what would packet switching enable? I'm sure there's something big here for sure. There's a lot big, right? And so remember this was a Department of Defense. They wanted to have forms of communication that were very robust, that were survivable. Packets could all find their own ways, be routed differently through the network. So if parts of the network failed, you could route around failures. Sounds like the reason for a request response type of structure. So you can see how the network architecture that wasn't designed to be 100 percent reliable inside the core of the network and had that complexity built into the edges of the network. To me, the really cool thing is you put this infrastructure in place,"
]
] |
UCftwRNsjfRo08xYE31tkiyw
|
https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
|
Biologist Explains One Concept in 5 Levels of Difficulty - CRISPR | WIRED
|
sweN8d4_MUg
| 1,013
|
[
{
"end_time": 28,
"start_time": 0,
"title": "Intro"
},
{
"end_time": 86,
"start_time": 28,
"title": "What is CRISPR"
},
{
"end_time": 183,
"start_time": 86,
"title": "What is a genome"
},
{
"end_time": 286,
"start_time": 183,
"title": "CRISPR"
},
{
"end_time": 437,
"start_time": 286,
"title": "Ethics"
},
{
"end_time": 585,
"start_time": 437,
"title": "Genetics"
},
{
"end_time": 708,
"start_time": 585,
"title": "Jurassic Park"
},
{
"end_time": 752,
"start_time": 708,
"title": "Mutations"
},
{
"end_time": 794,
"start_time": 752,
"title": "Data"
},
{
"end_time": 1013,
"start_time": 794,
"title": "Ethical Issues"
}
] |
[
{
"text": " Hi, I'm Sean Carroll. I'm a theoretical physicist here at the California Institute of Technology.",
"timestamp": [
0,
5.12
]
},
{
"text": " I've been challenged to explain dimensions to five different levels.",
"timestamp": [
5.12,
8.64
]
},
{
"text": " The idea of a dimension, sometimes in pop culture, is misunderstood.",
"timestamp": [
9.6,
14.16
]
},
{
"text": " Like, there's an extra place you can go, a mystical dimension or something like that.",
"timestamp": [
14.16,
18.52
]
},
{
"text": " To a physicist or a mathematician, a dimension is just the direction you can go in.",
"timestamp": [
18.52,
23.4
]
},
{
"text": " Up, down, left, right, forward, backward.",
"timestamp": [
23.4,
25.7
]
},
{
"text": " To you and me, we think there's three dimensions around us,",
"timestamp": [
25.7,
28.18
]
},
{
"text": " but then physicists start talking about extra dimensions.",
"timestamp": [
28.18,
31.06
]
},
{
"text": " How can you hide them?",
"timestamp": [
31.06,
32.42
]
},
{
"text": " You know, where might they be?",
"timestamp": [
32.42,
33.78
]
},
{
"text": " I'm hopeful that we'll learn something at each level.",
"timestamp": [
33.78,
36.42
]
},
{
"text": " We're gonna talk about some science.",
"timestamp": [
39.42,
41.14
]
},
{
"text": " Do you like science?",
"timestamp": [
41.14,
42.18
]
},
{
"text": " Yes, a lot.",
"timestamp": [
42.18,
43.34
]
},
{
"text": " Oh, very good.",
"timestamp": [
43.34,
44.16
]
},
{
"text": " You've come to the right place. So we're gonna think about physics. Have you heard the word physics before?",
"timestamp": [
44.16,
48.48
]
},
{
"text": " Do you know what that is? Yeah, kind of. What's your idea what physics is? I'm not",
"timestamp": [
48.48,
54.34
]
},
{
"text": " so sure. Okay, I just think of physics as, you know, the study of everything. What",
"timestamp": [
54.34,
58.84
]
},
{
"text": " stuff is, what stuff does. So today we're gonna talk about space and in particular",
"timestamp": [
58.84,
63.92
]
},
{
"text": " the idea of dimensions.",
"timestamp": [
63.92,
66.68
]
},
{
"text": " Have you heard about dimensions? At the camp I'm in a 3D printing one. 3D printing, good.",
"timestamp": [
66.68,
73.68
]
},
{
"text": " So I don't choose the size, all I have to do is the shape. But do you know what 3D means?",
"timestamp": [
73.68,
80.92
]
},
{
"text": " It's three dimensional. Three dimensional, as opposed to what is ordinary printing? So, ordinary printing would be 2D.",
"timestamp": [
80.92,
87
]
},
{
"text": " What do you say when something is one-dimensional?",
"timestamp": [
87,
89
]
},
{
"text": " What's an example of something that's one-dimensional?",
"timestamp": [
89,
91
]
},
{
"text": " Hmm, I think one-dimensional might be a circle, I guess, or maybe a line.",
"timestamp": [
91,
97
]
},
{
"text": " A line is a perfect example because it's one thing that's straight, right?",
"timestamp": [
97,
101
]
},
{
"text": " So here's some toys. We're going to build some dimensions, right?",
"timestamp": [
101,
104
]
},
{
"text": " So what would you say about this? That's one-dimensional. Exactly. It's're gonna build some dimensions, right? So what would you say about this?",
"timestamp": [
104,
105.68
]
},
{
"text": " That's one dimensional.",
"timestamp": [
105.68,
107
]
},
{
"text": " Exactly.",
"timestamp": [
107,
108
]
},
{
"text": " It's not really one dimensional, right?",
"timestamp": [
108,
110
]
},
{
"text": " Everything has to be one or two dimensional before it's three dimensional.",
"timestamp": [
110,
113.8
]
},
{
"text": " And how would you find yourself, like if someone said, where are you?",
"timestamp": [
113.8,
116.76
]
},
{
"text": " Like could you use some words or ideas to say where you are on that line?",
"timestamp": [
116.76,
122.08
]
},
{
"text": " I think I would be maybe there since I'm facing it.",
"timestamp": [
122.08,
126.96
]
},
{
"text": " But here's what I want you to think about.",
"timestamp": [
126.96,
128.36
]
},
{
"text": " If I say I'm at this point on the line,",
"timestamp": [
128.36,
130.64
]
},
{
"text": " I could translate that into saying",
"timestamp": [
130.64,
132.32
]
},
{
"text": " I'm at the three centimeter point.",
"timestamp": [
132.32,
134.8
]
},
{
"text": " If I were here, I'd be at the four centimeter point,",
"timestamp": [
134.8,
136.84
]
},
{
"text": " the five centimeter point, right?",
"timestamp": [
136.84,
138.8
]
},
{
"text": " So every point, every location on our little line.",
"timestamp": [
138.8,
142.48
]
},
{
"text": " Has its own unit.",
"timestamp": [
142.48,
143.88
]
},
{
"text": " Has its own unit, its own unit has one number",
"timestamp": [
143.88,
145.52
]
},
{
"text": " We need one number to tell you where we are. That's one dimension. That's what it means to be one-dimensional",
"timestamp": [
145.58,
151.12
]
},
{
"text": " I only need to tell you one number to figure out where we are",
"timestamp": [
151.12,
154.68
]
},
{
"text": " I'm like free dimensional",
"timestamp": [
154.68,
156.08
]
},
{
"text": " You have to tell a lot because if it's like a sphere you kind of have start using points. There you go",
"timestamp": [
156.08,
161.94
]
},
{
"text": " Exactly. We're gonna build a little",
"timestamp": [
162.14,
165.04
]
},
{
"text": " Two-dimensional space you want to do it you want to do the honors here? Why don't you put those two lines together?",
"timestamp": [
169.92,
170.16
]
},
{
"text": " If you make it",
"timestamp": [
172.16,
173.28
]
},
{
"text": " Dimensional is this a corner exactly another way is if you have this space in between",
"timestamp": [
180.08,
180.24
]
},
{
"text": " Is an angle I think you should be in this chair and you should be explaining this to me. You're much better than this than I am.",
"timestamp": [
185.08,
186.56
]
},
{
"text": " Yeah.",
"timestamp": [
186.56,
187.4
]
},
{
"text": " So those are the dimensions.",
"timestamp": [
187.4,
189.72
]
},
{
"text": " That's how we think about dimensions.",
"timestamp": [
189.72,
191.24
]
},
{
"text": " Remember, we just needed one number",
"timestamp": [
191.24,
193.9
]
},
{
"text": " to find ourselves on the line.",
"timestamp": [
193.9,
195.3
]
},
{
"text": " We need two numbers to find ourselves on the plane.",
"timestamp": [
195.3,
198.68
]
},
{
"text": " I think that would be an X or a Y axis.",
"timestamp": [
198.68,
201.64
]
},
{
"text": " There you go.",
"timestamp": [
201.64,
202.58
]
},
{
"text": " So do you think we could have more than three dimensions?",
"timestamp": [
202.58,
205.92
]
},
{
"text": " 3D is the maximum of dimensions for shapes.",
"timestamp": [
206.84,
211.52
]
},
{
"text": " Well as far as we know. This is why",
"timestamp": [
211.92,
214.76
]
},
{
"text": " physicists think about things we don't know about. We're wondering whether it could be extra dimensions",
"timestamp": [
215.48,
220.04
]
},
{
"text": " you've never seen that are tinier than atoms. So, okay, so what have you learned?",
"timestamp": [
220.04,
225.2
]
},
{
"text": " What do you know about dimensions now?",
"timestamp": [
225.2,
226.74
]
},
{
"text": " How do you think about dimensions",
"timestamp": [
226.74,
228.04
]
},
{
"text": " in a slightly different way than you did before?",
"timestamp": [
228.04,
230.14
]
},
{
"text": " So at least everything has a certain dimension.",
"timestamp": [
230.14,
233.72
]
},
{
"text": " Yeah, do you think you'd be excited",
"timestamp": [
233.72,
235.24
]
},
{
"text": " if physicists said that they found",
"timestamp": [
235.24,
236.62
]
},
{
"text": " extra dimensions of space?",
"timestamp": [
236.62,
238.92
]
},
{
"text": " That would be amazing, February.",
"timestamp": [
238.92,
242.16
]
},
{
"text": " The news would be spreaded around the world rapidly.",
"timestamp": [
242.16,
247.28
]
},
{
"text": " I think so, I think you're right.",
"timestamp": [
247.28,
248.72
]
},
{
"text": " All right, Hank, we want you to keep up studying,",
"timestamp": [
248.72,
251.5
]
},
{
"text": " learn a lot of math and physics,",
"timestamp": [
251.5,
252.74
]
},
{
"text": " and help us discover new dimensions someday.",
"timestamp": [
252.74,
254.52
]
},
{
"text": " Does that sound like a fun idea?",
"timestamp": [
254.52,
255.84
]
},
{
"text": " Yeah.",
"timestamp": [
255.84,
256.68
]
},
{
"text": " [\"Jingle Bells\"]",
"timestamp": [
256.68,
259.28
]
},
{
"text": " Do you like science?",
"timestamp": [
259.28,
260.12
]
},
{
"text": " Yeah, I do. Is that something",
"timestamp": [
260.12,
260.94
]
},
{
"text": " you think about?",
"timestamp": [
260.94,
261.78
]
},
{
"text": " What kind of science?",
"timestamp": [
261.78,
262.62
]
},
{
"text": " I like biology and computer science.",
"timestamp": [
262.62,
264.56
]
},
{
"text": " All right, you're in the wrong place.",
"timestamp": [
264.56,
266.08
]
},
{
"text": " We're not gonna be talking about biology, computer science.",
"timestamp": [
266.08,
268.64
]
},
{
"text": " So we wanna talk about the idea of dimensions.",
"timestamp": [
268.64,
271.4
]
},
{
"text": " Do you know what a dimension is?",
"timestamp": [
271.4,
272.44
]
},
{
"text": " How you define dimensions?",
"timestamp": [
272.44,
274.7
]
},
{
"text": " I guess, I don't know how to exactly define it,",
"timestamp": [
274.7,
277.88
]
},
{
"text": " but I know like the first four.",
"timestamp": [
277.88,
280.76
]
},
{
"text": " Right, you know the difference between like one dimension,",
"timestamp": [
280.76,
282.92
]
},
{
"text": " two dimensions, three dimensions, et cetera.",
"timestamp": [
282.92,
284.44
]
},
{
"text": " So let's do a little experiment here. So there's one dimension, I'll give that to you.",
"timestamp": [
284.44,
287.52
]
},
{
"text": " Now here's your task. I'm going to give you another dimension and I'm going to ask, hold those two",
"timestamp": [
287.52,
293.6
]
},
{
"text": " things at right angles to each other. It's easy to do. Yeah, there's no tricks here. I'm not trying",
"timestamp": [
294.16,
299.36
]
},
{
"text": " to fool you here. Okay, now this is gonna be slightly trickier. I'm going to give you this.",
"timestamp": [
299.36,
302.8
]
},
{
"text": " I want you to hold all three of them",
"timestamp": [
302.8,
305.74
]
},
{
"text": " at right angles to all the others at the same time.",
"timestamp": [
305.74,
308.64
]
},
{
"text": " There you go.",
"timestamp": [
312.22,
313.06
]
},
{
"text": " So what that's doing is when you had just two,",
"timestamp": [
313.06,
315.86
]
},
{
"text": " that was describing a two-dimensional plane, right?",
"timestamp": [
315.86,
318.46
]
},
{
"text": " Like the two things pick out a plane,",
"timestamp": [
318.46,
320.38
]
},
{
"text": " the three things pick out all three-dimensional space.",
"timestamp": [
320.38,
323.18
]
},
{
"text": " Now I'm gonna give you one more,",
"timestamp": [
323.18,
324.74
]
},
{
"text": " and I'm gonna ask you to hold that fourth one",
"timestamp": [
324.74,
327.14
]
},
{
"text": " So that it's at a right angle to all the other three at the same time",
"timestamp": [
327.32,
331.32
]
},
{
"text": " All right now I am",
"timestamp": [
335.72,
337.72
]
},
{
"text": " Right, you can't do it. So we just",
"timestamp": [
337.72,
339.72
]
},
{
"text": " Experimentally proved that space is three-dimensional",
"timestamp": [
340.32,
343.34
]
},
{
"text": " That's sort of what it means to be",
"timestamp": [
343.34,
345.16
]
},
{
"text": " Three-dimensional that there are three different directions you can move in and there's not four or five or six directions you can move in",
"timestamp": [
346,
352.64
]
},
{
"text": " Okay, there you go. Three-dimensional space, right? Mm-hmm. So have you thought about",
"timestamp": [
352.76,
357.36
]
},
{
"text": " Using coordinates in three dimensions. Yeah, I was actually doing SAT prep. There you go",
"timestamp": [
358.12,
364.56
]
},
{
"text": " Yeah, I was actually doing SAT prep. There you go.",
"timestamp": [
364,
365
]
},
{
"text": " It showed like the X, Y, and Z axis as well.",
"timestamp": [
365,
369
]
},
{
"text": " That's right. So that's exactly what these would be.",
"timestamp": [
369,
371
]
},
{
"text": " Have you heard that there are other coordinate systems other than X, Y, Z?",
"timestamp": [
371,
375
]
},
{
"text": " No.",
"timestamp": [
375,
376
]
},
{
"text": " But we could also say how far we are away from the center, just the distance,",
"timestamp": [
376,
381
]
},
{
"text": " and then the angle that our little line makes with, let's say, the x-axis.",
"timestamp": [
381,
386.08
]
},
{
"text": " Yeah.",
"timestamp": [
386.08,
386.58
]
},
{
"text": " So that's a different way of giving you two numbers and locating yourself, and we call those polar coordinates.",
"timestamp": [
386.58,
391.2
]
},
{
"text": " It's a different coordinate system. What we want to do as physicists is look for extra dimensions.",
"timestamp": [
391.2,
396
]
},
{
"text": " Can you imagine, can you think of any way that there could be extra dimensions?",
"timestamp": [
396,
399.28
]
},
{
"text": " Time?",
"timestamp": [
399.28,
399.78
]
},
{
"text": " Time. Yes, Einstein said that we can think of time as a fourth dimension, and that's a very fascinating thing that we could talk about all by itself.",
"timestamp": [
399.78,
407.34
]
},
{
"text": " But what about space? What about the solar system?",
"timestamp": [
407.34,
409.72
]
},
{
"text": " Like, if you wanted to tell me where a certain star was in the sky,",
"timestamp": [
409.72,
414.14
]
},
{
"text": " do you know what, how we do that?",
"timestamp": [
414.14,
416.4
]
},
{
"text": " I have no idea.",
"timestamp": [
416.4,
417.72
]
},
{
"text": " It's exactly the same thing as latitude and longitude,",
"timestamp": [
417.72,
421.06
]
},
{
"text": " but we put coordinates on the sky.",
"timestamp": [
421.06,
424.48
]
},
{
"text": " So astronomers call them right ascension and declination,",
"timestamp": [
424.48,
427.8
]
},
{
"text": " which are two terrible words.",
"timestamp": [
427.8,
429.56
]
},
{
"text": " But basically, you've seen on the globe",
"timestamp": [
429.56,
432.24
]
},
{
"text": " where you draw latitude and longitude, what it looks like.",
"timestamp": [
432.24,
434.96
]
},
{
"text": " Sort of the peels of an orange kind of thing, right?",
"timestamp": [
434.96,
437.6
]
},
{
"text": " So you can define something as well,",
"timestamp": [
437.6,
439.2
]
},
{
"text": " how high above a certain location on Earth it is,",
"timestamp": [
439.2,
442.6
]
},
{
"text": " but the Earth is rotating and revolving around the sun,",
"timestamp": [
442.6,
444.88
]
},
{
"text": " so we have to define separate celestial coordinates. So there's like mold how many dimensions would there be?",
"timestamp": [
444.88,
451.9
]
},
{
"text": " We don't know, you know",
"timestamp": [
452.62,
454.16
]
},
{
"text": " The optimistic view is that there are six but the thing is some of them might be really really really really really small",
"timestamp": [
454.16,
460.62
]
},
{
"text": " Like way too small for us to ever see. And some of them might be medium size",
"timestamp": [
460.62,
465.34
]
},
{
"text": " that hopefully we can see.",
"timestamp": [
465.34,
466.48
]
},
{
"text": " Oh, okay.",
"timestamp": [
466.48,
467.56
]
},
{
"text": " So since it's all theoretical,",
"timestamp": [
467.56,
469.24
]
},
{
"text": " like this could not be three dimensional.",
"timestamp": [
469.24,
472.04
]
},
{
"text": " Absolutely right.",
"timestamp": [
472.04,
472.86
]
},
{
"text": " And this is sort of the state of uncertainty",
"timestamp": [
472.86,
474.72
]
},
{
"text": " that physicists are stuck living in.",
"timestamp": [
474.72,
477.12
]
},
{
"text": " You know, honestly out there,",
"timestamp": [
477.12,
478.12
]
},
{
"text": " if you go out onto campus and talk to the physicists,",
"timestamp": [
478.12,
480.48
]
},
{
"text": " half of them will say probably extra dimensions exist",
"timestamp": [
480.48,
482.96
]
},
{
"text": " and half of them say, no, that's just nonsense. We really don't know.",
"timestamp": [
482.96,
486.16
]
},
{
"text": " Yeah.",
"timestamp": [
486.16,
486.66
]
},
{
"text": " Okay, after all this, someone comes up to you on the street and says, what's a dimension?",
"timestamp": [
486.66,
491.46
]
},
{
"text": " Oh man, I mean, I guess what I've learned today is just that there are not just three dimensions,",
"timestamp": [
492.48,
499.6
]
},
{
"text": " or at least we think. I mean, everything's theoretical. It's all just really kind of confusing.",
"timestamp": [
499.6,
504.96
]
},
{
"text": " That's right. And you know, if they're still bugging you, you can just like give them some",
"timestamp": [
505.68,
508.56
]
},
{
"text": " sticks and ask them to put them together and that would shut them up.",
"timestamp": [
508.56,
513.36
]
},
{
"text": " Yeah.",
"timestamp": [
513.36,
514.36
]
},
{
"text": " Where do you go to school and what do you study?",
"timestamp": [
514.36,
517.3
]
},
{
"text": " I'm going to be a sophomore at Pomona College and I study math and physics.",
"timestamp": [
517.3,
521.36
]
},
{
"text": " Oh, math and physics.",
"timestamp": [
521.36,
522.36
]
},
{
"text": " Okay, what kind of physicist do you want to be?",
"timestamp": [
522.36,
523.8
]
},
{
"text": " Do you know?",
"timestamp": [
523.8,
524.8
]
},
{
"text": " I really don't know. I like theory and experimental",
"timestamp": [
524.8,
527.44
]
},
{
"text": " So it's kind of tough for me to say usually if it's math and physics you end up as a theoretical physicist, right?",
"timestamp": [
527.44,
531.92
]
},
{
"text": " Yeah, experimental one. So our theme here today is dimensions",
"timestamp": [
531.92,
535.7
]
},
{
"text": " So this is great that you have some math backgrounds mathematicians think about dimensions in a different way. Yeah",
"timestamp": [
535.84,
541.28
]
},
{
"text": " So, how would you explain to your friends",
"timestamp": [
541.28,
545
]
},
{
"text": " who are not math and physics majors,",
"timestamp": [
545,
546.72
]
},
{
"text": " what is a dimension yourself?",
"timestamp": [
546.72,
548.28
]
},
{
"text": " My first intuitive thought is what are the coordinates?",
"timestamp": [
548.28,
551.6
]
},
{
"text": " So if we were looking at things,",
"timestamp": [
551.6,
553.56
]
},
{
"text": " if we're looking at a dot, or a line rather,",
"timestamp": [
553.56,
556.2
]
},
{
"text": " that's one dimensional because we can only measure it",
"timestamp": [
556.2,
558.04
]
},
{
"text": " one way, but then if we look at a square,",
"timestamp": [
558.04,
560.4
]
},
{
"text": " then we're increasing like that.",
"timestamp": [
560.4,
561.48
]
},
{
"text": " So it's all, basically what coordinates we can use",
"timestamp": [
561.48,
564.32
]
},
{
"text": " to measure something. That's exactly right. Then we're increasing like that. So it's like all basically the what coordinates we can use to",
"timestamp": [
564.32,
565
]
},
{
"text": " Measure something and that's exactly right. And so you've heard of space-time",
"timestamp": [
569.12,
569.16
]
},
{
"text": " Yeah being four-dimensional right now in some sense That's kind of trivial to you and me because of course you have space which is three-dimensional you have time which is one-dimensional",
"timestamp": [
572.54,
579
]
},
{
"text": " So space-time is four-dimensional, but it didn't turn out",
"timestamp": [
579.16,
583.12
]
},
{
"text": " It didn't occur to anyone that that was a sensible way to talk until really",
"timestamp": [
583.12,
587.82
]
},
{
"text": " relativity. This is the crucial thing, right, is that what Einstein realized is that",
"timestamp": [
587.96,
592.68
]
},
{
"text": " sure, there's both time and space, but how we divide",
"timestamp": [
593.48,
597.22
]
},
{
"text": " space-time into time and space can be different for different people and really there's a real sense in which",
"timestamp": [
597.8,
604.2
]
},
{
"text": " four-dimensional space-time is kind of a generalization of three-dimensional space and I think to really explain this we're gonna need a blackboard",
"timestamp": [
605.08,
612.44
]
},
{
"text": " Okay, let's bring one in",
"timestamp": [
612.44,
614.44
]
},
{
"text": " All right thing about relativity is that they really want you to think of space-time as one four-dimensional thing, right",
"timestamp": [
616.08,
623.34
]
},
{
"text": " It's kind of like space. It's not just three dimensions of space intime as one four-dimensional thing, right? It's kind of like space.",
"timestamp": [
623.34,
625.1
]
},
{
"text": " It's not just three dimensions of space",
"timestamp": [
625.1,
627
]
},
{
"text": " and one dimension of time.",
"timestamp": [
627,
628.1
]
},
{
"text": " Why, though?",
"timestamp": [
628.1,
629.1
]
},
{
"text": " Why? This is a very good question.",
"timestamp": [
629.1,
630.4
]
},
{
"text": " So, let's just start with space, right?",
"timestamp": [
630.4,
632.7
]
},
{
"text": " You know a little bit about space.",
"timestamp": [
632.7,
633.7
]
},
{
"text": " So, here's my simple-minded way of drawing space.",
"timestamp": [
633.7,
636.7
]
},
{
"text": " Two dimensions, because that's how many I can draw",
"timestamp": [
636.7,
638.5
]
},
{
"text": " on the blackboard, let's say, x and y.",
"timestamp": [
638.5,
640.4
]
},
{
"text": " And what is special about space?",
"timestamp": [
640.4,
642.1
]
},
{
"text": " There's many things, but one is that if I have, you know,",
"timestamp": [
642.1,
644.4
]
},
{
"text": " a curve or a path between two points",
"timestamp": [
644.4,
647.5
]
},
{
"text": " There's a distance that you can calculate right and the distance between those two points doesn't depend on your coordinates",
"timestamp": [
647.5,
654.9
]
},
{
"text": " It doesn't depend on whether you're in radial coordinates or Cartesian coordinates or whatever",
"timestamp": [
654.9,
658.68
]
},
{
"text": " I'm allowed to imagine a curve that does something like this",
"timestamp": [
658.68,
661.66
]
},
{
"text": " between those two points and if I were a",
"timestamp": [
662.22,
664.22
]
},
{
"text": " a curve that does something like this, between those two points, and if I were a person walking on that curve, I would have an odometer with me maybe, and I",
"timestamp": [
664.08,
669.36
]
},
{
"text": " would know, you would know, even without having done that, this path is",
"timestamp": [
669.36,
673.4
]
},
{
"text": " always going to be longer than that path. There's a formula. Pythagoras is the",
"timestamp": [
673.4,
677.16
]
},
{
"text": " error, it tells you what the shortest distance path is. That's the point, the",
"timestamp": [
677.16,
680.1
]
},
{
"text": " physicalness of what is real is the distance along a certain curve. So",
"timestamp": [
680.1,
683.56
]
},
{
"text": " spacetime is like that. That's why it is the distance along a certain curve. So space-time is like that.",
"timestamp": [
683.56,
685.28
]
},
{
"text": " That's why it is useful to think about space-time.",
"timestamp": [
685.28,
687.88
]
},
{
"text": " So let me draw space-time.",
"timestamp": [
687.88,
690.08
]
},
{
"text": " That's how we usually draw it.",
"timestamp": [
690.08,
691.28
]
},
{
"text": " I'll just say x, but all of space is condensed to this one direction.",
"timestamp": [
691.28,
695.92
]
},
{
"text": " And this is time.",
"timestamp": [
695.92,
697.44
]
},
{
"text": " OK?",
"timestamp": [
697.44,
698.24
]
},
{
"text": " So if you're a little person, you start at some event.",
"timestamp": [
698.24,
702.16
]
},
{
"text": " So you start, you're located somewhere in space, somewhere in the three coordinates of space, and whether you like it or not,",
"timestamp": [
702.16,
708.92
]
},
{
"text": " you're moving through space-time, just by getting older. Yeah, when people ask me,",
"timestamp": [
708.92,
713.08
]
},
{
"text": " can you travel through time? I say, yes, yesterday I traveled 24 hours into the",
"timestamp": [
713.08,
717.72
]
},
{
"text": " future and here I am, you know, a day later. So that's just this, okay? You're",
"timestamp": [
717.72,
722.68
]
},
{
"text": " moving through time, like it or not.",
"timestamp": [
722.68,
725.4
]
},
{
"text": " So what Einstein says is, look,",
"timestamp": [
725.4,
727.64
]
},
{
"text": " I can travel through space-time in different ways.",
"timestamp": [
727.64,
731
]
},
{
"text": " Like I could hop in a rocket ship",
"timestamp": [
731,
733.26
]
},
{
"text": " and fly out and then fly back.",
"timestamp": [
733.26,
735.92
]
},
{
"text": " And then I could meet you there.",
"timestamp": [
735.92,
736.76
]
},
{
"text": " So this is a different trajectory through space-time, right?",
"timestamp": [
736.76,
740.72
]
},
{
"text": " And it's almost exactly like the space story.",
"timestamp": [
740.72,
744.52
]
},
{
"text": " The space story says there's a distance",
"timestamp": [
744.52,
746.6
]
},
{
"text": " Distance is different along different curves",
"timestamp": [
747.28,
749.28
]
},
{
"text": " Einstein says there's something that measures the length of these curves and we call it the proper time",
"timestamp": [
749.92,
757.36
]
},
{
"text": " It is literally the time that you would read on your wristwatch",
"timestamp": [
757.48,
760.48
]
},
{
"text": " So it's kind of like our like fundamental time like our base time",
"timestamp": [
760.48,
763.48
]
},
{
"text": " Well kind of what Einstein wants to get across",
"timestamp": [
763.52,
766.3
]
},
{
"text": " is there's no such thing as fundamental.",
"timestamp": [
766.3,
767.96
]
},
{
"text": " Like, there's the universe's time, this big letter T",
"timestamp": [
767.96,
771.86
]
},
{
"text": " that might tell you how old the universe is,",
"timestamp": [
771.86,
773.9
]
},
{
"text": " but then every individual has a clock with them.",
"timestamp": [
773.9,
776.84
]
},
{
"text": " And they measure their own time depending",
"timestamp": [
776.84,
778.54
]
},
{
"text": " on how they're moving through the universe.",
"timestamp": [
778.54,
780.08
]
},
{
"text": " And the crucial difference is the time is not the same",
"timestamp": [
780.08,
784.24
]
},
{
"text": " for this person who stayed behind and sat in their chair and this person who zoomed out there.",
"timestamp": [
784.24,
788.56
]
},
{
"text": " Why is that that this one's shorter than?",
"timestamp": [
788.56,
790.16
]
},
{
"text": " There is what we call a metric on space-time.",
"timestamp": [
790.16,
793.2
]
},
{
"text": " And when we talk about Euclidean space versus a curved space versus a sphere or something, that's a different metric. Space-time has its own metric which says the following thing that the path between two events in space-time",
"timestamp": [
793.2,
805.92
]
},
{
"text": " That is a straight line will always be the longest time. I see. Okay. That's the difference. All right",
"timestamp": [
806.16,
813.04
]
},
{
"text": " So what when Einstein had this idea, oh gravity could be related to the curvature of space-time. He did some equations",
"timestamp": [
813.84,
821.08
]
},
{
"text": " Okay, so he got it. That's a long story. We'll put that aside",
"timestamp": [
821.12,
823.52
]
},
{
"text": " What he figured out was that rather than gravity living on top of space-time",
"timestamp": [
823.52,
827.72
]
},
{
"text": " It's a manifestation of the curvature of space-time",
"timestamp": [
827.84,
830.96
]
},
{
"text": " So when you have like the earth the Sun the moon they cause a gravitational field",
"timestamp": [
830.96,
835.72
]
},
{
"text": " They're actually warping the space-time around them. They're giving it a different geometry",
"timestamp": [
835.96,
840.24
]
},
{
"text": " Would it be if I had like a spring or not spring like a like a sheet and I dropped like a book in the",
"timestamp": [
840.24,
845.54
]
},
{
"text": " Sheet curves down. Yeah, exactly",
"timestamp": [
845.54,
847.54
]
},
{
"text": " If you if you had a sheet that was originally flat and you know",
"timestamp": [
847.54,
850.1
]
},
{
"text": " You send a marble on it would go in a straight line",
"timestamp": [
850.1,
852.46
]
},
{
"text": " But then if you put something on it, so it warps it that marble is now going to be deflected",
"timestamp": [
852.46,
856.9
]
},
{
"text": " I see Einstein says that gravity is just like that",
"timestamp": [
856.9,
859.06
]
},
{
"text": " I see but there are no straight lines because space-time itself is curved",
"timestamp": [
859.06,
862.46
]
},
{
"text": " So do you think if you had to explain relativity, what would you say?",
"timestamp": [
862.46,
865.92
]
},
{
"text": " I think I would go with the train paradox.",
"timestamp": [
865.92,
869.24
]
},
{
"text": " Let's say I'm stationary and someone's moving past me on the train.",
"timestamp": [
869.24,
871.94
]
},
{
"text": " They think they're stationary on the train.",
"timestamp": [
871.94,
873.8
]
},
{
"text": " They think that they're not accelerating.",
"timestamp": [
873.8,
875.6
]
},
{
"text": " But if they start walking through the train cars, then they are accelerating in their",
"timestamp": [
875.6,
879.12
]
},
{
"text": " frame.",
"timestamp": [
879.12,
880.12
]
},
{
"text": " But then from my outside frame, where I'm completely removed, I see they are accelerating.",
"timestamp": [
880.12,
885.08
]
},
{
"text": " So I guess that relativity is all about perspective,",
"timestamp": [
885.08,
887.78
]
},
{
"text": " I guess, in a way.",
"timestamp": [
887.78,
888.8
]
},
{
"text": " Yeah, that's right, and it goes exactly back",
"timestamp": [
888.8,
890.44
]
},
{
"text": " to what we drew on the board,",
"timestamp": [
890.44,
891.88
]
},
{
"text": " where how those two people in the train and on the ground",
"timestamp": [
891.88,
895.56
]
},
{
"text": " would divide space-time up differently to space and time.",
"timestamp": [
895.56,
899.36
]
},
{
"text": " That was pretty good.",
"timestamp": [
899.36,
900.2
]
},
{
"text": " I learned a lot.",
"timestamp": [
900.2,
901.04
]
},
{
"text": " It's a lot of fun stuff to talk about.",
"timestamp": [
901.04,
902.6
]
},
{
"text": " [\"The Fourth of July\"] So observational cosmology, so what would you look at? I don't know why. Yeah, it's a lot of fun stuff to talk about.",
"timestamp": [
902.6,
905.88
]
},
{
"text": " So observational cosmology, so like what do you look at?",
"timestamp": [
905.88,
909.34
]
},
{
"text": " So I work on two ground-based surveys in the optical, and we're basically trying to make",
"timestamp": [
909.34,
914.16
]
},
{
"text": " huge maps of the universe so that we can study dark energy.",
"timestamp": [
914.16,
917.02
]
},
{
"text": " I'm sure you've heard about extra dimensions a little bit.",
"timestamp": [
917.02,
920.12
]
},
{
"text": " I've heard it, yeah.",
"timestamp": [
920.12,
921.12
]
},
{
"text": " I'm thinking about the idea that there might be more than three dimensions of space.",
"timestamp": [
921.12,
925.52
]
},
{
"text": " What is your impression of theoretical physicists who think about things like extra dimensions",
"timestamp": [
925.52,
930.1
]
},
{
"text": " of space that they haven't ever seen?",
"timestamp": [
930.1,
932.58
]
},
{
"text": " I get a little scared because I think, how can you prove these theories?",
"timestamp": [
932.58,
937.84
]
},
{
"text": " One theory I've heard of, I don't know if this fits in with that, is bubble universes.",
"timestamp": [
937.84,
941.6
]
},
{
"text": " Is that an extra dimension?",
"timestamp": [
941.6,
943.84
]
},
{
"text": " Does that fit into that",
"timestamp": [
943.84,
945.1
]
},
{
"text": " or is that something?",
"timestamp": [
945.1,
946.3
]
},
{
"text": " It does. In fact, one way that different universes might sort of be created and be different",
"timestamp": [
946.3,
951.86
]
},
{
"text": " from each other is that different universes could have effectively different numbers of",
"timestamp": [
951.86,
956.54
]
},
{
"text": " dimensions. Like we have three dimensions around us, but there's people out there, aliens,",
"timestamp": [
956.54,
960.54
]
},
{
"text": " who could live in five dimensional universes.",
"timestamp": [
960.54,
962.78
]
},
{
"text": " And are each of those dimensions, are they governed by the same laws of physics?",
"timestamp": [
962.78,
966.6
]
},
{
"text": " Or is there like a separate Lagrangian for each universe?",
"timestamp": [
966.6,
970.52
]
},
{
"text": " Yeah.",
"timestamp": [
970.52,
970.88
]
},
{
"text": " How does that work?",
"timestamp": [
970.88,
971.88
]
},
{
"text": " We think that it would be, you know, all this is incredibly speculative and we don't know for sure.",
"timestamp": [
971.88,
976.48
]
},
{
"text": " But the idea is that there is some deep down underlying laws that are universal and the same,",
"timestamp": [
976.48,
981.48
]
},
{
"text": " but they show up differently.",
"timestamp": [
981.48,
982.96
]
},
{
"text": " So they appear different so the specific",
"timestamp": [
982.96,
985.06
]
},
{
"text": " Particles and forces and masses would be completely different in different parts of the multiverse",
"timestamp": [
985.56,
990.72
]
},
{
"text": " Okay",
"timestamp": [
991.36,
992.52
]
},
{
"text": " Why in the world would you think that there are extra dimensions right so you've heard of string theory I have so the string theory",
"timestamp": [
992.52,
998.76
]
},
{
"text": " Is basically a theory of quantum gravity mm-hmm so we have quantum mechanics right right? The theory of atoms and so forth and how those work.",
"timestamp": [
998.76,
1006.68
]
},
{
"text": " And then we have gravity.",
"timestamp": [
1006.68,
1008.12
]
},
{
"text": " And gravity doesn't seem to fit in.",
"timestamp": [
1008.12,
1011.28
]
},
{
"text": " It's the one force of nature that we can't really easily",
"timestamp": [
1011.28,
1014
]
},
{
"text": " fit into this quantum mechanical framework.",
"timestamp": [
1014,
1015.8
]
},
{
"text": " So string theory is one of the best ideas.",
"timestamp": [
1015.8,
1019.36
]
},
{
"text": " That's the good news.",
"timestamp": [
1019.36,
1020.24
]
},
{
"text": " The bad news is that it only seems to work",
"timestamp": [
1020.24,
1022.08
]
},
{
"text": " if spacetime is 10 dimensional.",
"timestamp": [
1022.08,
1024.48
]
},
{
"text": " So you would say, well, then it's wrong. It can't be right. Space-time is not 10-dimensional. Space-time is 4-dimensional.",
"timestamp": [
1024.48,
1029.32
]
},
{
"text": " We've observed that. But instead we say if space-time looks 4-dimensional to us, but string theory,",
"timestamp": [
1029.32,
1035.72
]
},
{
"text": " which might be the best theory we have of quantum gravity, says it must be 10-dimensional,",
"timestamp": [
1035.72,
1039.34
]
},
{
"text": " maybe we can hide those extra 6 dimensions somehow. So here is how we could get lucky.",
"timestamp": [
1039.52,
1044.88
]
},
{
"text": " We could imagine that there are extra dimensions of space that are curled up Maybe we could hide those extra six dimensions somehow. So here is how we could get lucky.",
"timestamp": [
1044.88,
1045.12
]
},
{
"text": " We could imagine that there are extra dimensions of space",
"timestamp": [
1045.12,
1047.38
]
},
{
"text": " that are curled up somehow,",
"timestamp": [
1047.38,
1049.32
]
},
{
"text": " that are so small that we can't see them.",
"timestamp": [
1049.32,
1050.86
]
},
{
"text": " This is actually an old idea.",
"timestamp": [
1050.86,
1052.24
]
},
{
"text": " It goes back to Kaluzza and Klein",
"timestamp": [
1052.24,
1054.12
]
},
{
"text": " right after general relativity was invented in 1915.",
"timestamp": [
1054.12,
1057.48
]
},
{
"text": " But there's a more recent idea",
"timestamp": [
1057.48,
1059.6
]
},
{
"text": " that says there could actually be",
"timestamp": [
1059.6,
1060.72
]
},
{
"text": " relatively large extra dimensions.",
"timestamp": [
1060.72,
1063.04
]
},
{
"text": " There could be extra dimensions that are actually that big,",
"timestamp": [
1063.04,
1065.44
]
},
{
"text": " like a millimeter across, that you would not have noticed.",
"timestamp": [
1065.44,
1068.28
]
},
{
"text": " But here's the new exciting idea.",
"timestamp": [
1068.28,
1070.5
]
},
{
"text": " So let's imagine, OK, this is a piece of paper.",
"timestamp": [
1070.5,
1074.08
]
},
{
"text": " But let's imagine this is our entire world.",
"timestamp": [
1074.08,
1077.48
]
},
{
"text": " So in other words, our real world is three dimensional.",
"timestamp": [
1077.48,
1080.36
]
},
{
"text": " But let's imagine that we're just idealizing it down",
"timestamp": [
1080.36,
1082.32
]
},
{
"text": " to two dimensions.",
"timestamp": [
1082.32,
1083.04
]
},
{
"text": " So we all live here.",
"timestamp": [
1083.04,
1083.96
]
},
{
"text": " You and I live here. But let's imagine that we're just idealizing it down to two dimensions. So we all live here you and I live here But let's imagine that we're embedded in this bigger space. So there are extra dimensions that are actually big",
"timestamp": [
1083.96,
1089.92
]
},
{
"text": " Okay, let's imagine that when I say we live on this three-dimensional world",
"timestamp": [
1090.16,
1093.7
]
},
{
"text": " What I mean is imagine that the particles that you and I are made of right the quarks the leptons the electrons and everything",
"timestamp": [
1093.7,
1099.84
]
},
{
"text": " all the forces we know about",
"timestamp": [
1100.16,
1102.16
]
},
{
"text": " Electromagnetism the weak nuclear force, the strong nuclear force,",
"timestamp": [
1102.92,
1105.5
]
},
{
"text": " imagine that they can't leave this surface.",
"timestamp": [
1105.5,
1108.5
]
},
{
"text": " This is what we call a brain. B-R-A-N-E.",
"timestamp": [
1108.5,
1112
]
},
{
"text": " Have you heard this word before?",
"timestamp": [
1112,
1113
]
},
{
"text": " I've heard, yes.",
"timestamp": [
1113,
1114
]
},
{
"text": " Do you know where it comes from?",
"timestamp": [
1114,
1115
]
},
{
"text": " No.",
"timestamp": [
1115,
1115.5
]
},
{
"text": " From membranes.",
"timestamp": [
1115.5,
1116.5
]
},
{
"text": " We have lines, one dimension.",
"timestamp": [
1116.5,
1118.5
]
},
{
"text": " We have two-dimensional surfaces.",
"timestamp": [
1118.5,
1120.5
]
},
{
"text": " So if you have a line that is a vibrating physical thing, you call it a string.",
"timestamp": [
1120.5,
1124
]
},
{
"text": " Right?",
"timestamp": [
1124,
1124.5
]
},
{
"text": " Right. If you have a two-dimensional surface that vibrates and is a physical thing, we call that a membrane.",
"timestamp": [
1124.5,
1129.08
]
},
{
"text": " Membrane theory goes back. It never was as popular as string theory, but it's been around for a while.",
"timestamp": [
1129.08,
1133.28
]
},
{
"text": " But if you have extra dimensions of space, then you can have three-dimensional vibrating things and four-dimensional vibrating things.",
"timestamp": [
1133.28,
1140.04
]
},
{
"text": " So how do these strings give rise to things like mass and charge and",
"timestamp": [
1140.04,
1146.04
]
},
{
"text": " Basically give us the properties of the particles we see well basically the strings are the particles that we see",
"timestamp": [
1147.04,
1153.08
]
},
{
"text": " It's exactly the same thing as we said you know for the straw if you look at it far away",
"timestamp": [
1153.08,
1156.24
]
},
{
"text": " It looks one-dimensional a little loop of string so a little one-dimensional circle that is vibrating",
"timestamp": [
1156.24,
1161.64
]
},
{
"text": " If you look at it from very very far away",
"timestamp": [
1161.64,
1163.36
]
},
{
"text": " It just looks like a particle so in theory, an electron is a little string.",
"timestamp": [
1163.36,
1167
]
},
{
"text": " A photon is a little string.",
"timestamp": [
1167,
1169
]
},
{
"text": " So is string theory part of what they call the grand unified theory?",
"timestamp": [
1169,
1173
]
},
{
"text": " Is it supposed to be the last thing that sort of unifies all the forces together?",
"timestamp": [
1173,
1179
]
},
{
"text": " Yeah, string theory is even better.",
"timestamp": [
1179,
1180
]
},
{
"text": " So the phrase grand unified theory was coined in the 1970s",
"timestamp": [
1180,
1184
]
},
{
"text": " for theories that",
"timestamp": [
1184,
1185.72
]
},
{
"text": " joined electricity and magnetism. So a good string theory is gravity plus a grand unified",
"timestamp": [
1185.72,
1191.8
]
},
{
"text": " theory. It's even better. It's the theory of everything. What would you tell a friend",
"timestamp": [
1191.8,
1196.32
]
},
{
"text": " of yours if they asked you what dimensions are, what extra dimensions are, what a brain",
"timestamp": [
1196.32,
1200.44
]
},
{
"text": " is?",
"timestamp": [
1200.44,
1201.56
]
},
{
"text": " So we have three spatial dimensions. A brain is sort of the next level.",
"timestamp": [
1201.56,
1206.92
]
},
{
"text": " So a brain is a higher dimensional object",
"timestamp": [
1206.92,
1209
]
},
{
"text": " that vibrates through space.",
"timestamp": [
1209,
1210.76
]
},
{
"text": " That's right, and we could live there.",
"timestamp": [
1210.76,
1212.12
]
},
{
"text": " The world we see around us, the three dimensions of space",
"timestamp": [
1212.12,
1214.56
]
},
{
"text": " around us, could reflect the fact",
"timestamp": [
1214.56,
1216.7
]
},
{
"text": " that we are somehow stuck on a three dimensional brain",
"timestamp": [
1216.7,
1219.8
]
},
{
"text": " trying to escape.",
"timestamp": [
1219.8,
1220.88
]
},
{
"text": " It was really cool to learn about strings and brains",
"timestamp": [
1220.88,
1223.56
]
},
{
"text": " and how looking at gravity on small",
"timestamp": [
1223.56,
1226.12
]
},
{
"text": " scales is actually connected to what I do in looking at gravity on these cosmological",
"timestamp": [
1226.12,
1230.76
]
},
{
"text": " scales and it's definitely something I'm going to think about in my research.",
"timestamp": [
1230.76,
1237.36
]
},
{
"text": " You're a string theorist, so tell us what kind of string theory you do, what it means",
"timestamp": [
1237.36,
1240.28
]
},
{
"text": " to be a string theorist.",
"timestamp": [
1240.28,
1241.46
]
},
{
"text": " One of the things that's key in the whole story of string theory is the piece of it that talks about quantum theories",
"timestamp": [
1241.46,
1247.8
]
},
{
"text": " of gravity.",
"timestamp": [
1247.8,
1248.76
]
},
{
"text": " So I'm very excited about what happens to space time,",
"timestamp": [
1248.76,
1251.4
]
},
{
"text": " what does it even mean at the quantum level.",
"timestamp": [
1251.4,
1253.52
]
},
{
"text": " Cool, so do you think a lot about extra dimensions",
"timestamp": [
1253.52,
1255.56
]
},
{
"text": " in your everyday life?",
"timestamp": [
1255.56,
1257
]
},
{
"text": " Yes, I do.",
"timestamp": [
1257,
1257.76
]
},
{
"text": " And so when you think about extra dimensions,",
"timestamp": [
1257.76,
1259.64
]
},
{
"text": " you put them together with brains and different fields",
"timestamp": [
1259.64,
1262.52
]
},
{
"text": " wrapping around the extra dimensions and so forth, right?",
"timestamp": [
1262.52,
1264.88
]
},
{
"text": " Yes. A lot of people, a lot of string theorists, they care a lot about all the different ways in which we could hide",
"timestamp": [
1264.88,
1270.16
]
},
{
"text": " the extra dimensions. As someone who cares about cosmology, I want to start asking",
"timestamp": [
1270.48,
1274.94
]
},
{
"text": " why are the extra dimensions small at all? How did that happen? Is this something you think about yourself?",
"timestamp": [
1274.96,
1280.96
]
},
{
"text": " Yes, well, ultimately we'd like to understand the observable universe.",
"timestamp": [
1280.96,
1286.64
]
},
{
"text": " If string theory turns out to be the thing that the universe cares about, we'd like to",
"timestamp": [
1286.64,
1290.48
]
},
{
"text": " know with all of these possibilities that are in string theory, how do we get the one",
"timestamp": [
1290.48,
1295.6
]
},
{
"text": " that looks like the world we live in?",
"timestamp": [
1295.6,
1298
]
},
{
"text": " The thing I want to talk about is this paper I wrote with Matt Johnson and Lisa Randall",
"timestamp": [
1298,
1301.76
]
},
{
"text": " where we realized there's another way to compactify extra dimensions",
"timestamp": [
1301.76,
1305.9
]
},
{
"text": " Spontaneously dynamically if you imagine starting with this big piece of paper you couldn't wrap up everything",
"timestamp": [
1306.42,
1312.6
]
},
{
"text": " But within some region of space you could make a tube okay, right and down there in the tube",
"timestamp": [
1312.7,
1317.84
]
},
{
"text": " It looks like you're a long thing that is compactified in one direction and infinitely extend in the other direction",
"timestamp": [
1317.84,
1323.84
]
},
{
"text": " So there's one less macroscopic dimension of space.",
"timestamp": [
1323.84,
1326.4
]
},
{
"text": " Hmm. Okay.",
"timestamp": [
1326.4,
1327.56
]
},
{
"text": " That sounds plausible to you?",
"timestamp": [
1327.56,
1329
]
},
{
"text": " It sounds like fun.",
"timestamp": [
1329,
1330.08
]
},
{
"text": " Uh, what I would immediately ask is whether the large dimensions come from in the first place.",
"timestamp": [
1330.08,
1336
]
},
{
"text": " Is that something you address or you just assume that large, all the dimensions are large as a starting point?",
"timestamp": [
1336,
1343.36
]
},
{
"text": " Yeah. So we certainly assume that they're all large as a starting point and it's worse than that.",
"timestamp": [
1343.36,
1347.08
]
},
{
"text": " So in our paper, we imagine you start in desitter space.",
"timestamp": [
1347.08,
1351.16
]
},
{
"text": " You start in a universe with no matter, no anything like that, just empty space,",
"timestamp": [
1351.38,
1356
]
},
{
"text": " but with an energy that is positive and all the dimensions are large.",
"timestamp": [
1356,
1359.3
]
},
{
"text": " But where did it come from?",
"timestamp": [
1359.4,
1360.9
]
},
{
"text": " It was always there.",
"timestamp": [
1360.9,
1362.4
]
},
{
"text": " Why?",
"timestamp": [
1362.4,
1363.4
]
},
{
"text": " Why not?",
"timestamp": [
1363.4,
1364.4
]
},
{
"text": " Okay.",
"timestamp": [
1364.4,
1365.72
]
},
{
"text": " Well, you know, I think that this is a good, again, this is...",
"timestamp": [
1365.72,
1368.32
]
},
{
"text": " You're replacing one prejudice with a different prejudice.",
"timestamp": [
1368.32,
1370.4
]
},
{
"text": " I would say that we shouldn't be prejudiced one way or the other.",
"timestamp": [
1370.4,
1373.52
]
},
{
"text": " Just a large, you know, 10 or 11 dimensions with a cosmological constant doesn't seem",
"timestamp": [
1373.52,
1379.88
]
},
{
"text": " like a fundamental starting point.",
"timestamp": [
1379.88,
1381.96
]
},
{
"text": " It sounds like there needs to be something to underlie that.",
"timestamp": [
1381.96,
1386.04
]
},
{
"text": " But it's a fun scenario.",
"timestamp": [
1386.04,
1387.36
]
},
{
"text": " Yeah, so let me tell you a little bit more",
"timestamp": [
1387.36,
1388.36
]
},
{
"text": " about the scenario.",
"timestamp": [
1388.36,
1389.2
]
},
{
"text": " So you know there are black holes, good, right?",
"timestamp": [
1389.2,
1391.88
]
},
{
"text": " I've heard of them.",
"timestamp": [
1391.88,
1392.72
]
},
{
"text": " There are black brains as well.",
"timestamp": [
1392.72,
1394.6
]
},
{
"text": " Indeed.",
"timestamp": [
1394.6,
1395.44
]
},
{
"text": " Why don't you explain to us what a black brain is?",
"timestamp": [
1395.44,
1397.2
]
},
{
"text": " Well, in some ways, it's very much like a black hole",
"timestamp": [
1397.2,
1400.96
]
},
{
"text": " in that you have far away from it,",
"timestamp": [
1400.96,
1403.12
]
},
{
"text": " you have these large, just flat dimensions.",
"timestamp": [
1403.12,
1406.92
]
},
{
"text": " As you move in, there's something in the interior.",
"timestamp": [
1406.92,
1410.12
]
},
{
"text": " It has itself higher dimensions,",
"timestamp": [
1410.12,
1411.88
]
},
{
"text": " and so because physicists love to joke,",
"timestamp": [
1411.88,
1414.24
]
},
{
"text": " they thought, well, it's like a membrane,",
"timestamp": [
1414.24,
1416.16
]
},
{
"text": " but it can have many different dimensions.",
"timestamp": [
1416.16,
1418.1
]
},
{
"text": " Let's use P to stand in for those number of dimensions,",
"timestamp": [
1418.1,
1421.4
]
},
{
"text": " and so they call them P-brains.",
"timestamp": [
1421.4,
1422.96
]
},
{
"text": " Yeah, I've been trying to explain that to lower levels,",
"timestamp": [
1422.96,
1425.4
]
},
{
"text": " and they always look at me like,",
"timestamp": [
1425.4,
1426.48
]
},
{
"text": " are you pulling my leg here a little bit,",
"timestamp": [
1426.48,
1428.26
]
},
{
"text": " or is this the real thing that they use?",
"timestamp": [
1428.26,
1429.64
]
},
{
"text": " Yes, it is the real thing they use.",
"timestamp": [
1429.64,
1431.08
]
},
{
"text": " We study these brains in the sitter space,",
"timestamp": [
1431.08,
1435
]
},
{
"text": " and so what we found is that there are black brain solutions",
"timestamp": [
1435,
1438.42
]
},
{
"text": " which, instead of having a singularity inside,",
"timestamp": [
1438.42,
1442.32
]
},
{
"text": " are non-singular and stable and compactified. Is this a familiar thing? I know things like this have been discussed. Yeah",
"timestamp": [
1442.32,
1448.5
]
},
{
"text": " Yeah",
"timestamp": [
1448.5,
1448.88
]
},
{
"text": " So a lot of the brains that are relevant for studying things to do with antidecidious spacetimes in various dimensions",
"timestamp": [
1448.88,
1454.78
]
},
{
"text": " Actually start out as these non-singular type brains and then you find in the core",
"timestamp": [
1455.18,
1459.68
]
},
{
"text": " There's actually an antidecidious spacetime. Right. Imagine that rather than going down to a point,",
"timestamp": [
1459.68,
1465.22
]
},
{
"text": " it just asymptotes to some fixed radius.",
"timestamp": [
1465.22,
1468.56
]
},
{
"text": " It continues infinitely far down.",
"timestamp": [
1468.56,
1470.24
]
},
{
"text": " But then you can ask, OK, what about the rest of the universe?",
"timestamp": [
1470.24,
1472.86
]
},
{
"text": " You have some sphere, some two dimensions compactified.",
"timestamp": [
1472.86,
1476.28
]
},
{
"text": " And the balance between the cosmological constant",
"timestamp": [
1476.28,
1479.66
]
},
{
"text": " and the electromagnetic field keeps it at a fixed distance.",
"timestamp": [
1479.66,
1483.4
]
},
{
"text": " But then the other dimensions, the transverse dimensions, don't need to be anti-de Sitter.",
"timestamp": [
1483.4,
1487.28
]
},
{
"text": " They can have either positive, zero, or negative cosmological constant. So you can basically get any sort of cosmological solution",
"timestamp": [
1487.28,
1493.6
]
},
{
"text": " times a compactified sphere.",
"timestamp": [
1493.84,
1495.68
]
},
{
"text": " Is it that these have the lowest action of all the things that could possibly, all the possible solutions?",
"timestamp": [
1495.68,
1500.44
]
},
{
"text": " I guess. I mean, maybe, maybe you think otherwise again, or maybe could change my mind.",
"timestamp": [
1500.44,
1503.8
]
},
{
"text": " I think that as long as it can happen, it will happen some of the time, right?",
"timestamp": [
1503.8,
1508
]
},
{
"text": " I mean, it's one of the things that could happen.",
"timestamp": [
1508,
1510
]
},
{
"text": " It's quantum, baby!",
"timestamp": [
1510,
1512
]
},
{
"text": " It's quantum, if it's allowed, it's going to happen.",
"timestamp": [
1512,
1515
]
},
{
"text": " I stole that from Keanu Reeves, I'm afraid.",
"timestamp": [
1515,
1517
]
},
{
"text": " Someone probably wrote it for you.",
"timestamp": [
1517,
1520
]
},
{
"text": " So it's possible that if you do have this starting point of an empty de Sitter",
"timestamp": [
1520,
1525.4
]
},
{
"text": " space with positive cosmological constants and fields lying around, you inevitably get",
"timestamp": [
1525.4,
1528.92
]
},
{
"text": " a multiverse. It just happens. It's just part of quantum nucleation to different things.",
"timestamp": [
1528.92,
1533.96
]
},
{
"text": " And then maybe you need to explain why we live in this universe rather than some other",
"timestamp": [
1533.96,
1537.46
]
},
{
"text": " one via the anthropic principle or something like that. So how does our kind of low-tech,",
"timestamp": [
1537.46,
1542.64
]
},
{
"text": " old-fashioned way of making new universes intersect with the kinds",
"timestamp": [
1542.64,
1545.8
]
},
{
"text": " of things you think about?",
"timestamp": [
1545.8,
1546.92
]
},
{
"text": " Well, it's interesting because there's",
"timestamp": [
1546.92,
1549.28
]
},
{
"text": " a lot of activity going on inspired by things",
"timestamp": [
1549.28,
1552.2
]
},
{
"text": " we learned from working in anti-de Sitter space,",
"timestamp": [
1552.2,
1554.92
]
},
{
"text": " where the cosmological constant has the wrong sign.",
"timestamp": [
1554.92,
1557.76
]
},
{
"text": " So you will find that there are a number of papers,",
"timestamp": [
1557.76,
1560.16
]
},
{
"text": " as many of which you've probably read.",
"timestamp": [
1560.16,
1561.7
]
},
{
"text": " Probably you've read more of them",
"timestamp": [
1561.7,
1563.08
]
},
{
"text": " than I have, which try then to take different kinds of brains,",
"timestamp": [
1563.08,
1568.14
]
},
{
"text": " these extended solutions,",
"timestamp": [
1568.14,
1569.72
]
},
{
"text": " and there are many different kinds doing different things.",
"timestamp": [
1569.72,
1571.86
]
},
{
"text": " We understand them well enough now",
"timestamp": [
1571.86,
1573.18
]
},
{
"text": " that we can put them together in various ways.",
"timestamp": [
1573.18,
1575.02
]
},
{
"text": " They intersect, they dissolve inside each other,",
"timestamp": [
1575.02,
1579.18
]
},
{
"text": " they wrap each other, they overlap.",
"timestamp": [
1579.18,
1581.46
]
},
{
"text": " And you do them in all sorts of different ways",
"timestamp": [
1581.46,
1584.66
]
},
{
"text": " and show that you can construct",
"timestamp": [
1584.66,
1587
]
},
{
"text": " four dimensional universes with a cosmological constant of your desire depending upon how",
"timestamp": [
1587,
1593.52
]
},
{
"text": " you did the construction.",
"timestamp": [
1593.52,
1595.64
]
},
{
"text": " Not everyone buys that.",
"timestamp": [
1595.64,
1596.84
]
},
{
"text": " Not everyone buys that.",
"timestamp": [
1596.84,
1597.84
]
},
{
"text": " There's a big discussion in the literature right now.",
"timestamp": [
1597.84,
1600.2
]
},
{
"text": " And if we put aside for a second the concerns of our colleagues in other parts of physics,",
"timestamp": [
1600.2,
1603.72
]
},
{
"text": " and it's just amongst us chickens, what do you think about the future of cosmology and",
"timestamp": [
1603.72,
1607.88
]
},
{
"text": " string theory and the dynamics of these extra dimensions?",
"timestamp": [
1607.88,
1610.2
]
},
{
"text": " I think it's going to get way more interesting than we're currently able to grapple with",
"timestamp": [
1610.2,
1615.56
]
},
{
"text": " right now, and I think there are hints of it.",
"timestamp": [
1615.56,
1617.32
]
},
{
"text": " There could be a description of the physics that might be our early universe that is like",
"timestamp": [
1617.32,
1622.66
]
},
{
"text": " that molecular description, and then from that emerges flat space-time",
"timestamp": [
1622.66,
1627.22
]
},
{
"text": " It's maybe four maybe some mechanism tells you it's four and not something else",
"timestamp": [
1627.22,
1630.42
]
},
{
"text": " I think that's where we're going if the viewers want to know more about how space-time can emerge from quantum mechanics",
"timestamp": [
1630.42,
1635.5
]
},
{
"text": " They could read the graphic novel you just wrote right? Yes",
"timestamp": [
1635.5,
1638.48
]
},
{
"text": " I wrote in geographic novel called the dialogues",
"timestamp": [
1638.48,
1640.82
]
},
{
"text": " conversations about the nature of the universe and I just wrote a book called Something Deeply Hidden about many worlds, quantum mechanics,",
"timestamp": [
1641.1,
1646.56
]
},
{
"text": " and how space-time can emerge from it.",
"timestamp": [
1646.56,
1648.52
]
},
{
"text": " Plenty of reading material for the audience out there.",
"timestamp": [
1648.52,
1650.6
]
},
{
"text": " Excellent.",
"timestamp": [
1650.6,
1651.6
]
},
{
"text": " So that was fun.",
"timestamp": [
1651.6,
1655.12
]
},
{
"text": " I hope that everyone did learn something.",
"timestamp": [
1655.12,
1656.68
]
},
{
"text": " I know that I did.",
"timestamp": [
1656.68,
1657.68
]
},
{
"text": " It was very nice to see how the idea of dimensions and space resonates in different ways with",
"timestamp": [
1657.68,
1663.28
]
},
{
"text": " different people, all the way up to talking to Clifford about the forefront of modern research.",
"timestamp": [
1663.28,
1667
]
},
{
"text": " I really do think that we're not done understanding how dimensions work.",
"timestamp": [
1667,
1671
]
},
{
"text": " There are three dimensions of space. Why that? Why not two? Why not 27?",
"timestamp": [
1671,
1676
]
},
{
"text": " I think that we really don't yet have the data or ideas to think about this,",
"timestamp": [
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},
{
"text": " but we're creeping up on it. I'm optimistic about progress in the near future.",
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},
{
"text": " about this, but we're creeping up on it. I'm optimistic about progress in the near future.",
"timestamp": [
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{
"text": " I'm a professor at the University of Waterloo.",
"timestamp": [
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{
"text": " And I'm a sleep scientist at UCSF.",
"timestamp": [
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{
"text": " Today I've been challenged to explain lasers.",
"timestamp": [
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{
"text": " To explain the topic of sleep at five different levels.",
"timestamp": [
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[
[
"Intro",
" Hi, I'm Sean Carroll. I'm a theoretical physicist here at the California Institute of Technology. I've been challenged to explain dimensions to five different levels. The idea of a dimension, sometimes in pop culture, is misunderstood. Like, there's an extra place you can go, a mystical dimension or something like that. To a physicist or a mathematician, a dimension is just the direction you can go in. Up, down, left, right, forward, backward. To you and me, we think there's three dimensions around us,"
],
[
"What is CRISPR",
" but then physicists start talking about extra dimensions. How can you hide them? You know, where might they be? I'm hopeful that we'll learn something at each level. We're gonna talk about some science. Do you like science? Yes, a lot. Oh, very good. You've come to the right place. So we're gonna think about physics. Have you heard the word physics before? Do you know what that is? Yeah, kind of. What's your idea what physics is? I'm not so sure. Okay, I just think of physics as, you know, the study of everything. What stuff is, what stuff does. So today we're gonna talk about space and in particular the idea of dimensions. Have you heard about dimensions? At the camp I'm in a 3D printing one. 3D printing, good. So I don't choose the size, all I have to do is the shape. But do you know what 3D means? It's three dimensional. Three dimensional, as opposed to what is ordinary printing? So, ordinary printing would be 2D."
],
[
"What is a genome",
" What do you say when something is one-dimensional? What's an example of something that's one-dimensional? Hmm, I think one-dimensional might be a circle, I guess, or maybe a line. A line is a perfect example because it's one thing that's straight, right? So here's some toys. We're going to build some dimensions, right? So what would you say about this? That's one-dimensional. Exactly. It's're gonna build some dimensions, right? So what would you say about this? That's one dimensional. Exactly. It's not really one dimensional, right? Everything has to be one or two dimensional before it's three dimensional. And how would you find yourself, like if someone said, where are you? Like could you use some words or ideas to say where you are on that line? I think I would be maybe there since I'm facing it. But here's what I want you to think about. If I say I'm at this point on the line, I could translate that into saying I'm at the three centimeter point. If I were here, I'd be at the four centimeter point, the five centimeter point, right? So every point, every location on our little line. Has its own unit. Has its own unit, its own unit has one number We need one number to tell you where we are. That's one dimension. That's what it means to be one-dimensional I only need to tell you one number to figure out where we are I'm like free dimensional You have to tell a lot because if it's like a sphere you kind of have start using points. There you go Exactly. We're gonna build a little Two-dimensional space you want to do it you want to do the honors here? Why don't you put those two lines together? If you make it Dimensional is this a corner exactly another way is if you have this space in between"
],
[
"CRISPR",
" Is an angle I think you should be in this chair and you should be explaining this to me. You're much better than this than I am. Yeah. So those are the dimensions. That's how we think about dimensions. Remember, we just needed one number to find ourselves on the line. We need two numbers to find ourselves on the plane. I think that would be an X or a Y axis. There you go. So do you think we could have more than three dimensions? 3D is the maximum of dimensions for shapes. Well as far as we know. This is why physicists think about things we don't know about. We're wondering whether it could be extra dimensions you've never seen that are tinier than atoms. So, okay, so what have you learned? What do you know about dimensions now? How do you think about dimensions in a slightly different way than you did before? So at least everything has a certain dimension. Yeah, do you think you'd be excited if physicists said that they found extra dimensions of space? That would be amazing, February. The news would be spreaded around the world rapidly. I think so, I think you're right. All right, Hank, we want you to keep up studying, learn a lot of math and physics, and help us discover new dimensions someday. Does that sound like a fun idea? Yeah. [\"Jingle Bells\"] Do you like science? Yeah, I do. Is that something you think about? What kind of science? I like biology and computer science. All right, you're in the wrong place. We're not gonna be talking about biology, computer science. So we wanna talk about the idea of dimensions. Do you know what a dimension is? How you define dimensions? I guess, I don't know how to exactly define it, but I know like the first four. Right, you know the difference between like one dimension, two dimensions, three dimensions, et cetera. So let's do a little experiment here. So there's one dimension, I'll give that to you."
],
[
"Ethics",
" Now here's your task. I'm going to give you another dimension and I'm going to ask, hold those two things at right angles to each other. It's easy to do. Yeah, there's no tricks here. I'm not trying to fool you here. Okay, now this is gonna be slightly trickier. I'm going to give you this. I want you to hold all three of them at right angles to all the others at the same time. There you go. So what that's doing is when you had just two, that was describing a two-dimensional plane, right? Like the two things pick out a plane, the three things pick out all three-dimensional space. Now I'm gonna give you one more, and I'm gonna ask you to hold that fourth one So that it's at a right angle to all the other three at the same time All right now I am Right, you can't do it. So we just Experimentally proved that space is three-dimensional That's sort of what it means to be Three-dimensional that there are three different directions you can move in and there's not four or five or six directions you can move in Okay, there you go. Three-dimensional space, right? Mm-hmm. So have you thought about Using coordinates in three dimensions. Yeah, I was actually doing SAT prep. There you go Yeah, I was actually doing SAT prep. There you go. It showed like the X, Y, and Z axis as well. That's right. So that's exactly what these would be. Have you heard that there are other coordinate systems other than X, Y, Z? No. But we could also say how far we are away from the center, just the distance, and then the angle that our little line makes with, let's say, the x-axis. Yeah. So that's a different way of giving you two numbers and locating yourself, and we call those polar coordinates. It's a different coordinate system. What we want to do as physicists is look for extra dimensions. Can you imagine, can you think of any way that there could be extra dimensions? Time? Time. Yes, Einstein said that we can think of time as a fourth dimension, and that's a very fascinating thing that we could talk about all by itself. But what about space? What about the solar system? Like, if you wanted to tell me where a certain star was in the sky, do you know what, how we do that? I have no idea. It's exactly the same thing as latitude and longitude, but we put coordinates on the sky. So astronomers call them right ascension and declination, which are two terrible words. But basically, you've seen on the globe where you draw latitude and longitude, what it looks like. Sort of the peels of an orange kind of thing, right?"
],
[
"Genetics",
" So you can define something as well, how high above a certain location on Earth it is, but the Earth is rotating and revolving around the sun, so we have to define separate celestial coordinates. So there's like mold how many dimensions would there be? We don't know, you know The optimistic view is that there are six but the thing is some of them might be really really really really really small Like way too small for us to ever see. And some of them might be medium size that hopefully we can see. Oh, okay. So since it's all theoretical, like this could not be three dimensional. Absolutely right. And this is sort of the state of uncertainty that physicists are stuck living in. You know, honestly out there, if you go out onto campus and talk to the physicists, half of them will say probably extra dimensions exist and half of them say, no, that's just nonsense. We really don't know. Yeah. Okay, after all this, someone comes up to you on the street and says, what's a dimension? Oh man, I mean, I guess what I've learned today is just that there are not just three dimensions, or at least we think. I mean, everything's theoretical. It's all just really kind of confusing. That's right. And you know, if they're still bugging you, you can just like give them some sticks and ask them to put them together and that would shut them up. Yeah. Where do you go to school and what do you study? I'm going to be a sophomore at Pomona College and I study math and physics. Oh, math and physics. Okay, what kind of physicist do you want to be? Do you know? I really don't know. I like theory and experimental So it's kind of tough for me to say usually if it's math and physics you end up as a theoretical physicist, right? Yeah, experimental one. So our theme here today is dimensions So this is great that you have some math backgrounds mathematicians think about dimensions in a different way. Yeah So, how would you explain to your friends who are not math and physics majors, what is a dimension yourself? My first intuitive thought is what are the coordinates? So if we were looking at things, if we're looking at a dot, or a line rather, that's one dimensional because we can only measure it one way, but then if we look at a square, then we're increasing like that. So it's all, basically what coordinates we can use to measure something. That's exactly right. Then we're increasing like that. So it's like all basically the what coordinates we can use to Measure something and that's exactly right. And so you've heard of space-time Yeah being four-dimensional right now in some sense That's kind of trivial to you and me because of course you have space which is three-dimensional you have time which is one-dimensional So space-time is four-dimensional, but it didn't turn out It didn't occur to anyone that that was a sensible way to talk until really"
],
[
"Jurassic Park",
" relativity. This is the crucial thing, right, is that what Einstein realized is that sure, there's both time and space, but how we divide space-time into time and space can be different for different people and really there's a real sense in which four-dimensional space-time is kind of a generalization of three-dimensional space and I think to really explain this we're gonna need a blackboard Okay, let's bring one in All right thing about relativity is that they really want you to think of space-time as one four-dimensional thing, right It's kind of like space. It's not just three dimensions of space intime as one four-dimensional thing, right? It's kind of like space. It's not just three dimensions of space and one dimension of time. Why, though? Why? This is a very good question. So, let's just start with space, right? You know a little bit about space. So, here's my simple-minded way of drawing space. Two dimensions, because that's how many I can draw on the blackboard, let's say, x and y. And what is special about space? There's many things, but one is that if I have, you know, a curve or a path between two points There's a distance that you can calculate right and the distance between those two points doesn't depend on your coordinates It doesn't depend on whether you're in radial coordinates or Cartesian coordinates or whatever I'm allowed to imagine a curve that does something like this between those two points and if I were a a curve that does something like this, between those two points, and if I were a person walking on that curve, I would have an odometer with me maybe, and I would know, you would know, even without having done that, this path is always going to be longer than that path. There's a formula. Pythagoras is the error, it tells you what the shortest distance path is. That's the point, the physicalness of what is real is the distance along a certain curve. So spacetime is like that. That's why it is the distance along a certain curve. So space-time is like that. That's why it is useful to think about space-time. So let me draw space-time. That's how we usually draw it. I'll just say x, but all of space is condensed to this one direction. And this is time. OK? So if you're a little person, you start at some event. So you start, you're located somewhere in space, somewhere in the three coordinates of space, and whether you like it or not,"
],
[
"Mutations",
" you're moving through space-time, just by getting older. Yeah, when people ask me, can you travel through time? I say, yes, yesterday I traveled 24 hours into the future and here I am, you know, a day later. So that's just this, okay? You're moving through time, like it or not. So what Einstein says is, look, I can travel through space-time in different ways. Like I could hop in a rocket ship and fly out and then fly back. And then I could meet you there. So this is a different trajectory through space-time, right? And it's almost exactly like the space story. The space story says there's a distance Distance is different along different curves Einstein says there's something that measures the length of these curves and we call it the proper time"
],
[
"Data",
" It is literally the time that you would read on your wristwatch So it's kind of like our like fundamental time like our base time Well kind of what Einstein wants to get across is there's no such thing as fundamental. Like, there's the universe's time, this big letter T that might tell you how old the universe is, but then every individual has a clock with them. And they measure their own time depending on how they're moving through the universe. And the crucial difference is the time is not the same for this person who stayed behind and sat in their chair and this person who zoomed out there. Why is that that this one's shorter than? There is what we call a metric on space-time. And when we talk about Euclidean space versus a curved space versus a sphere or something, that's a different metric. Space-time has its own metric which says the following thing that the path between two events in space-time"
],
[
"Ethical Issues",
" That is a straight line will always be the longest time. I see. Okay. That's the difference. All right So what when Einstein had this idea, oh gravity could be related to the curvature of space-time. He did some equations Okay, so he got it. That's a long story. We'll put that aside What he figured out was that rather than gravity living on top of space-time It's a manifestation of the curvature of space-time So when you have like the earth the Sun the moon they cause a gravitational field They're actually warping the space-time around them. They're giving it a different geometry Would it be if I had like a spring or not spring like a like a sheet and I dropped like a book in the Sheet curves down. Yeah, exactly If you if you had a sheet that was originally flat and you know You send a marble on it would go in a straight line But then if you put something on it, so it warps it that marble is now going to be deflected I see Einstein says that gravity is just like that I see but there are no straight lines because space-time itself is curved So do you think if you had to explain relativity, what would you say? I think I would go with the train paradox. Let's say I'm stationary and someone's moving past me on the train. They think they're stationary on the train. They think that they're not accelerating. But if they start walking through the train cars, then they are accelerating in their frame. But then from my outside frame, where I'm completely removed, I see they are accelerating. So I guess that relativity is all about perspective, I guess, in a way. Yeah, that's right, and it goes exactly back to what we drew on the board, where how those two people in the train and on the ground would divide space-time up differently to space and time. That was pretty good. I learned a lot. It's a lot of fun stuff to talk about. [\"The Fourth of July\"] So observational cosmology, so what would you look at? I don't know why. Yeah, it's a lot of fun stuff to talk about. So observational cosmology, so like what do you look at? So I work on two ground-based surveys in the optical, and we're basically trying to make huge maps of the universe so that we can study dark energy. I'm sure you've heard about extra dimensions a little bit. I've heard it, yeah. I'm thinking about the idea that there might be more than three dimensions of space. What is your impression of theoretical physicists who think about things like extra dimensions of space that they haven't ever seen? I get a little scared because I think, how can you prove these theories? One theory I've heard of, I don't know if this fits in with that, is bubble universes. Is that an extra dimension? Does that fit into that or is that something? It does. In fact, one way that different universes might sort of be created and be different from each other is that different universes could have effectively different numbers of dimensions. Like we have three dimensions around us, but there's people out there, aliens, who could live in five dimensional universes. And are each of those dimensions, are they governed by the same laws of physics? Or is there like a separate Lagrangian for each universe? Yeah. How does that work? We think that it would be, you know, all this is incredibly speculative and we don't know for sure. But the idea is that there is some deep down underlying laws that are universal and the same, but they show up differently. So they appear different so the specific Particles and forces and masses would be completely different in different parts of the multiverse Okay Why in the world would you think that there are extra dimensions right so you've heard of string theory I have so the string theory Is basically a theory of quantum gravity mm-hmm so we have quantum mechanics right right? The theory of atoms and so forth and how those work. And then we have gravity. And gravity doesn't seem to fit in. It's the one force of nature that we can't really easily"
]
] |
UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Virtual Reality Engineer Explains One Concept in 5 Levels of Difficulty | WIRED
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akveRNY6Ulw
| 952
| [{"end_time":23.0,"start_time":0.0,"title":"JOHN CARMACK"},{"end_time":364.0,"start_time":23.0,"titl(...TRUNCATED)
| [{"text":" I'm Donna Strickland. I'm a professor at the University of Waterloo. I study lasers and i(...TRUNCATED)
| [["JOHN CARMACK"," I'm Donna Strickland. I'm a professor at the University of Waterloo. I study lase(...TRUNCATED)
|
UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Blockchain Expert Explains One Concept in 5 Levels of Difficulty | WIRED
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hYip_Vuv8J0
| 1,070
| [{"end_time":225.0,"start_time":0.0,"title":"<Untitled Chapter 1>"},{"end_time":520.0,"start_time":2(...TRUNCATED)
| [{"text":" Hi, I'm Hilary Mason.","timestamp":[0.0,1.84]},{"text":" I'm a computer scientist,","time(...TRUNCATED)
| [["<Untitled Chapter 1>"," Hi, I'm Hilary Mason. I'm a computer scientist, and today I've been asked(...TRUNCATED)
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UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Musician Explains One Concept in 5 Levels of Difficulty ft. Jacob Collier & Herbie Hancock | WIRED
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eRkgK4jfi6M
| 941
| [{"end_time":16.0,"start_time":0.0,"title":"Intro"},{"end_time":64.0,"start_time":16.0,"title":"Leve(...TRUNCATED)
| [{"text":" My name is Eric Prather and I'm a sleep scientist at UCSF.","timestamp":[0.0,3.36]},{"tex(...TRUNCATED)
| [["Intro"," My name is Eric Prather and I'm a sleep scientist at UCSF. I study the causes and conseq(...TRUNCATED)
|
UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Quantum Computing Expert Explains One Concept in 5 Levels of Difficulty | WIRED
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OWJCfOvochA
| 1,167
| [{"end_time":138.0,"start_time":0.0,"title":"Intro"},{"end_time":377.0,"start_time":138.0,"title":"T(...TRUNCATED)
| [{"text":" Hi, my name's Talia Gershon, and I'm a scientist at IBM Research.","timestamp":[0.0,3.68](...TRUNCATED)
| [["Intro"," Hi, my name's Talia Gershon, and I'm a scientist at IBM Research. Today I've been challe(...TRUNCATED)
|
UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Physicist Explains Dimensions in 5 Levels of Difficulty | WIRED
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3KC32Vymo0Q
| 1,704
| [{"end_time":36.0,"start_time":0.0,"title":"Intro"},{"end_time":512.0,"start_time":36.0,"title":"Dim(...TRUNCATED)
| [{"text":"- Hi, I'm Sean Carroll.","timestamp":[0.14,1.32]},{"text":"- Hi, I'm Sean Carroll.","times(...TRUNCATED)
| [["Intro","- Hi, I'm Sean Carroll.I'm a theoretical physicisthere at the California\nInstitute of Te(...TRUNCATED)
|
UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Physicist Explains Lasers in 5 Levels of Difficulty | WIRED
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3eTogq7rknQ
| 1,477
| [{"end_time":1.0,"start_time":0.0,"title":"<Untitled Chapter 1>"},{"end_time":555.0,"start_time":1.0(...TRUNCATED)
| [{"text":"- I'm Donna Strickland.","timestamp":[0.51,1.55]},{"text":"- I'm Donna Strickland.","times(...TRUNCATED)
| [["<Untitled Chapter 1>","- I'm Donna Strickland."],["Donna Strickland, PhD","I'm a professor at the(...TRUNCATED)
|
UCftwRNsjfRo08xYE31tkiyw
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https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
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Scientist Explains Sleep in 5 Levels of Difficulty | WIRED
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OB61yG8WDyU
| 1,419
| [{"end_time":24.0,"start_time":0.0,"title":"Intro"},{"end_time":278.0,"start_time":24.0,"title":"Gir(...TRUNCATED)
| [{"text":"- My name's Aric Prather and\nI'm a sleep scientist at UCSF.","timestamp":[0.25,3.47]},{"t(...TRUNCATED)
| [["Intro","- My name's Aric Prather and\nI'm a sleep scientist at UCSF.I study the causes and\nconse(...TRUNCATED)
|
UCftwRNsjfRo08xYE31tkiyw
|
https://www.youtube.com/channel/UCftwRNsjfRo08xYE31tkiyw
|
Astrophysicist Explains Gravity in 5 Levels of Difficulty | WIRED
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QcUey-DVYjk
| 2,191
| [{"end_time":1.0,"start_time":0.0,"title":"<Untitled Chapter 1>"},{"end_time":324.0,"start_time":1.0(...TRUNCATED)
| [{"text":"- Hi, I'm Janna Levin,\nI'm an astrophysicist,","timestamp":[0.2,3.32]},{"text":"- Hi, I'm(...TRUNCATED)
| [["<Untitled Chapter 1>","- Hi, I'm Janna Levin,\nI'm an astrophysicist,"],["Janna Levin, PhD","and (...TRUNCATED)
|
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