About a hundred and fifty million years ago, there lived a genus of,
little dinosaurs called Archaeopteryx. It was about a half a metre long
weighed less than a kilogram and might not have been very
remarkable at the time. But its fossil's are some of the most
important we've every found. Because this little dinosaur had both wings
and incredibly well developed feathers. Which
made it crucial to our understanding of how birds- which are
technically dinosaurs -evolved. And new research published
this week in the journal Nature Communications provides some of the
first solid evidence that it used those wings and
feathers for actual powered flight
as opposed to just gliding. Archaeopteryx wasn't a direct
ancestor of today's birds as far as we can tell it was more like
a close cousin
of that lineage. But even though all of its descendants eventually died
out. It's so closely related to the lineage that lead to modern
birds that it can tell us a lot about how they evolved.
Archaeopteryx basically had a mix of both bird and
non-Avian dinosaur traits. It had a long boney tail
and jaws with sharp teeth like a dinosaur.
Along with contour feathers. The kind that help
birds fly on its fore-limbs and tail. But we don't know exactly
how it used those feathers and there's a lot of debate about
whether Archaeopteryx could only glide or if it
was capable of active flight. Researchers knew that to figure out the answer
they'd have to look at the internal structure of the
dinosaur's bones. But we've only got eleven fossils
of these guys so they weren't gonna just start choppin'. To get around that problem, this new study involved
a special non-invasive scanning technique called Synchrotron Microtomography, which uses X-Rays to construct a detailed
picture in this case, of the architecture of a fossilised bone. In addition to Archaeopteryx
they also looked at the internal bone structure of a range of other species
including other dinosaurs, pterosaurs, and
modern birds. The results confirmed something other researchers
had found that in general bone architecture
predicts an animal's flight ability. Across the
species the researchers looked at, all the ones that could fly
shared the same thin, lightweight bones. And if the species
actively flew as opposed to just gliding, it's bones were
structured in a way that would make them more resistant
to the twisting forces that come with flapping wings. Which is what
they saw in Archaeopteryx too. Its bones were
light and their architecture looked a lot like what
you would find in birds that mostly fly in short bursts, like pheasants.
With that said Archaeopteryx's skeleton
was still very different to that of a lot of today's birds and there are
lots of reasons to think it couldn't fly. For one thing its shoulder joints
have a simpler structure the would make it tough to flap the way modern
birds do. It also didn't have the big keel on
its breastbone that bird's flight muscles anchor to.
The authors of this new study suggested that Archaeopteryx wing beats were
just very different from what we're used to. Moving
in a more front to back grabbing type motion than the birds around today.
So Archaeopteryx clearly wasn't a great
flyer but it may have been the earliest flying dinosaur we know of,
foreshadowing all the flying dinosaurs living in
your backyard today. Speaking of firsts, our
abilities to make graphene, the first two-dimensional material
ever discovered just levelled up. Graphene is
built up of a single layer of carbon atoms arranged into a
type of lattice. That's what makes it 2-D. Which would be cool enough on its
own but the material's physical properties sound like
something out of a sci-fi. It can carry a thousand times as much
current as copper. And its a hundred and fifty times stronger
than steel. But still like pliable and
stretchy. Its potential applications include new types of
computer chips, solar cells and super long lasting batteries
among lots of other things. That is
if we could figure out how to mass produce it.
And in a paper published this week in the journal Nature Materials
researchers brought that goal a little closer to reality
with a way to manufacture large sheets as
single crystals. There are two traditional ways of making
graphene. you can separate graphite, the form of carbon
in pencils into thinner and thinner flakes.
Or you can grow it from scratch by pumping in carbon containing gas
over a layer of something else that acts as a catalysts
to help get the carbon out of the gas and arrange it into a
sheet one atom thick. This is a new twist on that second method that allows
for much tighter control of the process.
The technique involves using a
hydrocarbon gas. A gas with molecules made up of hydrocarbon
combined with a nickel-copper foil.
When the gas hits that foil it reacts in way that
results in a layer of carbon atoms being positive. The researchers
new innovation was to carefully control where the carbon atoms
went. Growing the graphene sheet along a
specific leading edge rather than letting carbon
clusters form all over. Doing it this way required extremely
hot temperatures over 1000 degrees
celsius and blowing a stream of hydrogen-argon gas ahead
of the growth front, to keep the clusters of
carbon atoms from forming where they weren't wanted.
But by careful controlling the conditions this way the researchers
could make sure that the fastest growing orientation of
graphene crystals beat out the others. You end up with a
sheet that's essentially one big single
crystal instead of mish-mash of different ones. That makes it
stronger ad more conductive than graphene produced
the old less precise way. This concept is known as evolutionary selection growth and its been
previously used for making 3-D materials but not
a 2-D material like graphene. And the researchers could
grow these graphene crystal films at a rate of about
2.5 cm an hour. That may not sound like much
but considering that some of the more traditional
method would only get you about 0.3 cm an hour its pretty
fast. Could graphene produced this way become into chip or battery near you?
Well we're not quite at that point yet
but this new method of making it could help us
get to it. In the meantime though there's still some pretty amazing
stuff out there in the world right now. In November we
launched SciShow Finds. A corner of the internet where
we have curated artefacts that were remind us
how the universe fills us with wonder. We're thrilled
that you all cared about the special things as much as we did.
So we're doing it again. We have a couple repeats that
were requested. Like the Mars socks and more Trilobite fossils
though slightly different Trilobite fossils 'cos look at them,
they're cool and old and used to be everywhere and now they're nowhere
and we have some new items that you can use to experiment
in the world and share your science enthusiasm. Including mystical fire which turns any wood burning fire
into a weird rainbow, be careful with this one
obviously but also just throw it in there and don't
tell your friends and they'll be like, "what am I onnnn?".
We''ve scoured the universe for the best refrigerator magnet
in existence and we think that we've found that. They look like
pushpins but they're so powerful
they're actually pull pins. They need that
so that you can get them off. And you know that
I can't include a favourite book. This story of Earth by Robert M Hazen
is the origin story that precludes
all origin stories and it's amazing. When he found
out that we wanted to feature his book on SciShow Finds
Doctor Hazen even decided to write a letter to all the
readers with updates on what he's learned the
book was published. Just like last time we have a limited number
of these special finds. Last time a lot of them sold out pretty immediately.
We're gonna keep them up until we will run out
and then we will find new special things that show off and
foster our love of the world. So head over to
Scishowfinds.com to buy something from SciShow Finds. Now that you're supporting people
who make and find these cool things and also
supporting SciShow. (Cue Outro)