BRADY HARAN: What's your favorite number, and why?
Please leave a comment under this video so I can
compare them all.
And in the meantime, here are the answers given by some of
the top people on YouTube.
Now, I had to interview some of these people in unusual
locations, like up trees and in toilets.
So it's a bit of a hodgepodge.
But it's also a bit of fun.
DEREK MULLER: I'm Derek Muller from Veritasium.
And my favorite number is i--
HANK GREEN: We're in the toilets at YouTube.
DEREK MULLER: --the square root of negative 1.
HANK GREEN: I'm Hank Green of SciShow and also CrashCourse
and Vlogbrothers.
And I'm a big fan of the number 2.
STEVE SPANGLER: So my name is Steve Spangler.
MICHAEL STEVENS: I am Michael from the channel Vsauce.
STEVE SPANGLER: I grew up in a family of
professional magicians.
MICHAEL STEVENS: My favorite number is the number 17,
because I love making 7's with this little guy in the middle,
so that you know it's not a 1.
It's something that my dad always did, and I just adopted
without ever thinking about it.
STEVE SPANGLER: Number 13 has to be my absolute all time
favorite number.
ANGELA LIN: Hi, I'm Angela from YouTube EDU.
STEVE SPANGLER: If you really wanted to see a real
magician's magic wand, it's exactly 13 inches long.
ANGELA LIN: My number is 7.
And I know it's kind of generic, but when I was really
young, people told me that it was a lucky number.
MICHAEL STEVENS: 17 was also the channel of Nickelodeon in
Stillwell, Kansas, where I grew up.
ANGELA LIN: So then I played a bunch of sports.
And every single sport that I played-- volleyball, tennis,
whatever it was-- my number was 7.
BRADY HARAN: Michael from Vsauce has a little line.
But you--
ANGELA LIN: You know, I went through a phase--
I went through a phase where I definitely
drew it with the line.
And then I just decided, you know what, simpler is better.
ALEX DAINIS: I'm Alex from BiteSciZed, and
my number is 27.
ANGELA LIN: Every year on 7/7, on July 7, I
do something special.
So I started it on 7/7/07.
And I remember I went kayaking that day, because I'd never
been kayaking before.
ALEX DAINIS: As I was growing up, my favorite number was
actually always my brother's age.
But when I was 13, I decided that was silly.
And so the last one stuck.
And so my favorite number has always stuck at 27.
BRADY HARAN: Oh, you do one of those things.
ALEX DAINIS: I do.
I do.
BRADY HARAN: Why?
ALEX DAINIS: I don't know.
I think it kind of distinguishes it.
Sometimes my handwriting is terrible.
And so my 7's look like 1's.
So I'll toss a little dash on it.
MICHAEL STEVENS: And 17 is also
significant for another reason.
How come I can't remember it?
It's prime.
What was the other thing?
This is called not respecting your
favorite number well enough.
DESTIN: I'm Destin.
My number is 21.
It's really hard to explain why.
MIKE RUGNETTA: My name is Mike Rugnetta
from PBS Idea Channel.
And my number is 1024.
BRADY HARAN: Hang on, why'd you-- what's with that?
MIKE RUGNETTA: Zero fill.
It's a compulsion just from handwriting so many-- my
handwriting is really bad.
CAITLIN HENDRICKSON: I'm Caitlin
Hendrickson, work at YouTube.
My number is 16.
JOHN GREEN: Hi, I'm John Green of the Vlogbrothers, and my
favorite number is 37, because it was the dorm room that I
first lived in when I went to boarding school.
CAITLIN HENDRICKSON: Growing up, I wanted to drive.
So 16 in the US is when you can drive.
BRADY HARAN: Do you do that with your 7's?
MIKE RUGNETTA: I do.
I do that with my 7's.
And I do my 1's like this, too.
BRADY HARAN: All right, dude.
1024-- why?
MIKE RUGNETTA: 1024.
It's a very sort of nice, round number in computing.
Having a degree in computer science, it has a magical
quality about it, I guess.
ALEX DAINIS: So actually, I also have a little bit of
synesthesia.
So numbers have colors for me.
So 2 is green, and 7 is yellow.
So 27 is actually a very greenish yellow number.
DESTIN: You've heard of synesthesia.
I don't have it, but I think it's amazing.
To me, there's a certain
sharpnesses for certain numbers.
HENRY REICH: My name's Henry.
I make MinutePhysics videos.
And my favorite number is j.
MICHAEL STEVENS: My first kiss wasn't until I was 18.
So it was the last full year I live before I knew
what lips felt like.
CAITLIN HENDRICKSON: And I always wanted to have a sweet
16 birthday party, which my parents never gave me.
But I'll make up for that maybe, when I turn 30 in a
couple of years.
MICHAEL STEVENS: Oh, then the 17th floor is the floor that I
lived on in New York, when I lived in Brooklyn.
But I almost actually lived on the 16th floor, because the
building skipped the 13th.
The elevators went right from 11 to 12 to 14, 15, 16, 17.
Boom.
He's been with me my whole life, basically.
DESTIN: So certain numbers are sharper than others.
So, like, a 1 would be kind of sharp.
A 2 is very dull.
But a 3 is very, very high.
They have this sharpness to them.
I don't know what it is.
So it's like this.
And if I take 3 and 7 and multiply them
together, I get 21.
And for some reason, 21 seems to be this very bright,
cheerful, proper number.
BRADY HARAN: So how high will 21 be on the sharpness scale.
DESTIN: Oh, it's way up here.
It's like, it's off the page.
PATRICK JONES: Hi, I'm PatrickJMT.
And my favorite number, or one of my
favorite numbers, is 1729.
HENRY REICH: Now, before you say j isn't a number, I mean,
j is a number.
COLIN GREGORY PALMER GREY: I'm CGPGrey, and my favorite
number is 0.
I like 0 because it's not an obvious number.
You can have counting systems--
there's one thing, two things, three things, four things.
But mathematics existed for a long time without having a 0
as part of it.
So it's a number, but it also isn't
anything in and of itself.
VI HART: I'm Vi Hart.
You have to tell me what a number is if I'm going to
choose one.
All right, I'm having trouble with this.
HENRY REICH: Similar to the way i is the square root of
negative 1.
But what it actually means is that i squared is negative 1.
J squared is plus 1.
But j is not 1.
COLIN GREGORY PALMER GREY: But one of the other things that I
like about 0 is that it's the kind of unsung workhorse of
the mathematical world.
You have 0.
And then if you want to make 10, you put a one in
front of that 0.
And now we have 10 things.
And people focus on the 1.
But it's really the 0 that is doing all the work
to make that a 10.
And then the same thing with 100 or 100,000.
We keep adding 0's.
We keep adding nothing, but making the
numbers much, much larger.
VI HART: Students in school are like, oh, what's i?
That's not really a number.
And then there's j.
j's a good one.
It's already taken.
BRADY HARAN: You know that Derek-- you can see on there
that Derek chose i.
You chose j.
What's the difference?
Why'd you pick that one?
HENRY REICH: Who wants to pick the team that's going to win
all the time?
Who wants to pick the New York Yankees, you know?
You want to pick the underdog.
You don't want to pick what everyone else has
already gone for.
VI HART: Star, which is not a number.
It's like a number.
The thing is it's smaller than all the positive numbers, and
it's larger than all the negative numbers,
but it's not 0.
It gets confused with the 0.
This is one of those weird things you get in
combinatorial game theory.
And I like it.
I think the very not-numberness of it, I think
that's what appeals about a lot of these numbers to us,
like the weirdness of j, the weirdness of i, the
weirdness of 0.
COLIN GREGORY PALMER GREY: I like 0's non-obviousness and
its incredible usefulness.
BRADY HARAN: Does j exist?
HENRY REICH: Does j exist?
I mean, does any number exist?
-So what we're going to be talking about today is whether
or not numbers exist.
We're going to be thinking about three different schools
of thought on this.
BRADY HARAN: Don't forget to leave your favorite number and
the reason under the video.
And if you're wondering what I'm going to do with this,
well, I don't exactly know yet.
But when I decide, I'll probably let you know via the
numberphile Facebook and Twitter.
So make sure you're following us on there.