Why Scientists and Artists Want The Blackest Substances on Earth

This is an ultra-black.

And in case you missed the memo,

ultra-blacks are the new black.

These light-capturing coatings have been used

to cover luxury cars, and even make art projects.

[popping]

Like this black hole, which was so black

a viewer actually fell in.

Their depth perception rendered useless

by the optical illusion.

That black hole is an artwork by the artist Anish Kapoor,

who controversially secured exclusive rights to use what was

then the blackest coating called Vantablack in his work.

That upset a lot of other artists who also wanted

to use these blackest blacks.

And the whole art community were like,

We can't take this!

This is so out of order!

This is so rude.

You've gotta make a black that's better than his black.

That's Stuart Semple, and he created this paint,

which is one of the blackest paints you can buy.

[Stuart] Black 3.0 is literally the closest you can get

to a black hole in a bottle.

[Arielle] But here's the thing, there are blacker blacks.

And scientists are measuring just

how much light they can capture.

Our blacks are the blackest that we know of.

[Arielle] That's John Lehman, a scientist at

the National Institute for Standards and Technology.

He's helped develop one of the blackest ultra-blacks yet.

The not-so-secret sauce?

Carbon nanotubes, which can only really

be seen under powerful magnification.

Carbon nanotubes are a structure made of a layer

of graphenes a millionth of the diameter of a human hair.

Those nanotube blacks might have military applications,

be useful for photography,

and to make ever more accurate sensors.

So, why do we care?

I spoke to both Semple and Lehman

to find out what's behind this race to make

the most light trapping substances yet.

But first, let's watch some paint dry.

For you this journey really began with Anish Kapoor,

and this sort of locking up of the blackest black.

If that hadn't happened, would there be this race

to create the blackest black in the art world?

I don't think there would have been,

because I don't think the art world would have even known

that there was a material like this.

I mean if it had stayed in astronomy, or defense,

or military or something, we wouldn't have known it existed.

But because Anish was using it,

artists sort of tuned into it,

and then we realized that we wanted

to have a go and use something like that, too.

We're artists.

We're interested in what you can see with your eye.

So really, it doesn't matter what it is doing in

the infrared spectrum, and UV spectrum in a science lab.

What we want is a really flat black looking black

we can make work with.

So, if you put it next to Vantablack,

yeah it kinda looks similar to the naked eye.

But if you start measuring it in a lab,

there's miles of difference.

Why do you think people are so excited about

the idea of creating the blackest black paint?

I think artists have always been very interested in black

because it's actually not a color.

We're talking about the absence of light,

and that's just been exciting since the beginning of time.

So when you're going about trying to make

a paint that is not a color,

but the absence of color, where do you begin?

A lot of the other super black things

that you see are scientific processes.

And they're incredible, but they're made in labs,

and they grow nanotubes,

and they're made in vacuum chambers.

It's complicated.

We approached it like paint makers.

So, Black 3 isn't the same thing

as these Vantablacks or Singularity black.

Although it does have nano particles in it,

it is very much a paint.

So we had to create an new pigment

from scratch called Black Magic, which is born matte.

Can you tell me about some of the ways

you've seen Black 3.0 being used in the wild?

I've seen it used in so many exciting ways.

You know, we always wanted to make something usable,

so that was the whole point.

But astronomers are using it,

amateur astronomers inside their telescopes,

so they reflect less light.

Photographers are using it inside camera bodies.

Magicians are using it.

[Arielle] Sure, this paint is cool,

and it makes for some pretty neat art projects,

but scientists are pushing

for these light absorbing materials for different reasons.

This is a microscopic image of a forest of carbon nanotubes.

That's what makes the most light absorbing

ultra-blacks work so well.

Carbon nanotubes are a structure made

of a layer of graphenes a millionth

of the diameter of a human hair.

[Arielle] So, how do these carbon nanotubes

capture particles of light, or photons

as scientists call them?

So basically what we're doing when

we make something very black

is we're creating this topology wherein

if photons intersect this coating,

they rattle around until they get absorbed.

But making light-absorbing carbon nanotubes isn't easy.

It has to be done under careful conditions.

Each lab does it a little differently,

but the basics are roughly the same.

So, when you're developing this extremely black,

light-absorbing surface,

you have to start with these nanotubes.

How are those grown or developed?

So, let's say we're gonna make some carbon nanotubes.

So, we do in fact grow them in an evacuated oven.

That is it has a vacuum.

And we're gonna introduce carbon into that oven,

and that's gonna be the basis of the nanotube.

So we're gonna grow the nanotubes on a substrate,

which is in our case is silicon.

You can think of that as a cookie sheet.

Then we're gonna grease the cookie sheet with iron,

and then as the substrate heats up,

and the carbon is introduced,

the nanotube will start to grow from the substrate.

And the longer we bake it, so to speak,

the taller the nanotube will grow.

After that, we take it out of the oven,

and we have a wafer with nanotubes on it.

So, the whole point of this is more

than just a vanity project.

We're not just trying to make the blackest black

because it makes for cool art,

or because it's a great thing to brag about.

But because there are real practical applications

of this stuff.

Exactly.

What do you think are some of the most important things

we can do with these blackest blacks?

We're not just trying to make the blackest black,

we're trying to make useful detectors, right?

So, the carbon nanotube coatings on a detector allow us

to do better measurements of the temperature of the earth.

There is room for 10 times improvement

over what's been done.

The temperature measurements we have

of the earth right now could be improved

by a factor of 10 with your instruments?

There's a difference between what we can do

in the lab on Earth, and what we can do in space.

So, our goals for what we're doing in space

are approaching a 10 times improvement.

And because we can put them on small, fast,

relatively inexpensive detectors means we can put

them into space more readily.

I'm imagining these sort of satellites painted with

the blackest black coating being launched into space.

Is that sort of accurate?

Or can you describe what you've actually sent into space?

So, for the blackest coatings that we put on detectors,

they're typically part of a larger instrument.

So, the detector might be a few millimeters by a millimeter,

and it's buried inside this instrument that has a prism,

and some optics, and so on.

So it's taking that light, dispersing it,

picking a wavelength and looking at it very closely.

And do you just have the one satellite,

or what kind of scale are we talking about?

Right now we just have one satellite.

We've just launched our first one,

and we have another one planned.

[Arielle] This obviously isn't the first attempt

to make an ultra-black black.

There are other materials like Vantablack is one

that's been in the headlines a lot.

Black 3.0 paint is another one.

What makes your black different than those ones?

We are interested scientifically in this question

of what's the blackest black,

and to be frank, we have a publication which shows

that our blacks are the blackest that we know of.

And we've rigorously defended the uncertainties

and the measurement method.

And in a spirit of scientific progress,

I would challenge anybody else to do the same

and see if the agree with us.

By your own measurements,

the material you've developed captures some small percentage

of more light than anything else out there.

That's what we believe.

When we get to this level of blackness,

we're in this realm of, well,

is it really the blackest black,

or is it the best measurement of the blackest black?

And so at least in the scientific world for us,

where we have to know very accurately,

we put effort into that.

So I don't know how much blacker we can make something

and actually know that we made it blacker.

Because there's such a small amount

of light being reflected back that it

becomes increasingly hard to measure

at that amount of light.

Yes, exactly. Exactly.

Thank you so much for joining us.

Yeah, it's great to talk to you.

Thank you.

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