back to indexWas This Man Responsible For Inventing The Computer?
Chapters
0:0 Cal's intro
1:0 Sam Harris and quitting Twitter
3:35 Who is responsible for invention of computer
4:35 Alan Turing
5:45 The Turing Machine
10:20 The Imitation Game
10:50 Claude Shannon
00:00:00.000 |
So the topic I want to discuss might seem unusual at first, but there is a backstory here. 00:00:17.960 |
I was a guest on Sam Harris's podcast making sense. 00:00:23.480 |
I don't know if you've heard that one yet, Jesse. 00:00:25.320 |
Uh, but it's an episode that's creating quite a stir. 00:00:29.720 |
Not because of me, but because the episode is, uh, begins with a 45 minute 00:00:36.360 |
monologue from Sam, where he explains why he decided a few days before 00:00:44.080 |
So here is where, if we had a, uh, applause sound effect, a confetti and 00:00:49.960 |
applause sound effect is where, where we would, where we would hear it. 00:00:52.880 |
So Sam quit, uh, Twitter and it sort of made sense to attach his 00:01:00.680 |
I'd recorded with him a few weeks earlier, because obviously when you 00:01:03.000 |
talk to Cal Newport, you're going to, you're going to hear a lot about 00:01:05.360 |
tech and tech and society and not necessarily a very positive view of Twitter. 00:01:09.240 |
Now, interestingly in that interview, later in the interview, and we're 00:01:14.360 |
talking about Twitter, Sam is cataloging a lot of his concerns about it. 00:01:19.120 |
And I took a swing and made a pitch in the interview directly. 00:01:28.280 |
Sam actually specifically addresses this at the end of his monologue. 00:01:31.600 |
He says, as you will hear, I already had doubts when I was doing this 00:01:37.120 |
I didn't quit Twitter because Cal told me to, but he was one of the voices 00:01:42.720 |
So I'm going to take, let's take a partial W yeah, on that Jesse. 00:01:47.080 |
Um, but anyways, obviously I'm glad he did it, not just for his own sanity, 00:01:56.680 |
No, my issue is not with the existence of these social media platforms. 00:02:04.960 |
The idea that everyone has to use the platform. 00:02:10.800 |
I care that it's a big deal that I don't use it. 00:02:13.120 |
And so when we have more high profile people like Sam opt out, it opens 00:02:18.720 |
up that possibility to others, others who maybe feel like the. 00:02:24.200 |
It makes it easier and easier for those who follow in his wake to say, you know 00:02:29.320 |
I got a lot of heat when I originally left Twitter, Sam, who's way more 00:02:33.280 |
well-known to me is getting a huge amount of heat right now, but more of us 00:02:37.000 |
who go through this, the easier it will become for those who follow. 00:02:44.080 |
A lot of it, we're dealing with tech issues, a lot of tech and 00:02:49.040 |
A lot of new theories you haven't heard me talk about before. 00:02:52.720 |
But earlier in the show, Sam and I wandered across a bunch of esoteric 00:02:57.720 |
topics that just sort of popped to our head as we were chatting. 00:03:00.520 |
And one of the topics that came up relatively early in the conversation 00:03:05.200 |
was this thought experiment that Sam had considered before, where he was 00:03:11.240 |
thinking if I could go back in time, somewhere between the 1930s, the 1940s. 00:03:21.000 |
If my goal was to delay as long as possible, the development of the 00:03:25.040 |
modern computer, which individual would you kill now, obviously that's a, 00:03:29.640 |
maybe a, a, a violent construction for what's an actually the very interesting 00:03:33.400 |
question, you know, who was probably most singly influentially responsible for 00:03:39.040 |
I thought that was a cool thought experiment. 00:03:41.360 |
Now, one of the names that often comes to people's mind when they think about the 00:03:50.320 |
And as Sam and I talked about, I think Turing gets too much credit as a, uh, 00:03:58.200 |
initiator of the development of modern digital computing. 00:04:02.640 |
I teach Turing to our doctoral students at Georgetown. 00:04:07.120 |
He's the father of theoretical computer science and incredibly 00:04:10.040 |
influential thinker and a very original thinker, but his role in the invention 00:04:17.440 |
of the computer, I think has been inflated in recent decades, he would 00:04:20.880 |
not be, in other words, my choice of who to go back and, and, uh, rub out. 00:04:24.920 |
If I was trying to delay the development of the computer. 00:04:27.160 |
Now I'll tell you soon who I think that person is, but first let's 00:04:34.120 |
So what did he do that became so connected to computing in the modern minds? 00:04:41.240 |
Well, it really comes down to the notion of the Turing machine. 00:04:44.240 |
If you want to understand the notion of the Turing machine, and I promise you, 00:04:47.080 |
I'm not going to get into professor mode here. 00:04:48.440 |
I'll be very brief, but if we want to get into the notion of the Turing machine, 00:04:51.960 |
you have to go back to this paper he wrote called on computable numbers and 00:04:56.320 |
their connection to the Einstein problem, which is a German name for a problem that 00:05:01.440 |
was posed in the late 19th century by David Hilbert. 00:05:04.520 |
Now this problem had nothing to do with computers. 00:05:08.440 |
But what it asked is, can we come up with what they would call back 00:05:16.800 |
Today, we might call this an algorithm, but back then they would 00:05:20.560 |
That is a step-by-step series of instructions for solving any 00:05:26.400 |
Does every math problem have a step-by-step way to solve it? 00:05:30.200 |
This was a big question in mathematical logic. 00:05:32.320 |
A lot of people were working on it and Turing came up with an answer. 00:05:37.360 |
And the way he came up with an answer is he said, let's have a formal 00:05:43.000 |
And that's when he came up with this thought experiment of the Turing machine. 00:05:46.160 |
It's a set of instructions, an infinite tape, a read head that can move from 00:05:52.080 |
position to position on the tape, read what's there, look up in the instructions 00:05:55.880 |
what to do, maybe overwrite what's there, move one direction or the other. 00:05:59.600 |
Turing made this argument that this abstract machine in theory could implement 00:06:06.520 |
So every effective procedure has a corresponding Turing machine. 00:06:11.880 |
He then did a bit of mathematical logical tricks where he said, look, we could 00:06:15.160 |
describe any such Turing machine with a sequence of whole numbers. 00:06:19.440 |
And we could just put those whole numbers together and just get a really big whole number. 00:06:23.120 |
So every Turing machine and therefore every effective procedure has 00:06:29.640 |
It might be a couple hundred thousand digits long, but just conceptually speaking, 00:06:33.720 |
there is a way to label every possible effective procedure with the whole number. 00:06:38.480 |
Then he looked at what do we mean by a problem? 00:06:41.960 |
And he focused in on a subset of problems you might try to solve. 00:06:46.800 |
He did a little bit of mathematical logic and he argued every problem can be 00:06:55.480 |
That is a number, a decimal point number that has an infinite number of decimal places. 00:07:04.840 |
And in fact, there's a one-to-one correspondence there that you could, you 00:07:07.520 |
could, you could take every real number and that exactly describes a particular decision problem. 00:07:13.480 |
This was a big deal because there is a well-known result going back to Cantor. 00:07:20.640 |
Now we're going back to the 19th century that says there are many more real numbers 00:07:24.880 |
There exists no way to map every natural number onto a real number such that you've 00:07:34.400 |
The impact of that is, okay, if we, if we map every possible effective procedure to 00:07:39.760 |
the problem it solves, there'll be many problems left over that aren't being mapped 00:07:48.960 |
And the conclusion is there's many more problems out there in the universe and 00:07:52.520 |
there are algorithms or effective procedures that can solve them. 00:07:54.840 |
Most things that most problems out there can't be solved by effective procedures. 00:07:59.640 |
This was the question that Hilbert was trying to answer. 00:08:04.320 |
So this was all about logic, mathematical logic, foundational math that was going 00:08:11.640 |
The reason why we connect this to modern digital computing is you can say Turing's 00:08:18.960 |
notion of a Turing machine is an abstract notion of a computer because you have this, 00:08:25.440 |
that the tape could have on it instructions that a Turing machine could run. 00:08:29.480 |
He talked about in his original paper, something called the universal Turing 00:08:32.560 |
machine, where the input on the tape is a description of another Turing machine and 00:08:36.760 |
So you do have some of the conceptual basics there of a computer reading a 00:08:42.800 |
Also, we do know that von Neumann at Princeton was familiar with Turing's work. 00:08:47.760 |
He met Turing when Turing was visiting the Institute for Advanced Study in 00:08:52.280 |
Von Neumann later advanced the von Neumann architecture for modern computers, which 00:08:57.360 |
So there's a little bit of an influence there as well. 00:09:00.640 |
But the idea that Turing single handedly sort of introduced this idea that we could 00:09:05.120 |
have these universal computing machines, that's just not true. 00:09:07.680 |
Before Turing even did this work, well before this work was well known outside of 00:09:13.520 |
esoteric mathematical circles, we already had general purpose analog electronic 00:09:19.360 |
We had, for example, Vannevar Bush's differential analyzer at MIT. 00:09:22.920 |
In the mid 1930s, we got the very first, we began to get the very first ideas being 00:09:28.720 |
proposed for making fully electronic computing machines. 00:09:32.320 |
As the war went on, there was a huge push to have more advanced electronic 00:09:37.160 |
They were using these to calculate artillery tables and to help aim at the 00:09:41.680 |
aircraft guns and some sort of cybernetic sensors. 00:09:45.440 |
And while it's true that Turing after the war got involved in a project in the UK to 00:09:51.920 |
develop an electronic computer, this was one of at least a half dozen ongoing 00:09:58.760 |
I think the ENIAC at Penn, for example, there was a Van Nuyman's project at 00:10:05.040 |
A lot of people were working on this problem. 00:10:10.600 |
The final thing people point to is they saw that that movie about whatever it was 00:10:19.240 |
And like, well, didn't he invent these sort of computing machines to break the 00:10:29.200 |
Turing was just building a more advanced version of those machines. 00:10:33.280 |
So they used the initial work that the Poles had put into breaking the enigma 00:10:38.360 |
I love Turing, but he didn't invent the computer. 00:10:42.080 |
So who would I go back and rub out if I was trying to delay the computer? 00:10:47.960 |
I would say Claude Shannon in the early 1930s. 00:10:54.000 |
Claude Shannon in the early 1930s wrote the most important master thesis that 00:11:01.120 |
It was called a symbolic analysis of relay and switching circuits. 00:11:04.240 |
This master thesis is what figured out the entire field of digital electronics. 00:11:09.320 |
This was the really key breakthrough that everything else was built on. 00:11:14.360 |
Shannon had been interning at Bell labs where he was seeing electromagnetic 00:11:21.000 |
relays, phone networks use electromagnetic relays to automatically connect calls 00:11:27.080 |
He was also studying for a degree in mathematics at MIT. 00:11:31.280 |
He put those two things together and he said, wait a second, you can take purely 00:11:37.440 |
logical statements expressed in Boolean algebra and you can implement them with 00:11:41.360 |
electronic circuits using these electromechanic relays. 00:11:45.040 |
So you can take an arbitrary mathematical specification of a logical circuit and 00:11:49.640 |
build it, anything you can come up with, any Boolean algebra statement you can 00:11:52.720 |
come up with, we have a systematic way of building that with wires and magnets. 00:12:02.880 |
He said this later in life, it just happened that no one else was familiar 00:12:08.720 |
So he happened to be in both worlds, math, phone company came together. 00:12:13.880 |
That was probably the single biggest innovation because once we realized we 00:12:18.200 |
can build arbitrary logic into electrical circuits, that's what opened up the whole 00:12:22.640 |
hope that whatever idea we have that we want to implement, whatever adding circuit 00:12:26.760 |
or logic circuit or whatever we need to implement our conceptual design of a 00:12:31.160 |
computer, whatever we can come up with, if we can specify it mathematically, we can 00:12:35.000 |
So if we're going to follow this sort of oddly Marshall exploration of early 00:12:42.240 |
computing, Shannon in the thirties, getting rid of Shannon in the thirties would