>> Sean: We have had some questions in from some of the fans, some of the viewers of Computerphile
And we thought it would be a be nice idea to have a
chat and you tell us what you think. So, I've picked a few [questions] that maybe hopefully will
go together and and we may well do some others at another time. We're going to kick
off with this one here from Patrick Orton, who I think you may actually ...
>> DFB: Yes! Hi Patrick! He was one of my project students a year or two ago. Yeah! Hi Patrick!
>> Sean: He's asked four questions. So we'll whip through these before getting on to some others.
So: what is your favourite area of computer science ? >> DFB: my favorite area of
computer science? Well, it's split into two really. Although it's very
very applied computer science I really do like everything to do with digital
documents - right through from the sort of XML structural stuff right down to the
nitty gritty typesetting, fonts and PostScript stuff. I love that. But if you
were to say is there an area I like doing videos on which fascinates me
- although it's not really my specialist area - the answer is, what we're doing at
the moment, which is Regular Expressions. I think they're fascinating! They're so
easy but so difficult. You get Regular Expression wars between commenters.
They're wonderfu!lThere's a way to go yet on REs before we finally say
"That's enough!" Yeah, >> Sean: well, it's interesting because you kind of roll these first two
questions together, so we'd ask the favourite area to work in and the area you're most
interested in. What's the area of computer science that you'rer best at?
>> DFB: Do you know that's a very good question Patrick. I can tell you are one of the
students that I supervised. How well you know me! The answer, truthfully, is that I
don't consider myself an outstanding computer scientist in any of the areas.
I suppose you could say, insofar as I have some expertise, the whole digital
documents / electronic publishing, low-level, PostScript/PDF stuff, yes.
But actually what am I really best at? It finally dawned on me, and thanks to you
and Brady, you have given me the ability to exploit this. I'm best at explaining
things to people and, as I've often said, I, when I was younger, had to teach myself
and there's [potentially] a whole extra episode on why, to be competent in a wide range of things.
And being forced to teach something is the best way to learn it. So I think I am
good at that. The problem I had was if I was like Brian Kernighan and had the
tenacity to write lots of books, that would have been a way to propagate my
expertise. I don't really have the patience to write books. What I wanted
was somebody to come and just talk to me and make videos from my waffle! And you
and Brady - honestly I remember that first visit, and it's been solidly downhill for
seven years ever since then, hasn't it? 2013? something like that yeah?!
>> Sean: Patrick also had a question, which connects to a couple of other questions, so I'm going to roll
these together if that's all right with you. What is the area of computer science
that looks to be most important in the near future? which connects to one
Richard Denton's asked about " ... your extensive history in the new field of
computer science, what direction is it heading in and Gregor who said: " ... which
area of CS will in the near future be used the most and which do you think
there's no future to? >> DFB: I'm not very good at futurology! I could list all of the
things which I've come across in computing and have said " ... that will *never*
catch on!" But then, six months later, it's the lead
topic in the whole field! Now I think, all right, let's just say recently the thing
this has quite taken my breath away has been the whole stuff about Neural Nets
Deep AI and so on. And now it's fascinating because ... I'll tell you what is the
most fascinating thing. You had Deep Blue playing chess basically by brute force
methods [looking mny moves ahead] and back in the 80s -- I don't play chess by the way but I do find it fascinating --
it was Deep Blue, IBM's Deep Blue, I think, that defeated Kasparov for
the first time, Wow! you know. And I felt: "Well it's just brute force and ignorance that [is]"
But on the other hand the moment you start doing neural networks, which
learn and adapt and once you start feeding in the fact that you can play
yourself in a computer rendering of the game. You know what they've done on GO
and chess and all that, now, is to say we don't just hard-code the rules and
look thirty moves ahead. We'd get it to find out what unlikely things have
come up, in me playing myself, where it just went berserk and went off on a tangent
And I thought " ... that's a lost game" But it wasn't! It found a back-door way in and
triumphed. And I think that's what took the GO guy - was it Lee Sedol - apart.
He just thought:" ... that's ridiculous I'm gonna win this one!" Then, about 20 moves later
he hadn't! And I think he found that shattering, and I can well imagine that.
And I think my understanding is very limited of this - is that the Deep Mind
people have now started applying all that they did to GO to apply it back to
chess. And don't use brute force just build up millions of games and let it
learn what's a good thing to do. And I think I'm right in saying that that
piece of software, using the neural net statistical whatever, is now more
successful than the original Deep Blue was, but I'm not sure. So what you
can say is [that] taming big data via AI is a tremendous area. It's I mean Big
Data is important and the degree to which you can tame it with so-called
AI is fine but the big question still is [this]. You go to the authors of these
"highly intelligent" programs but they're not - and you say: "Can it do 'common sense' ? "
"No! not a hope! it's brilliant at go because it's still a narrow and
well-defined field but don't ask it to pontificate on the state of politics in
the Western Hemisphere". It hasn't a clue! So, there we are, right, something that I know
I'm interested in. I know very little about but does seem to me to be a real
marker for the future. >> Sean: Maybe onto a different subject. We had a question from
Erik Stens and he said: "As engineers we all have our pet project. What have been
some of your hobby projects - computer related - that you're most proud of.
And would you tell us a bit about them all? >> DFB: Right! Well, I suppose I should say at the
start that one of the advantages I've got being the ripe old age I am, is that
I've been what's called an Emeritus Professor for well over ten
years now and that this does give me the ability to pursue lunatic things that
would never ever have got me promoted to Professor but I was there already.
>> Sean: can you tell people what 'emeritus' means For those who don't know those who aren't in academia?
>> DFB: What happens with Emeritus Professors is that it's basically a way of pension ah--you
off but in a gentle way. The idea of an Emeritus Professor - the Latin of course
means 'E' = 'out of 'merit. i.e. "because of merit" You are given this honorary position. It
varies very much as to which university are in as how active an Emeritus you
want to be, but for me, back in 2005, I came off the regular payroll
as a professor and 'cut a deal', as it were, where I will be brought back on a
renewable yearly contract to do fill-in teaching on stuff I likeds but the good
thing was: " ... with no major administrative responsibilities". So I took my pension I
got some extra top-up from the School of Computer Science and really, I think, the
last actual taught course I did, given that I formerly 'went Emeritus' in 2005,
I was still teaching classes through to 2013. And why did I change
tack then? Well, once upon a time, two hirsute guys came into my office and said:
"Hello, we're Brady and Sean. We're going to reshape your future" you've wanted to
find somebody idiotic enough to record your waffle?
That's us! Well, it's true isn't it ? I always love the teaching but to be able
to teach in a way like this - which would never have got me promotion to anything
had I tried to do it as a 30-year-old, you know. Which is why, in many ways, I'm
so glad that Steve {bagley] and Mike {Pound] are still happy to do it because it can be part of
what you do but it can't be the totality of what you do. And yet, for me now, it
really is almost a totality of what I do. You've given me an avenue to spread the
gospel or something. Yeah! so that's what it means to be an Emeritus Professor
It's given me complete freedom to do, for example, the stuff we did rescuing the
banned paper [memorandum] about the Linotype 202 typesetter. Now, it was such a good
project because it was Brian Kernighan's work - [he's] virtually a Computerphile
regular now although the [corona]virus has confined him to the States for the moment -
but yes it was his work way back in the late 1970s
which had been banned from publication. A mutual friend of both of us, Chuck
Bigelow who's the co-designer of the Lucida typefaces.
[He] basically said, to both of us, we know him well. He said: "You two you should be
telling the story now - it's not sensitive any more". So we did all those videos on it.
But in order to get the story total I said to Brian: "What we have to do is
not just resurrect this memo, which was on yellowing paper that had been
photocopied in 1978. We've got to recreate it using modern PostScript/PDF
fonts technology at the quality that was innately there off the virgin-fresh
bromide that came out of the 202. And it's got to be really good and Postscript's
up to the job, you know, that is the the glue that binds it all together we can
we can do it but I wanted it to be a perfect resuscitation as it were. And
getting that last few percent right was just very rewarding, but very frustrating.
I mean we had it published. It's had very good reception. People love it when
they find it. But could I seriously have beem on the end of a yearly [personal] review
having to say this 'caper' that we did: does that count towards making me a Professor ?!
I I think my previous heads of department would have said: "No! it's frivolous!"
>> Sean: It's interesting because it kind of leads on too many other questions which is
from Jonathan Lystrom, I hope I'm saying that right: "Ask Professor
Brailsford how he learned to be so pedagogic well-versed and an absolute
joy to listen to". That's going to be nice to hear. I assume I'm saying 'pedagogic' right?
>> DFB: I think you are. Well, thank you for the implied flattery - is it Jonathan?
Thank you. The thing is, of course, that my style doesn't appeal to everybody.
Some people find it too waffly, too 'hand wavy', and although I love explaining
things to people I just love it when I get real experts come at me - just the odd
one - and it's always: "David, you did a good job. But you were on thin ice! You
very nearly started telling things that were all flatly untrue. And I thought, I
thought, this is it! He's gonna fall down into the ice-pit ... at the
last minute, Oh! you know you rescued yourself! You didn't tell an untruth but
it's not the way to explain it!" To which my retort is: "If I get people saying 'I
didn't remotely understand it until [you] explained it [your] way' ", then I rest my case
I was new I enjoyed teaching but the answer is very simple when we were
turning from a Computer Science Group in a Maths Department, this was in 1986, to
being a full-fledged Computer Science department eventually, it didn't dawn on
me - because I was leading the charge on this - that we'd actually have to teach
across the whole range of Computer Science. So we took a first few Single
Honours computer science students in 1986 and then it suddenly hit me that, by
1989, we'd got to give them a full-blown Computer Science experience. And how many
people did I have? Six and that includes one technician and a pet cat [joke]. "Oh my lord, how are we gonna
do this?" And I said to people, I remember, [at] one of the first departmental meetings,
I remember saying: "Look, we are very very short-staffed. I think that the University
will help us out with one or two [extra academics] but it won't be as many as we need: Sorry folks
we've all got to be prepared to teach well outside our comfort zone!"
And that is the answer to the real question [which] is: "Why can you teach over such a broad range?"
I had to! I had to learn about Chomsky, Regular Expressions, Turing
Machines and all that because at the time I didn't have specialists to teach it
But it comes back to the main thing: I enjoy
teaching difficult things just by saying: "I found it [this topic] difficult, here's how I got to
grips with it" And if that style of explanation suits you then it's a
win-win situation. >> Sean: We've had a question from a very
familiar name here, Graham Hutton. Have you heard of this character?
>> DFB: Well, yes,you know it 'rings a bell' (!) >> Sean: If you could have invented one idea in computing what
would it be?" >> DFB: Again first obvious answer is : ... would it have been invention or would it
have been 'discovery'. Was it in some sense 'there already'? I have often thought about
this but the the stuff I would love to have been more involved in, I would love
to have been at the right place to be heavily involved in it: In the early
60s to late 70s - it was over a long span is the whole area of Chomsky Types 3 anbd 2
which covers, really regularexpressions, [plus a single stack] when do they run out of steam?
What theorems can you prove about them? Now it's an area that we're
still coming back at, but the one person - sorry to be boring; everybody venerates
him for different reasons, still with us and I reserve the right to come back and
do a biography of him, in some sense, from my knowledge of him: Ken Thompson. I mean
there were Regular Expressions invented by Stephen Kleene and, yes, they were
fine but not a lot of people understood them. But one of the people who really
understood them was not a sort of avowed, declared, theoretician but .... Ken Thompson -
the world's ultimate super-duper computer [system] programming practitione.
He just understood in a very very deep way what a Regular Expression could do,
and couldn't do. And, more to the point. there was a very important theoretical
paper by Dana Scott and Michael Rabin which
basically said: "These Regular Expressions give rise to automata diagrams, which
we've done [on Computerphile] but of course, a lot of these automata diagrams basically say:
"Well, what's the next character in your input stream? A letter 'a' ? Oh! I can go in three
possible directions [in this automaton] on an 'a' Which one do you want me to take?" And the trouble is,
if you guess wrong, you end up down a blind-alley. And you have to backtrack
out and you have to re-do and put back again every variable you set in trying
to analyze it. You've got a reset and that's massively expensive you see.
So, what Scott and Rabin did was to prove that everything that was
non-deterministic could - by an algorithmic process be turned into
a deterministic [one]. Except it might have a lot of extra states and it might have a lot
of extra escape chutes labelled 'empty' that took you down to a false ending. and
you had to build to cope with that . Ken kind of instinctively understood that, you know.
the idea that you could make it deterministic. This is what Lex does for
those of you who are into using UNIX tools. And I was just appalled and amazed
that that was possible. I thought I'd love to have done that but I would have
loved [also] to have had Ken's sure-footedness. In his favourite editor, QED,
he built in the whole deterministic/ non-deterministic thing. In ordinary UNIX
'ed' he decided that the labour involved wasn't worth the candle, you know, and he
quite happily a- nd what better programmer to do it - said [that] at times, although
recursive backtrack is deprecated, a little bit of it - so long as you don't do
too much - I know how to do it. And he was just such a master programmer
he could make it work either way.