and apparently, he's out of his mind.

This is a container of human feces.

CHIENG: Why is one of the richest men in the world

carrying a jar of his own shit?

I went to Seattle to find out

what's wrong with Bill Gates.

Mr. Gates, it's a huge honor to meet you.

Just a quick question.

What the (bleep) is wrong with you?

I mean, are you okay?

Yeah, I'm great. Love what I'm doing.

Okay, so why are you carrying around your own poop in a jar?

I did, uh, have a beaker of human feces

when I was explaining why we need a reinvented toilet.

You don't need to reinvent a toilet.

We shit in it, then we push a button,

then the shit disappears. It's perfect.

Well, toilets are something we take for granted,

but billions of people don't have them.

Even in these growing cities in poor countries,

they can't afford to build sewers,

and that causes diseases.

And so we have to come up with a very different way

of taking care of that waste.

CHIENG: And because so much of the world

lacks a sanitary place to poo, Bill launched

the Reinvent the Toilet Challenge.

It funds scientists to redesign toilets

that don't need a sewer system.

We put several hundred million into this

-to show that it can be done. -Wait, sorry, hang on.

You put several hundred million dollars into toilets.

Giving it away, you bet.

CHIENG: Oh, my God. Is Bill Gates

literally flushing his fortune down the toilet?

To find out, I flew all the way to University of South Florida,

where Professor Daniel Yeh and his team

are using Gates' funding

to make some sort of magic poop box.

So, what we have here, essentially,

is a miniature version of the wastewater treatment plant,

and we can put this anywhere in the world.

In the bioreactor, we have microorganisms.

They, uh, eat the poop and turn it into clean water.

Okay, why do the microbes eat the poop?

The microbes eat the poop because that's what they do.

Did you ask them if they want to do that?

Well, uh...

Yeah, why don't you give them a muffin or something?

Maybe they'd like a muffin.

Uh, okay, I'll make a note of that,

but, um, when you show them the poop, they love it.

Despite his crazy talk, there's just something about this guy.

I don't know what it is, but I trust him.

So I decided to give his machine a try.

♪ ♪

(exhales)

So, normally, uh, we would have a block of toilets, right,

and then the waste from the toilets would come here,

it'll go into the machine, and then, using solar power,

we can turn the poopy water into clean water.

-So, you stand by this? -Yeah.

Well, prove it.

Okay.

♪ ♪

-Did it work? -Yeah.

Well, how many times did it not work

and you ended up drinking your own shit?

Well, it's worked so well that,

um, we're actually working with NASA.

Astronauts have to poop,

and we can turn that poop into clean water

and nutrients and even energy.

-Wait, did you say "energy"? -Yeah.

The, uh, microbes in the bioreactor make methane.

That's the same stuff that's in natural gas,

and you can burn it.

Bill Gates, you sneaky bastard.

You just found a filthy little back door

into the most profitable industry in the world,

energy.

You didn't say anything about energy!

Yeah! One way to make it cheap

to process the sewage is to sell these outputs.

You should open with that next time.

Don't open with the "saving the world, kids, and disease" thing.

Open with, "Yo, we're making toilets

that can convert shit into energy."

We need to make these toilets as expensive as possible,

'cause, based on my research,

everyone poops.

I mean, everybody.

Well, unless we make them super cheap,

they're not gonna get out to the poorest

who need them the most.

Look, I know you've made your money.

Some of us here are still trying to win this game.

Well, if you have an idea, let us know.

I've got nothing but ideas for this.

-Okay. -So, this is an iPad.

-(chuckles) -Great device.

-I love using it. Um, so, -Hey, hey, yeah.

what's the worst seat on a plane? Next to the toilet.

But what if every seat was a toilet?

Poop-powered planes.

To keep the plane in motion,

we have to keep shitting.

High pressure, I know,

but it gives the airlines incentive to feed us.

I-I'm not sure the numbers work.

How 'bout this? It's a toilet that you shit in,

and it powers a cannon that shoots the shit out

to my neighbor's house.

(laughing)

Why are you laughing?

That's not legal.

Listen, man, I'm up here just trying to come up

with ideas here to save the world, okay?

-What are you doing? -Um...

that's what I'm doing.

No, that's what I'm doing.

I'm here giving you ideas.

All you're doing is shitting on them.

Well, I don't think...

those ideas are-are ready yet.

But we do have a lot of ideas

that are in the field,

uh, being tested in Durban.

Trying to cover the 30% of their residents

that don't have, uh, great sewage processing.

We are gonna completely change the future.

Everybody's gonna have a great toilet.

Well, here's to everyone having a great toilet.

Cheers.

-(gulps, sighs) -(sighs)

Not bad.

Now guess where that came from.

You just drank my shit.

How's it taste?

That's a very successful process there.

It-it tasted like normal water.

Good job.

CHIENG: Thank you, Bill.

There's more where that came from.

(laughter)