July 9, 2025 • 29 mins
What makes diamonds so hard? And could anything beat it? (The answer is yes.) Jorge gets the hard answers from physicist Jodie Bradby.
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Speaker 1 (00:00):
Hey, welcome to Sign Stuff, a production of iHeartRadio. I'm
More hitch Ham, and today we are answering a really
hard question, maybe the hardest we've ever tried to answer,
which is is there anything harder than diamonds? Okay, that
was a silly pun, but we've all heard the slogans
the diamond is forever, it's a girl's best friend. But
(00:24):
it's a diamond? Really that sturdy? Let break if I
hit it with the hammer? What happens if I stick
one in the oven? We're going to talk to an
expert on heart materials and we're going to ask her
all the tough questions. See I could have said hard,
but I didn't. Anyways, get ready to quit our ring
on it as we bling out and find out is
(00:47):
there anything harder than diamonds? Enjoy? Hey everyone, Today we're
answering a pretty basic question, which is are diamonds the
hardest material known to humans? Now, for this episode, I
interviewed a really cool expert, Professor Jody Bradby, from the
(01:10):
Australian National University, and I learned a lot of cool
things about diamonds I didn't know before, Like, for example,
did you know you can make a diamond out of
peanut butter. Yeah, this is something scientists actually tested and
it's true. Okay, I'm gonna let doctor Bradby explain it.
Speaker 2 (01:30):
I'm Professor Jody Bradby. I'm head of a high pressure
physics group at the Australian National University.
Speaker 1 (01:36):
Great. Now, when you say it's high pressure, is it
like there's a lot of pressure on everyone working there or.
Speaker 2 (01:41):
There are so many puns. In my fields, we have
a high stress environment. Yeah, definitely, but we create really
high pressures to make new materials.
Speaker 1 (01:53):
Oh, very exciting. So today we're trying to answer the
question is there anything harder than diamonds? So I thought
we could start having you talked to us just about
diamonds themselves. What makes diamonds so hard?
Speaker 2 (02:05):
Yeah, So basically diamond consists of carbon atoms. So if
you arrange the carbon atoms in a particular crystal structure,
then that's what makes the diamond.
Speaker 1 (02:17):
How do the atoms get into a crystal structure?
Speaker 2 (02:20):
Okay, so you get your carbon atoms, and now we've
got to do something to trick those carbon atoms to
form a crystal lattice. So nature uses two things to
do this. It uses temperature and pressure, so we have
to have really high pressures and really high temperatures. So
the pressure forces the carbon atoms close together, and then
(02:41):
the little electrons in the atoms go, oh dear, we're
going to have to rearrange and we need to make
different friends. So they form different bonds, and they form
what's called a convalent bond.
Speaker 1 (02:51):
So it's just carbon.
Speaker 2 (02:52):
Yes, yes, it's one of the beauties of diamond making.
There's like carbon everywhere. I think some scientists famously a
diamond out of peanut butter once just to prove that
you could do it.
Speaker 1 (03:05):
How do you make a diamond out of peanut butter?
Speaker 2 (03:07):
So they just got a bit of peanut butter and
squeeze the life out of it. Basically it released a
lot of other things like hydrogen and things. I think
it actually broke the system that they were using, but
they did make like tiny little diamonds, which is a
really cute experiment.
Speaker 1 (03:22):
Oh wow, was it the chunky or the smooth kine
or the shiny.
Speaker 3 (03:27):
Code I don't know.
Speaker 1 (03:31):
Yeah, So you can make diamonds out of anything with carbon,
even peanut butter, which means you can make diamonds in
a jiff, get it like peanut butter brand No, actually,
naturally occurring diamonds take a long time. But here's the
next interesting thing I learned about diamonds. Scientists don't really
know how long it takes to make them.
Speaker 2 (03:55):
So we famously know that diamonds are formed deep into
the earth in a kind of a GOLDI lie for
diamond formation.
Speaker 3 (04:02):
It also takes.
Speaker 2 (04:03):
Potentially billions of years for this process to happen.
Speaker 1 (04:06):
Why does it take a long time?
Speaker 2 (04:08):
Well, that's actually interesting. We don't really know how long
diamonds take to form deep in the earth. We don't
know exactly how the process works. It's one of those
things you do if you read the textbook, it says, yes,
you need this temperature and this pressure, but we can't
actually explain the science so that we can't look down
that deep in the earth and watch what's happening.
Speaker 1 (04:29):
That's right. The actual way in which diamonds form is
still a mystery. The only reason we think it takes
a long time is that when we take carbon in
a lab and squeeze it super hard and make it
super duper hard, nothing happens. So we assume that it
must take a long time, maybe billions of years, but
(04:52):
we're not really sure. Now you might be thinking, wait
a minute, a joorhe I thought we could make diamonds
in the lab and in factories, we can make artificial diamonds.
How do we make those? Well, it turns out that
to make a diamond in a lab you have to sheath.
Speaker 2 (05:11):
We can play tricks up on the surface of the
earth where we add metallic catalysts, and that can just
help the process go a lot faster, and therefore we
can make it on a time period that you know,
we don't have to wait around billions of years to
get your engagement ring. That's where you could create like
a coke cans worth of diamonds in about an hour.
(05:32):
And these massive presses and really high temperatures, huge industrial
process and the diamonds you're talking about here are generally
in diamonds that you might put them on the top
of a drill bit, and it did cost about the
same as a sandwich.
Speaker 1 (05:48):
So we can make diamonds artificially in a lab or
in a factory, but to get the really natural, pure ones,
like the ones made inside the earth, you have to
wait potentially billions of years. And by the way, if
you're waiting billions of years for an engagement ring, you
might want to consider either an artificial diamond or a
(06:09):
new girlfriend or boyfriend. Okay, the next question I had
for doctor Bradby was what makes diamonds so hard? If
they're just carbon atoms, what makes them different than a
lump of coal or graphite, which is what your pencil
lead is made out of. Both of those things are
also made of pure carbon, And the answer is that
(06:32):
it's all about how those carbon atoms are arranged. So
coal is just carbon. What's the difference between that and diamonds?
Speaker 2 (06:43):
Yeah, excellent question. So that is how we arrange those
atoms within the structure. So diamond has what we call
a tetrahedral lattice. That means each carbon atom is attached
to four of its bodies in a particular structure. It's
really really and it goes on forever. In this three
dimensional structure. Coal is basically made of black carbon graphite,
(07:08):
which is layers of carbon. Now those layers are attached
to their bodies in three bonds in one sort of plane.
They're really really strong, but they can move over each
other really really easily.
Speaker 3 (07:21):
They're quite slippery.
Speaker 1 (07:23):
The sheets of graphites are slippery, that's right.
Speaker 3 (07:26):
They slip over each other.
Speaker 2 (07:27):
That's why when you touch coal, it comes off on
your hand, but if you touch diamond it does not.
Speaker 1 (07:34):
So the secret beween diamond's heartners is a lucky combination
of two things. The first is that the carbon atoms
form really strong bonds with each other. If you remember
from high school chemistry, carbon has four electrons in its
outer shell, so it forms perfect covalent bonds with itself,
and these are the strongest types of bonds there are,
(07:57):
as opposed to ionic bonds, which is what all table
salt together, for example, or hydrogen bonds, which is what
holds water molecules to each other. But here's the kicker, though,
The bonds that carbon forms in diamonds are not the
strongest kinds of covalent bonds that carbon can make. The
carbon in graphite actually form stronger bonds what are called
(08:21):
SP two bonds, which are stronger than SP three bonds,
which is what carbon uses in diamonds. So technically graphite,
which is what you use in your pencil to write
that smears when you rub it against paper, is stronger
than diamonds. But how is that possible? Well, as doctor
Bradby said, the carbon in diamonds forms a three D structure.
(08:45):
Think of it like the scaffolding and a building before
you put on the walls and floors in it, whereas
the carbon in graphite forms two D grids or sheets
which slip past each other and make the graphite crumply.
Speaker 2 (09:01):
So you might have heard of carbon nanotubes. They were
these sort of wrap around tubes of graphite essentially, and
they joined up in a big tube and they were
very very strong, and there were people saying that they
were going to build elevators to the moon with these
carbon nano structures because they were so very very strong.
So that is a very strong bond, but it's only
(09:22):
one layer, so you can play tricks to try to
make it kind of three dimensionally strong. But you don't
need to do that with diamond because its crystal structure
is already three dimensional strong in all the directions, and
that's why it's super hard. So nearly all materials that
are relatively hard have the same properties, have that same
(09:43):
two things, a really strong bond and a essentially isotropic
or the same in every direction bonding network.
Speaker 1 (09:53):
It's just that magic combination and only carbon will do that. No,
there's other materials as well, all right, and that brings
us to the big question of the episode, which is
is there anything harder than diamonds? We're going to find
out and I think the answer will surprise you. Stay
(10:14):
with us, We'll be right back. Welcome back. All right.
We talked about how you can make diamonds out of
peanut butter, how we're not quite sure how diamonds are
made under the ground, and about the magic sauce that
(10:35):
makes diamonds so hard. Now the question is how hard
are they? Are there other materials that are harder? I
asked our expert, doctor Bradby this question. Okay, so then
now the question is harder materials that are harder than diamond?
Or could there be materials harder than diamond? Yes?
Speaker 2 (10:55):
Yes, So this is one of those intriguing scientific questions
because because when you get out into the literature, there's
always a little bit of ajibaji discussion around this. So
you have some groups claiming that they've created this material
that is theory should be harder than diamond. And this
is the crux of the things. There's a lot of
(11:16):
theoretical calculations that might predict a material to be harder
than diamond.
Speaker 1 (11:22):
Whoa, whoa, whoa, Wait a minute. We can create materials
or invent materials that don't exist.
Speaker 3 (11:30):
Oh, we do that all the time.
Speaker 2 (11:32):
We can use machine learning techniques and we do these
things what's called a random property search. So essentially, what
the modeling people do is they get a whole lot
of atoms and they put them in a can. Now
the cans in their computer, but they still call it
a sample, and they apply various conditions to that sample.
(11:52):
They might provide a pressure at temperature, they might suddenly
unload it quickly. They do something to that, and they
look at what the energy of that system is. And
if there is a little dip, that means like the
atoms might be stuck down there. They're all in that
little configuration. That could indicate that that is a stable structure.
(12:12):
So then they go, oh, what happened there? And then
they pull those atoms out at that particular point and
they look at the structure and they go, oh, this
is a good structure.
Speaker 1 (12:22):
Uh huh.
Speaker 2 (12:23):
Maybe this is going to be really important in terms
of a super conducting magnet or it might be really
really hard.
Speaker 1 (12:32):
Well, this is pretty cool. Scientists can now basically simulate
nature and basically roll the dice and see if they
can get atoms to form new kinds of materials that
maybe we've never seen before. I always thought in movies
when they mention the fictional material like vibrinium or adamantium
in the Marvel movies, that it was all made up.
(12:54):
But there really could be materials out there that can
do things we can't even imagine right now. Of course,
though this is all in the computer. The real question is.
Speaker 2 (13:07):
Can we physically create that material, And sometimes the answer
is no, or can we physically create enough of it
that we can measure it to actually confirm that it's
harder than diamond. It's possible, we can never get there physically,
Like it's just impossible in the terms of pressure, temperature,
thermodynamics to get to that structure.
Speaker 1 (13:27):
It's impossible to get atoms to make that structure, even
though it's technically possible. Getting there is a whole different
thing possible. Yeah.
Speaker 2 (13:36):
Yeah, So there's many, many of these structures proposed. I
think carbon's got ten or twenty, maybe hundreds of structures
of carbon that have been proposed to exist.
Speaker 1 (13:48):
Uh huh.
Speaker 2 (13:48):
And this is carbon that's bonded in the same way
the covalent bond. And we've really only found two that
we can confirm.
Speaker 1 (13:58):
Okay, there are two materials that scientists think should be
harder than diamonds. The first one is a material that's
found in meteorites. Okay, so what are these two materials?
Speaker 3 (14:11):
Okay?
Speaker 2 (14:12):
Some one is a different arrangement which is called Lonsterlight.
Speaker 1 (14:15):
What's it called again, Lonsterlight lines Delight Okay.
Speaker 2 (14:19):
So it's named after Kathleen Lonsdale, who is a carbon
scientist in the UK. Amazing person, really worth going down
a rabbit hole with her, and in honor of the
work that she did in carbon, the lons Light structure
was named after her.
Speaker 1 (14:36):
So it's also made out of carbon.
Speaker 2 (14:38):
It's made out of carbon. It's also made out of
convalently bonded carbon. It's also in a continuous three dimension network,
so it ticks the boxes that we've been talking about.
Speaker 1 (14:49):
Huh.
Speaker 2 (14:49):
But it's got a different structure.
Speaker 3 (14:52):
So the way the.
Speaker 2 (14:53):
Atoms are physically arranged is slightly different. So instead of
having a repeating box that is a ubique structure. It's
got a slightly different structure to that, and we call
it a hexagonal structure. Now that doesn't mean that it's
sort of arranged in a hexagonal latters. What it means
is you can create a hexagonal repeating cell within the
(15:16):
framework of the crystom. It is predicted to be harder
than diamond.
Speaker 1 (15:24):
Okay, So the first material scientists think could be harder
than diamonds is called lonstelate, and it's basically a diamond,
but with its structure tweaked so that overall its grid
repeats itself in a hexagonal pattern. It actually has been
found in nature in meteorites that have crashed on Earth.
(15:45):
Notably who's found in fragments of the Canyon Diablo meteorite,
which is what made the huge crater at meteor Crater
landmark in Arizona. It's also been reportedly found in a
diamond deposit in Kazakhstan. Now, in theory, according to the
computer simulations, this lancelide should be harder than diamonds.
Speaker 2 (16:06):
But but there's a butt, And usually with all this
harder than diamond work, there is a butt. And the
butt is that it is only on one particular poking direction.
Speaker 1 (16:19):
Okay, it's only strong in one direction.
Speaker 2 (16:22):
Yeap, only in one direction, and that is because of
the way that breaking of bonds, that movement of things,
how that works.
Speaker 1 (16:32):
What doctor Bradby is saying is that some materials are
harder or softer depending on which direction you try to
squeeze them. Sort of like if you had a box
in front of you and you try to squeeze it
from top to bottom or from the sides, it might
feel hard in all of those directions, but if you
squeeze it at the corners, it might collapse more easily.
(16:54):
The same thing happens in crystal materials, and in lancelide,
one of those directions is predicted to be harder than diamonds.
The reason for that is a little technical, but basically,
when you press down on a material and it yields
or it gives, the atoms tend to rearrange themselves a
little bit. And in lons oflide, because of its tweak
(17:15):
diamond structure, the crystal has to rearrange itself twice, which
is what makes it a harder material. Okay, you might
have noticed that we keep saying loss of lighte might
be harder than diamonds. You're probably thinking, if we found
lons of light in meteorites here on Earth, why can't
we just test it, you know, smash it against diamonds
(17:35):
and see which one survives. But the problem is that
lonz of lte has only been found as tiny, little
microscopic crystals that are too small to put in a
machine to test, and also no one's quite been able
to make it in the lab.
Speaker 2 (17:52):
There is definitely a crystal structure called lonster light that
is definitely different to the cubic structure. But whether the
diamond can form enough of this material to be perfect
and be in a bulk like structure, we have never
been able to successfully make that.
Speaker 1 (18:08):
Yet.
Speaker 2 (18:09):
We've made tiny amounts of the lunsterlite. You could imagine
a little one centimeter rock of this stuff, but each
individual crystal is still really small, like it's not a
perfect single crystal. It would be lovely if we could
make a perfect single crystal of this material that was
about a centimeter, because then we could put it in
(18:30):
all our machines, we could look at it from every
direction and we could confirm that is, yes, this is
exactly that structure. And more importantly, we could actually measure
and see if it was indeed harder than diamond.
Speaker 1 (18:45):
I see, but we can't because the sample that you
have created is really small.
Speaker 2 (18:50):
And of course then we get to the thorny question
of what do you poke it with? Because at the
moment all our pokey tools are made of diamond.
Speaker 3 (18:59):
Of course, So this is a.
Speaker 2 (19:02):
Problem I pose to every first year class that I think,
I am trying to measure something harder than diamond, but
the only thing I have to measure with is diamond.
Speaker 3 (19:11):
If you want to come and talk.
Speaker 2 (19:12):
To me about the solution to this, please how work.
Speaker 3 (19:15):
In my lab?
Speaker 1 (19:18):
All right, when we come back, we're going to learn
about another material scientist think might be harder than diamonds.
And then we're going to talk about two things that
are definitely harder than diamonds. Don't go anywhere. You're listening
to sign stuff, Welcome back. So then this long slight
(19:47):
would be stronger, but only in certain directions. In the
other directions, it wouldn't be stronger than diamond.
Speaker 3 (19:51):
Correct, Ye?
Speaker 1 (19:53):
Now, is that the only one that we know about
that might be harder?
Speaker 2 (19:56):
No, there's another few. So there is more on nitri
that you can get a cubic structure of that or
hexagonal structure.
Speaker 1 (20:04):
Okay, so that one's not just pure carbon atoms. It's different.
Speaker 2 (20:08):
No, it's got nitrogen in it as well, so it's hydrogen, helium,
lithium boron. So we're still talking about a low atomic number.
Speaker 3 (20:16):
And this does.
Speaker 2 (20:17):
Seem to be the case that all the harder elements
are low atomic numbers. They're high up there on the
periodic table.
Speaker 1 (20:24):
You might not remember this from high school chemistry. I
certainly didn't, but atoms high on the periodic table are
smaller and lighter, and it means that electrons are closer
to their nuclei, which means the bonds they form with
other atoms are shorter, which makes them stronger. It's also
(20:45):
no coincidence that boron and nitrogen, the main components of
or nitrite, are just to the rate and just to
the left of carbon in the periodic table, so they're
kind of the closest you can get to a carbon bond.
But now the question is is this boron nitride harder
than diamonds?
Speaker 2 (21:07):
That's also predicted to be a super hard material, perhaps
harder than diamond, but it's not really, I'm not convinced.
Speaker 3 (21:14):
Put it that way.
Speaker 1 (21:15):
Okay, So why are you not convinced?
Speaker 2 (21:17):
Because I am an experimental scientist and one of the
sayings in my lab is nice story, Now show.
Speaker 1 (21:25):
Me the data. So there's no data for this material
not convincing no meaning like people have made it, but
they haven't tested it. What does it mean?
Speaker 2 (21:36):
Yes, well, if you test it using a diamond and
you poke it, if you're approaching the hardness of the
diamond and you push them together, you can imagine that
there's going to be some sort of giving in the
tip in the diamond.
Speaker 3 (21:51):
As well as the sample.
Speaker 2 (21:53):
And currently that's not accounted for in many of the measurements.
Speaker 1 (21:57):
But the diamond makes a whole a divid in the
boron like yeah.
Speaker 2 (22:00):
Yeah, I mean the diamond can make a divot in
other diamond. But that doesn't mean that diamond is harder
than the tip diamond.
Speaker 1 (22:07):
H What is it? Because if it is harder that
it's hard to tell.
Speaker 2 (22:13):
Yeah, I would say the evidence that it's harder has
not been compelling.
Speaker 1 (22:19):
So what would it take to convince you if we
switched it?
Speaker 2 (22:22):
If somebody made an indented tip from oron nitride and
use that to indented diamonds surface. And there was just
an indent in the diamond surface. And we looked at
the tip before and after, and we analyzed it, and
we looked down with an electron microscope, and we saw
that there was no defects in that tip.
Speaker 3 (22:42):
That might be a.
Speaker 1 (22:43):
Pretty good proof, meaning the tip didn't crack when it
hit the diamond. Where hasn't anyone done that?
Speaker 3 (22:48):
That's a good question. I don't know.
Speaker 2 (22:52):
I strongly suspect that it wouldn't actually turn out that way.
Speaker 1 (22:58):
So we come once again to the edge of scientific knowledge.
This is the hard line literally between what we know
and what we don't know. We have two pretty good
contenders for materials that could be harder than diamonds, but
we're not sure, either because they're hard to make or
(23:19):
because it's hard to test hardness. I mean, if someone
gave you a block of something and told you it
was the hardest thing in the universe, how would you
check it? Could you tell exactly how hard it was?
What will you use to check it? So, whether lanzolite
and boron nitrite are harder than diamonds, the answer is
(23:42):
stay tuned. The crown for hardest material on Earth still
belongs to diamonds, or does it. I told you I
learned a lot of interesting things about diamonds from director Bradby,
and one of the things I learned was how fragile
that crown is. There are several things that can knock
that grown off if you just put a little effort
(24:04):
into it. The first is that it turns out that
diamonds have a soft spot, or at least a soft direction.
Speaker 2 (24:16):
And I sort of said a little bit that the
diamond is isotropic, the same in all directions, but not
quite isotropic. In some directions. It's slightly stronger than others,
not much, but we can definitely see that.
Speaker 1 (24:30):
So if it has weaker directions, does that mean you
can break it?
Speaker 3 (24:34):
Diamonds very easy to break.
Speaker 2 (24:35):
Actually, if you get a diamond and you tap it
on a particular axis, uh huh, then you can get
it to fracture. Uh.
Speaker 1 (24:42):
Well, that's how the sheep diamonds.
Speaker 3 (24:44):
That's right.
Speaker 2 (24:45):
When you start off you we'd probably fracture them and
then you would polish them with diamond paste.
Speaker 1 (24:52):
So diamond is not strong in all directions.
Speaker 2 (24:55):
Uh yeah, Well, if you push it measuring the hardness.
It's strong, but if you you give it a sharp tap,
then you could get like a stress wave that would
go through and fracture it. So it's actually it's not
really brittle obviously, But if you hit diamond with a hammer, yeah,
you're going to break it.
Speaker 1 (25:12):
Oh really, But I've seen YouTube videos where people try
to hit diamonds with a hammer and it doesn't crack.
Speaker 2 (25:17):
Well, maybe they have to hit it along a particular axis.
Speaker 1 (25:23):
See once again, you can't believe everything you see on YouTube. Okay,
the second thing I learned about diamonds that make them
less impressive is that on the surface of planet Earth,
diamonds are only meta stable, which means the shiny crystal
structure that makes diamonds so pretty it's not absolutely hop
(25:43):
Carbon atoms want to be arranged. Graphite is.
Speaker 2 (25:50):
Yeah, so we have this concept of what is the
most stable structure at particular points in a pressure temperature region,
and where we are here on Earth, the lowest energy
material for carbon.
Speaker 3 (26:07):
Is this graphitic structure.
Speaker 1 (26:08):
Okay, so if.
Speaker 2 (26:09):
We had a bunch of diamond in our can and
we heated it, it would.
Speaker 3 (26:14):
Transform to graphite. Because it's like, if.
Speaker 2 (26:17):
You give me a chance I'm going to lower my
free energy and form down into this really comfy where
I want to be phase. So this is the concept
of meta stability.
Speaker 1 (26:29):
Yeah. So basically, if you stick a diamond in the oven,
eventually it'll turn to graphite. And again, graphite is what's
in every pencil on planet Earth. And if there's oxygen
in the air at around eight hundred and fifty degrees
celsius or about fifteen hundred degrees fahrenheit, diamond will actually
(26:50):
spontaneously combust or burn. They'll turn to CO two and
graphite ashes. So diamonds are only the as materials we
currently know about in a very limited situation, which is
on the surface of planet Earth. If you go somewhere
else it could be a different story. Ah. So like
(27:15):
if we lived then Venus, where it's nine hundred degrees fahrenheit,
a diamond armor would not help me.
Speaker 3 (27:21):
It would not help you. Do not get the diamond arbor.
Speaker 1 (27:27):
You'd be better off with a steel armer.
Speaker 2 (27:30):
A nine hundred degrees steel is probably having problems as well,
getting a bit soft. At that point, what would I
get Maybe a ceramic Yeah, you know, you could still
use carbon, but you could change the way the atoms
are bonded. Maybe you'd use something like a disordered black
carbon called glassy carbon that is stable up to about
(27:52):
three thousand degrees. See ah, and it would be light.
Speaker 1 (27:56):
Okay, tell me about this material again.
Speaker 2 (27:58):
So glassy carbon is the black form of carbon, so
growfitique like but instead of sheets, it's like we got
all the paper and we scrunched them into a big
ball and they're all into linked so they're really stuck.
We call it glassy because it's kind of disordered.
Speaker 1 (28:13):
Uh huh.
Speaker 2 (28:14):
But it's incredibly stable because it's all stuck like that.
We use them as crucible, so we put things in
them when we want to heat them up in a
furnace to say three thousand degrees, and it's super resilient
to deformation as well. Like I've shoved it in a
diamond anvil cell and squeezed it and it just stays
like that up into really really high pressures. It's a
crazy material.
Speaker 3 (28:35):
It'd be a great.
Speaker 1 (28:36):
Armor on venus because your diamond armor at that point,
but would evaporate.
Speaker 2 (28:41):
Yeah, that would evaporate, but your glassy carbon would still
be there. It'd be nice and light because it's made
of carbon ha ha, Yeah, you'd be fine.
Speaker 1 (28:51):
All right, Well we did it. We found something that
is definitely harder than diamonds on venus. If you're a
girl on Venus, you just find yourself a new best friend.
And hey, look we made it all the way to
the end without another dad pun proof. I have to
say it wasn't easy. In fact, was pretty hard. Thanks
(29:16):
for joining us. See you next time you've been listening
to Science Stuff. Production of iHeartRadio written and produced by
me or Hey Cham, edited by Rose Seguda, executive producer
Jerry Rowland, and audio engineer and mixer Kasey Pegram and
you can follow me on social media to search for
PhD comics and the name of your favorite platform. Be
(29:39):
sure to subscribe to Sign Stuff on the iHeartRadio app,
Apple Podcasts, or wherever you get your podcasts, and please
tell your friends we'll be back next Wednesday with another episode.
Hey, welcome to Sign Stuff, a production of iHeartRadio. I'm
More hitch Ham, and today we are answering a really
hard question, maybe the hardest we've ever tried to answer,
which is is there anything harder than diamonds? Okay, that
was a silly pun, but we've all heard the slogans
the diamond is forever, it's a girl's best friend. But
(00:24):
it's a diamond? Really that sturdy? Let break if I
hit it with the hammer? What happens if I stick
one in the oven? We're going to talk to an
expert on heart materials and we're going to ask her
all the tough questions. See I could have said hard,
but I didn't. Anyways, get ready to quit our ring
on it as we bling out and find out is
(00:47):
there anything harder than diamonds? Enjoy? Hey everyone, Today we're
answering a pretty basic question, which is are diamonds the
hardest material known to humans? Now, for this episode, I
interviewed a really cool expert, Professor Jody Bradby, from the
(01:10):
Australian National University, and I learned a lot of cool
things about diamonds I didn't know before, Like, for example,
did you know you can make a diamond out of
peanut butter. Yeah, this is something scientists actually tested and
it's true. Okay, I'm gonna let doctor Bradby explain it.
Speaker 2 (01:30):
I'm Professor Jody Bradby. I'm head of a high pressure
physics group at the Australian National University.
Speaker 1 (01:36):
Great. Now, when you say it's high pressure, is it
like there's a lot of pressure on everyone working there or.
Speaker 2 (01:41):
There are so many puns. In my fields, we have
a high stress environment. Yeah, definitely, but we create really
high pressures to make new materials.
Speaker 1 (01:53):
Oh, very exciting. So today we're trying to answer the
question is there anything harder than diamonds? So I thought
we could start having you talked to us just about
diamonds themselves. What makes diamonds so hard?
Speaker 2 (02:05):
Yeah, So basically diamond consists of carbon atoms. So if
you arrange the carbon atoms in a particular crystal structure,
then that's what makes the diamond.
Speaker 1 (02:17):
How do the atoms get into a crystal structure?
Speaker 2 (02:20):
Okay, so you get your carbon atoms, and now we've
got to do something to trick those carbon atoms to
form a crystal lattice. So nature uses two things to
do this. It uses temperature and pressure, so we have
to have really high pressures and really high temperatures. So
the pressure forces the carbon atoms close together, and then
(02:41):
the little electrons in the atoms go, oh dear, we're
going to have to rearrange and we need to make
different friends. So they form different bonds, and they form
what's called a convalent bond.
Speaker 1 (02:51):
So it's just carbon.
Speaker 2 (02:52):
Yes, yes, it's one of the beauties of diamond making.
There's like carbon everywhere. I think some scientists famously a
diamond out of peanut butter once just to prove that
you could do it.
Speaker 1 (03:05):
How do you make a diamond out of peanut butter?
Speaker 2 (03:07):
So they just got a bit of peanut butter and
squeeze the life out of it. Basically it released a
lot of other things like hydrogen and things. I think
it actually broke the system that they were using, but
they did make like tiny little diamonds, which is a
really cute experiment.
Speaker 1 (03:22):
Oh wow, was it the chunky or the smooth kine
or the shiny.
Speaker 3 (03:27):
Code I don't know.
Speaker 1 (03:31):
Yeah, So you can make diamonds out of anything with carbon,
even peanut butter, which means you can make diamonds in
a jiff, get it like peanut butter brand No, actually,
naturally occurring diamonds take a long time. But here's the
next interesting thing I learned about diamonds. Scientists don't really
know how long it takes to make them.
Speaker 2 (03:55):
So we famously know that diamonds are formed deep into
the earth in a kind of a GOLDI lie for
diamond formation.
Speaker 3 (04:02):
It also takes.
Speaker 2 (04:03):
Potentially billions of years for this process to happen.
Speaker 1 (04:06):
Why does it take a long time?
Speaker 2 (04:08):
Well, that's actually interesting. We don't really know how long
diamonds take to form deep in the earth. We don't
know exactly how the process works. It's one of those
things you do if you read the textbook, it says, yes,
you need this temperature and this pressure, but we can't
actually explain the science so that we can't look down
that deep in the earth and watch what's happening.
Speaker 1 (04:29):
That's right. The actual way in which diamonds form is
still a mystery. The only reason we think it takes
a long time is that when we take carbon in
a lab and squeeze it super hard and make it
super duper hard, nothing happens. So we assume that it
must take a long time, maybe billions of years, but
(04:52):
we're not really sure. Now you might be thinking, wait
a minute, a joorhe I thought we could make diamonds
in the lab and in factories, we can make artificial diamonds.
How do we make those? Well, it turns out that
to make a diamond in a lab you have to sheath.
Speaker 2 (05:11):
We can play tricks up on the surface of the
earth where we add metallic catalysts, and that can just
help the process go a lot faster, and therefore we
can make it on a time period that you know,
we don't have to wait around billions of years to
get your engagement ring. That's where you could create like
a coke cans worth of diamonds in about an hour.
(05:32):
And these massive presses and really high temperatures, huge industrial
process and the diamonds you're talking about here are generally
in diamonds that you might put them on the top
of a drill bit, and it did cost about the
same as a sandwich.
Speaker 1 (05:48):
So we can make diamonds artificially in a lab or
in a factory, but to get the really natural, pure ones,
like the ones made inside the earth, you have to
wait potentially billions of years. And by the way, if
you're waiting billions of years for an engagement ring, you
might want to consider either an artificial diamond or a
(06:09):
new girlfriend or boyfriend. Okay, the next question I had
for doctor Bradby was what makes diamonds so hard? If
they're just carbon atoms, what makes them different than a
lump of coal or graphite, which is what your pencil
lead is made out of. Both of those things are
also made of pure carbon, And the answer is that
(06:32):
it's all about how those carbon atoms are arranged. So
coal is just carbon. What's the difference between that and diamonds?
Speaker 2 (06:43):
Yeah, excellent question. So that is how we arrange those
atoms within the structure. So diamond has what we call
a tetrahedral lattice. That means each carbon atom is attached
to four of its bodies in a particular structure. It's
really really and it goes on forever. In this three
dimensional structure. Coal is basically made of black carbon graphite,
(07:08):
which is layers of carbon. Now those layers are attached
to their bodies in three bonds in one sort of plane.
They're really really strong, but they can move over each
other really really easily.
Speaker 3 (07:21):
They're quite slippery.
Speaker 1 (07:23):
The sheets of graphites are slippery, that's right.
Speaker 3 (07:26):
They slip over each other.
Speaker 2 (07:27):
That's why when you touch coal, it comes off on
your hand, but if you touch diamond it does not.
Speaker 1 (07:34):
So the secret beween diamond's heartners is a lucky combination
of two things. The first is that the carbon atoms
form really strong bonds with each other. If you remember
from high school chemistry, carbon has four electrons in its
outer shell, so it forms perfect covalent bonds with itself,
and these are the strongest types of bonds there are,
(07:57):
as opposed to ionic bonds, which is what all table
salt together, for example, or hydrogen bonds, which is what
holds water molecules to each other. But here's the kicker, though,
The bonds that carbon forms in diamonds are not the
strongest kinds of covalent bonds that carbon can make. The
carbon in graphite actually form stronger bonds what are called
(08:21):
SP two bonds, which are stronger than SP three bonds,
which is what carbon uses in diamonds. So technically graphite,
which is what you use in your pencil to write
that smears when you rub it against paper, is stronger
than diamonds. But how is that possible? Well, as doctor
Bradby said, the carbon in diamonds forms a three D structure.
(08:45):
Think of it like the scaffolding and a building before
you put on the walls and floors in it, whereas
the carbon in graphite forms two D grids or sheets
which slip past each other and make the graphite crumply.
Speaker 2 (09:01):
So you might have heard of carbon nanotubes. They were
these sort of wrap around tubes of graphite essentially, and
they joined up in a big tube and they were
very very strong, and there were people saying that they
were going to build elevators to the moon with these
carbon nano structures because they were so very very strong.
So that is a very strong bond, but it's only
(09:22):
one layer, so you can play tricks to try to
make it kind of three dimensionally strong. But you don't
need to do that with diamond because its crystal structure
is already three dimensional strong in all the directions, and
that's why it's super hard. So nearly all materials that
are relatively hard have the same properties, have that same
(09:43):
two things, a really strong bond and a essentially isotropic
or the same in every direction bonding network.
Speaker 1 (09:53):
It's just that magic combination and only carbon will do that. No,
there's other materials as well, all right, and that brings
us to the big question of the episode, which is
is there anything harder than diamonds? We're going to find
out and I think the answer will surprise you. Stay
(10:14):
with us, We'll be right back. Welcome back. All right.
We talked about how you can make diamonds out of
peanut butter, how we're not quite sure how diamonds are
made under the ground, and about the magic sauce that
(10:35):
makes diamonds so hard. Now the question is how hard
are they? Are there other materials that are harder? I
asked our expert, doctor Bradby this question. Okay, so then
now the question is harder materials that are harder than diamond?
Or could there be materials harder than diamond? Yes?
Speaker 2 (10:55):
Yes, So this is one of those intriguing scientific questions
because because when you get out into the literature, there's
always a little bit of ajibaji discussion around this. So
you have some groups claiming that they've created this material
that is theory should be harder than diamond. And this
is the crux of the things. There's a lot of
(11:16):
theoretical calculations that might predict a material to be harder
than diamond.
Speaker 1 (11:22):
Whoa, whoa, whoa, Wait a minute. We can create materials
or invent materials that don't exist.
Speaker 3 (11:30):
Oh, we do that all the time.
Speaker 2 (11:32):
We can use machine learning techniques and we do these
things what's called a random property search. So essentially, what
the modeling people do is they get a whole lot
of atoms and they put them in a can. Now
the cans in their computer, but they still call it
a sample, and they apply various conditions to that sample.
(11:52):
They might provide a pressure at temperature, they might suddenly
unload it quickly. They do something to that, and they
look at what the energy of that system is. And
if there is a little dip, that means like the
atoms might be stuck down there. They're all in that
little configuration. That could indicate that that is a stable structure.
(12:12):
So then they go, oh, what happened there? And then
they pull those atoms out at that particular point and
they look at the structure and they go, oh, this
is a good structure.
Speaker 1 (12:22):
Uh huh.
Speaker 2 (12:23):
Maybe this is going to be really important in terms
of a super conducting magnet or it might be really
really hard.
Speaker 1 (12:32):
Well, this is pretty cool. Scientists can now basically simulate
nature and basically roll the dice and see if they
can get atoms to form new kinds of materials that
maybe we've never seen before. I always thought in movies
when they mention the fictional material like vibrinium or adamantium
in the Marvel movies, that it was all made up.
(12:54):
But there really could be materials out there that can
do things we can't even imagine right now. Of course,
though this is all in the computer. The real question is.
Speaker 2 (13:07):
Can we physically create that material, And sometimes the answer
is no, or can we physically create enough of it
that we can measure it to actually confirm that it's
harder than diamond. It's possible, we can never get there physically,
Like it's just impossible in the terms of pressure, temperature,
thermodynamics to get to that structure.
Speaker 1 (13:27):
It's impossible to get atoms to make that structure, even
though it's technically possible. Getting there is a whole different
thing possible. Yeah.
Speaker 2 (13:36):
Yeah, So there's many, many of these structures proposed. I
think carbon's got ten or twenty, maybe hundreds of structures
of carbon that have been proposed to exist.
Speaker 1 (13:48):
Uh huh.
Speaker 2 (13:48):
And this is carbon that's bonded in the same way
the covalent bond. And we've really only found two that
we can confirm.
Speaker 1 (13:58):
Okay, there are two materials that scientists think should be
harder than diamonds. The first one is a material that's
found in meteorites. Okay, so what are these two materials?
Speaker 3 (14:11):
Okay?
Speaker 2 (14:12):
Some one is a different arrangement which is called Lonsterlight.
Speaker 1 (14:15):
What's it called again, Lonsterlight lines Delight Okay.
Speaker 2 (14:19):
So it's named after Kathleen Lonsdale, who is a carbon
scientist in the UK. Amazing person, really worth going down
a rabbit hole with her, and in honor of the
work that she did in carbon, the lons Light structure
was named after her.
Speaker 1 (14:36):
So it's also made out of carbon.
Speaker 2 (14:38):
It's made out of carbon. It's also made out of
convalently bonded carbon. It's also in a continuous three dimension network,
so it ticks the boxes that we've been talking about.
Speaker 1 (14:49):
Huh.
Speaker 2 (14:49):
But it's got a different structure.
Speaker 3 (14:52):
So the way the.
Speaker 2 (14:53):
Atoms are physically arranged is slightly different. So instead of
having a repeating box that is a ubique structure. It's
got a slightly different structure to that, and we call
it a hexagonal structure. Now that doesn't mean that it's
sort of arranged in a hexagonal latters. What it means
is you can create a hexagonal repeating cell within the
(15:16):
framework of the crystom. It is predicted to be harder
than diamond.
Speaker 1 (15:24):
Okay, So the first material scientists think could be harder
than diamonds is called lonstelate, and it's basically a diamond,
but with its structure tweaked so that overall its grid
repeats itself in a hexagonal pattern. It actually has been
found in nature in meteorites that have crashed on Earth.
(15:45):
Notably who's found in fragments of the Canyon Diablo meteorite,
which is what made the huge crater at meteor Crater
landmark in Arizona. It's also been reportedly found in a
diamond deposit in Kazakhstan. Now, in theory, according to the
computer simulations, this lancelide should be harder than diamonds.
Speaker 2 (16:06):
But but there's a butt, And usually with all this
harder than diamond work, there is a butt. And the
butt is that it is only on one particular poking direction.
Speaker 1 (16:19):
Okay, it's only strong in one direction.
Speaker 2 (16:22):
Yeap, only in one direction, and that is because of
the way that breaking of bonds, that movement of things,
how that works.
Speaker 1 (16:32):
What doctor Bradby is saying is that some materials are
harder or softer depending on which direction you try to
squeeze them. Sort of like if you had a box
in front of you and you try to squeeze it
from top to bottom or from the sides, it might
feel hard in all of those directions, but if you
squeeze it at the corners, it might collapse more easily.
(16:54):
The same thing happens in crystal materials, and in lancelide,
one of those directions is predicted to be harder than diamonds.
The reason for that is a little technical, but basically,
when you press down on a material and it yields
or it gives, the atoms tend to rearrange themselves a
little bit. And in lons oflide, because of its tweak
(17:15):
diamond structure, the crystal has to rearrange itself twice, which
is what makes it a harder material. Okay, you might
have noticed that we keep saying loss of lighte might
be harder than diamonds. You're probably thinking, if we found
lons of light in meteorites here on Earth, why can't
we just test it, you know, smash it against diamonds
(17:35):
and see which one survives. But the problem is that
lonz of lte has only been found as tiny, little
microscopic crystals that are too small to put in a
machine to test, and also no one's quite been able
to make it in the lab.
Speaker 2 (17:52):
There is definitely a crystal structure called lonster light that
is definitely different to the cubic structure. But whether the
diamond can form enough of this material to be perfect
and be in a bulk like structure, we have never
been able to successfully make that.
Speaker 1 (18:08):
Yet.
Speaker 2 (18:09):
We've made tiny amounts of the lunsterlite. You could imagine
a little one centimeter rock of this stuff, but each
individual crystal is still really small, like it's not a
perfect single crystal. It would be lovely if we could
make a perfect single crystal of this material that was
about a centimeter, because then we could put it in
(18:30):
all our machines, we could look at it from every
direction and we could confirm that is, yes, this is
exactly that structure. And more importantly, we could actually measure
and see if it was indeed harder than diamond.
Speaker 1 (18:45):
I see, but we can't because the sample that you
have created is really small.
Speaker 2 (18:50):
And of course then we get to the thorny question
of what do you poke it with? Because at the
moment all our pokey tools are made of diamond.
Speaker 3 (18:59):
Of course, So this is a.
Speaker 2 (19:02):
Problem I pose to every first year class that I think,
I am trying to measure something harder than diamond, but
the only thing I have to measure with is diamond.
Speaker 3 (19:11):
If you want to come and talk.
Speaker 2 (19:12):
To me about the solution to this, please how work.
Speaker 3 (19:15):
In my lab?
Speaker 1 (19:18):
All right, when we come back, we're going to learn
about another material scientist think might be harder than diamonds.
And then we're going to talk about two things that
are definitely harder than diamonds. Don't go anywhere. You're listening
to sign stuff, Welcome back. So then this long slight
(19:47):
would be stronger, but only in certain directions. In the
other directions, it wouldn't be stronger than diamond.
Speaker 3 (19:51):
Correct, Ye?
Speaker 1 (19:53):
Now, is that the only one that we know about
that might be harder?
Speaker 2 (19:56):
No, there's another few. So there is more on nitri
that you can get a cubic structure of that or
hexagonal structure.
Speaker 1 (20:04):
Okay, so that one's not just pure carbon atoms. It's different.
Speaker 2 (20:08):
No, it's got nitrogen in it as well, so it's hydrogen, helium,
lithium boron. So we're still talking about a low atomic number.
Speaker 3 (20:16):
And this does.
Speaker 2 (20:17):
Seem to be the case that all the harder elements
are low atomic numbers. They're high up there on the
periodic table.
Speaker 1 (20:24):
You might not remember this from high school chemistry. I
certainly didn't, but atoms high on the periodic table are
smaller and lighter, and it means that electrons are closer
to their nuclei, which means the bonds they form with
other atoms are shorter, which makes them stronger. It's also
(20:45):
no coincidence that boron and nitrogen, the main components of
or nitrite, are just to the rate and just to
the left of carbon in the periodic table, so they're
kind of the closest you can get to a carbon bond.
But now the question is is this boron nitride harder
than diamonds?
Speaker 2 (21:07):
That's also predicted to be a super hard material, perhaps
harder than diamond, but it's not really, I'm not convinced.
Speaker 3 (21:14):
Put it that way.
Speaker 1 (21:15):
Okay, So why are you not convinced?
Speaker 2 (21:17):
Because I am an experimental scientist and one of the
sayings in my lab is nice story, Now show.
Speaker 1 (21:25):
Me the data. So there's no data for this material
not convincing no meaning like people have made it, but
they haven't tested it. What does it mean?
Speaker 2 (21:36):
Yes, well, if you test it using a diamond and
you poke it, if you're approaching the hardness of the
diamond and you push them together, you can imagine that
there's going to be some sort of giving in the
tip in the diamond.
Speaker 3 (21:51):
As well as the sample.
Speaker 2 (21:53):
And currently that's not accounted for in many of the measurements.
Speaker 1 (21:57):
But the diamond makes a whole a divid in the
boron like yeah.
Speaker 2 (22:00):
Yeah, I mean the diamond can make a divot in
other diamond. But that doesn't mean that diamond is harder
than the tip diamond.
Speaker 1 (22:07):
H What is it? Because if it is harder that
it's hard to tell.
Speaker 2 (22:13):
Yeah, I would say the evidence that it's harder has
not been compelling.
Speaker 1 (22:19):
So what would it take to convince you if we
switched it?
Speaker 2 (22:22):
If somebody made an indented tip from oron nitride and
use that to indented diamonds surface. And there was just
an indent in the diamond surface. And we looked at
the tip before and after, and we analyzed it, and
we looked down with an electron microscope, and we saw
that there was no defects in that tip.
Speaker 3 (22:42):
That might be a.
Speaker 1 (22:43):
Pretty good proof, meaning the tip didn't crack when it
hit the diamond. Where hasn't anyone done that?
Speaker 3 (22:48):
That's a good question. I don't know.
Speaker 2 (22:52):
I strongly suspect that it wouldn't actually turn out that way.
Speaker 1 (22:58):
So we come once again to the edge of scientific knowledge.
This is the hard line literally between what we know
and what we don't know. We have two pretty good
contenders for materials that could be harder than diamonds, but
we're not sure, either because they're hard to make or
(23:19):
because it's hard to test hardness. I mean, if someone
gave you a block of something and told you it
was the hardest thing in the universe, how would you
check it? Could you tell exactly how hard it was?
What will you use to check it? So, whether lanzolite
and boron nitrite are harder than diamonds, the answer is
(23:42):
stay tuned. The crown for hardest material on Earth still
belongs to diamonds, or does it. I told you I
learned a lot of interesting things about diamonds from director Bradby,
and one of the things I learned was how fragile
that crown is. There are several things that can knock
that grown off if you just put a little effort
(24:04):
into it. The first is that it turns out that
diamonds have a soft spot, or at least a soft direction.
Speaker 2 (24:16):
And I sort of said a little bit that the
diamond is isotropic, the same in all directions, but not
quite isotropic. In some directions. It's slightly stronger than others,
not much, but we can definitely see that.
Speaker 1 (24:30):
So if it has weaker directions, does that mean you
can break it?
Speaker 3 (24:34):
Diamonds very easy to break.
Speaker 2 (24:35):
Actually, if you get a diamond and you tap it
on a particular axis, uh huh, then you can get
it to fracture. Uh.
Speaker 1 (24:42):
Well, that's how the sheep diamonds.
Speaker 3 (24:44):
That's right.
Speaker 2 (24:45):
When you start off you we'd probably fracture them and
then you would polish them with diamond paste.
Speaker 1 (24:52):
So diamond is not strong in all directions.
Speaker 2 (24:55):
Uh yeah, Well, if you push it measuring the hardness.
It's strong, but if you you give it a sharp tap,
then you could get like a stress wave that would
go through and fracture it. So it's actually it's not
really brittle obviously, But if you hit diamond with a hammer, yeah,
you're going to break it.
Speaker 1 (25:12):
Oh really, But I've seen YouTube videos where people try
to hit diamonds with a hammer and it doesn't crack.
Speaker 2 (25:17):
Well, maybe they have to hit it along a particular axis.
Speaker 1 (25:23):
See once again, you can't believe everything you see on YouTube. Okay,
the second thing I learned about diamonds that make them
less impressive is that on the surface of planet Earth,
diamonds are only meta stable, which means the shiny crystal
structure that makes diamonds so pretty it's not absolutely hop
(25:43):
Carbon atoms want to be arranged. Graphite is.
Speaker 2 (25:50):
Yeah, so we have this concept of what is the
most stable structure at particular points in a pressure temperature region,
and where we are here on Earth, the lowest energy
material for carbon.
Speaker 3 (26:07):
Is this graphitic structure.
Speaker 1 (26:08):
Okay, so if.
Speaker 2 (26:09):
We had a bunch of diamond in our can and
we heated it, it would.
Speaker 3 (26:14):
Transform to graphite. Because it's like, if.
Speaker 2 (26:17):
You give me a chance I'm going to lower my
free energy and form down into this really comfy where
I want to be phase. So this is the concept
of meta stability.
Speaker 1 (26:29):
Yeah. So basically, if you stick a diamond in the oven,
eventually it'll turn to graphite. And again, graphite is what's
in every pencil on planet Earth. And if there's oxygen
in the air at around eight hundred and fifty degrees
celsius or about fifteen hundred degrees fahrenheit, diamond will actually
(26:50):
spontaneously combust or burn. They'll turn to CO two and
graphite ashes. So diamonds are only the as materials we
currently know about in a very limited situation, which is
on the surface of planet Earth. If you go somewhere
else it could be a different story. Ah. So like
(27:15):
if we lived then Venus, where it's nine hundred degrees fahrenheit,
a diamond armor would not help me.
Speaker 3 (27:21):
It would not help you. Do not get the diamond arbor.
Speaker 1 (27:27):
You'd be better off with a steel armer.
Speaker 2 (27:30):
A nine hundred degrees steel is probably having problems as well,
getting a bit soft. At that point, what would I
get Maybe a ceramic Yeah, you know, you could still
use carbon, but you could change the way the atoms
are bonded. Maybe you'd use something like a disordered black
carbon called glassy carbon that is stable up to about
(27:52):
three thousand degrees. See ah, and it would be light.
Speaker 1 (27:56):
Okay, tell me about this material again.
Speaker 2 (27:58):
So glassy carbon is the black form of carbon, so
growfitique like but instead of sheets, it's like we got
all the paper and we scrunched them into a big
ball and they're all into linked so they're really stuck.
We call it glassy because it's kind of disordered.
Speaker 1 (28:13):
Uh huh.
Speaker 2 (28:14):
But it's incredibly stable because it's all stuck like that.
We use them as crucible, so we put things in
them when we want to heat them up in a
furnace to say three thousand degrees, and it's super resilient
to deformation as well. Like I've shoved it in a
diamond anvil cell and squeezed it and it just stays
like that up into really really high pressures. It's a
crazy material.
Speaker 3 (28:35):
It'd be a great.
Speaker 1 (28:36):
Armor on venus because your diamond armor at that point,
but would evaporate.
Speaker 2 (28:41):
Yeah, that would evaporate, but your glassy carbon would still
be there. It'd be nice and light because it's made
of carbon ha ha, Yeah, you'd be fine.
Speaker 1 (28:51):
All right, Well we did it. We found something that
is definitely harder than diamonds on venus. If you're a
girl on Venus, you just find yourself a new best friend.
And hey, look we made it all the way to
the end without another dad pun proof. I have to
say it wasn't easy. In fact, was pretty hard. Thanks
(29:16):
for joining us. See you next time you've been listening
to Science Stuff. Production of iHeartRadio written and produced by
me or Hey Cham, edited by Rose Seguda, executive producer
Jerry Rowland, and audio engineer and mixer Kasey Pegram and
you can follow me on social media to search for
PhD comics and the name of your favorite platform. Be
(29:39):
sure to subscribe to Sign Stuff on the iHeartRadio app,
Apple Podcasts, or wherever you get your podcasts, and please
tell your friends we'll be back next Wednesday with another episode.
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