But I see a few people out there

who are standing,

we've got some over here,

and standing takes more work than lounging.

Using the Live Strong Organization's online database

of weight loss resources,

you can calculate

that by the time I'm done with this speech,

those of you who are standing

will have burned 7.5 more calories

than those of you who are bean-bagging it.

Okay, here's a question,

speaking of weight loss, specifically weight,

this speech is live.

I'm actually here in front of you guys,

we're all here together.

But this speech is being recorded

and it will become a video

that people can access all over the world

on computers,

mobile devices,

televisions.

I weight about 190 pounds.

How much will the video weigh?

Asking questions like that

is what I do every week on my channel Vsauce.

For the last two years,

I have been asking really fun questions,

mind-boggling questions,

and approaching them

as sincerely as I can,

celebrating scientific concepts and scientists.

And I research

and write

and produce

and host

and edit

and upload

and run the social media all by myself,

but it's not lonely

because Vsauce has more than 2 million subscribers,

and every month, my videos are seen

by more than 20 million people.

Yeah.

It's very exciting.

I've found that asking a strange question

is a great way to get people in,

not just people, but fans.

And fans are different than just viewers or an audience

because fans want to come back.

They subscribe to you on YouTube

and they want to watch everything you've made

and everything you plan to make in the future

because we are curious people

and sparking curiosity is great bait.

It's a great way to catch a human.

And once you've caught them,

you have this captive audience that you can,

with the goal in mind of answering the question,

accidentally teach a lot of things to.

So, let's take a look at some of my videos.

Here are eight of them.

But down here in the lower-right corner,

"What Color is a Mirror?"

When people see that,

it's very difficult not to click because you think,

"Come on, are you serious?

How could you possibly answer that question?"

Well, so far, 7.6 million people have watched

this five-minute video about what color a mirror is.

And in that episode, I answer the question

and I get a chance to explain

what would normally be kind of dry topics:

optics,

diffuse versus specular reflection,

how light works,

how light works on the retina,

and even the etymology of color terms

like white and black.

Okay, spoiler alert:

mirrors are not clear,

they are not silvery

like they're often illustrated.

Mirrors, technically speaking,

are just a tiny, tiny, little bit

green.

You can demonstrate this

by putting two mirrors next to each other,

facing so they reflect back and forth

and back and forth forever.

Look down that infinite reflection

and it will get dimmer

because some light is lost or absorbed every time,

but it will also become greener

because green light,

that is light of a wavelength

that we perceive as green,

is best reflected by most mirrors.

Okay, so, how much does a video weigh?

Well, when you stream a video onto your computer,

that information is temporarily stored

using electrons.

And the number of electrons on your device

won't actually increase or decrease.

But it takes energy to store them in one place,

and we know,

thanks to our friend Albert Einstein,

that energy and mass are related.

Okay, so here's the thing:

let's say you're watching a YouTube video

at a really nice resolution, 720p.

Assuming a typical bit rate,

we can figure that a minute of YouTube video

is going to need to involve

about 10 million electrons on your device.

Plugging all those electrons

and the energy it takes to hold them

in the correct place for you to see the video

into that formula,

we can figure out

that one minute of YouTube video

increases the mass of your computer

by about 10 to the negative 19th grams.

Written out, it looks like this.

That's like nothing.

That's, you could call that nothing

and you wouldn't really get in trouble

because the best scales we've ever invented

that we could try to use

to actually to detect that change

are only accurate to 10 to the negative 9th grams.

So, we can't measure it,

but we can, like we just did,

calculate it.

And that's really cool

because when I was a kid,

my school had two shelves of science books.

That was really cool,

but I read all of them within, like, two grades,

and it was hard to get more books

because books are heavy

and you need space for them

and moving books around is a lot tougher

than what we can do today.

With numbers that small,

I can fit thousands of books

on my own little personal electronic reader.

I can stream hours and hours

and days and days of YouTube video

without my computer ever getting measurably heavier.

And as information becomes that light,

it becomes a lot more democratic,

meaning that more teachers

and presenters

and creators

and viewers than ever before

can be involved.

Right now on YouTube

there is an explosion of content

like this happening.

The three Vsauce channels

are down there in the corner.

But everyone else, all together,

collectively,

their views dwarf what I can do alone

or with the people that I work with,

and that is really, really exciting.

It turns out that tapping into people's curiosity

and responsibly answering their questions

is a brilliant way to build fans and an audience

and get in viewers.

It's even a great way for brands and companies

to build trust.

So, calculating the weight of a video

is kind of a funny question,

but I cannot wait to see

what we ask and answer next.

As always, thanks for watching.