back to indexPo-Shen Loh: Mathematics, Math Olympiad, Combinatorics & Contact Tracing | Lex Fridman Podcast #183
Chapters
0:0 Introduction
1:43 Planes and bridges
5:21 Writing a computer game from scratch
7:46 Programming competitions
11:21 Math is hard
16:52 Contact tracing that preserves privacy
54:9 Math Olympiad
69:49 Hard math problem
77:6 Is math discovered or invented?
82:2 Intelligence
88:52 Math education
93:3 How to learn math
101:58 Combinatorics
105:5 Voting trees
115:29 Stochastic coalescence
125:15 P=NP
129:32 Tolkien and WWII
131:52 Advice for young people
133:57 Meaning of life
00:00:00.000 |
The following is a conversation with Po Shen Lo, 00:00:02.720 |
a professor of mathematics at Carnegie Mellon University, 00:00:06.300 |
national coach of the USA International Math Olympia Team, 00:00:11.920 |
that does online education of basic math and science. 00:00:17.080 |
an app that takes a really interesting approach 00:00:23.120 |
and it gives you statistical information about COVID cases 00:00:34.240 |
In my opinion, we desperately needed solutions like this 00:00:49.680 |
need ideas that emphasize freedom and knowledge. 00:01:01.240 |
Check them out in the description to support this podcast. 00:01:14.120 |
I really enjoyed Po sharing his passion for math with me 00:01:20.000 |
in the coming months that are educational in nature, 00:01:31.280 |
books, martial arts, and other random things, 00:01:42.980 |
You know, you mentioned you really enjoy flying 00:01:46.540 |
and experiencing different people in different places. 00:01:51.200 |
I don't know if you have the same experience, 00:02:08.120 |
It's incredible that humans are able to get into a box 00:02:19.960 |
So when I observe them, it's quite fascinating 00:02:22.520 |
because I see that cleanly mapping to the world 00:02:25.920 |
where we're now in rockets and traveling to the moon, 00:02:30.920 |
traveling to Mars, and at the same kind of way, 00:02:43.600 |
when you fly, have the same kind of magical experience 00:02:46.440 |
of how the heck did humans actually accomplish this? 00:02:49.100 |
- So I do, especially when there's turbulence. 00:02:58.120 |
even the flight attendant had to hold on to the side. 00:03:06.680 |
But then I often think about it and I'm like, 00:03:14.440 |
And now we just take it completely for granted 00:03:23.220 |
- Yeah, again, I'm the same way with elevators, 00:03:39.160 |
like structurally just the earthquakes and the vibrations, 00:03:49.960 |
I mean, to me, one of the most beautiful things, 00:03:54.800 |
I used to build bridges in high school from like toothpicks, 00:03:57.600 |
just like out of the pure joy of like physics 00:04:05.840 |
Understanding like from a civil engineering perspective, 00:04:12.080 |
than another kind of structure, like suspension bridges. 00:04:26.520 |
It makes you realize how dependent we are on each other. 00:04:33.400 |
but there's a certain element in which we little ants 00:04:41.920 |
And then we're depending on a network of knowledge 00:04:51.160 |
has to do with the richness of that network of knowledge, 00:04:58.360 |
and then sort of the ability to build on top of it. 00:05:15.000 |
And eventually we'll have AI that runs all of us humans. 00:05:17.160 |
But anyway, but speaking of abstractions and programming, 00:05:21.320 |
in high school you wrote some impressive games for MS-DOS. 00:05:26.120 |
I got a chance to, in browser somehow, it's magic. 00:05:34.640 |
What's the hardest part about programming those games? 00:05:48.080 |
- That's a good starting point for anything, right? 00:05:59.960 |
but I actually also like seeing execution of an idea 00:06:03.800 |
all the way from beginning to end in something that works. 00:06:08.040 |
I was lucky enough to grow up in the late '90s 00:06:13.320 |
could hope to make something sort of comparable 00:06:18.720 |
I say the word sort of, like still quite far away, 00:06:21.280 |
but at least I didn't need to hire a 3D CG artist. 00:06:31.680 |
is it possible for me to try to do those things 00:06:38.440 |
to draw letters on the screen in a particular font. 00:06:58.320 |
almost building a computer graphics library from scratch? 00:07:03.120 |
was some code I copied off of a book in assembly 00:07:05.600 |
of how to put a pixel on a screen in a particular color. 00:07:14.440 |
but then the other ones were in C++ after that. 00:07:18.200 |
- How's the emulation in the browser work, by the way? 00:07:26.520 |
- Ah, so it's literally making an MS-DOS environment, 00:07:29.360 |
which is literally running the old .exe file. 00:07:33.960 |
That could be more amazing than the airplane. 00:07:41.400 |
can you build something really cool from scratch? 00:07:45.440 |
- And you did a bunch of programming competitions. 00:07:50.280 |
What was your interest, your love for programming? 00:07:59.680 |
has taken a long journey through mathematics. 00:08:11.560 |
of why it is that I saw some power in the computer. 00:08:25.560 |
then you could conceivably achieve more things. 00:08:35.880 |
Those contests were effectively write a function 00:08:42.480 |
then you can unlock more of the power of the computer. 00:08:47.440 |
There's a time element from the human perspective 00:08:54.880 |
So there's an almost like an athletics component 00:09:14.840 |
So it's not necessarily you have to type fast. 00:09:42.600 |
was understanding that the kinds of computations 00:09:47.120 |
we could conceivably do on like a four core cloud machine 00:09:57.880 |
to have that back of the envelope calculation 00:10:08.200 |
If you think about how you grow anything from small to big, 00:10:17.680 |
- And also the nice thing about programming competitions 00:10:22.360 |
is that you actually build a thing that works. 00:10:37.560 |
To have a system that successfully takes in inputs 00:10:40.600 |
and produces outputs and solves a difficult problem 00:10:43.400 |
and that directly transfers to building a startup, 00:10:46.560 |
essentially that can help some aspect of this world 00:10:50.040 |
as long as it's mostly based on software engineering. 00:10:56.760 |
That's why people like Elon Musk are so impressive 00:11:05.360 |
It's like you have to actually have factories 00:11:07.680 |
that build cars and there's a million components 00:11:16.200 |
But in software, one person can change the world, 00:11:29.680 |
- For me, I think I've always been very attracted 00:11:47.120 |
And with the mathematics, the math competitions 00:11:55.040 |
but for which I could conceivably try to learn 00:11:59.120 |
So, I mean, there are other things that are hard 00:12:00.480 |
called like get something to Mars, get people to Mars. 00:12:08.200 |
On the other hand, the math problems struck me 00:12:14.760 |
And maybe they would actually even be useful. 00:12:25.120 |
because a lot of people say that math is hard. 00:12:37.400 |
that all things that are worth having in this world, 00:12:46.440 |
whether it's sports, whether it's art, music, 00:12:52.760 |
it's going to be hard if you want to do something special. 00:12:56.560 |
So is there something you could say to that idea 00:13:03.880 |
- So I think maybe I want to dig in a little bit 00:13:14.800 |
that you didn't know how to start doing it before. 00:13:33.320 |
instead of somebody else spoon feeding you that technique. 00:13:45.440 |
just tell somebody, here's how you do something. 00:13:48.040 |
I actually prefer to say, here's an interesting question. 00:14:06.360 |
I'm trying to say a lot of people consider math to be hard 00:14:15.560 |
and I don't think of it as a memory hardness. 00:14:17.600 |
I think of it as a, can you invent something hardness? 00:14:24.360 |
how to do that art of invention in a pure cognitive way, 00:14:28.680 |
not as hard as the actual hardware stuff, right? 00:14:36.400 |
then suddenly, actually they might not even find math 00:14:45.440 |
I have the capability of looking at something 00:14:55.040 |
- So hard in the same way that invention is hard, 00:14:59.520 |
So maybe you can dig in that a little bit longer, 00:15:03.640 |
which is, do you see basically the way to teach math 00:15:08.640 |
is to present a problem and to give a person a chance 00:15:22.840 |
how do you build that muscle of invention in a student? 00:15:30.960 |
Actually, one of them is, in fact, this semester, 00:15:32.960 |
because all my classes were remotely delivered. 00:15:35.560 |
I even threw them all onto my YouTube channel. 00:15:37.200 |
So you can see how I teach at Carnegie Mellon. 00:15:39.960 |
But I'd often say, "Hey, everyone, let's try to do this. 00:15:44.680 |
And that actually changes my role as a professor 00:15:50.040 |
with a script of what I want to talk through. 00:15:55.680 |
there's something that we want to learn how to do, 00:16:00.120 |
I'm talking about the same method as improv comedy, 00:16:09.320 |
And then together, we're going to come up with a proof 00:16:11.880 |
of this concept where you were deeply involved 00:16:19.800 |
because it's based on how the students came up with it. 00:16:25.760 |
I also have another line of courses that we make 00:16:34.560 |
It was just, "Here's an interesting question. 00:16:39.400 |
And then automatic hints, we feed automatically hints 00:16:42.240 |
through the internet to go and let the person try to invent. 00:16:47.560 |
So that's like a more rigorous prodding of invention. 00:16:56.000 |
and you've been doing some very interesting stuff 00:16:58.160 |
from a mathematical, but also software engineering angle 00:17:13.840 |
under the flag of Novid and both the software 00:17:18.840 |
and the technical details of how the thing works? 00:17:34.560 |
So the idea was indeed that we stepped forward 00:17:50.760 |
And at that time, it started as a figment of an idea, 00:17:59.520 |
could potentially be combined with smartphones 00:18:02.480 |
and some kind of health information, anonymized. 00:18:11.400 |
we ended up accidentally discovering a new way 00:18:17.000 |
which is now what is the main impetus of all of this work, 00:18:41.800 |
If we describe how usually people control disease, 00:18:53.280 |
and you try to remove all of those people from society 00:19:05.520 |
because then the people you're trying to control 00:19:11.960 |
This is actually related to something you said earlier 00:19:14.240 |
about even like how skyscrapers stay in the air. 00:19:19.400 |
You actually want to, or even how an airplane stays, 00:19:27.080 |
And what we observed was that the feedback control loop 00:19:32.160 |
to be removed from society against their will 00:19:37.640 |
and you suddenly are trying to control 7 billion, 00:19:40.200 |
8 billion people in ways that they don't individually want 00:19:46.160 |
And this is inspired by the fact that at the core of our team 00:19:51.280 |
That's actually, in fact, the first thing I knew we needed 00:19:53.920 |
when we started was to bring user experience at the core. 00:20:07.040 |
You would want a way to be able to live your life 00:20:13.640 |
Can we make an app to help you avoid getting sick? 00:20:17.400 |
Notice how I've just articulated the problem. 00:20:21.840 |
so that after you are around somebody who's sick, 00:20:27.080 |
It's, can we make an app so that you can avoid getting sick? 00:20:32.360 |
I don't know if I want to call it positive or negative, 00:20:38.880 |
The only problem is that you don't know who's sick 00:20:44.160 |
if I see somebody who looks perfectly healthy, 00:20:47.000 |
the disease spreads two days before you have any symptoms. 00:21:02.440 |
tell everybody how many physical relationships 00:21:09.680 |
The trivial idea was the distance between you and a disease 00:21:22.040 |
like these six degrees of separation, like LinkedIn. 00:21:33.040 |
which for example, let me now jump to a non-COVID example 00:21:40.920 |
Imagine there was Ebola or some hemorrhagic fever. 00:21:44.080 |
Imagine it spread through contact, through the air, in fact. 00:21:54.680 |
And as you die, you're bleeding out of every orifice. 00:22:03.240 |
So the question is, suppose that such a disease broke, 00:22:06.560 |
who would want to install an app that would tell them 00:22:17.080 |
In fact, almost, I don't want to say almost everyone. 00:22:24.600 |
Like the more deadly and transmissible the disease, 00:22:28.400 |
the stronger the incentive to install it in a positive sense, 00:22:46.320 |
So it's sometimes muddled with how we think about it. 00:22:53.760 |
you want to create a system that has a set of incentives 00:23:01.000 |
and is contributing in a positive way to the system. 00:23:07.800 |
There was another person I talked to who pointed out 00:23:09.760 |
that it's very interesting that this feedback loop 00:23:12.840 |
is even more effective when the disease is worse. 00:23:20.680 |
If you're trying to help civilization keep running. 00:23:29.360 |
they dynamically figure out how bad the disease is. 00:23:39.680 |
like semantic information, natural language information, 00:23:43.480 |
is closely aligned with the reality of the disease, 00:23:51.040 |
how we sort of make sure there's not misinformation 00:23:55.000 |
But that aside, okay, so this is a really nice property. 00:24:00.920 |
actually just talking more about what that could do 00:24:04.480 |
it's that not only would people want to install it, 00:24:15.080 |
but they said as we saw it getting closer, we would hide. 00:24:21.840 |
But now you notice what this has just achieved. 00:24:34.880 |
And for the entirety of the past contact tracing approaches, 00:24:39.720 |
you tried to get set A to do things that might not be 00:24:55.760 |
attempt to remove themselves from this interface. 00:25:04.560 |
and suddenly B is in their incentive to do so. 00:25:09.000 |
So there's a virus that jumps from human to human. 00:25:18.440 |
It hops from person to person to person to person. 00:25:28.240 |
We have close friends and relations and so on. 00:25:45.200 |
But so can I be explicit about the kind of people 00:26:00.240 |
theoretic sense, there's some weights or something 00:26:08.840 |
the duration of visits and all of those kinds of things. 00:26:26.280 |
And the number of hops away it is on that network 00:26:46.320 |
and not whatever the opposite of authoritarian is. 00:27:01.960 |
to protect yourself against you getting the disease 00:27:12.040 |
But can you maybe elaborate, first of all, brilliant. 00:27:25.140 |
but it's also probably relevant for future diseases as well. 00:27:43.560 |
2020, the whole time I'm just sitting like this, 00:27:56.060 |
But in terms of institutions and all that kind of stuff, 00:28:09.400 |
Okay, mathematically, can you maybe elaborate 00:28:17.680 |
- Sure, first I'm gonna reply to something you said 00:28:29.600 |
to free market economy as opposed to central planning. 00:28:34.880 |
If you just line up the set of incentives correctly 00:28:38.120 |
so that people have in their purely selfish behavior 00:28:47.720 |
And the point of what we do, I guess, in mathematics 00:28:52.800 |
to go and find out as many possibilities as there are. 00:28:55.040 |
And in this case, it's an applied search space. 00:28:58.080 |
That's why the inputs from design, user experience design 00:29:02.720 |
But you asked about, I guess, the mathematical 00:29:14.760 |
And so in order to do that, what gave me the confidence 00:29:17.840 |
to, I guess, lead our team to run at the beginning 00:29:23.800 |
So technically what's going on is if two smartphones, 00:29:29.040 |
if two smartphones have this thing installed, 00:29:31.460 |
they just communicate with each other by Bluetooth 00:29:40.280 |
And then they can find out that these two phones 00:29:42.040 |
were approximately such and such distance apart. 00:29:44.880 |
And that kind of relative proximity information 00:29:50.640 |
- Okay, so the physical network is constructed 00:29:56.040 |
and you don't have to specify your exact location, 00:30:01.200 |
- I'm not using the Pythagorean theorem basically. 00:30:08.520 |
Distance formula, whatever you wanna call it. 00:30:13.720 |
- Yeah, so we're not doing the old Pythagorean 00:30:28.600 |
about physical connection to another human being? 00:30:37.400 |
That sounds like a really strong, like low hanging fruit. 00:30:46.880 |
is there extra information you can add on top of that? 00:30:53.520 |
- So first of all, we actually do estimate the duration, 00:31:00.440 |
in the sense that every so often, every few minutes, 00:31:14.440 |
However, fortunately, we're using probability. 00:31:20.120 |
is it's not super important if you run into that person 00:31:25.640 |
If that's a stranger that you run into 10 minutes 00:31:28.920 |
that's not going to be relevant for our paradigm 00:31:35.000 |
and might therefore have gotten infected by already. 00:31:40.200 |
We change from, I mean, the standard paradigm 00:31:42.360 |
was what already happened, quick damage control. 00:31:46.600 |
If you run into that person once in the grocery store today 00:31:57.960 |
at which point if you're scanning every five to eight minutes 00:32:03.240 |
it's going to come out as a strong relationship 00:32:05.400 |
and a person in the grocery store is going to wash out 00:32:15.880 |
So you said, one, there's the mathematical component 00:32:21.280 |
And then there's the user experience component. 00:32:26.080 |
just like you built the video game, "Alien Attack", 00:32:40.860 |
that just having an app doesn't make it useful 00:32:53.740 |
So that's again, why I said that the team is incredible. 00:32:58.840 |
let's just say that the technology that we use to make it 00:33:04.960 |
If you think about a standard iOS app or Android app, 00:33:08.660 |
those are a user interface that contacts a web server 00:33:37.180 |
at the very surface level provided on the phone? 00:33:40.660 |
- Well, I don't want to call them permissions. 00:33:43.260 |
that's not what you usually do with Bluetooth. 00:33:50.720 |
So I go and say, do I have headphones nearby? 00:33:53.140 |
Or do I have another phone nearby, which is doing something? 00:34:02.180 |
which actually a lot of people had tried unsuccessfully. 00:34:20.900 |
And so there was quite a lot of effort required 00:34:25.420 |
- So the whole point, this thing would run in the background 00:34:36.900 |
especially when it's eating up your battery, right? 00:34:42.260 |
So that one, we actually are very proud of the fact 00:34:47.780 |
Actually, even if compared to Apple's own system. 00:34:52.420 |
So what else is required to make this thing work? 00:35:12.300 |
you also need the servers to be able to compute fast enough, 00:35:17.340 |
computer programming competitions and math Olympiads. 00:35:20.020 |
In fact, our team that was working on the algorithm 00:35:25.440 |
who had been in these competitions from before, 00:35:33.340 |
And so we were able to bring people in to build servers, 00:35:40.100 |
so that we could support significant numbers of people 00:35:45.340 |
- Is there some distributed algorithms working here 00:35:47.980 |
or you basically have to keep in the same place 00:35:53.700 |
'Cause especially the more and more people use it, 00:35:58.240 |
I mean, this is very difficult scaling problem, right? 00:36:04.100 |
this computer algorithm competition stuff was handy. 00:36:15.140 |
So if you can make your algorithms linear time 00:36:17.500 |
or almost linear time, a computer operates in gigahertz. 00:36:22.300 |
I only need to do one run, one recalculation every hour 00:36:25.940 |
in terms of telling people how far away these dangers are. 00:36:42.020 |
there's N squared potential connections between people. 00:36:45.980 |
So how do you get around the fact that, you know, 00:36:51.380 |
that we, you know, the potential set of relationship 00:36:59.180 |
That's the potential amount of data you have to be storing 00:37:05.260 |
- So the way we dealt with that is we actually expect 00:37:10.820 |
The technical term sparse would mean that the average degree 00:37:14.820 |
or the average number of connections that a person has 00:37:17.580 |
is going to be at most like a hundred strong connections 00:37:22.500 |
If you think of it almost in terms of the heavy hitters, 00:37:27.580 |
if we just kept track of their top hundred interactions, 00:37:37.660 |
I'm saddened to think that I might not be even 00:37:41.980 |
- Oh, I was intentionally giving a crazy number 00:37:49.940 |
the people who are like the social butterflies. 00:37:52.940 |
- I need to, I'd love to know that information 00:37:56.260 |
about myself, by the way, that, do you expose the graph? 00:38:14.020 |
like how their connections are interconnected. 00:38:16.820 |
- But at the same time, we do expose also to everyone 00:38:24.260 |
Here's how many at distance two, meaning via people. 00:38:29.540 |
And the reason we do that is that actually ends up 00:38:42.700 |
that they are indirectly connected to hundreds 00:38:45.940 |
or thousands of other people, they get excited 00:38:52.860 |
especially looking at the screenshots people gave, 00:38:58.500 |
has two or three other direct connections on the system, 00:39:02.540 |
because that means that our app has reached a virality 00:39:07.620 |
The key is we were making a viral app to fight a virus 00:39:10.820 |
spreading on the same network that the virus spreads on. 00:39:21.340 |
What have you learned from this whole experience 00:39:28.740 |
is it possible to use the power information here 00:39:33.700 |
of networked information as the virus spreads 00:39:37.100 |
and travels in order to basically keep the society open? 00:39:41.340 |
Is it possible for people to protect themselves 00:39:53.580 |
- We are trying to answer that question right now. 00:39:59.220 |
that now the idea has started to become more widely known, 00:40:10.940 |
who is telling everybody, "This will definitely work." 00:40:13.620 |
But because of the potential power of this approach, 00:40:17.580 |
especially the potential power of this being an end game 00:40:21.060 |
for COVID, we have gotten the interest of real researchers. 00:40:26.060 |
And we're now working together to try to actually understand 00:40:34.020 |
"Here's why there's some hope that this would work." 00:40:36.660 |
And that's because I'm talking about end game now. 00:40:51.460 |
And now when we talk about the dynamic process that makes, 00:41:03.500 |
is because we know that many vaccine makers have said 00:41:06.540 |
they're preparing for the next dose next year. 00:41:11.700 |
where you just always need a new vaccine every year, 00:41:15.820 |
to make sure we have as many other techniques as possible 00:41:23.180 |
- Yeah, so actually, no matter how deadly the virus is, 00:41:29.700 |
it's still useful to be having this information. 00:41:32.780 |
- To stay home or not, depending on how risk, 00:41:50.100 |
- So I think that actually makes a lot of sense. 00:42:00.500 |
if there are some people who maybe are more risk tolerant 00:42:14.500 |
that this R naught of the infection spreading 00:42:33.700 |
with information somehow mapping to privacy violation. 00:42:38.300 |
But I, first of all, in the approach you're describing, 00:42:49.260 |
from the very beginning, from March and April of last year, 00:43:01.420 |
And not map based on sort of the exact location of people, 00:43:05.220 |
but where people usually hang out kind of thing. 00:43:07.620 |
And maybe not necessarily about actual location, 00:43:15.260 |
Like just to have information about what is good to do 00:43:27.780 |
I just feel like we're operating in the blind. 00:43:29.660 |
And then what you had is a very imperfect signal, 00:43:41.620 |
They have a bunch of smart scientists telling them stuff. 00:43:44.140 |
And the scientists themselves, also, very important, 00:43:49.620 |
Epidemiology is not, is as much an art as a science. 00:43:54.620 |
You're desperately trying to predict the future, 00:44:06.500 |
But then they think like, if I say I'm not sure, 00:44:14.100 |
and you say, I'm sure, it's going to lead to more distrust. 00:44:16.880 |
So there's this imperfect, like just chaotic, 00:44:25.340 |
And what you're proposing is just a huge amount 00:44:49.620 |
But speaking the umbrella idea of contact tracing, 00:44:58.820 |
why their approaches haven't been fully adopted? 00:45:03.220 |
Is there reasons why Novid might be a better idea 00:45:06.400 |
moving forward, in general, just about adoption? 00:45:10.700 |
I always have respect for the methods that other people use. 00:45:13.300 |
And so it's good to see that other people have been trying. 00:45:16.180 |
But what we have noticed is that the difference 00:45:23.900 |
delivered by everything that was made before, 00:45:26.500 |
is that, unfortunately, the action of installing 00:45:30.500 |
a standard contact tracing app will then tell you 00:45:34.500 |
after you have already been exposed to the disease, 00:45:37.740 |
so that you can protect other people from you. 00:45:40.660 |
And what that does to your own direct probability 00:45:47.120 |
should I or should I not install one of those apps? 00:45:50.040 |
What does that do to your own probability of getting sick? 00:46:00.020 |
Not sad, I suppose it's the way the world is. 00:46:03.340 |
The only incentive there is to just help other people, 00:46:09.700 |
is anything that allows you to help yourself. 00:46:19.860 |
I think it's based on, if you make a system of incentives 00:46:23.260 |
so that everybody trying to maximize their own situation 00:46:28.740 |
that's a game theoretic solution to a very hard problem. 00:46:31.780 |
And so this is actually basically mechanism design. 00:46:34.180 |
Like we've basically come up with a different mechanism, 00:46:40.920 |
Because actually, whenever we've been rolling it out, 00:46:45.220 |
like say in a university is, do you know what Novavax does? 00:46:48.140 |
And most of them have read about the other apps 00:46:51.900 |
after you've been around someone so you can quarantine. 00:46:55.380 |
actually, Novavax never wants to ask you to quarantine. 00:47:01.180 |
We just want to let you know if something is coming close 00:47:13.380 |
it's because you're shutting the door from the inside, 00:47:28.780 |
- I am actually still an academic and a researcher. 00:47:35.580 |
with other public health researchers at other universities 00:47:39.140 |
to actually work on pilot deployments together 00:47:46.060 |
And so for example, if anyone's watching this 00:47:47.820 |
and you happen to be a public health researcher 00:47:49.780 |
and you want to be involved in something like this, 00:47:52.380 |
I'm just gonna say, I'm still incentive thinking. 00:47:55.280 |
There is something in it for the researchers too. 00:47:57.380 |
This could open up an entire new way of controlling disease. 00:48:08.080 |
well, it could actually be good for their careers too. 00:48:14.420 |
- So you mean like from a research perspective, 00:48:20.300 |
about how to, from a sort of a network theory perspective, 00:48:25.300 |
understand how we control the spread of a pandemic. 00:48:31.740 |
is this is basically interdisciplinary research 00:48:33.780 |
where maybe our side is bringing the technology 00:48:46.860 |
in the Philippines as it is in the United States. 00:48:53.620 |
should not be trying to figure out how to do that. 00:48:55.340 |
But if we can work with the researchers who are based there, 00:48:57.900 |
now suddenly we might come up with a solution 00:49:42.800 |
I did not come to tell everyone to install the app 00:49:44.780 |
because it works best if your local health authority 00:49:51.060 |
It's because, this is back to the game theory. 00:50:01.480 |
that we have a massive outbreak on finals week. 00:50:10.280 |
But this idea is similar to what Google and Apple do, 00:50:14.880 |
is working with this, they can, for everyone who's positive, 00:50:17.960 |
give them a passcode that expires in a short time. 00:50:20.680 |
So for ours, if you're on the app and saying, "I'm positive," 00:50:23.600 |
you can either just say that, and that's called unverified, 00:50:28.360 |
that you got from the local health authority. 00:50:30.280 |
So basically, for anyone who's watching this, 00:50:32.420 |
it's not that you should just go and download it, 00:50:34.000 |
unless you wanna go and look at it, that's cool. 00:50:37.480 |
if you happen to know anyone at the local health authority 00:50:39.840 |
which is trying to figure out how to handle COVID, 00:50:42.600 |
well then, I mean, we'd be very happy to also work with you. 00:50:46.400 |
- Gotcha, so the verified there is really important, 00:50:54.560 |
in order to make sure that it's not possible to manipulate, 00:50:59.040 |
because it's ultimately about trust and information, 00:51:25.560 |
I think our response to the virus, economically speaking, 00:51:38.360 |
there's people who financially and psychologically 00:51:42.720 |
I'll say incompetent response to the virus across the world, 00:51:59.360 |
to these kinds of events much better in the future, 00:52:07.180 |
Let's step back to the beauty of mathematics. 00:52:16.000 |
which is, what do you find beautiful about mathematics? 00:52:19.740 |
- I think that being able to look at a complicated problem, 00:52:28.520 |
and then to be able to change the perspective 00:52:32.440 |
and suddenly see that there's a nice solution. 00:52:42.120 |
that cause difficult things to get simplified 00:52:44.600 |
and crystallized and factored in certain ways is beautiful. 00:52:48.560 |
Actually, that's related to what we were just talking about 00:52:57.560 |
by the number of relationships in the physical network, 00:53:20.000 |
and our relationships as kind of edges in that graph, 00:53:31.880 |
This is true for Twitter, social networks, and so on, 00:53:36.920 |
how we expand the kind of things we talk about, 00:53:42.200 |
if you have this little bubble, quote-unquote, 00:53:46.880 |
it's nice from a recommender system perspective, 00:53:53.600 |
YouTube was working on that, Twitter's working on that, 00:54:05.160 |
sociological perspective there, within those graphs. 00:54:08.540 |
But if we look at the cleanest formulation of that, 00:54:13.360 |
of looking at a problem from a different perspective, 00:54:27.640 |
but once you look at them differently, can become easy. 00:54:31.140 |
But that little jump of innovation is the entire trick. 00:54:38.560 |
can you say what is the International Mathematical Olympiad? 00:54:44.600 |
for people who aren't yet in college, math competition, 00:54:47.860 |
which is the most prestigious one in the entire world. 00:54:52.860 |
but only for people who aren't yet in college. 00:54:55.040 |
Now, the kinds of questions that they ask you to do 00:54:59.600 |
Usually you're not supposed to find that the answer is 42. 00:55:03.800 |
Instead, you're supposed to explain why something is true. 00:55:13.560 |
to solve three questions, and this is one day, 00:55:16.940 |
which is four and a half hours, three questions. 00:55:25.220 |
And by the way, even though there are six questions, 00:55:27.400 |
if you solve any one of them, you're a genius, 00:55:32.960 |
So what about, is it one person, is it a team? 00:55:35.360 |
- Ah, so it's each country can send six people, 00:55:38.760 |
and the score of the country is actually unofficial. 00:55:42.360 |
There's not an official country versus country system, 00:55:45.400 |
although everyone just adds up the point scores 00:55:53.420 |
I should say that there's a bunch of countries, 00:55:56.580 |
including the former Soviet Union and Russia, 00:56:03.500 |
most important competitions that the country participates in. 00:56:08.380 |
It was a source of pride for a lot of the country. 00:56:20.340 |
that Russia and the Soviet Union truly took pride in. 00:56:28.660 |
it was one of them for many years, is still one of them. 00:56:33.780 |
We don't think about it this way in the United States. 00:56:38.260 |
but it's not nearly as popular in the United States 00:56:42.420 |
in terms of its integration into the culture, 00:56:45.580 |
into just basic conversation, into the pride. 00:56:52.420 |
or if you won the Superbowl, you can walk around proud. 00:56:59.260 |
Not as much the case in the United States, I think. 00:57:13.540 |
there's people, this was a multi-year training process. 00:57:20.700 |
And this is everything that they're focused on. 00:57:29.340 |
And it's, I mean, it's as serious as Olympic sports. 00:57:34.540 |
like young athletes participating in gymnastics. 00:57:36.620 |
This is as serious as that, if not more serious. 00:57:38.940 |
So I just wanna give that a little bit of context 00:57:41.380 |
'cause we're talking about serious, high-level math, 00:57:46.380 |
- Yeah, and actually I also think that it made sense 00:57:51.420 |
Because if you look at what these people do eventually, 00:58:00.620 |
Even though they, I say, even though they won 00:58:07.820 |
in research mathematics or research other things. 00:58:10.580 |
And that's showing the generalization, generalizability 00:58:15.980 |
Because ultimately we're just playing with ideas 00:58:22.380 |
And if you get pretty good at inventing creative ways 00:58:29.020 |
observe neat ways to turn messy things into simple crystals. 00:58:34.020 |
Well, if you're gonna try to solve any real problem 00:58:36.180 |
in the real world, that could be a really handy tool too. 00:58:41.180 |
I think it clearly worked well for Soviet Union. 00:58:47.060 |
People sometimes ask me, you go up under communism, 00:58:58.140 |
because it's not, communism is one of those things 00:59:25.160 |
not even knowledge, it's wisdom and the skill of invention, 00:59:34.140 |
So we're not talking about a selection process 00:59:37.240 |
where you pick the best students in the school 00:59:51.640 |
could be the next Einstein, anybody could be the next, 00:59:56.880 |
And so you're forcing an education on the populace 01:00:16.960 |
because we don't want to leave anyone behind. 01:00:19.200 |
The Russian system was anyone can be the strongest student 01:00:25.040 |
and we're going to teach you the strongest student 01:00:26.880 |
and we're going to pretend or force everybody, 01:00:40.640 |
This is why people struggle when they go to MIT, 01:00:49.800 |
And that mathematics was certainly one of those things. 01:00:56.400 |
as opposed to kind of a spelling bee in the United States, 01:01:00.760 |
which I guess you spell, I'm horrible at this, 01:01:07.200 |
doesn't generalize well to the future skills. 01:01:10.020 |
Mathematics, especially this kind of mathematics, 01:01:13.320 |
is essentially formalized competition of invention, 01:01:31.960 |
that will come to do some incredible stuff in the future. 01:01:47.160 |
And that's actually why I spent some of my efforts 01:01:58.860 |
about training very hard for football or baseball, 01:02:01.940 |
or basketball, basketball is very, very accessible, 01:02:06.660 |
Well, actually, I think that what was going on 01:02:09.900 |
with the authoritarian thing was at least the message 01:02:13.540 |
that was universally sent was being a good thinker 01:02:23.380 |
- There's no reason why that message can't be sent. 01:02:29.740 |
The second thing is what you commented about, 01:02:35.720 |
and what could people do with Olympiads afterwards. 01:02:37.960 |
So that's actually my interest in the whole thing. 01:02:40.340 |
I don't just coach students how to do problems. 01:02:45.340 |
In fact, I'm not even the best person for that. 01:02:50.820 |
at making problems and teaching people how to solve problems. 01:02:53.300 |
In fact, when the Mathematical Association of America, 01:03:01.280 |
when they were deciding whether or not to put me in 01:03:06.900 |
I had a conversation with their executive director 01:03:19.840 |
with 60 very strong minds as picked through this system, 01:03:27.700 |
I said, I'm actually not going to define my success 01:03:33.100 |
I said, I wanted to maximize the number of the students 01:03:36.060 |
that I read about in the New York Times in 20 years. 01:04:05.480 |
I won't have the energy or the insight to solve problems. 01:04:10.500 |
And hopefully some of these people will step up and do it. 01:04:17.300 |
'cause that's such a great metric for education, 01:04:32.740 |
Do you think that's generalizable to education 01:04:39.100 |
Like even you saying this feels like a rare statement, 01:04:42.700 |
almost like a radical statement as a goal for education. 01:04:45.900 |
- So actually the way I teach my classes at Carnegie Mellon, 01:04:49.900 |
is not equivalent to the average in the world, 01:04:52.420 |
but it's already not just the top 60 in the country 01:04:58.980 |
I have exams in my class, which are 90% of the grade. 01:05:03.900 |
And the way that I let students prepare for the exams 01:05:06.620 |
is I show them all the problems I've ever given 01:05:10.380 |
And the exam that they will take is open notes. 01:05:14.820 |
And the guarantee is that the exam problems this time 01:05:20.980 |
as well as no overlap with anything I taught in the class. 01:05:32.140 |
when I teach you, I don't want you to have remembered 01:05:36.700 |
I want you to have learned enough about this area 01:05:53.860 |
And the first exam, usually people have a rough time 01:05:56.100 |
because it's like, what kind of crazy class is this? 01:05:58.420 |
The professor doesn't teach you anything for the exam. 01:06:05.300 |
they have learned how to solve anything in the area. 01:06:12.300 |
- Can we walk back to the Mathematical Olympiad? 01:06:20.860 |
- So the way it works is that each of the six students 01:06:37.220 |
And now the way that they're scored, by the way, 01:06:46.380 |
Okay, if you explain why, you get seven points. 01:06:48.740 |
If you make minor mistake, maybe you get six points. 01:07:07.620 |
It's not like the answer was 72 and you wrote 71 01:07:15.300 |
Oh, but that's pretty close because you were, 01:07:29.340 |
who helped me in the US delegation for coaches. 01:07:32.380 |
We actually debate with the country which is organizing it. 01:07:39.500 |
brings about 50 people to help judge the written solutions. 01:07:45.140 |
And you schedule these half hour appointments 01:07:52.340 |
opposite side is two or three people from the host country. 01:07:55.540 |
And they're just looking over these exam papers saying, 01:08:09.340 |
In fact, sometimes we go to this table and we will say, 01:08:16.260 |
If you give us too much, we say, no, you gave us too much. 01:08:19.700 |
However, the reason why this is an interesting process 01:08:26.740 |
And so if you're trying to grade the Mongolian scripts 01:08:31.020 |
if you don't read Mongolian, which most people don't, 01:08:47.140 |
you have a jury that where they're deliberating, 01:08:49.860 |
but unlike a jury, there's the members of the jury 01:09:01.660 |
'cause it's probably really, really competitive, 01:09:10.300 |
like how do you prevent manipulation here, right? 01:09:15.220 |
- Well, we just hope that it's not happening. 01:09:20.260 |
therefore everything that the US does, everyone can look at. 01:09:36.500 |
And although we do this for the six people who go 01:09:41.460 |
we really want that everyone touched at any stage 01:09:48.980 |
- So I don't know if you can say something insightful 01:09:54.820 |
makes a really hard math problem on this Olympiad, 01:09:58.660 |
maybe in the courses you teach or in general, 01:10:04.220 |
You've seen, I'm sure, a lot of really difficult problems. 01:10:08.620 |
- So I could quantify it by the number of leaps of insight, 01:10:12.940 |
of changes of perspective that are along the way. 01:10:16.460 |
This is like a very theoretical computer science 01:10:19.300 |
Okay, it's that each reframing of the problem 01:10:26.100 |
When you say, oh, wow, now I see I should kind 01:10:29.020 |
of put these plugs into those sockets, like so. 01:10:47.380 |
how many different possibilities you could try. 01:10:55.020 |
that is not three times as hard as a one insight problem, 01:10:59.900 |
it's not clear that that was the right track necessarily. 01:11:09.260 |
You're saying there's problems like on the math Olympia 01:11:27.220 |
and I found out I was very bad at reading math textbooks. 01:11:29.980 |
A math textbook has a long page of stuff that is all true, 01:11:47.860 |
So the way that I taught myself math eventually was, 01:11:51.380 |
the way I read a math textbook is I would look at 01:12:16.140 |
So when I'm doing my own way of solving the problem, 01:12:24.900 |
In a math contest, I look, is it problem one, two, or three? 01:12:39.780 |
somebody out there is gonna try to formally prove this. 01:12:44.180 |
There are cases where maybe it's not quite linear, 01:12:48.380 |
and some of it is style, and all those kinds of things, 01:12:53.900 |
- Yes, within the same book on the same subject. 01:12:58.780 |
- Because you know, if it's a two-page proof, 01:13:00.420 |
you just know this is gonna be insane, right? 01:13:27.020 |
you have no idea if this is going to go down a path 01:13:41.140 |
I have a lot of really good ideas every single day, 01:13:44.740 |
but like, and I'll go inside my head along them, 01:14:04.820 |
he spent seven years attacking the same thing, right? 01:14:19.500 |
and string them together, it feels really good. 01:14:35.660 |
and there's a sense like this might be the insight 01:14:38.980 |
So at least for me, I just enjoy that rush of positivity, 01:14:49.820 |
In fact, that's how I know whether I might want 01:14:54.340 |
It's like, if I still see that I'm getting some insights, 01:15:01.940 |
Actually, he was a real big inspiration on my life. 01:15:05.740 |
In fact, he grew up in the former Soviet Union. 01:15:08.100 |
He was from Georgia, but he's an incredible person. 01:15:12.260 |
But one thing I learned was choose the problems to work on 01:15:21.100 |
Because that's why, for example, we dug into COVID. 01:15:31.020 |
- Yeah, and I think COVID, the way you're approaching COVID 01:15:38.260 |
One, it might help with COVID or another pandemic. 01:15:41.740 |
But two, I mean, just this whole network theory space, 01:15:53.100 |
that might have nothing to do with the pandemic. 01:16:00.460 |
And the same thing is with Andrew Wiles' proof. 01:16:03.300 |
I don't understand, but apparently the pieces of it 01:16:18.300 |
might be really powerful for unexpected reasons. 01:16:23.820 |
This is something that I learned from another friend of mine 01:16:33.820 |
We were both grad students together at the same time. 01:16:39.940 |
You gotta find good people to learn things from. 01:16:44.340 |
if you solve a math problem and have this math proof, 01:16:50.300 |
He always asks, what have we learned from this 01:16:53.400 |
that we could potentially use for something else? 01:17:01.520 |
in the course of solving this that you had to invent 01:17:15.000 |
They'll prove something, it'll be a totally new result, 01:17:25.080 |
We did this offline in another illustration he showed to me. 01:17:30.220 |
It's interesting to see the different perspectives 01:17:35.560 |
It kind of points like there's just very few novel ideas, 01:17:43.280 |
are just looking at different perspective on the same idea. 01:17:47.200 |
And it makes you wonder this old silly question 01:17:53.840 |
do you think mathematics is discovered or invented? 01:18:09.180 |
or are we actually, is math almost like a shovel 01:18:13.440 |
where we're digging to this core set of truths 01:18:24.680 |
that I like to choose what questions to work on 01:18:27.360 |
are questions that maybe we'll get to learn something 01:18:49.320 |
into an intelligent other species in the universe, 01:18:58.880 |
between both of us realizing that pi is important. 01:19:03.560 |
Why humans, do humans like circles more than others? 01:19:19.880 |
will have, depending on different cognitive capabilities 01:19:30.320 |
And so if it's discovered, it will still be pointing 01:19:37.200 |
mathematical concepts, but it's interesting to think 01:19:42.280 |
of how many things we would have to still align, 01:19:45.680 |
not just based on notation, but based on understanding, 01:19:48.480 |
like just the, like some basic mathematical concepts, 01:20:01.680 |
I mean, his son helped with the movie "Arrival," 01:20:07.200 |
like how would aliens communicate with humans? 01:20:12.900 |
to be the most promising thing, but even like math, 01:20:15.880 |
like how do you visualize mathematical ideas? 01:20:20.880 |
It feels like there has to be an interactive component, 01:20:26.520 |
There has to be, this is something we don't, I think, 01:20:31.420 |
with somebody who doesn't know anything about math, 01:20:35.440 |
or any other natural language, how would we describe, 01:20:42.400 |
How would we, through visual proofs, have a conversation 01:20:50.160 |
the way we see it, does that make sense to you? 01:20:58.840 |
And then go back and forth in this kind of way. 01:21:01.440 |
So purely through mathematics, I'm sure it's possible 01:21:03.760 |
to have those kinds of experiments with like tribes 01:21:05.880 |
on earth that don't, there's no common language. 01:21:15.640 |
like the summation of the odds and adds up to the squares. 01:21:33.520 |
that the curiosity of like discovering math together 01:21:42.840 |
willing to commit violence in order to gain those resources. 01:21:47.920 |
become more and more intelligent as a species, 01:21:50.080 |
I'm hoping we would value more and more of the knowledge 01:21:54.880 |
to gain more resources so we won't be so resource starved. 01:21:59.000 |
That's a hopeful message for when we finally meet aliens. 01:22:02.080 |
- See, the cool thing about the math Olympiad, 01:22:07.100 |
I don't know if you know work from Francois Chollet 01:22:11.360 |
from Google, he came up with this kind of IQ test slash, 01:22:31.120 |
but very difficult for AI to illustrate exactly 01:22:34.340 |
why we're just not good at seeing a totally new problem. 01:22:39.080 |
We, sorry, AI systems are not good at looking 01:22:50.560 |
or there's a pattern that hasn't seen before. 01:22:58.760 |
but it's not so obvious to find that kind of, 01:23:22.140 |
What do you think is the thing that allows us 01:23:25.740 |
And how hard is it to build a machine to do that? 01:23:33.000 |
because if I just think of the raw search space, it's huge. 01:23:37.000 |
And if I think about what makes somebody good 01:23:38.960 |
at doing these things, they have this heuristic sense. 01:23:42.320 |
It's almost like a good chess player of saying, 01:23:53.000 |
Because that, if you asked them to explain to you, 01:24:14.020 |
So there's basically a function being computed. 01:24:16.900 |
But it's hard to articulate what that function is. 01:24:19.180 |
Now, the question is, could a computer get as good 01:24:21.740 |
at computing these kinds of heuristic functions? 01:24:27.860 |
but one bit of me has always been a little bit curious 01:24:30.320 |
of whether or not the human brain has a particular tendency 01:24:34.180 |
due to its wiring to come up with certain kinds of things, 01:24:39.520 |
that the topology of the neurons and whatever is there, 01:24:43.520 |
for which if you tried to just build from scratch 01:24:47.280 |
would it naturally have different tendencies? 01:24:53.640 |
- Well, this is a good thing that mathematics shows 01:25:01.840 |
that's different than our descendants of a brains operate in. 01:25:06.840 |
So it allows us to have multiple, many, many dimensions. 01:25:15.520 |
I would like topology as a discipline is just weird to me. 01:25:23.600 |
differential geometry and all those kinds of things 01:25:25.920 |
where it's totally outside of our natural day-to-day 01:25:40.080 |
we can discover the processes of intelligence 01:25:46.320 |
outside the limited nature of our own human experiences. 01:25:57.240 |
I find that we know so little about intelligence 01:26:02.240 |
that I think, I honestly think like almost children 01:26:06.800 |
are more expert at creating artificial intelligence systems 01:26:18.200 |
And those little, I found people should check out 01:26:27.080 |
I don't know if you've ever done this for yourself, 01:26:33.400 |
you kind of then trace back and try to figure out 01:26:47.340 |
Why did I start rotating that cube in my head in that way? 01:26:53.120 |
If I were to try to build a program that does that, 01:26:58.200 |
So I tried to do this to teach middle school students 01:27:02.760 |
how to learn how to create and think and invent. 01:27:14.120 |
and for the first time look at those questions 01:27:17.520 |
The reason I do this is to let the middle school students 01:27:23.480 |
just see what exactly goes on through someone's head 01:27:27.440 |
as they go and attempt to invent what they need to do 01:27:37.640 |
I think about that because whenever I want to explain 01:27:44.160 |
why it's intuitive to do the following things, 01:27:51.900 |
But why this is the right way, if that makes sense. 01:27:54.680 |
So my point is I'm actually always thinking about that. 01:27:57.280 |
Like, how would you think about these things? 01:27:58.960 |
And then I eventually decided the easiest way to expose this 01:28:01.800 |
would just be to go live on YouTube and just say, 01:28:05.200 |
I've never seen any of these questions before, here we go. 01:28:07.840 |
- Don't you get, that's anxiety inducing for me. 01:28:22.020 |
The live comments come in and students say, try this. 01:28:30.480 |
guess what, potion though can't do this, that's fine. 01:28:33.180 |
But then what ends up happening is you will then see 01:28:44.080 |
not all suggestions are the same power, if that makes sense. 01:28:53.340 |
but is there a moment for the middle school students, 01:29:04.400 |
where they maybe fall in love with mathematics 01:29:09.800 |
Is there something to be said about like discovering 01:29:16.400 |
to get them to understand that mathematics is, 01:29:23.120 |
- Yes, I actually do think that the middle school 01:29:26.840 |
because that's the place where your mathematical 01:29:37.680 |
I'm honestly not very good at teaching you new insights. 01:29:45.760 |
and when you know how to add and how to multiply 01:29:51.240 |
at that point to me, the whole world opens up 01:29:57.360 |
the things that made the Greek mathematicians 01:30:24.520 |
when the combinatorics shows up in the geometry. 01:30:29.360 |
Okay, so it's the combinatorics in the geometry. 01:30:33.080 |
So first of all, the nice thing about geometry, 01:30:35.240 |
this is the same nice thing about computer vision, 01:30:39.120 |
So geometry, you can draw circles and triangles and stuff. 01:30:42.720 |
So it naturally presents itself to the visual proof. 01:31:04.960 |
The idea of proofs I think is most easily shown in geometry 01:31:12.280 |
So that to me is like, if I were to think about 01:31:15.440 |
when I first fell in love with math, it would be geometry. 01:31:25.020 |
in the journey of a student and it kind of disappears 01:31:32.280 |
which there may be like differential geometry. 01:31:39.760 |
you could start to think about like computational geometry 01:31:49.300 |
But yeah, it was always, that was the most beautiful one. 01:31:53.000 |
Everything else, I guess calculus can be kind of visual too. 01:31:57.800 |
But is there something you try to look for in the student 01:32:05.360 |
to see like, how can I inspire them at this moment? 01:32:09.920 |
Or is this like individual student to student? 01:32:13.880 |
- So first of all, I really think that every student 01:32:23.680 |
actually oftentimes if I'm looking at a particular student, 01:32:39.600 |
So I think that the key is to show that they have some, 01:32:42.120 |
let them see that they have some power to invent. 01:32:45.960 |
by trying to give a question that they don't know how to do. 01:32:51.120 |
that they can think about and then they can solve. 01:32:54.480 |
And then suddenly they say, my gosh, I've had a situation. 01:32:57.800 |
I've had an experience where I didn't know what to do. 01:33:03.320 |
- Is there advice you can give on how to learn math 01:33:18.060 |
- I actually think that these math competition problems, 01:33:22.000 |
middle school and high school are really good. 01:33:25.040 |
So if you haven't had this kind of experience before 01:33:29.120 |
and you grab a middle school math competition problem 01:33:32.920 |
from the state level, which is used to decide 01:33:37.000 |
in the United States, for example, those are pretty tricky. 01:33:45.480 |
and you're not a middle school student, you'll struggle. 01:33:48.260 |
So I find that these things really do teach you things 01:33:53.080 |
- Is there a Googleable term that you can use 01:33:56.760 |
for the organization for the state competitions? 01:34:03.600 |
One of them is called Math Counts, M-A-T-H-C-O-U-N-T-S. 01:34:10.480 |
There's also a mathleague.org, mathleague.org, 01:34:15.360 |
also has this kind of tiered tournament structure. 01:34:18.660 |
There's also the American Math Competitions, AMC8. 01:34:22.600 |
AMC also has AMC10, that's for 10th grade and below, 01:34:27.240 |
These are all run by the Mathematical Association of America. 01:34:30.260 |
And these are all ways to find old questions. 01:34:32.880 |
- What about the daily challenges that you run? 01:34:36.820 |
But I mean, the difference was, that one's not free. 01:34:42.080 |
The things that I've just mentioned are also not free. 01:34:44.280 |
Not all of those things I mentioned just now are free either. 01:34:46.760 |
- People can figure out what is free and what's not. 01:34:48.760 |
But this is really nice to know what's out there. 01:34:51.040 |
But can you speak a little bit to the daily challenges? 01:34:58.480 |
how would I try to develop that skill in people 01:35:02.060 |
if we had the power to architect the entire system ourselves? 01:35:05.380 |
So that's called the daily challenge with Poch and Lo. 01:35:07.420 |
It's not free because that's actually how I pay 01:35:12.860 |
But the concept was, aha, now let's invent from scratch. 01:35:27.100 |
But it's like, I say, hey, here's an interesting question. 01:35:37.000 |
a big hint pops on the screen, and you still think. 01:35:41.260 |
hopefully you got some ideas, you try to answer. 01:35:43.700 |
And then suddenly there's this pretty extended explanation 01:35:47.300 |
of, oh yeah, so here's multiple different ways 01:35:51.580 |
And by accident, you also just learned this other concept. 01:35:56.340 |
- Is it targeted towards middle school students, 01:35:59.500 |
- It's targeted towards middle school students 01:36:01.340 |
with competitions, but there's a lot of high school students 01:36:12.760 |
You need to give people the chance to, on their own, 01:36:20.340 |
- And people can find it, I think, what, daily.-- 01:36:31.940 |
And so day to day, week to week, month to month, 01:36:36.260 |
year to year, what does the lifelong educational process 01:36:42.820 |
For yourself, but for me, what would you recommend 01:36:50.260 |
Or sort of as opposed to studying for a test, 01:36:52.620 |
but just like lifelong expanding of knowledge 01:37:13.660 |
And I will say it's great if one wants to build that 01:37:23.060 |
I just think, what do I know now that I didn't know 01:37:32.140 |
- And if you just have that attitude, it brings more. 01:37:38.260 |
like it is a skill, like I've been using Anki, 01:37:50.720 |
started doing this daily of setting aside time 01:37:54.980 |
to think about an idea that's outside of my work. 01:37:59.980 |
Let's say, it's all over the place, by the way, 01:38:07.160 |
Is it good to have a lot of guns or not in society? 01:38:15.020 |
I do at least 10 minutes, but I try to do 30, 01:38:19.000 |
And I kind of outline it for myself from scratch, 01:38:24.960 |
And I think the practice of that is really important. 01:38:44.140 |
So I'm kind of interested in, you know, math has, 01:38:49.140 |
because especially 'cause I've gotten specialized 01:39:03.900 |
Even just not math, like pure knowledge math, 01:39:13.320 |
Is that something you see a person be able to do 01:39:29.600 |
because I'm just thinking out loud right now. 01:39:33.740 |
Because what I have noticed is that, for example, 01:39:36.000 |
if you do have kids who are in elementary school 01:39:37.800 |
or middle school, if you yourself go and look 01:39:43.120 |
to think about interesting ways that you can teach 01:39:45.320 |
your elementary school or middle school kid, it works. 01:40:01.440 |
I'm always thinking, how do you make it practical, right? 01:40:03.880 |
And the way to make it practical is if the timer 01:40:06.240 |
on the automatically daily is that you are going 01:40:08.600 |
to automatically daily do something with your own kids. 01:40:14.800 |
that if you want to learn something, you should teach it. 01:40:27.080 |
But outside of that, I do want to integrate math 01:40:32.080 |
So I'll definitely check out the daily challenges 01:40:48.200 |
that they don't speak to the thing that I'm referring to, 01:40:56.320 |
They kind of show you the beauty of a particular problem 01:41:01.320 |
in mathematics, but they're not a daily ritual. 01:41:05.760 |
And I'm in search of that daily ritual mathematics. 01:41:16.880 |
'Cause I think math gives you a perspective on the world 01:41:23.120 |
- So I like what you said about the daily also, 01:41:40.880 |
who have been following it, who are not in my class at all, 01:41:49.880 |
you don't really need to know calculus to follow it, 01:41:52.720 |
So it's actually something that people could follow. 01:41:58.640 |
- Well, speaking of combinatorics, what is it? 01:42:03.800 |
What do you find beautiful about combinatorics? 01:42:07.240 |
- So combinatorics to me is the study of things 01:42:11.480 |
where they might be more finite and more discrete. 01:42:23.240 |
might be something related to graphs or networks. 01:42:25.960 |
And they're very discrete because if you have a node, 01:42:33.520 |
It's like you got one node and then you jump one step 01:42:37.440 |
So that notion is different from say calculus, 01:42:39.840 |
which is very continuous, where you go and say, 01:42:42.800 |
I have this speed, which is changing over time. 01:42:52.600 |
So the kinds of things that you do when you reason 01:42:59.320 |
often might be iterative, algorithmic, inductive. 01:43:03.240 |
These are ideas where I go from one step to the next step 01:43:08.160 |
I guess I actually personally like all kinds of math. 01:43:13.520 |
because I met a really interesting PhD advisor. 01:43:21.920 |
He seemed like he did good stuff, interesting stuff, 01:43:26.640 |
And I said, let me just go and learn whatever you do. 01:43:29.200 |
Even though my prior practice and preparation 01:43:40.560 |
and discrete stuff is it's often really difficult to solve 01:43:45.560 |
from a sort of running time complexity perspective. 01:44:00.640 |
Do you find it useful, do you find it interesting? 01:44:03.120 |
Do you find that lens of studying the difficulty 01:44:08.200 |
of how difficult the computer science problem 01:44:16.160 |
Because if you want to make something practical, 01:44:22.720 |
the computational complexity to me is almost question one. 01:44:29.040 |
of when we started doing this stuff with disease control. 01:44:35.360 |
would we be able to support a large population 01:44:45.340 |
- Yeah, and there the question is very much linear time 01:44:59.800 |
you have a bunch of really interesting papers. 01:45:01.360 |
If I could ask, maybe we could pull out some cool insights 01:45:05.240 |
Can you describe the data structure of a voting tree 01:45:22.240 |
that we just can't seem to understand enough about. 01:45:32.740 |
where if you have only two candidates, that's kind of easy. 01:45:38.600 |
But as you know, once you have more candidates, 01:45:40.680 |
it's very difficult to decide who wins the election. 01:45:43.120 |
And there's an entire voting theory around this. 01:46:01.800 |
because it's sort of like electrical engineering 01:46:05.680 |
You might imagine having a bunch of leads that carry signal, 01:46:09.260 |
which are going through AND gates and OR gates and whatnot, 01:46:11.600 |
and you've managed to compute beautiful things. 01:46:13.600 |
This is just from a purely abstract point of view. 01:46:23.440 |
Now can you build some kind of a circuit board, 01:46:28.000 |
will play against five and see who wins and so on. 01:46:35.800 |
could I make a big circuit board to feed an election into? 01:46:40.640 |
whoever wins at least is preferred over a lot of people. 01:46:45.200 |
So for example, if you ran in 1,024 candidates, 01:46:54.080 |
Actually, in any system where there are 1,024 candidates, 01:47:08.040 |
- I'm trying to make sense of that mathematical fact. 01:47:17.840 |
The way it works is that, think of it this way. 01:47:21.400 |
Every time, I think, imagine I have all these candidates 01:47:26.080 |
everyone is like compared with everyone else at some point. 01:47:30.640 |
Whenever there's a comparison, somebody gets a point. 01:47:34.240 |
That's the one who is better than the other one. 01:47:39.480 |
is at least half of how many other people there are. 01:47:44.880 |
like my intuition is very close to that being true, 01:48:00.560 |
you didn't give one point, but you gave two points. 01:48:07.080 |
We really want to give one point to the winner of the match, 01:48:12.280 |
If you gave two points to everyone on every matchup, 01:48:15.920 |
actually everyone has the same number of points. 01:48:24.400 |
- No, no, everything is same makes perfect sense. 01:48:26.200 |
- Okay, so the point is if for every comparison 01:48:29.480 |
between two people, which I'm doing for every two people, 01:48:40.240 |
For each matchup, you give one point only to the winner. 01:48:47.080 |
So now the deal is if in the original situation, 01:48:54.880 |
Now there's only half the number of points to go around. 01:48:57.640 |
So what ends up happening is that there's always going to be, 01:49:04.720 |
is going to be half of how many other people there are. 01:49:19.320 |
where you're at least as big as the expected value. 01:49:21.600 |
- Yeah, when you describe it like that, it's obvious. 01:49:23.720 |
But when you're first saying in this little circuit 01:49:26.680 |
that there's going to be one candidate better than half, 01:49:38.640 |
but ultimately you're trying to with a voting tree, 01:49:43.920 |
but to have a circuit that's like compact, that's small. 01:50:01.600 |
of running through, of computing the circuit. 01:50:28.680 |
and then the winners play against each other. 01:50:32.560 |
seven against eight, the winners play against each other. 01:50:34.680 |
You understand, it's like a giant binary tree. 01:50:36.440 |
- Yeah, it's a binary, like a balanced binary tree? 01:50:55.260 |
just the 10 that they need to beat on their way up, 01:51:04.760 |
My point is it is possible to outsmart that circuit 01:51:18.960 |
And you might have a system of inputs that go in there 01:51:24.800 |
which is the people they had to beat on their way up. 01:51:26.720 |
- So you want to have a circuit where there's as many, 01:51:29.720 |
like the final result is as strong as possible. 01:52:01.600 |
about what kind of circuit, what that looks like? 01:52:04.600 |
- I can give an idea of one of the tools inside. 01:52:08.360 |
- But the actual execution ends up being more complicated. 01:52:12.800 |
is building a system where you have like a candidate 01:52:16.960 |
who plays like one part of the whole huge, huge tree 01:52:20.720 |
is that that same candidate, let's call him seven. 01:52:29.320 |
Seven's also going to play against B separately. 01:52:33.720 |
And the winners of each of those will play each other. 01:52:39.680 |
And the winners are going to play each other. 01:52:41.080 |
And the winners are going to play each other. 01:52:45.000 |
Well, seven against like everyone from a bunch of- 01:52:48.560 |
So there's some nice overlap between the matchups. 01:52:56.520 |
at the base of this giant circuit, like this is a widget. 01:53:03.440 |
you have lots of things which are seven against someone, 01:53:05.640 |
seven against someone, seven against someone. 01:53:33.600 |
Well, F beat seven on the way at the beginning. 01:53:41.320 |
you know that the seven actually beat a bazillion people. 01:53:43.960 |
If you see anyone else, at least you know they beat seven. 01:53:47.040 |
- Yeah. Then you can prove that it has a nice property. 01:53:54.160 |
perhaps going completely outside of what we're talking about 01:54:09.080 |
- I mean, is there, like, do you ever see as, 01:54:11.720 |
as there be, do you see as there being a lot of opportunities 01:54:19.160 |
Like from your, I don't know if you saw parallels, 01:54:23.680 |
but, you know, it seems like if this actually kind of maps 01:54:34.280 |
similar kind of effects of how we decide other things 01:54:53.200 |
was based on this, is it called ranked choice 01:54:56.080 |
where you eliminate the bottom and the runoff elections? 01:55:09.720 |
- That's a whole nother, that's not a math solution. 01:55:12.720 |
That's a, well, it's math in the sense that it's game theory 01:55:28.000 |
- That's a whole nother conversation, I think. 01:55:33.240 |
talk a little bit about stochastic coalescence 01:55:40.760 |
but I guess it's a super linear, super logarithmic time 01:55:44.760 |
and you came up with some kind of trick that make it faster. 01:55:47.680 |
Just, can you just talk about it a little bit? 01:55:51.720 |
when I was at Microsoft Research for a summer 01:55:54.200 |
and I'm putting that context because that shows 01:55:56.720 |
that it has some practical motivation at some point. 01:56:03.720 |
- It doesn't need to, it can be beautiful and it's all right. 01:56:05.240 |
- Yeah, so the easiest way to describe this is, 01:56:13.320 |
And you wanna know how many total hours of sleep 01:56:18.840 |
that sounds like a linear time algorithm of saying, 01:56:26.120 |
- But there's a way to do this if you remember 01:56:27.680 |
that there are people and they presumably know how to add. 01:56:30.440 |
You could make a distributed algorithm to make this happen. 01:56:33.480 |
For example, while we're thinking of these trees, 01:56:38.640 |
If you could just say, hey, person number one 01:56:40.760 |
and person number two, you will add your hours of sleep. 01:56:46.120 |
and person number one is gonna remember the sum. 01:56:50.960 |
and person three takes charge of remembering it. 01:56:54.880 |
Now this like person one knows the sum of these two, 01:56:57.000 |
person three knows the sum of those two, they talk. 01:57:11.400 |
the amount of time it takes to get the total sum 01:57:14.600 |
is actually just the number of layers in the tree, 01:57:20.360 |
to add up the number of hours that people slept today. 01:57:30.560 |
- So if, for example, you just went out into downtown 01:57:32.680 |
and said, hey, get these thousand people, go. 01:57:35.960 |
and by the way, you're one and you're two and you're three, 01:57:40.520 |
So now the question is how to do this in a distributed way. 01:58:09.920 |
they will have delegated responsibility to themselves 01:58:31.360 |
- And at the very beginning, you're your own representative. 01:58:35.120 |
So at the beginning, you're your own representative. 01:58:38.040 |
- Yep, and the way this works is that at every time step, 01:58:41.560 |
someone blares a ding dong on the town clock or whatever. 01:58:45.840 |
And each person flips a coin themselves to decide, 01:58:48.720 |
am I going to hunt for somebody to give my number to 01:58:55.120 |
Or am I going to sit here and wait for someone to come? 01:59:02.640 |
Some of the people start asking other people saying, 01:59:04.840 |
hey, I would like you to be my representative. 01:59:10.240 |
But the problem is that there's limited bandwidth 01:59:13.280 |
It's like you can't go out to prom with five people. 01:59:22.640 |
by all these people, well, they'll have to decide 01:59:29.480 |
When they randomly choose one, all the others are rejected 01:59:31.920 |
and they don't get to delegate anything in that round. 01:59:34.960 |
But now if this person has absorbed this one who said, 01:59:48.920 |
In the next round, when they do the coin flipping, 01:59:56.160 |
It's that anyone who has the pointers themselves, 02:00:14.360 |
if you just keep doing this process, what ends up happening? 02:00:18.680 |
if you decide that you want to go reach out to other people, 02:00:27.400 |
you have no idea who in this crowd is an agent 02:00:30.760 |
or somebody who delegated it to someone else. 02:00:46.120 |
And you can do like path compression in the algorithm 02:00:49.120 |
to make it so you don't consistently do lots of walking up. 02:00:52.040 |
But the bottom line is that what ends up happening 02:00:57.280 |
Whenever you're one of the ones reaching out, 02:00:59.120 |
you can think of it as each agent is responsible 02:01:03.360 |
It's almost like they're the leader of a bunch. 02:01:15.720 |
where the probability of them hitting that lump 02:01:20.160 |
That is the one funny thing about this process. 02:01:42.800 |
you're hoping that this has a small number of steps. 02:01:45.440 |
But here's a bad situation that could happen. 02:01:52.040 |
Imagine that you have exactly square root of N lumps left 02:01:57.040 |
of which almost all of them are just one person 02:02:01.480 |
who's still their own boss, their own manager. 02:02:20.320 |
that you really are limited by this large one 02:02:42.120 |
was showing that that was a joint work with A.L. Lubezki. 02:02:45.120 |
That one was showing that actually in that thing, 02:02:50.920 |
And so it's not the purely logarithmic number of steps. 02:03:02.400 |
possibly relayed along by a couple of different people, 02:03:10.400 |
that actually does enough to even hold it up. 02:03:19.000 |
a little adjustment can make all the difference in the world. 02:03:28.440 |
these networking systems are so fascinating to study. 02:03:37.640 |
Like maybe as opposed to me voting for a president, 02:03:52.560 |
And then we naturally construct those kinds of networks 02:03:55.120 |
because that feels like I can have a good conversation 02:03:58.880 |
with you and figure out that you know what you're doing 02:04:01.800 |
And in that way, construct a representative government, 02:04:08.400 |
That feels really nice as opposed to like us, 02:04:19.560 |
for layers of representation to form organically 02:04:27.040 |
and the digital space where we're so well connected, 02:04:29.520 |
just like with the Novid app to distribute information 02:04:36.960 |
we can in the same way, in a distributed sense, 02:04:39.200 |
form anything like any kind of knowledge bases 02:05:02.560 |
This is where almost like network graph theory 02:05:11.800 |
but most of the application will be in the 21st, 02:05:28.080 |
who have very strong interest in trying to show that it is. 02:06:05.440 |
or gaps in our knowledge about computer science, 02:06:11.000 |
which allow us to think like flatten all problems. 02:06:14.760 |
- Yeah, so I don't know the answer to this question. 02:06:22.520 |
and being around the theoretical computer scientists, 02:06:24.880 |
I know enough about what I don't know to say. 02:06:28.840 |
- I'm the wrong person to answer this question. 02:06:33.240 |
- Well, Scott Aronson, who's now here at UT Austin, 02:06:37.800 |
puts the probability of P not equals to NP at 3%. 02:06:46.800 |
When you ask, it's very rare in science and academics, 02:07:02.800 |
like what are the chance that there's aliens in our galaxy, 02:07:17.680 |
There's something very pleasant about just having, 02:07:29.640 |
And then everything, this is the power of human psychology, 02:07:39.240 |
but because it's placed in a book with humor around it, 02:07:43.920 |
it has the meme effect of actually creating reality. 02:07:48.920 |
I mean, you could say that 42 has a strong contribution 02:07:57.720 |
it gave the whatever existential crisis to many of us, 02:08:09.880 |
and that humor is spreading through our minds, 02:08:12.320 |
and somehow this like silly number just had an effect. 02:08:15.160 |
In that same way, after Scott told me the 3% chance, 02:08:32.200 |
is actually motivating a large number of researchers 02:08:37.920 |
- Because for the potential impact that that might have. 02:08:46.480 |
I feel like humans are only able to really think 02:09:53.880 |
I don't necessarily have an exact name of these old things, 02:10:11.360 |
it could be possible for somebody who's crazy enough 02:10:16.360 |
to go up against adversity after adversity after adversity, 02:10:21.080 |
I mean, those are false, those are fictitious, 02:10:26.600 |
I was interested somehow in like World War II history, 02:10:32.360 |
but nevertheless, the idea of difficulty, strategy, 02:10:41.640 |
but just pushing on even when things are difficult. 02:10:44.520 |
I guess these are the kinds of general stories 02:10:47.760 |
that made me, I guess, want to work on things 02:10:55.600 |
It could be that you work on something for a year, 02:11:06.320 |
I've obviously been, don't shout about it recently, 02:11:10.720 |
especially on the Hitler side and the Stalin side. 02:11:13.280 |
Some of that has really affected my own family, 02:11:29.480 |
and you can truly have an impact on the world, 02:11:46.320 |
Sometimes we think we're just reacting to the world, 02:11:49.880 |
but we have the full power to actually change the world. 02:12:07.400 |
for college students, career or life in general? 02:12:14.680 |
and to make sure you're not just learning how to mimic, 02:12:23.160 |
and then repeating X many times with different inputs. 02:12:26.360 |
I've just been very generic in explaining this, 02:12:28.520 |
but I guess this is just my own attitude towards the world. 02:12:31.840 |
I didn't like ever following anyone's directions exactly. 02:12:34.960 |
Even if you told me this is the way to do your homework 02:12:45.680 |
but I do encourage that if you can learn how to invent 02:12:52.760 |
But then the second piece that comes with that 02:12:56.320 |
which was, "Well, make sure that what you're working on 02:13:01.280 |
And so in that sense, I usually advise to people 02:13:10.480 |
Try to see if you can aim for something which is hard, 02:13:15.760 |
which might be important, which might make a difference. 02:13:19.000 |
And it's more of, I guess, rather than worrying, 02:13:25.800 |
There's also the regret of, what if I didn't try? 02:13:31.560 |
I don't operate based on, did I succeed or fail? 02:13:34.600 |
If I did this novid thing and the whole thing failed, 02:13:39.440 |
But would I have had the regret of not jumping in? 02:13:45.520 |
don't worry about the failing part as much of the, 02:13:50.720 |
at those potentially unbounded opportunities. 02:13:55.160 |
- You almost make it sound like there's a meaning to it all. 02:14:13.440 |
- See the pen and pencil discussion from earlier, yes. 02:14:16.840 |
So, I mean, my thing is, I guess I personally 02:14:33.880 |
And it didn't matter if it's necessarily attributed to me. 02:14:41.760 |
I guess that is very inspired by how scientists work. 02:14:45.560 |
It's like, why do we keep talking about Newton? 02:14:47.720 |
It's because Newton discovered some interesting things. 02:14:56.240 |
- Well, let's hope it's infinity, but pretty high. 02:15:05.440 |
You're going for, so like Newton is like four digits, 02:15:08.880 |
probably like a thousand years or a person lifetimes. 02:15:13.160 |
Like, how do you like to think about, what are we? 02:15:19.920 |
His is like going to be billions or trillions, right? 02:15:30.040 |
I found some simple way to solve quadratic equations 02:15:40.720 |
into the number of hours in the lifetimes as well. 02:15:56.040 |
for like 10 years of their life, that would count as 10. 02:16:02.480 |
- So if there was one person who for 10 years 02:16:06.200 |
that counts as a score of 10 and we add up overall people. 02:16:13.480 |
that the score would be very finite in the sense that 02:16:19.040 |
that might potentially help a lot of generations 02:16:21.360 |
in a forever way, then your score will be finite 02:16:35.000 |
that that actually might make it into textbooks. 02:16:39.080 |
the chance that there'll be an easier way discovered 02:16:42.680 |
So in that case, then the score might get bigger. 02:16:47.760 |
already have been achieved in a non-trivial way. 02:16:52.920 |
- It's fun to think about, 'cause it could be different. 02:16:54.600 |
You can achieve a high score by a small number of people 02:17:05.960 |
if we do spread, colonize, become multi-planetary species, 02:17:28.280 |
the kids of kids will use it, it will spread, 02:17:30.080 |
and you'll have that impact in that kind of way. 02:17:34.920 |
because I was like, well, that's kind of dumb, 02:17:39.880 |
But so what I meant is I didn't want to count that 02:17:47.880 |
with some kind of device that everyone would want to use, 02:17:51.520 |
'cause coffee seems to be the prevalent performance 02:17:57.160 |
So I'll have to think about those kinds of metrics. 02:18:02.560 |
of I guess what I found meaningful in general, 02:18:06.200 |
whether or not that quadratic thing is important or not. 02:18:13.520 |
That's just how I choose what problems to work on. 02:18:17.240 |
is ideas that you've invented living on long after you 02:18:27.200 |
are like meat vehicles that carry ideas for brief, 02:18:32.200 |
for just a few years, may not be the important thing. 02:18:38.760 |
Like we get a bunch of baby ideas in our head. 02:18:45.080 |
and then you one might have a life of its own. 02:18:51.200 |
for many centuries to come, unless we destroy ourselves. 02:18:54.960 |
But maybe AI will borrow it and we'll remember Poe 02:19:15.240 |
So it's truly an honor that you would talk with me today. 02:19:18.520 |
It means especially a lot that you would travel out 02:19:33.820 |
It's actually a real honor for me to talk to you 02:19:51.400 |
Check them out in the description to support this podcast. 02:19:54.480 |
And now let me leave you with some words from Isaac Newton. 02:19:58.320 |
I can calculate the motion of heavenly bodies,