Does colour exist? | Andrew Parker | TEDxSydney

Andrew Parker studied marine biology and physics at the Australian Museum and Macquarie University, and then moved to Oxford University. After founding the "Light Switch Hypothesis" - that the Big Bang of evolution was triggered by the evolution of the eye - he now works on biomimetics, copying good design found in nature. This includes hummingbird colours for paints, non-reflective surfaces on insect eyes for solar panels, and water-capture devices in Namibian beetles for collecting clean drinking water in Africa.

He was selected as a 'Scientist for the New Century' by The Royal Institution (London) and wrote the popular science books "In the Blink of an Eye" and "Seven Deadly Colours" (Simon & Schuster). Today he is a Research Leader at The Natural History Museum, London and Green Templeton College, Oxford University.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

First of all, colour doesn't exist
in the outside world:

it exists only in the minds
of animals with eyes.

And we still don't fully understand

how our images of the world
are put together.

But that's not an issue for nature.

Nature doesn't need
to understand how things work;

it just gets on with inventing things
through trial and error, random mutations.

Now I'm going to talk about
how I came across these two facts,

and how they led me
to a subject called biomimetics,

which is learning from nature,

taking inspiration from nature
to effect our commercial products.

This all began about 20 years ago,

working on a group of animals called
seed shrimps or ostracod crustaceans.

They are fairly obscure animals,
about the size of a tomato seed,

not very well known, but very, very
common in Australian waters.

They're well known to produce
bioluminescent light.

They light up in the dark
when there's no light to reflect,

and you can find them
on beaches around Sydney at night,

as you can see in this image here.

That was well known,

but I've often quoted that my research
began with a flash of green light,

green or blue light, and that's true.

When I was looking at some
preserved ostracods under a microscope,

I moved them around and started to find
flashes of blue and green light.

This wasn't known for ostracods,
so I thought, "What's going on here?"

Also, when I videoed
live animals during courtship,

they were using these
iridescent flashes of light

as a courtship display
to attract each other.

So, I decided to put some ostracods
in electron microscopes

to find out what's going on.

Here you can see
the images of a diffraction grating

on the surface of the hairs

that are splitting up white light
into its component colours.

Diffraction gratings are well known
in physics and in commerce.

They have a number of uses in technology.

But they weren't known
in ostracods or animals in general.

Now, the interesting thing here is that,

because they were being used
as a courtship display,

they had a function.

So they'd evolved
to be very, very efficient.

Nature had been working on these
over millions of years,

fine-tuning them to be optimal
at doing their job.

Now I knew what I was looking for,

I thought, "Where else
do diffraction gratings occur in nature?"

So I looked at all sorts of animals,

and found them in a range of things.

From worms, as you can see here,

and also on the claws
of, in this case, a galatheid lobster.

You can see how the colour changes
with change in direction.

These are the very bright,
metallic-looking colours

that you find also in hummingbirds
and beetles, for example.

These are physical structures
just like bones.

So I thought, "Well, I wonder
if it occurs in fossils too."

And in fact they did.

We started to look at fossils.

I found them
in 45-million-year-old beetles

that came out of the rocks
just looking like living beetles,

sparkling with all their metallic colours;

in 85-million-year-old ammonites
as you can see here.

You can also see how light is reflecting

from the different layers
in this reflector.

The layers, they're about 100th
of a hair's width in size,

really, really tiny nanostructures, even.

The oldest were the Burgess Shale fossils,

508 million years old
from the Cambrian period.

This got me thinking, "We can take
colour back this far in time,

but how far can you go here?

When did colour first begin on earth?"

That led me to search
for the very first eye that existed.

It turned out to be a trilobite
that had this very first eye,

a type that you can see here.

You can see one of the ridges
on one of the eyes, for example.

Really, really good eyes in fact,

they could produce image
just as well as we can today.

But this animal lived
521 million years ago.

Before that there was no vision,
so colour didn't matter.

There was really no such thing as colour,
just wavelengths of light.

I looked at the animals
that existed at that time.

The trilobite had really
armoured parts, hard parts,

and it had a very modern lifestyle.

It moved very quickly,

and it had hard parts
to tear animals apart.

It was a predator.

It could see animals around it.

But just before that,
all the animals were soft bodied,

even the predecessor of the trilobite,

and they moved around very slowly
on the seafloor just bumping into things.

They didn't really interact
with each other very well.

They did have a light sensor.

The most sophisticated
light sensor of the time

would have produced
this image of the world.

This is the best way animals
could have seen their environment

with such a sensor.

You can see the direction
where light is coming from,

so you know where up and down is
in the water column, for example.

But you can't find
a friend or foe around you.

You can't identify all the other animals
and see what there is.

Then perhaps the most dramatic event
in the history of life happened.

One of those light sensors evolved lenses.

Suddenly an image was cast
on the back of an eye,

the very first image on earth,

which would have looked
something like this.

You can see all the other
animals around you.

You can identify what's possibly prey.

Therefore, selection pressures,
evolutionary pressures,

start acting on that animal
to evolve swimming parts to get there,

a hard part to tear it apart,

and feed on all of those
soft-bodied animals,

which are essentially
chunks of protein waiting to be eaten.

It actually triggered
the Cambrian explosion,

the Big Bang in evolution,

where all animals
went from being soft bodied,

like worms and jellyfish,

into having the whole range of bodies
that you see today,

the whole range of behaviours.

Life suddenly became complex.

Vision was introduced to the world,
and it was here to stay.

Today, over 95% of animals have eyes,

and vision is the most powerful
stimulus on earth.

Everywhere you go,
you leave an image on a retina,

and, from then onwards,
animals had to be adapted

and could at any time
be caught by a predator.

Evolution has led to a design process

where trillions upon trillions
of strands of DNA are mutating,

producing endless designs
of new types of colours.

They've been working on this
over millions of years,

hundreds of millions of years
to produce optimal colours.

A designer in commerce
would be lucky to get a year

to come up with a new colour.

So, why not just go to nature
and see what they have to offer,

see if we can copy some of the things?

Even if we don't understand
how the colours are produced,

that doesn't matter,

just simply copy those nanostructures
that's there in nature,

then you will have the same colours.

After all, we're working
towards the same goal:

the effect on the eye.

So let's go to industry now and ask:

"What type of colours would you like?"

"Would you like a very bright colour
that lights up in the dark,

that even when there's no sunlight,
you can produce light?"

For example in glow sticks,

or in certain applications
in farmers' fields,

where, if a crop is attacked by a virus,

it lights up at night to tell the farmer
where the attack is.

That's exactly what we're doing
with bioluminescent chemicals.

Bioluminescence is where two chemicals
interact in the presence of oxygen

and produce light as a by-product.

It's a very efficient light.

Almost all of the energy
is converted into light,

very little heat, as opposed
to light bulbs, for example.

Bioluminescence causes the light
in fireflies or glow worms.

It's very common in the deep sea,

where over 90% of all animals
produce bioluminescent lights.

Would industry like to have
pigments, perhaps?

These are really common in nature,
for example, in this milk snake here.

There's a pigment in this case
that produces an orange effect.

So, what happens here
is the molecule is struck by white light

with all the different colours
or wavelengths.

Most of those wavelengths
are eaten up and turned into heat,

but the energy remaining
in those that aren't eaten up

is back-reflected or scattered out
into the environment,

so you see those colours.

There's another way that nature
can offer pigments to industry.

That's through chromatophores,
or colour change cells.

These are cells
that can expand or contract

and are filled with pigment.

When they expand,

they are large enough
to be seen as a pixel,

and when they contract,
they become invisible.

This is the way that chameleons
change colour, or cuttlefish or squid.

You can imagine packing red, blue
and green chromatophores together

and expanding and contracting those
to produce any colour you want to.

Now I'm working with Georgia Tech

to try to produce colour change
surfaces and materials,

which is great for camouflage
colours, for example.

We could produce fluorescent colours
for industry as well,

plenty of those around,

particularly in parrots,
Australian parrots in particular.

These are head feathers
from the sulphur-crested cockatoo

that fluoresce.

You'll see there's a picture there
showing the yellow pigment

and then also showing
the fluorescence only.

What's happening is that
the fluorescence is also yellow

and is enhancing
the effect of the yellow pigment.

I found that some yellow feathers
are producing fluorescence

and others are not.

In fact, those that
are used for courtship,

those in areas of the plumage
used to attract a female,

they've got the fluorescent pigment.

So it's not just incidental
of a yellow pigment.

Evolution has acted on this

to be very, very efficient
at producing the yellow light.

Fluorescence results from
an effect at the atomic level,

where white light comes in,
including ultraviolet light.

Ultraviolet, which we don't see,

is eaten up and rejected again
in a longer wavelength.

So some of the high energy
that is contained in ultraviolet light

is used up when an electron jumps
into an outer shell.

When the electron immediately
drops down back to its original shell,

that energy is re-emitted,
but a little is lost as heat,

so there's less energy,

which means a longer wavelength
or yellow light, for example.

So we go from ultraviolet light,
which we don't see,

to yellow light, which we do.

Now, this is my favourite subject,

this is structural colour,
nature's nanotechnology, if you like.

These are physical structures made
from completely transparent materials.

It's the architecture at the nanoscale

that's important in determining
what colour is reflected,

or what type of light effect
that you can see.

Here we have the spines
of a sea mouse called Aphrodita

found around Sydney's beaches.

It's a strange-looking animal;
it looks like a little iridescent mouse.

But it's a marine animal,

and it's covered
in these iridescent spines.

If you cut through those spines,

you can see these tiny nanotubes

that form what's called
a photonic crystal fibre.

Photonic crystals were only discovered
in physics in the 1980s,

and they've since been used in all sorts
of technological applications.

They're going to revolutionize
computers in the future

with optical chips
instead of electronic chips.

These types of photonic crystal fibres

are already used
in the telecommunications industry.

But we've got designs in nature
that aren't known in physics,

and we don't fully understand
how it works in physics yet.

So, let's just copy
what nature's got for now.

And in fact, I didn't find this one.

This was the first photonic crystal
found in nature,

which I found in the year 2000.

But we'd have saved
ourselves a lot of time

if we'd started looking at nature earlier.

Butterflies are really good examples
of photonic crystals.

A butterfly's wing contains
about a hundred thousand scales

overlapping like tiles on a roof.

Each of those scales
are filled with nanostructures

that interact with light waves
in various ways.

And you'll see by these next slides -

we've got electron micrographs
showing the fine details on those scales,

again about 100th
of a hair's width in size -

you'll see how those structures change

almost like the shape
of a building can change,

but when it's on that nanoscale,
around the wavelength of light in scale,

then they will change the colour effect.

So you can see these various
architectures producing different colours,

and they can change the way
that colour changes.

As you walk around these scales,

you can get a change in colour,
or you can get constant colour,

you can get very bright scales,
or you can get duller examples.

A good example
of a photonic crystal is opal,

the gemstone opal as you can see
in this top-left picture there.

Opal is filled with tiny nanospheres.

They're close-packed together.

Light rays come in

and bounce around inside this structure
and interact with each other

to produce these iridescent colours.

But interestingly, I found opal,
in 2005, in a weevil, an animal.

So, a living thing producing opal.

Well, opal does have
lots of technological applications

such as it will appear in computer chips.

Industry makes it at high energy costs;

we need high temperatures and pressures.

But nature, animals, are doing this
at room temperatures and pressures.

They're magically
mixing together chemicals,

and out comes this perfect opal,
using very, very low energy.

So, this is something
we're trying to do at moment.

We're trying to image these scales
in living weevils

to work out how they're
making these devices,

and see if we can copy it
and bring this process to industry.

Some optical devices in nature
don't produce any colour at all.

In fact the opposite:

they prevent any kind of reflections,

all the light passes through a surface,

such as I found on the eye
of this 45-million-year-old fly

preserved in amber.

This very fine structure
you can just about see

in this electron micrograph,
these very fine striations.

When I made this onto a perspex surface,
as you can see in the bottom right,

in the centre there,
you've got this structure,

and you can see how the reflections
are being cut down.

It allows all the light to pass through
instead of being reflected.

If you put this onto a glass window,

you'd no longer see
reflections of yourself.

But put onto solar panels,
we get a 10% increase in energy capture.

Now, several years ago,

I started to expand my interest
in biomimetics, in optics or colour,

into other subjects,

such as looking at strong materials
in beetles or mantis shrimps,

looking at glues that work underwater,

designs of buildings based
on natural animals and plants,

and also air-conditioning systems,
such as found in termite mounds,

to put into buildings,

which require very little power.

One thing that really grabbed me is water.

Just quickly, here's an example
of a Namibian beetle,

where I found a structure

that collects water from desert fogs
very, very efficiently.

It's now being put into
air-conditioning systems

to extract the water out and to recycle.

But nature is telling us

that there's a whole airborne
source of water to tap into,

which animals and plants
are doing in deserts, for example.

That's what I'm working on now
in collaboration with MIT,

and we hope to get
the first devices out into Africa

to collect water for drinking
and medicine quite soon.

So, unfortunately, I can't reveal exactly
the plans that I have next.

We've got some very exciting things
coming up, particularly next year,

but at least I've been able to give you
an introduction to the subject

and say where it all began,

which was 520 million years ago.

Thank you very much.

(Applause)