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)