0:00:19.626,0:00:24.460
What is the best kind of cheese[br]to use to catch a bear?

0:00:25.752,0:00:27.639
Someone knows over here?

0:00:28.099,0:00:30.893
Obviously, the answer is "come here bear."

0:00:30.894,0:00:32.043
Camembert!

0:00:32.052,0:00:33.166
(Laughter)

0:00:33.167,0:00:34.376
Camembert!

0:00:34.391,0:00:35.555
(Applause)

0:00:37.135,0:00:38.481
Thank you.

0:00:39.461,0:00:42.833
I have a head full of cheese puns,

0:00:42.834,0:00:46.543
but I was told I had to keep it 'brie'-f.

0:00:46.546,0:00:47.796
(Laughter)

0:00:48.716,0:00:51.518
What did the piece of cheese say

0:00:51.519,0:00:54.412
when it looked into the mirror?

0:00:57.417,0:01:00.851
No. It said, "Halloumi."

0:01:00.852,0:01:02.261
(Laughter)

0:01:02.262,0:01:03.742
Hello me!

0:01:04.382,0:01:08.544
What can I say guys? I love a good pun.

0:01:09.854,0:01:12.744
Why?

0:01:13.214,0:01:14.669
I don't know;

0:01:14.670,0:01:17.263
because puns are funny, right?

0:01:18.493,0:01:19.576
Why?

0:01:19.577,0:01:22.760
Well, because there is[br]a bit of a surprise factor.

0:01:22.761,0:01:26.452
You feel outsmarted for a second[br]until you get the double meaning.

0:01:27.208,0:01:28.353
Why?

0:01:29.323,0:01:32.142
Because that's the way language works.

0:01:34.352,0:01:37.209
OK. I get what these slides are doing.

0:01:37.210,0:01:40.663
They're playing the why game

0:01:40.664,0:01:43.953
where you keep asking,[br]"Why, why, but why?"

0:01:43.954,0:01:45.686
after everything someone says.

0:01:45.687,0:01:47.718
Kids do it all of the time

0:01:48.648,0:01:53.188
and adults should do it more often.

0:01:53.189,0:01:55.118
I'm just kidding. Don't. It's annoying.

0:01:55.119,0:01:56.566
(Laughter)

0:01:58.266,0:02:02.376
You can ask why, over, and over,[br]and over again for ever,

0:02:02.377,0:02:05.391
even if one day, we explain

0:02:05.392,0:02:07.601
every physical interaction,[br]and scientific law,

0:02:07.602,0:02:12.680
and hope, and dream, and regret[br]with a single elegant equation.

0:02:12.681,0:02:17.413
You could still ask,[br]"Why? Why that equation?

0:02:17.414,0:02:22.058
Why doesn't the universe operate[br]with some different equation?"

0:02:22.059,0:02:27.260
So, yes; the why game[br]is irritating, it's annoying,

0:02:27.261,0:02:29.061
and it's what I do for a living.

0:02:30.601,0:02:32.844
Every week, for the past few years,

0:02:32.845,0:02:37.690
I have researched a big question,[br]a funny why question.

0:02:37.709,0:02:40.724
I've researched the science's,[br]the mathematics’s recent theories

0:02:40.844,0:02:43.231
behind all kinds of things.

0:02:43.250,0:02:47.521
I do this on my YouTube channel: Vsauce.

0:02:47.522,0:02:51.541
So, Vsauce, in the last couple[br]of years, has grown phenomenally.

0:02:51.542,0:02:53.281
It's hard to believe.

0:02:53.282,0:02:57.436
I'm now doing more than 30 million views[br]every single month,

0:02:57.437,0:02:59.656
with five and a half subscribers

0:02:59.657,0:03:03.297
growing more[br]than 10,000 new subscribers every day.

0:03:04.437,0:03:06.889
It's awesome. I love it.

0:03:06.890,0:03:10.485
I get to ask[br]some pretty ridiculous questions.

0:03:10.486,0:03:13.584
For instance, "Is anything real?"

0:03:14.134,0:03:17.935
Come on! How can you possible answer that?

0:03:17.936,0:03:19.563
Well, that's not really the point.

0:03:19.564,0:03:22.175
The point is to bring people in[br]with a great question,

0:03:22.176,0:03:24.768
make them curious, and once they're there,

0:03:24.769,0:03:28.774
accidentally teach them a whole bunch[br]of things about the universe.

0:03:28.775,0:03:30.494
(Laughter)

0:03:30.495,0:03:34.603
Some examples[br]of other questions I've asked:

0:03:36.930,0:03:39.270
how much does a shadow weigh?

0:03:40.150,0:03:43.676
What does it mean to ask[br]a question like that, "What us a shadow?"

0:03:46.432,0:03:48.352
What color is a mirror?

0:03:49.252,0:03:51.645
In answering this question,[br]you could explain a lot

0:03:51.765,0:03:55.220
about specular reflection,[br]the physics of light.

0:03:55.221,0:03:59.232
This is one of my favorites,[br]"Why are things creepy?

0:03:59.233,0:04:00.399
(Laughter)

0:04:02.259,0:04:06.270
I often go into psychology[br]- that's more where my background is in -

0:04:06.271,0:04:12.179
but a question I have yet to answer,[br]- hopefully, someone out there knows -

0:04:12.180,0:04:15.655
please tell me[br]why is this called your 'bottom'

0:04:15.656,0:04:17.857
if it's technically[br]in the middle of your body?

0:04:17.976,0:04:19.172
(Laughter)

0:04:19.173,0:04:20.300
It's ridiculous.

0:04:20.301,0:04:22.019
But it's a really good question.

0:04:22.021,0:04:26.415
I ask questions all of the time,[br]but today, this is my question.

0:04:28.085,0:04:30.062
Why do we ask questions?

0:04:31.102,0:04:32.900
Seriously. I mean, what's the point?

0:04:32.901,0:04:36.576
Who cares why things are creepy?[br]They just are.

0:04:36.577,0:04:39.430
Who cares why this is called my bottom?

0:04:39.431,0:04:41.096
It's gross, don't do that anymore.

0:04:45.054,0:04:46.240
Questions.

0:04:47.380,0:04:52.862
How do I get people[br]to care about these questions?

0:04:52.863,0:04:56.342
Especially people who think[br]that learning is boring.

0:04:57.022,0:05:03.471
I like to believe that the limits[br]of what you can be interested in

0:05:03.472,0:05:05.350
are unlimited.

0:05:05.351,0:05:06.570
And this is my story.

0:05:07.720,0:05:10.804
I began making YouTube videos[br]about six years ago,

0:05:10.805,0:05:14.383
but only recently did I start[br]making explanatory videos.

0:05:14.384,0:05:16.213
I've no idea what took me so long.

0:05:16.214,0:05:19.297
I have been explaining things[br]my entire life.

0:05:19.298,0:05:24.017
Except, usually, I did it alone, out loud.

0:05:24.018,0:05:27.618
I talk to myself[br]when I'm alone; all the time.

0:05:27.619,0:05:30.514
If you snuck up on me[br]when I didn't think anyone was around,

0:05:30.515,0:05:34.861
you would overhear me explaining[br]the most mundane stuff.

0:05:34.862,0:05:37.382
It's kind of weird, maybe.

0:05:38.822,0:05:42.375
OK, it's really weird,[br]but for me, it is a great way,

0:05:42.376,0:05:46.780
for me to know that I kind of know[br]more what I'm talking about

0:05:46.781,0:05:49.328
if I can verbally explain it.

0:05:51.238,0:05:52.723
As Albert Einstein said,

0:05:52.724,0:05:57.553
"If you can't explain it simply,[br]you don't understand it well enough."

0:05:57.554,0:06:02.452
When I was a teenager, I discovered[br]a competitive speaking program

0:06:02.453,0:06:04.783
and one of the events[br]was informative speaking,

0:06:04.784,0:06:09.018
where you literally got to write a speech[br]explaining something to judges,

0:06:09.019,0:06:12.593
and then you were given points and medals[br]if you were good enough.

0:06:12.594,0:06:18.062
My very first informative speech ever[br]was about ketchup:

0:06:20.022,0:06:23.451
the history of ketchup.[br]the etymology of the name,

0:06:23.452,0:06:27.333
its legal status, the physics[br]of its viscosity, and how it flowed.

0:06:27.334,0:06:30.600
It was super nerdy stuff.

0:06:30.601,0:06:35.935
But at my very, very first[br]public speaking tournament

0:06:35.936,0:06:38.583
I took first place.

0:06:38.584,0:06:39.709
Hey!

0:06:39.720,0:06:41.533
(Applause)

0:06:41.534,0:06:42.663
Look at that guy.

0:06:42.664,0:06:44.254
(Applause)

0:06:45.844,0:06:50.169
Some of the hair here moved down here,[br]but other than that,

0:06:50.170,0:06:51.848
I'm the same guy.

0:06:51.849,0:06:54.072
Seriously, I'm still doing the same thing.

0:06:56.432,0:06:59.889
To be at that tournament and to see[br]the expression on someone's face

0:07:00.749,0:07:06.074
when they suddenly understand[br]and are fascinated by something,

0:07:06.075,0:07:08.430
in the same way that you are

0:07:09.510,0:07:10.939
is a phenomenal feeling.

0:07:10.940,0:07:12.821
I've learned two things from this:

0:07:12.822,0:07:16.090
first of all, people love[br]a good explanation.

0:07:16.091,0:07:17.630
They hunt them down.

0:07:17.631,0:07:21.859
Even people who say they hate learning,[br]and hate books, and all that stuff,

0:07:21.876,0:07:24.059
pff, they love explanations.

0:07:24.060,0:07:26.955
Second of all, if you look closely enough

0:07:27.905,0:07:29.896
and you take the time,

0:07:29.897,0:07:33.812
anything can be interesting to anyone

0:07:33.813,0:07:37.320
because everything is related[br]in some way to something they care about.

0:07:38.880,0:07:40.596
Richard Feynman called

0:07:40.597,0:07:45.982
"the pleasure of finding things out"[br]a "kick in the discovery."

0:07:45.983,0:07:49.687
And I agree, but I think[br]there might be a little bit more to that.

0:07:49.688,0:07:51.680
Let's get rid of this picture of me.

0:07:51.681,0:07:56.494
We want to express ourselves,

0:07:56.495,0:07:58.362
everyone wants to express themselves.

0:07:58.363,0:08:01.760
They do it through the music[br]they listen to, the clothing they wear,

0:08:01.761,0:08:06.179
the way they act,[br]but they also do it with knowledge.

0:08:06.180,0:08:09.260
The things they know[br]about the stuff they like,

0:08:09.261,0:08:11.927
Their interests, their hobbies.

0:08:11.928,0:08:14.730
I've noticed[br]that the most operative motive

0:08:14.731,0:08:19.978
behind someone sharing one of my videos,[br]promoting me by word of mouth,

0:08:19.979,0:08:24.345
isn't so much about me[br]as it is about them.

0:08:24.346,0:08:28.641
"Hey! Look what I found!", "I like this."

0:08:28.642,0:08:31.294
"I am like this."

0:08:33.424,0:08:36.899
Whenever you share a video,[br]whenever you share anything,

0:08:36.900,0:08:40.179
a few of the attributes[br]of that thing reflect back onto you.

0:08:41.609,0:08:46.520
I've found that one of the best ways[br]to gain attentive listeners

0:08:47.840,0:08:52.523
is not to be who you think[br]your audience wants you to be,

0:08:52.524,0:08:56.185
but instead, to say,[br]and make, and show things

0:08:56.186,0:09:01.630
that allow your audience or your students[br]to be who they want to be.

0:09:05.556,0:09:08.202
I once discussed in a video,

0:09:09.792,0:09:11.844
"Why the sky is blue?"

0:09:14.374,0:09:18.754
And backstage, when I was going through[br]what I want to to talk about,

0:09:18.755,0:09:20.143
I ran into this girl.

0:09:20.144,0:09:23.355
This seriously actually happened[br]backstage, go find her.

0:09:23.356,0:09:26.001
I said, "Do you know why the sky is blue?"

0:09:27.161,0:09:31.493
She said, "I think I used to know,[br]but it didn't really mattered."

0:09:31.494,0:09:33.509
Exactly. Exactly.

0:09:33.510,0:09:35.591
And I knew[br]that was going to be a problem.

0:09:35.592,0:09:37.232
It turns out that the sky is blue

0:09:37.233,0:09:40.700
because of the way light[br]scatters in our atmosphere.

0:09:40.701,0:09:42.614
It's called Rayleigh scattering.

0:09:42.626,0:09:47.445
A light of shorter wave lengths[br]scatters more,

0:09:47.446,0:09:49.169
so, greens, blues, and violets.

0:09:49.170,0:09:51.758
That's why when you look at the sky[br]away from the Sun,

0:09:51.759,0:09:53.999
you see this beautiful sky blue;

0:09:54.000,0:09:56.491
it's all of those shorter[br]wave lengths combining.

0:09:56.492,0:09:59.818
When you look directly at the Sun[br]- which you shouldn't do very often;

0:09:59.819,0:10:01.200
don't do it ever -

0:10:01.209,0:10:05.459
you see the longer wave lengths[br]which are surviving that scattering.

0:10:05.460,0:10:08.927
That's why the Sun looks yellow[br]during the day.

0:10:08.928,0:10:12.421
Of course, when the Sun's light[br]needs to travel through a whole lot of air

0:10:12.541,0:10:13.766
to get into your eyeball,

0:10:13.767,0:10:15.833
a lot of scattering occurs,

0:10:15.834,0:10:19.251
and only really, really long wave lengths[br]make it all the way there

0:10:19.280,0:10:20.489
directly from the Sun,

0:10:20.490,0:10:24.791
which is why it looks orange,[br]or sometimes red at sunrise or sunset.

0:10:25.561,0:10:29.369
I think that's really cool,[br]but obviously, some people

0:10:29.375,0:10:32.334
- including someone[br]backstage right now -, don't.

0:10:32.338,0:10:35.808
Or maybe they already know it,

0:10:35.809,0:10:39.259
or could probably figure out[br]if they thought about it.

0:10:39.260,0:10:40.577
So what do you do?

0:10:40.578,0:10:43.600
I'm trying to collect[br]the largest audience possible that I can,

0:10:43.601,0:10:47.435
I want to appeal to and attract[br]as many people as possible.

0:10:48.385,0:10:52.217
So what I do is[br]I camp out with the subject.

0:10:52.218,0:10:54.469
In this case, Rayleigh scattering.

0:10:54.470,0:10:57.418
I've learned as much about it as I can.

0:10:57.419,0:10:59.695
What else is it responsible for?

0:10:59.696,0:11:04.497
Who is it named after? Who did he love?

0:11:04.498,0:11:07.412
Whatever I can find[br]that could become a great hook

0:11:07.413,0:11:10.566
to bring in just the right person.

0:11:10.567,0:11:13.582
So, in this case, I've read[br]about Rayleigh scattering,

0:11:13.583,0:11:17.062
and I realized--[br]I didn't realize, I learned,

0:11:18.272,0:11:23.432
that blue eyes are blue[br]for the exact same reason.

0:11:24.702,0:11:27.856
Blue eyes do not have[br]blue pigment in them.

0:11:27.857,0:11:29.762
Ouch! That would hurt if that was real.

0:11:31.482,0:11:33.535
Blue eyes don't have blue pigment in them

0:11:33.536,0:11:36.506
any more than the air[br]has blue pigment in it.

0:11:37.256,0:11:42.154
If you were to rip out my iris,[br]I would be like, "Ouch!" but then

0:11:42.155,0:11:43.464
(Laughter)

0:11:43.465,0:11:47.299
if you grounded it up into a fine powder,[br]it wouldn't be blue anymore

0:11:47.300,0:11:51.094
it would be[br]a dull brownish-blackish color.

0:11:51.095,0:11:54.077
Instead, blue eyes are blue[br]because at a microscopic level,

0:11:54.078,0:11:56.363
their texture scatters light

0:11:56.364,0:12:00.593
just like the air in our atmosphere[br]scatters the Sun's light

0:12:00.594,0:12:02.214
to make the sky blue.

0:12:03.024,0:12:05.805
Maybe you already know[br]why the sky is blue,

0:12:05.806,0:12:07.302
maybe you don't care,

0:12:07.303,0:12:09.972
but maybe you will be fascinated[br]by something like this.

0:12:09.973,0:12:12.813
This is why my episodes often seem[br]to go all over the place.

0:12:12.814,0:12:16.155
It's not just because I'm crazy[br]it's also because I want to have

0:12:16.156,0:12:18.011
as many hooks out as possible

0:12:18.012,0:12:20.852
to catch as many people[br]and to make them interested.

0:12:21.309,0:12:23.640
I once did a video about rainbows.

0:12:24.340,0:12:27.121
I thought, "Some people[br]might think rainbows are lame."

0:12:27.122,0:12:30.487
I'll teach about rainbows.

0:12:30.488,0:12:33.602
What other types of bows are there?

0:12:34.292,0:12:37.970
Well, like when a string, like a knot...

0:12:37.971,0:12:40.500
Is a bow a knot?

0:12:40.501,0:12:44.576
Why do headphones[br]always get tied up into knots?

0:12:45.186,0:12:48.343
I researched the mathematics[br]behind this; it's fascinating.

0:12:48.344,0:12:49.926
([Laughter)

0:12:51.396,0:12:53.205
I'll spare you all of the details;

0:12:53.206,0:12:55.689
also, this will allow you[br]to go check out my videos

0:12:55.690,0:12:58.035
and give me many, many views[br]rather than just one.

0:12:59.292,0:13:05.248
In the 1950s, Harold Edgerton[br]took a series of amazing pictures

0:13:05.249,0:13:07.023
of nuclear explosions.

0:13:07.024,0:13:08.873
This is a detonation

0:13:08.874,0:13:10.802
just milliseconds after happening,

0:13:10.803,0:13:14.503
with an exposure time[br]of one billionth of a second.

0:13:15.293,0:13:18.774
You can see the energy[br]of this plasma ball,

0:13:18.775,0:13:22.604
the energy of the explosion is vaporizing[br]the metal wires holding up the tower.

0:13:22.605,0:13:25.585
That's where these glowing,[br]spindly legs come form.

0:13:26.225,0:13:31.964
His work attracted wider and new interest[br]to physical phenomenon

0:13:31.965,0:13:33.814
simply because he featured something

0:13:33.815,0:13:36.815
that people couldn't help[br]but want to look at.

0:13:37.515,0:13:39.713
A moment you couldn't witness alone.

0:13:40.363,0:13:43.714
He famously said, "The trick to education

0:13:45.130,0:13:47.553
is to teach in such a way

0:13:47.554,0:13:51.249
that people only find out[br]they're learning when it's too late."

0:13:51.250,0:13:52.723
(Laughter)

0:13:52.724,0:13:54.044
It works for me.

0:13:54.045,0:13:56.778
So recently, I took on[br]the most difficult question ever,

0:13:56.779,0:13:58.796
but also the most requested,

0:13:58.797,0:14:05.129
"How do I know that the colors[br]I see are the same to you?

0:14:06.049,0:14:09.141
How do I know[br]that when I look at something red,

0:14:09.142,0:14:12.234
you don't look at the same thing[br]and see what I would call green,

0:14:12.235,0:14:15.114
but you call it red because that's[br]what you've always heard,

0:14:15.115,0:14:17.374
and we both agree,[br]and go on our separate lives

0:14:17.375,0:14:20.535
never knowing just how different[br]our perceptions were.

0:14:22.315,0:14:25.554
There's no such thing[br]as a stupid question,

0:14:25.555,0:14:28.057
but there are questions[br]that makes us feel stupid.

0:14:28.058,0:14:29.549
This is one of them

0:14:29.550,0:14:33.899
because there is no way for me[br]to crawl inside someone else's mind

0:14:33.900,0:14:36.759
to see the world as they see it.

0:14:36.760,0:14:39.229
I thought that might be[br]frustrating to my viewers,

0:14:39.230,0:14:41.125
that there really wasn't a good answer.

0:14:41.126,0:14:43.046
I couldn't finish this once and for all.

0:14:43.047,0:14:47.216
So I started looking[br]more generally into questions.

0:14:47.217,0:14:49.928
And the more I read[br]about them, and their history,

0:14:49.929,0:14:55.452
the more I realized that questions[br]might be quite unique to humans.

0:14:57.292,0:15:02.252
Apes that have been taught to use[br]sign language can communicate with us.

0:15:03.492,0:15:07.173
They can answer complex questions,

0:15:07.174,0:15:10.713
they can convey novel thoughts,[br]and they can express their emotions,

0:15:10.714,0:15:13.758
but an ape who knows sign language

0:15:13.759,0:15:18.929
has never been observed to ask a question.

0:15:21.979,0:15:26.377
Soliciting information from an organism[br]belies this assumption

0:15:26.378,0:15:30.622
that other organisms, in some way,[br]have access to information that you don't;

0:15:30.623,0:15:33.895
that they have different,[br]unique intentions or desires.

0:15:33.896,0:15:35.695
It's often called the Theory of Mind,

0:15:35.696,0:15:39.648
and it is incredibly difficult to show[br]that animals have such a thing.

0:15:40.922,0:15:43.608
But of course,[br]we intuitively feel that we do.

0:15:43.609,0:15:45.655
Chimpanzees are clever,

0:15:45.656,0:15:50.875
but they fail a pretty simple,[br]seeming test - deciding who to go to

0:15:50.876,0:15:54.121
to get food that's been hiding in a room:

0:15:54.122,0:15:58.732
a person who was literally in the room[br]and saw where the food was hidden,

0:15:58.733,0:16:01.232
or a person who was also in the room,

0:16:01.233,0:16:03.783
but has had a bucket[br]on their head all day.

0:16:06.043,0:16:12.262
Whether or not animals have the capacity[br]to ask questions is still being debated.

0:16:13.432,0:16:19.540
But after reading all of this, I realized[br]that questions are very special.

0:16:20.590,0:16:24.078
We ask them because it's fun.

0:16:24.079,0:16:27.149
Learning things is a fun experience,

0:16:27.156,0:16:30.175
it's what Feynman called,[br]"a kick in the discovery."

0:16:30.176,0:16:31.450
We also ask questions

0:16:31.451,0:16:34.981
because learning things allows us[br]to explore what we like

0:16:35.731,0:16:39.106
and to show off what we know about it,[br]to show what we are.

0:16:39.107,0:16:43.970
But we also ask questions because we can;

0:16:43.971,0:16:48.855
because perhaps uniquely here on Earth,[br]we know that other people can help.

0:16:50.105,0:16:53.822
And that's a great reason[br]to ask more and more questions,

0:16:53.823,0:16:57.497
to celebrate more and more whys.

0:16:58.427,0:17:00.586
We all want to be "kicked[br]in the discovery,"

0:17:00.587,0:17:04.332
it feels great, but we don't all have[br]a discovery in the same place.

0:17:04.333,0:17:07.505
Taking the time to find[br]where someone's discovery is

0:17:07.506,0:17:09.454
so you can give them a kick there

0:17:09.455,0:17:15.571
isn't just about whys,[br]it's also a very wise thing to do.

0:17:16.382,0:17:18.058
And as always, thanks for watching.

0:17:18.059,0:17:19.417
(Applause)