>> Amy Draves: Thanks so much for coming here my name is Amy Draves and I'm delighted to
welcome Matt Parker to the Microsoft Research Visiting Speaker Series. Matt is here to discuss
his book, Things to Make and Do in the Fourth Dimension, which seeks to reconnect us with the
numbers around us. He is the standup mathematician and can be seen talking about math on
TV, in newspapers and on stages across the UK. He is the public engagement and mathematics
fellow at Queen Mary University in London and cofounder of the Festival of the Spoken Nerd.
Please join me in giving him a very warm welcome. [applause]
>> Matt Parker: Calm down, calm down. Okay. That was a very efficient calming down. Thank
you all very much for coming along to my talk and thank you kindly everyone who bought the
book. Apparently, they have sold out of books, so that concludes my presentation today.
[laughter]. I think I'm still contractually obliged to hang around and actually do the talk. And if
you didn't get a book that's fine. I'll still be around if you have questions and you want to come
and see me. And that's my e-mail address so at the end if you don't want to take notes as we
go along you can just send me an e-mail and I'll give you a copy of the lecture handout. That is
technically a joke, and that's the website for the book which is bordering on up and running.
It's all coded. I've just got to, I haven't written a copy so that will be up before you know it.
Amy, very correctly, gave me my full title today. Well done. Very few people get that correct.
I'm based at the University in East London and I'm only there part-time. I do one day a week
and my role there is the public engagement in mathematics fellow, because I was allowed to
write my own job title. My work there involves training the academics and the undergraduates
to communicate math to other humans and the rest of my time is spent doing anything I can to
get more people more excited about mathematics. I used to be a high school math teacher.
Back in the day I taught math to young people and I'm from Australia originally, but I have an
English accent. That's fine. I moved to London about a decade ago to teach math and I was
working in a few local schools in London. I gradually started to drift away from being a
standard classroom teacher. First of all, I went and worked for the University for a while. I
worked for an education company for a little bit and after a while I started to get nostalgic for
the classroom, so I actually went back. I went back and did six months in a London, like a
proper inner-city state school and that just cleared that right up. At the end of that I said I'm
done. Since then I still probably one day a week is still working with school, one day a week at
the University I'll do Festival of the Spoken Nerd, so I do a lot of math standup, I guess, is the
way to put it. For a while I worked part-time teaching, so I was teaching math to teenagers
during the day and then part-time as a standup, so I was telling jokes to drunk people in
comedy clubs at night, which is a surprisingly similar skill set, to be honest. Did you know that
you can confiscate drunk people's phones? Brilliant. But after a while I realized what I really
enjoy doing is the very nerdy standups. That's where things like the Festival of the Spoken Nerd
which is three of us who do, we are all standups who enjoy science or math-based things. The
rest of my time is writing, doing bits of radio, little bits of TV. Most of it is in the UK, though,
bits from the BBC. I do Infinite Monkey Cage which is a Radio 4 program with some chump
named Brian Cox and I did a show on Discovery which means no one is watching it. Outrageous
Facts of Science, season three coming soon. And I do a little work on YouTube, so if I looked
familiar but in higher resolution than normal, I'm on the Numberphile channel on YouTube and
I get to talk about math and numbers and all sorts of great things, which is good fun. All of this
will reappear at the end of the talk. The book is called Things to Make and Do in the Fourth
Dimension, but I thought that it would be a bit mean to come all the way down here and make
you listen to me talk about things that you then need to buy the book for. So I'm going to do
the wildly different talk, Things to See and Hear in the Fourth Dimension, which is just me
talking for approximately half an hour and you all listening quietly. That's pretty much the plan.
We are going to do some math. That's not an idle threat. I should make that very clear. In fact,
we'll start with a bit of performance math. Can everyone who brought your calculators with
you, can you take those out now? Really? Anyone? Or phones, do any of you have phones?
Some of you are opening up Wolf from alpha, well done, okay. Whatever your calculation
device or aid of choice is, I'm going to do a quick performance stunt for you, so I want you to
put any two digit number you fancy into your calculation devices. I then want you to find the
cube of that two digit number. If you are doing this with friends and family afterwards or if you
are doing it with school kids what you need to very carefully say is put in two digits, multiply
them by the same two digits and then multiply them by the same two digits a third time and
then hit equals. If you're not careful you get a fourth power. If you're very careful you should
get the third power of that two digit number and what you are doing is a kind of long tedious
part of math. This is why we have calculators to speed this up. The fun part of math is what
you can do with the answer. Is there anyone who's prepared to share the answer on their
screen, someone who's -- okay. Sir, here, what answer have you got on your screen?
>>: 195,112.
>> Matt Parker: Okay. So you had to put in 58 and then cube that. Okay. If I get them right
instead of silent nodding, okay, thumbs up is a step in the right direction. [laughter]. How
about…
>>: That's amazing.
>> Matt Parker: Right. In fact, so if I get the number right can you go wow. The thumbs up is
optional, but still highly recommended. How about just a yes? A concise yes if I get them right?
Has anyone else got an answer? All right over here.
>>: 314,432.
>> Matt Parker: You put in 68, one off the most hilarious option available. Thank you. I do this
with school kids every time. We think they are delicate flowers. Anyway. I'll do three more
and then if I get all three, you burst into the appropriate proportion of applause. Okay. Wait,
whoa whoa. Remain calm. Remain calm. You need a friend to help. Wait, wait. Wait, wait.
Perfect. I need two more. Remain calm. Are there two more people who are going to join me?
I've got one there who is barely holding it back. I've got one over here and then, I like triangles,
a right? So we're going to go you, and then you and then you, only if I get all three correct.
Here we go. What have you got? Go.
>>: 658,503.
>> Matt Parker: 87.
>>: Good.
>>: 3375.
>> Matt Parker: 15.
>>: Yep.
>>: 681,472.
>> Matt Parker: 88.
>>: Yep. [applause]
>> Matt Parker: Some of you are applauding sarcastically, and that's fine. I'd not just
memorized every single two digit numbers cubed. I should make that very clear. I have a lot of
free time but not quite that much. Nor am I doing a difficult calculation. If anyone knows this,
that trick, it's a fairly straightforward bit of performance math where all I've done is I've looked
at the answers you get when you cube two digit numbers and there are two patterns that
appear in the answers. One pattern gives you the first digit of the starting number and the
other pattern gives you the second digit, so all I'm doing as you are reading the numbers out is
I'm scanning them for those two patterns and they tell me what the two digits are. It's actually
a fairly straightforward mental arithmetic. It doesn't require much thinking. It's much more
impressive than it should be, which is why I'm not going to explain it. I am going to try
something that is a lot more complicated to do. Even if you know how this one is done you
should be still slightly impressed. We'll see where we go. For this one you do not need a
calculation device, but I need someone who has one and is prepared to read out a product they
have possibly in a can which has a bar code on it. I need someone who's got item with a
standard North American barcode on it and they are happy to read out the digits of that
barcode. I'm not going to use the book, sir. Nothing personal. Okay there slightly because it's
not my book; is it? [laughter]. But I will explain why. I think some of you know why I'm not
going to use the book. Has anyone else got something that's come from a recent -- okay. What
beverage is that?
>>: Diet Doctor Pepper.
>> Matt Parker: Diet Doctor Pepper. Okay. I haven't looked at the barcode because it may
have come in a multipack. Don't tell me what they are you got a tiny digit to the left of the
lines?
>>: Yes.
>> Matt Parker: And a tiny digit to the right?
>>: Yes.
>> Matt Parker: Okay. We will give this one a go. This should work. What I'm going to get you
to do is to read out the digits of that our code, in a second, very slowly and do not tell me the
final digits. So when we get right to the end just say there's one more. I'm going to calculate
what it is. If I get it right you say wow, everyone goes bananas.
>>: Just to be clear, the last digit is the one to the right?
>> Matt Parker: Yes. The little one off to the right. So you start with the little lonely one off to
the left or the ones underneath, not the one off to the right.
>>: Okay.
>> Matt Parker: I'm just getting in the math zone. [laughter]. I've got to be focused. Okay.
Right. Okay. First digit is…
>>: Zero.
>> Matt Parker: Okay. Zero. Give me a second. Right, got it. Next digit.
>>: Seven.
>> Matt Parker: Hang on. Seven, yep seven, yep.
>>: Eight.
>> Matt Parker: Hang on a second, yep.
>>: Three.
>> Matt Parker: Yep.
>>: Two.
>> Matt Parker: Yep.
>>: Three.
>> Matt Parker: Yep.
>>: Zero.
>> Matt Parker: Yep.
>>: And one digit left.
>> Matt Parker: It's a seven.
>>: It's a nine.
>> Matt Parker: Okay. That's all right. Does anyone else have a product for the barcode?
[laughter]. No. I suspect that it has been bulk purchased in like a catering pack. It was a lot
shorter than I was expecting. I think that we're not going to attend to that because we are
going to do it again because this would get embarrassing. This will get more embarrassing.
[laughter]. Does anyone else have an item that they bought -- Amy it's going to look like I gave
that to you before we started. That's okay.
>> Amy Draves: [indiscernible]
>> Matt Parker: What is that?
>>: It's an Xbox controller.
>> Matt Parker: Well aren't you on brand, sir? Well done. [laughter]. Okay. Can you have a
look at the, now that's the code that would be scanned in a shop, right?
>>: Yes, it's the retail code.
>> Matt Parker: And it's got the little digits to the left and to the right? Okay. Let's give it a go.
Afterwards, if you finish that -- she's hiding now. If you finish that can, I want to have a look at
it afterwards and see where I went wrong. Okay, here we go. Can you start with the little one
on the left nice and slow. I'll work out the one on the right. Here we go. Here we go. Okay,
ready?
>>: Eight.
>> Matt Parker: Okay, so the eight is off by itself on the side?
>>: Yep.
>> Matt Parker: Give me a second. Yep.
>>: Eight.
>> Matt Parker: So there's two eights? Okay, yep.
>>: Five.
>> Matt Parker: Yep.
>>: Three.
>> Matt Parker: Yep.
>>: Seven.
>> Matt Parker: Yep.
>>: Zero.
>> Matt Parker: Yep.
>>: Eight.
>> Matt Parker: Yep.
>>: One.
>> Matt Parker: Yep.
>>: Four.
>> Matt Parker: Yep.
>>: One.
>> Matt Parker: Yep.
>>: Six.
>> Matt Parker: Last digit is a three.
>>: Correct. [applause].
>> Matt Parker: I see you have brought your applause down slightly to punish me for how long
that took. [laughter]. What I'm doing, those of you who know what I'm attempting to do, there
is a check digit in, of course, all barcodes. And so all of the numbers that are being read out do
not come across check digits. All of the ones being read out by the actual product code and the
final digit is put there to put a mathematical pattern into that barcode. If you learn to do this, if
you want to be at school at parties as I am, the pattern is as someone is reading out the
barcode you need to add together every second digit. So you start with the first digit, you add
it to the third one, the fifth one all the way down. Once you have managed to sum every
second digit you multiply that subtotal by three and then you go back and add on the other
digits you skipped. If you add every second digit and multiply by three, add the other digits the
grand total is always a multiple of 10, and so the missing digit is -- okay. Now you are slightly
more impressed. The missing digit is whatever you need to get up to the whole next multiple of
10. Of course, I've streamlined it slightly. If you watch my foot at the front it's ticking
backwards and forwards. That's me keeping track of it. If I have to multiply by three or not as
I'm adding to the total and then I'm just keeping track of what I need to get up to the next
multiple of 10 and so the calculation in my head ended in a three so I knew that it must be a
seven to bring it up to the next whole multiple of 10. And obviously it's fantastic because most
people have no idea that this math is going on in the background whenever they buy a product.
They have no idea when they scan something in the supermarket; people think that it just
magically knows what the product is. But, you know, as the lasers are bouncing off of that
barcode -- you know but lasers actually make a lot of mistakes. Lasers are not that accurate,
huh, physics, right? [laughter]. Thankfully, map comes to the rescue because it gets it right
every time and what it does is it checks the calculation. If the pattern works it knows it
probably scanned correctly. If it doesn't work it knows that it has been mis-scanned, without
this kind of error detection going on with most people having no idea it even exists, our modern
shopping wood and work. And of course the same thing happens for any kind of data transfer.
There's a nice analogy for the error correction behind text messages. Most people think they
type their message into their phone and it magics itself to another phone and it's there. But we
know that the pattern that you put into a text message, there are three different mathematical
patterns that are embedded before it's sent. Effectively, you can think of it taking all of the
characters, turning them into numbers, putting the numbers into a grid and then it goes
through and there’s an extra mathematical pattern for every single row of the grid. There's
another pattern for every single column and then there's intersections and there's a third
pattern for each section. If that sounds a little bit familiar, it's because it's turning your text
message into a Sudoku puzzle. These, people understand if you give them one of these and
there are three mathematical patterns, rows, columns and sections that literally protect
messages and it's -- Reed-Solomon, Reed-Solomon. It's the one with actually -- what was that?
>>: Reed-Solomon.
>> Matt Parker: Reed-Solomon, right. But that's more, correct me if I'm wrong but they do it
more as a cube, so there's one, you can visualize there it's a cube and it's in three different
directions and its coefficients of the polynomial. End of my knowledge. Whereas here, people
appreciate, the patterns are much more straightforward, but what they're doing is of they're
re-creating lost data. And people will calculate all the missing numbers, which I think is
absolutely amazing. If you see someone solving one of these on a train just go all, I didn't know
you were into error correction as well. Blank expression [laughter]. And people don't seem to
equate this with math, either. They go I hate math. I love Sudoku. I love lining up numbers in
boxes. [laughter]. Suddenly it's fun. Without this, without that kind of error correction behind
the scenes, as we know, all modern technology would work and so I think on one hand it's great
but that happens and it makes our lives possible, but it's a bit of a shame that people don't
appreciate it. But the whole point is it's done automatically and behind-the-scenes. I do try to
show people math which is actually useful immediately in their lives. I'm going to try to teach
you all hopefully a new piece of mathematics which will make your lives better going forward.
It's a superior way to tie your shoes. I'm going to teach you the mathematical way to tie your
shoes. To do that I have to have, because I realize you can't all see my foot. People watching
this online you ought to zoom in on that. I've got here a web cam which I have rigged up to my
presentation so that I can do is if I bring this out to here, you should be able to see my foot. Is
that working?
>>: Yes.
>> Matt Parker: And you can see it more than once. There you go, perfect. [laughter]. It's like
the world's nerdiest chorus line. [laughter]. Just zoomed in on my foot now so you can see.
What I'm going to do is I'm going to tie my shoelaces in the mathematically superior manner.
What you do, normally, when people type their laces, they get to hoops and do all sorts of, you
know, mashing and ridiculousness. What you can actually do is if you just hold one shoelace in
each hand, if you cross it over it will tie itself like that. If I speed that up slightly I'm holding two
laces, hold the laces cross them tight. Okay. You're keeping your excitement at a manageable
level. [applause] [laughter]. Don't patronize me. Would you like to try this? If you want to
have a go, choose your favorite shoe, undo the lace. If you're not wearing laces, that's fine.
The person next to you is probably using up to 50 percent of their shoes to try this, so borrow
the other one. If you undo the laces and then do a little foundation knot like that. I've actually,
I'm going to give you pictures as we go along. You start by holding one place so it loops up and
down and you hold it on the way down. The other one loops up and back and you hold it on
the way down. And then all you're doing is you're taking each bit that you're holding and put it
under the other loop. So that one is under that one. You pull them tight and there is you are
knot. [applause]. Actually I'll give you 30 -- some of you have your shoes untied. I'll give you
30 seconds to see if you get that to work. I'll do it once more here and then you have a second
to put your shoes back on again and we'll carry-on. You have 30 seconds to have a go. There
are the laces, cross, knot. The disturbing thing is to some of you the most impressive part of
this talk will be how I managed to embed a live web cam feed into a PowerPoint presentation.
The secret, in case you are you wondering, is an expansion pack called Keynote. [laughter].
Actually, they broke it. I use Quartz editor to make the input for this and the new version of
Keynote, they have broken it. It doesn't work anymore. I can imagine someone at Apple going
what? People are adapting our product to do what they want to do slightly differently? None
of that. [laughter]. So I've got to stay on the old version of Keynote for that bit to keep
working. It's disappointing. Actually, for the first time in a decade, this is like a treat for myself,
I've been building my own PC from scratch. I haven't done that since I was at University and
very cheap. I'm going to do this and my wife doesn't understand how for me troubleshooting is
like a competitive sport, so she comes down to find me swearing at heat sinks but I've pretty
much got it going. I'm just trying to get back into text stuff, but slowly. Most of you should
have your shoes back on. The knot you tied, by the way, is exactly the same as the knot if you
do it the long way. Mathematically, it's an identical knot. And a lot of people don't appreciate
knot theory, like this study of knots is quite a big mathematical discipline. It's a reasonably new
one as well and they have the delightful name of the called knot theorists, which is quite nice
[laughter]. Yes, are you a theorist? I'm a knot theorist. But the knot theorists, part of what
they're trying to do is work out the best way to undo knots. At the moment humans are
terrible at undoing knots. We haven't got a good mathematical theory for the best way to undo
any given knot. I've got here a picture of one knot that at the moment we have no idea how to
undo. I got this put as a diagram in my book. If you have not seen knot diagrams before here it
looks like there's a break in the string. What's actually happened there is the string has gone
underneath the other one and come up the other side, so we draw a gap in the string to
indicate going underneath. I mean a trivial way for a knot to come undone would be if one of
the ends goes through it, right? That's a bit too easy, so for mathematical knots you join the
two ends together, so you get a continuous piece of string, so there is no beginning or end and
it's got a knot in it. If you pick it up and you shake it and it becomes a complete untangled loop
you know that it's been unknotted and you know that it wasn't a knot in the first place. This
one, this is a knot called the 10-11 knot. You can't just shake it. It won't come undone that
way. What you need to do is call the crossing switch. To do a crossing switch to cut the string
on one side of where it's crossing and move it around to the other one and reattach it. It
switches from crossing underneath to crossing over. At the moment the best method we have
for undoing this not takes three crossing switches. No one has ever found a way to undo it with
two crossing switches. No one has ever proved that you can't undo it with two crossing
switches. This is still an open problem in mathematics. We do not know if we have found or
what is the best method for undoing that knot. My theory is I'm encouraging people to make
out of string and then try. Because if you make that out of string in that arrangement and pick
it up and jumble it around and put it back down again, because we have tried all the crossing
switches in that arrangement. And part of why it's so difficult is there are so many ways to
rearrange the knot before you do the crossing switches. But we feel that if enough people have
a go at it sooner or later someone, if it is possible, someone will find a way to do it in two
crossing switches and mathematical fame and fortune are theirs. [laughter]. For a very narrow
definition of fame and fortune, but you would be mathematically famous. I mean that's pretty
cool, right? And there are other ones. We haven't got any systematic way of undoing knots
and the reason we care about this is at the moment bacteria are better than we are at
untangling things. When bacteria reproduce to go from one cell to two their DNA has to divide.
In that process it gets very tangled and knotted. Before it can separate off completely it has to
unknot its DNA. It's got tiny enzymes that do this and they perform crossing switches. So they
latch on, they cut one bit of DNA, move it to the other side of a different strand and reconnect
it. At the moment bacteria are better at doing that than humans. They are far more efficient
and they can find ways that we wouldn't, or we can't work out how they're doing it. So there
are knot theorists from the math departments at various universities working with the biologist
to try and find ways, partly to understand what the bacteria, what these enzymes are doing and
then to find ways to impede it or to slow it down. Because if we can stop them from untangling
their DNA that's a whole new wave of possible antibacterial. You know, medical therapies are
available, but because mathematicians are working with biologists to look at the knots in the
DNA of bacteria, which I think is absolutely fantastic. I got approximately a quarter of an hour
left, so what I'm going to do is I'm going to show you a ridiculous project I did recently involving
computing and then I'm going to finish with the Christmas present my mother gave me two
years ago. It's relevant to the book. It's not just like hey check out this jumper. It's a proper
thing. The ridiculous project I'm going to show you first. I wanted to find a way to
communicate to the general public how computer processes actually work. At a very
fundamental level, how does circuitry do calculations? So I tried to find a really nice kind of
macro big hands-on example of sending information down a circuit. And what I stumbled
across was using chains of dominoes as a circuit, because here I have very carefully balanced
these dominoes. I've heard rumors you can use dominoes to play some kind of game. I don't
believe that. [laughter]. We all know you balance them up in a long line and you knock one
over and it goes all the way along. What you're doing is you are essentially sending information
in a chain. If I bump that domino, that signal will get sent along and the output domino falls
over as well. You could use this practically. If your doorbell stops working, you could, from
your front door have a chain of dominoes and have a sign saying if you are at the door please
bump the domino, right all the way across your house into your living room. And so then if
someone is at the door they'll bump that domino and the signal comes through. The one in the
living room falls over and you know someone is at the door. The downside is they take a long
time to reset. It depends how frequently you have guests [laughter]. But it would in theory
work. But we can do better. Why just send one bit of information when you can have the
circuit interacting with itself? So here I've now got two inputs. For those of you who know
where I'm going with this, try not to skip ahead to the punch line. I've got two inputs over here.
I've got a single output over there. If you want to know more about who is at the door, like let's
say you've ordered a pizza. You could have two inputs at the door. One says are you at the
door? Please bump this domino. The other one says have you got a pizza? Please bump this
domino. Only if you bump both of them will the signal go through. If you bump either one by
itself the signal stops. So this way if you bump this one these topple over and it stops. If you
bump that one the signal splits and it blocks itself before it comes through. But if I knocked
both of these this would've stopped it from stopping itself and the signal would have gone all
the way across. We call this an and gate. We can do a truth table for our friend the and gate.
So you've got all the scenarios. You've got no one at the door and they haven't got a pizza,
nothing happens. Someone's at the door and they have a pizza it doesn't come through. Okay.
For completeness [laughter] somehow a sentient pizza has arrived at the door on its own. It's
managed to parse the sign and bumped over -- okay. It won't get through, thank goodness.
What a horrifying sight that would be if you went to the door. Whereas, here the guy with the
pizza, the signal goes through. There's our and gate made out of dominoes. Of course, why
stop at and? Here is our exclusive or table where the signal only goes through if it's one or the
other one, if you have not come across these before. The exclusiveness is it's one or the other,
but not both. Exclusively date single signal will go through, whereas, no signal moment and two
signals won't. Here it is made out of dominoes a bit in the middle so that if you bump both
inputs at the same time the signals will collide and cancel out in the center there. Either one by
itself would have carried through and out the other side. If you want more tolerances, of
course, you can make this a bit longer or zigzag that in the center so the signals can be a little
bit further apart. If you want to build one of these, by the way, this is about 100 dominoes.
You can make one of these. If you buy a standard large tin of dominoes, you will have enough
to make some of these single gates. But disappointingly, you won't have enough to start
combining them because if you have two inputs and you have the and gate and the exclusive or
outputs you have now got a circuit which counts the number of inputs that have been bumped,
so we've got our units column and our twos column in binary for a binary readout of how many
inputs. This is an enactment set of objects. It's a series of dominoes balanced on a table and it
can count how many inputs you knock and you require 2 to 300 dominoes if you want to build
one of these. I had to build one of these. It looks a little bit like this. Basically it's a clip on, it's
a mod for the exclusive or, which means you get an x1 over there for your other output. This
circuit will count, it's a binary half adder and will count two inputs and someone is off to get
some dominoes right now to give this a go. I couldn't resist either. [laughter]. Wouldn't it be a
shame to stop there? We are so close [laughter] to the full adder, where you've got your two
inputs. You've got a carry from a previous calculation and you've got the carry out and you've
got the output. What this means is you can have a rollover coming from a previous step of the
calculation. You can have your two new digits you're adding and then you can send something
onto the next step well have your output. If you make one of these, the full binary adder, this is
the basic unit for all addition using circuits. This is what I really want to get to, but I get the
numbers to make one of these, you would need 1000 dominoes and it would look a little bit like
this. [laughter]. I may have bought 1000 dominoes. This is me at Manchester University. I've
got some friends who work up there. This is Katie showing you just how excited you should be
at this point than we were able to buy, we bought 1000 dominoes. We used the concrete floor
and we got a working binary full adder built out of dominoes. And then in theory if we had
enough dominoes we could start chaining these. If you had three of these in a row, you could
add any three digit binary numbers and get the four digit readout. We worked out that would
be coming up with about 10,000 dominoes and it would look like this. [laughter]. I contacted a
domino wholesaler. Those were the weirdest phone calls of my life. Eventually, they delivered
them for me and said this is powerful calculator built out of dominoes. I'm going to set the
video going and this is when we actually ran it. It took 12 of us all day to set this up and to pick
what we were adding we picked a domino at random. Over here, these are the two unit inputs.
Nothing has happened because we picked the domino which was 4+6 and so there were no
units to sum. But there is a two, so the six is going to have a two. Over here in the twos
column you see one of them is come through, so one of the twos went through. Two, put a one
in we left gaps in the circuit. For a one week filled in. For a zero we left it empty, so you can
see the one two has gone in. The outputs are over here and they go from the bottom, from
your point of view they go ones, twos, fours and eights going up the screen in that direction.
And then finally, because it's 4+6 you can see over here we have our fours input. They both
have gone in. They canceled out. It's carried over and the crowd has gone wild, excellent. And
there is our readout. A two and an eight. We were able to show conclusively that 4+6 does
indeed equal 10. [laughter]. [applause]. One more mischievous onlooker said it took us 12
people. We started at eight good morning and ran this at six o'clock at night. We had it in the
middle of a science museum, so people were coming by all the time. Someone pointed out that
it took 12 people all day to prove that 4+6 equals 2+8, joke. [laughter]. And we're building this
in front of, this is right in front of the rebuild of Ellen Shearing's first baby computer which was
built at Manchester University, so behind us we had the machine. You can still see all the
valves and everything. It's so good. That was the first computer with electronic programmable
memory and I was allowed to play on it once. To entertain there is a row of buttons and each
button corresponds to a single bit and you just hit the ones you want to be ones and that's how
you program it, absolutely incredible. So we got to build this. And, of course, we thought it
would be a real shame to stop there because we had, you know, a little more effort and a bit
more coming we could make something that could add two four digit binary numbers and give
a five digit readout, which would look like this. Okay. This one didn't work. I have found the
cutting edge of domino computing. It is here with a five bit readout. We were briefly
calculating what Moore's Law would be based on the rate at which we were building bigger
circuits. It's not promising. [laughter]. This one went wrong in two ways and they were both
because of the constraints. We had this space in the museum for the weekend we did the first
one on Saturday, so we didn't have any more space on the Sunday and we didn't have any more
dominoes. So we had to make it much more packed in and the last one there was a lot of space
to walk around and to set it all up. This one was crammed in much more dense and we had to
cut back on a lot of the timing, so all these delay lines, this is too slow one signal down before it
goes in so the signals had to come in at the right stage. We had loads of delay lines to allow for
that. Two things went wrong. One we had signal bleed. We had crosstalk between two of the
lines, so here this domino is not supposed to fall over. This change is not meant to topple. You
can see the signal has already come around here and gone. This should remain stationary. A
signal is going to come in this way and watch this, ready, watch. The other signal comes
through, ahh. And again, in slow motion [laughter] here it comes. No. That was a phantom bit
that came out and so we got that on top of the answer. I think he became a two or something.
It was really annoying. And the other one, this one here went wrong. This was a
synchronization issue. We had a timing problem where this signal over here should not get out.
That is the carry signal and it needs to be blocked. Over here, this is the signal that is going to
stop it. This one is going to come racing along here to the gate there and bam, it's going to
block it. I've been watching a lot of American football since I have been over. It was supposed
to stop there but it didn't work. The signal got there before the blocking signal arrived, so it
closed the gate after the signal had left. Here it comes, watch. This one is still going to get
there first, like that is totally going to reach it in time. Here we go, and it comes and ahh. So
there you are, this is cutting-edge domino computing. If we were in England I would tell you
you are now welcome to borrow my 10,000 dominoes. Schools have been using them to try
and build their own circuits and get into this ridiculousness. All the circuit diagrams are in the
book. In fact, if you didn't get a book, you don't want to pay the money for it, just walk over
there and get it and discreetly get your phone out and it's in the answers in the back of the
book, because I wanted to put it in the book and my editor was like no. You're not putting, no.
I said what if I, am I allowed answers at the back of the book? And they were like okay. So a
huge chunk of the book and all the things I wasn't allowed in the normal bit of the book I have
hidden in the back of the book, so the circuit diagrams are in the back. The other thing, if you
want to get most of the value out of the book, because pretty much any other book that you
get, oh, I didn't use your book before because often it's the ISBN which is used in the barcode. I
have not learned, they changed ISBNs a few years ago and I have not learned either of the ISBN
methods, so I do apologize. My free time is finite. But if you open any other book and you look
at it and you look at the page numbers and open to a random page, the page number on the
left will be even and the page number on the right will be odd. Almost without exception in any
other book it's always even on the left and odd on the right. Not get my book. You look in my
book and it's odd on the left and even on the right because I start on page 0. [laughter]. Oh my
God, the e-mails it took to be allowed, first of all, I got the zeroth chapter. They are like what
the introduction? And I said no, the zeroth chapter. And then they started on page 0, so it
shifts all the, oh good. In fact, that is half the value of the book. If you don't want to buy it
[laughter], just pick it up and marvel at the page numbers and put it back. You're done. That's
half the fun. The last thing I was going to show you and then I will put my e-mail address and
everything up again if you want to copy. Is the Christmas present that my mom gave me two
years, and you should have seen my giddy face on Christmas morning, when I unwrapped this.
It is a knitted scarf made entirely out of ones and zeros. It's a binary scarf. Okay. Some of you
are impressed but not all. [applause]. Fine. It's a binary scarf. You either like it or you don't.
>>: What does it say?
>> Matt Parker: What does it say? That is the first time I have had that heckle. Very neat, I like
it. Originally, because my mom is not that into math, so initially, I thought that she just did
random ones and zeros because she knows I like binary codes and so she made the scarf. And
then suddenly I realized every single row starts 010, every single one. That means it's a proper
actual code, right? Every single row is a capital letter because my mum knits the way she text
messages [laughter]. I was like, so what does it say? I was like I got to work it out. So I got the
back of the wrapping paper and I got my pen out and I -- what a lovely Christmas morning that
was. I got to sit down with the family and calculate my present. As I was decoding it she found
an interview I had done for a website and so it's a quote of one of my answers. It was a quote I
gave at the website. I try to be bilingual. I tend to say math when I'm in North America. In
England we would say math, same as in Australia where I'm from and so the actual quote,
precisely, is math is fun. Keep doing math. Which certainly sounds like me. Then I was like
well, mum how on earth, how did you get it correct, because my mum loves knitting. That
much is very obvious, but she's not that into math. It turns out she cheated. She e-mailed my
brother Steve who is also a massive nerd. Steve gave her a link to one of the websites where
you can type your message and hit convert and it just gives you all of the ones and zeros
underneath. The reason Steve knows about the website is because we e-mail each other in
binary [laughter]. Which I can't over recommend by the way, it is so good. Although, you can
go too far I got an e-mail in from Steve. It came in in all ones and zeros, classic Steve. I put it in
the converter and hit convert and it came back out as Morse code, too far. Seriously, what a
geek. My mum was able to do this and she met this scarf and I was so pleased. And then I
almost didn't tell her this because she made a mistake. Part way down she swapped a one with
a zero and turned a U into a V in the code. If you decode this precisely it actually says math is
fvn. Keep doing math. Ah mom, I hate to ruin your fvn. That's what happens when you replace
a one with a zero. And she wanted to fix it. She was quite upset. This isn't math class. You
don't have to fix it because to make the scarf long enough the message actually repeats four
times, front and back front and back. She only made a mistake in one of those. So what that
means is all I have to do is calculate the average value across all four versions and that gives me
back the original accurate message without the mistake. So Microsoft, I can present to you the
world's first error correcting scarf [applause]. I will leave the scarf at the front if you would like
to come and meet it. It also signs autographs. You've got to pick it up and write your own
name. Obviously, I'm now fluent in binary. It's a lot less impressive in this room, to be honest,
but I can -- when people come up and get me to sign a book, I'm like okay. Do you want this in
normal letters or binary code? I can do ASCII. I can't do Unicode when anyone comes up and
demands, I can't do it in hex, but if you want the straight ones and zeros of ASCII, I'm your guy.
I'll be around. I'm about to do Q&A now, so I'm going to answer questions if you've got things
you just desperately got to rush off to, that's fine. But I will do Q&A for approximately a
quarter of an hour and then I will loiter around afterwards if anyone wants to come up and say
hello. I believe we've got the space until three o'clockish. It depends on where people need to
go. I'm happy. If you want me to deface and lower the resale value of your copy of the book, I
am more than happy to do that, but on that note here is all of my information back up on the
screen and that is officially the end of my talk. Thank you very much. [applause]. Okay. Any
questions? I mean it was a very comprehensive talk, so I can understand. Was that one in the
back or are you stretching?
>>: Did you read Flatland when you were younger?
>> Matt Parker: Did I read Flatland when I was younger? Yes I did. I read a romance in many
dimensions because I believe that's a subtitle. When I was about 14 I read a book called The
Boy Who Reversed Himself, which was a kind of young adult fiction book about the fourth
dimension as well. It's like Flatland without the Victorian error misogyny. I read that as a young
kid and then later on read Flatland. The title of the book is a reference to the fact, partly, it was
a nice catchy title that the editor liked, and there's a whole chapter on the fourth dimension in
there. There's obviously several about two and 3-D shapes on the way up. And there are
amazing 4D shapes that you can talk about in that chapter. And there's a later chapter about
high dimensional spaces beyond that. I thought it was a real shame that there are amazing bits
of mathematics that require four dimensions and you can so rarely get to them because it takes
a lot of background reading and a bit of a run-up. But I knew in a book I would have the time to
kind of seed the path along the way with everything people would need so by the time they get
to chapter 10, as it turns out, you're ready to go into the fourth dimension. But in a short talk I
very rarely would do it in a standard book talk because it takes so much momentum to get
there. A lot of people are just I don't understand it. I don't want to reinforce that aspect of
math where it's just confusing and people don't get it. But if you have not come across, there is
a whole new platonic solid in 4D; it's brilliant. Yes? Is there a question from online?
>> Amy Draves: Yes. It's a little personal, but you mentioned that your…
>> Matt Parker: Read it out loud. That's fine. [laughter]
>> Amy Draves: You mentioned that your brother is also a spectacular nerd, but your mother is
not. What about dad?
>> Matt Parker: That's a very good question. My brother is a massive nerd. In fact, he's a
physicist, but, you know, you can't choose your family. We have a sister as well and she's a
physiotherapist so we kind of count that. My dad's an accountant, so, in fact, as a small child
he brainwashed me into liking math. He used to buy me like arithmetic books as a treat
[laughter] and so I got to school going brilliant math and everybody else's like what? Say what
you like about brainwashing; it's effective. [laughter]. I grew up enjoying -- my mother loves
like puzzles and logic and stuff and so it was quite a nerdy pastime. And I have since married a
physicist, so my wife is one also, so I am surrounded by them. I have a soft spot for physics. I
think that's, people say I'm good at math. I'm not good at math. It's hereditary, all of this, I
think having been a high school teacher a huge amount is the support of the parents. The
number of parent-teacher nights where the parents make excuses for their own kids, things like
I'm terrible at math. I never got it and of course my kid can't do it. I think that's ridiculous. It is
not as innate as people think it is. I think supportive parents make all of the difference as to
how far you go into those subjects. Good question online person. Anymore questions here or
virtual? Yes?
>>: For the fourth dimension do you mean time as the fourth dimension?
>> Matt Parker: So the question was, it was a twofold question in case you missed it. He said is
the fourth dimension time and is the fifth dimension really love? [laughter]. If you haven't
seen Interstellar, spoiler alert, there you are. [laughter]. It's interesting you say that before
the, forget it. Is the fourth dimension time? Physicists have a habit of when they get stuck in
physics they walk over to see what mathematicians are up to. I'm just going to borrow some of
this and then they go back over here and do physics with it. Obviously, the math behind 4D
originally was done the spatial, so you fall directions in which you can move. A height
dimension is still often visualized or at least understood in terms of spatial dimensions,
whereas, physicists, specifically Einstein and actually a lot of mathematicians working in the
area are very close to similar sorts of equations, realized that they could use time as a fourth
dimension and the equations work out really nicely. There's this great thing in physics where if
the equations work out nicely that tends to imply that they are probably right. And there's no
real reason why -- there's this thing called reasonable effectiveness of mathematics, where map
shouldn't predict the way reality works, but it seems to. I use the fourth dimension as a
direction you can move in, but exactly the same math applies using it as time, and a slight
tweak on the equations means you can apply it to love. [laughter]. Actually there's a great
thing about physics, there's a lot of hard work. The one big difference, but in physics if you
want to get new physics, you've got to do experiments and data and theories. Whereas, in
math just like, I'd like some more math. I'll think hard for new math. [laughter]. And math,
what a better way to go about it. Sorry. Other questions? I will go in the aisle and then we'll
go online.
>>: I loved your Sudoku point on people enjoying that are enjoying math. As people get more
computationally sensitive, are you seeing these things like perhaps Minecraft, kids aren't doing
good math at school, but all of the sudden they are creating circuit boards because it's
something visualized? What about AR, BR? How do you feel education computation and
mathematics in 140 characters or less?
>> Matt Parker: I will obviously be as concise as I can. Minecraft is a very good example. I
think there are students definitely doing things in Minecraft that there is no way they would be
doing at school and so when I show the domino computer a lot of kids do logic gates. In
Minecraft there's a 3-D printer in there. There's amazing things. I did a project recently on
building fractals to making minga sponges out of origami and so a lot of kids then went and
made them in Minecraft afterwards. What I think Minecraft is doing, because I don't think it's
creating any new nerds, but I think the students who like those things, it's giving them an outlet
for it. I think YouTube is actually feeling a very similar role, where previously, if you were into
math and science you would get very bored quite quickly in high school. Whereas, now there is
somewhere you can go to access that wider community so that you are not alone. You are not
unusual, and there's an outlet and it’s the fun bit. It's the playing with the subject which I think
keeps kids interested. And we spend a lot of time at school making them learn the skills
without ever showing them where the skills can be used and so I think Minecraft is a brilliant
place where the skills they are learning at school they can deploy them in a fun, social
environment, and so I think it's a fantastic outlet in that regard. In terms of if it's an evangelical
tool as to converting new people to tech, I don't know. I suspect it's catering to people who
could have easily fallen by the wayside otherwise, but I don't know if it's bringing new people
into the fold. Okay. We will go online.
>> Amy Draves: We actually have two questions, completely unrelated.
>> Matt Parker: Same person?
>> Amy Draves: What?
>> Matt Parker: Same person two questions?
>> Amy Draves: Two questions, two different people.
>> Matt Parker: Okay.
>> Amy Draves: One person is really curious about how you became a standup mathematician.
And the second question is Star Trek or Star Wars? [laughter].
>> Matt Parker: Now we're getting down. Education, we're getting into the serious subject
matter now. I'll start with the inconsequential in, Star Wars. In terms of standup, the way I got
into standup is I was working as a math teacher. I worked for some universities. I had gone
back to teaching and I knew I wanted to move into doing, my skill set was less being a good
classroom teacher and more about going into schools and doing workshops and activities and
priming the students to then be more enthusiastic afterwards to working with the teachers. It's
dangerous going into a school and doing a whizbang presentation. When you leave the
students go to their teacher and say why don't you do that all the time? And so it can be
counterproductive. Because I've been a teacher, I can go in and work with the teachers to
make this really useful and ongoing. I also want to get adults more excited about mathematics.
Part of that was seeing parents who didn't value math and thought they were terrible at it. Part
of the problem is in the wider culture. I looked at doing public speaking training, because I
wanted to get better at doing math presentations. A lot of it is very, all of the courses I found
very corporate. It was like having to give a business presentation and all of these sorts of
things. I found an evening course in standup comedy. And I was like brilliant. I'll do an evening
course like one night a week for like 10 weeks. I go in there and I get all of those transferable
skills and get back out again. I started doing the course and absolutely loved it. About halfway
through was a course, there was about 12 or 15 of us in the course, part way in a few of us
were like how hard can this be? And we're in London and we're like we're one of the best
standup things going. This could be an open mic night. So three of us signed up for a local
open mic night. Only I showed up. [laughter]. I was, I'm doing it, and I absolutely loved it. I
started working part-time doing standup, but originally, it was purely my academic approach. If
I want to be good at this I will do a course in it. But then I realized if I could actually do it and
work on the circuit I could get even better and get more skills. I ended up absolutely loving it.
It's a fantastic art form and if any of you have ever wondered would you be good at standup, I
don't know about Seattle, but a lot of cities have a course you can do or they have an open mic
scene. I would highly recommend. It's like extreme public speaking training and so I highly
recommend it to people. I think I missed the window to get into Star Trek at the right time. A
friend of mine is really big on the math of Star Trek. He is all over that. Whereas, Star Wars I
think I was at the right age at the right time, so I'm going to go Star Wars over Star Trek. There
is some fantastic math. Someone did a video for a channel I'm involved with on YouTube, a
channel called Head Squeeze, about the naming system that George Lucas used and his serial
codes for the robots in no way matchup with the production levels of robots that would be
going on in that universe. The numbers of C3PO and all those, that doesn't scale. Again, the
universe has got some mathematical holes in it but I'm going to go with Star Wars on that one.
[laughter]. I'll do between one and two, I'll do approximately one and a half questions if
anyone. I won't take it personally if there's not. That's fine.
>> Amy Draves: There's one more online.
>> Matt Parker: There's more online?
>> Amy Draves: Yes.
>> Matt Parker: This is like doing YouTube live. [laughter]. The questions coming in as I'm
here.
>> Amy Draves: What would be a recommendation from math books for like younger kids,
middle schoolers?
>> Matt Parker: A recommendation for math books? I hear Things to Make and Do in the
Fourth Dimension is available second of December. [laughter]. One thing I still recommend,
they are a little bit antiquated. It depends on how involved you want to be with the kid who is
reading it. All the old Martin Gardner books are still very good. Some of them will find the
language and the structure foreign, but that's fine. I highly recommend if you get Martin
Gardner's old books and a collection of his columns from Scientific America, then there are
some fantastic content in there for kids. I'm not the only person writing new books about
mathematics. There are loads of great ones out there. Anything that makes them think at the
same time. There is an author called Simon Singh who wrote The Codebook and he wrote
Fermat’s Last Theorem and so Fermat’s Last Theorem is a really good book into the insight of
what it's like to be a mathematician. And actually Marcus du Sautoy wrote a book, The Music
of the Primes, which is a really nice one, again, of what it's like to be a mathematician. In terms
of actually hands-on puzzles, Martin Gardner’s stuff is very difficult to be. On that note, I'm
going to wrap up because people have to get back to your jobs. However, I will be around for
as long as people want to come up and say hi or deface books, anyone's books, not only mine.
[laughter]. But on that note, thank you all very much and for listening so well. [applause]