Daniel and Kelly’s Extraordinary Universe - Why is mercury liquid at room temperature?
Episode Date: May 13, 2025Daniel and Kelly take a detour into the fascinating world of chemistry to explore why mercury is liquid at room temp. The answer is relatively surprising!See omnystudio.com/listener for privacy inform...ation.
Transcript
Discussion (0)
This is an I-Heart podcast.
Get fired up, y'all.
Season two of Good Game with Sarah Spain is underway.
We just welcomed one of my favorite people,
an incomparable soccer icon, Megan Rapino, to the show,
and we had a blast.
Take a listen.
Sue and I were, like, riding the lime bikes the other day,
and we're like, we're like, we're like, people ride bikes because it's fun.
We got more incredible guests like Megan in store,
plus news of the day and more.
So make sure you listen to Good Game with Sarah Spain on the IHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
Brought to you by Novartis, founding partner of IHeart Women's Sports Network.
I always had to be so good, no one could ignore me.
Carve my path with data and drive.
But some people only see who I am on paper.
The paper ceiling.
The limitations from degree screens to stereotypes that are holding back over 70 million stars.
workers skilled through alternative routes rather than a bachelor's degree.
It's time for skills to speak for themselves.
Find resources for breaking through barriers at tetherpapersealing.org.
Brought to you by Opportunity at Work and the Ad Council.
Tune in to All the Smoke Podcast, where Matt and Stacks sit down with former first lady, Michelle Obama.
Folks find it hard to hate up close.
And when you get to know people and you're sitting in their kitchen tables and they're talking like we're talking.
And, you know, you hear our story, how we grew up, how Barack grew up.
And you get a chance for people to unpack and get beyond race.
All the Smoke featuring Michelle Obama.
To hear this podcast and more, open your free IHeartRadio app.
Search All the Smoke and listen now.
Have you ever wished for a change but weren't sure how to make it?
Maybe you felt stuck in a job, a place, or even a relationship.
I'm Emily Tish Sussman, and on she pivots, I dive into the inspiring pivots of women
who have taken big leaps in their lives and careers.
I'm Gretchen Wittmer, Jody Sweetie,
Monica Patton, Elaine Welteroff.
Learn how to get comfortable pivoting because your life is going to be full of them.
Listen to these women and more on She Pivotts,
now on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.
Even before we could pry open molecules and see the structure of atoms,
we knew there was something fascinating going on.
There had to be some kind of internal structure there.
Why did we think so?
How did we know?
Well, because the periodic table is periodic.
There are groups of atoms with similar behavior.
As you march across column by column, atoms in those same columns have similar behaviors,
conductivity, reactivity.
That can't just be random.
And of course, it isn't.
It's because of the structure inside each atom, which was long invisible to us.
The structure of the atom is, of course, dictated by quantum mechanics, which also reveals something about the basic laws of the universe.
And now electron structure is a source of torture for high school chemistry students and physics podcast hosts.
But it also completely and totally defines our world.
It's why metals exist, why things are hard or soft or liquid or solid.
It's not magic, but changes to these properties can have dramatic effects on element's behavior and the nature of the world.
of our experience.
And today we're gonna dig deep into what might be
the weirdest element on the periodic table,
one that isn't just sensitive to quantum mechanics,
but to our other great theory of physics, relativity.
Mercury, and here I mean the element,
not the planet whose orbit was famously predicted by relativity,
is very strange because it's liquid at room temperature.
It's the only metal we know that is liquid at room temperature,
that you can pour without ever heating it up.
It's even liquid if you put it on ice or snow.
This is knowledge we share with the ancients.
The name Mercury comes from its Greek name,
which I won't try to pronounce, but means watery silver.
Why?
What is so special about mercury?
What is going on inside that atom?
Welcome to Daniel and Kelly's extraordinarily chemical universe.
Hello, I'm Kelly Weiner-Smith.
I studied parasites and space.
And because I was a child of the 90s and we got ourselves into all sorts of trouble,
I had a necklace that was a vial of mercury.
Oh, no.
And now I'm just glad it never got like smashed on me or something.
Are you sure it wasn't permeable in some way?
It would explain a lot.
Folks, Kelly would be so much smarter if it wasn't for that necklace.
Oh, ouch, ouch.
I mean, she's already super smart.
I don't think we could handle an even smarter, Kelly.
Oh, good cover.
I love it.
Well, I'm Daniel.
I'm a particle physicist, and I'm not a big fan of chemistry,
but I am in awe of its influence over our world.
Yeah, I was surprised to see that you picked a chemistry topic,
that you did this to us on purpose.
And so let's try to focus on positives for,
chemistry for like half a second. What was your favorite moment in a chemistry class?
Ooh, I remember taking the final and being done with it.
Amazing. No, I was recently talking to the daughter of a friend of mine and asking her what
you wanted to study in college. And she said, chemistry. And I said, cool, why? And she said,
chemistry is very tactile. It relates to things that are right in front of us. It controls how things
operate. It's almost like you can do magic. And she was right, you know, like particle
physics is very cool and reveals the fundamental nature of reality, blah, blah, blah, but it talks
about things you can't see, really. And so, like, how do you know the electrons are following those
rules or the quarks are doing this or that? Whereas, like, you can see stuff flow or boil or bond
or reflect or whatever. It really does determine the nature of our experience. Yeah, I agree and
I disagree. I agree on like a global level. So I did my senior honors research work in an organic
chemistry lab. Because even though I talk about how much I dislike chemistry, I had a lot of chemistry
friends and I was kind of into it for a while. Didn't know that about you, Kelly. Hmm. Oh my God.
Recalibrating over here. I made so many mistakes in the chem lab, though. I'm so lucky I didn't die.
But you know, I would mix things together and I'd be like, all right, clear liquid, mixed with clear
liquid and it still looks like a clear liquid. Did I do the reaction I was trying to do? I don't
know. And so I know there's a lot of stuff where it's like you can see stuff's happening,
but there's also a lot of stuff where you have to just like expect the thing happened
that you thought was going to happen. And it's, yeah, I don't know. I like fish. You can really
see what's going on with fish. You can see fish guts, but you can't see atomic guts. That's the
issue. That's right. You can't see the backside attack happening in real time. I think that was
the chemistry reaction that my friends and I may be focused on a little bit too much.
But anyway, we had some fun.
Yeah.
Well, you know, underlying chemistry is physics,
and there's a close relationship between chemistry
and, like, quantum physics
that determines the nature of the atoms.
And what we're going to discover today
is that the answer to the question of the episode
might not actually be chemistry.
It might be physics after all.
Oh, that's...
Whoa!
I think we just found our video clip for this episode.
But you have the right voice for an evil scientist laugh.
Wow.
Yeah, I'll put that in my next grand proposal.
Okay.
So today we're talking about why mercury is liquid at room temperature.
And I didn't know the answer to this before reading the outline.
And, you know, to be honest, since it's a brief outline, I still don't think I know what the answer is, but I will by the end of the hour.
And so let's see what our audience thinks about why mercury is liquid at room temperature.
So think about it for a moment yourself. Do you know the answer? Is it chemistry? Is it physics? Is it some weird combination? Is it physical chemistry? Here's what our audience had to say.
Just characteristics of that particular element. Based off of the chemistry of the item. So this sounds like we'll make for a very interesting episode.
Mercury may not be very good at sharing its electrons. And that's why it is a liquid.
at room temperature.
I think it's because the amount of energy that's required to break the bonds to turn into a liquid
is really low because it's just a bit weak.
And yeah, like my son, I think it's because of dragons as well.
Something to do with its electron orbitals.
I guess that the heavier the element, the more solid it should be,
but Mercury is a half-metal, so this might not be an adequate explanation.
Maybe this is related on how the molecules of Mercury are formed.
Because of the way it's electrons behave actually.
It has to do with the way that they are bonding or in this case not bonding.
So it's a very weak chemical interaction.
Maybe it has something to do with how the electrons are arranged.
I thought Mercury was a liquid at room temperature for a similar reason as to why water is as well.
how the bonds between the atoms work and interact.
Mercury is liquid at room temperature because it's solid at a different temperature, a lower temperature.
I don't really know why metals are liquid at any temperature.
I don't know.
Now I'm curious.
Cervalance electrons are paired, which I guess makes it less.
necessary for it to form the kind of crystal structure that you get in most metals.
Because its outer most electron shell loses electrons easily and does not form strong bonds.
It has to do with the specific heat of the substance.
I knew, I forgot.
That at room temperature, the chemical bonding between the atoms are weaker than in cold.
where they get stronger.
I love the answer that they would love to know this.
There are so many amazing patterns in the periodic table.
I love that curiosity about chemistry.
You and I should maybe try to channel that a little bit more.
I totally agree with that answer.
I think it is amazing the patterns in the periodic table.
And I love how it reveals the structure of the universe.
And it is very, very cool.
It's just also very complicated.
Wow, it's not easy.
So, you know, my fear of chemistry is mostly in awe of the people.
who can do it because I can't.
I found it very difficult.
Mostly I was spilling the chemicals on myself
or dropping the glassware.
But my favorite moment in chemistry actually
was the very first college chemistry class I took
where we got the melting point
and some other features of some unknown substance
and by calculating these different features
of the unknown substance,
we were able to figure out what we had been given.
And that felt like amazing,
like forensic science, CSI sort of stuff.
I just loved that.
So I have a soft spot in my heart for calculating melting points, which is maybe not something
I imagined I'd be saying when I was a kid.
But I've never been cool, so I'm leaning in.
So Daniel, what determines melting points?
Yeah, this is very cool, you know, that we even have melting points for stuff, that
things have phases.
I think phases are super fascinating.
You can have like the same set of atoms and at a slightly different temperature, they're
dramatically different behavior, right? This is not like a smooth transition where it's like
kind of mushy and then kind of gassy. It goes from like solid to flowy. You know, it's really
incredible that phases even exist. And I just want to nerd out about phases for another minute
before we dive in because phases are a much more general concept in science and in physics
than just like the state of matter. We use phases to describe anytime there are a set of
equations that have limited applicability. Like you could talk about Newton's equations for the
motion of stuff applied to a certain phase of matter when things are not very massive and not
very fast. It's like the Newton phase of mechanics. So I think it's really a fascinating concept
because it admits that all our laws are limited, the way that like the laws of fluid mechanics
only apply to fluids and the laws of crystal lattices only apply to crystals and not to everything.
So anyway, I think that's sort of deep and philosophical.
I think I'm not following. All of the things that you just said still sound like you're talking about phases. So you said something about like how fast something's moving. And to me, that makes me think about the transition from a liquid to a gas or something. I think I'm missing the point. No, you're right. And they're all linked to like the behavior of the stuff. But, you know, think about like the very early universe. We think there was a time when things were so hot and so dense that even our laws of quantum field theory might not apply. So there's like a phase in the universe when quantum field theory applies. And there's a phase.
when it doesn't apply, right?
Because it's not like a fundamental theory of everything.
It's an approximation that only works under some conditions.
In the same way, like the laws of the liquid phase of water only work when water is liquid.
They don't work when water is solid or when water is a gas.
All of our laws are approximate that way and only work in a certain phase.
Okay, right.
So when I was in my goth phase, the only thing that worked for me was black clothing.
Exactly.
And I get it.
Phase is a more general word.
Yeah.
Okay.
Moving on.
So what's happening here, the listeners were bright.
Things melt when the bonds between them loosen, right?
So a solid often is a crystal.
You have like these pieces click together into a crystal lattice.
Not everything ends up like a crystal.
You know, glass, for example, it's like a big disordered mess.
But lots of things click together to form a crystal.
You can imagine like the Lego pieces snap together, and it's very solid.
It acts like a big chunk, right?
And that happens because there are bonds between them, right?
These things don't just click together physically.
It's not like you're just physically sharing the space.
They are connected to each other.
They are bound together because of what their electrons are doing.
So if you have strong bonds between stuff and the stuff doesn't have a lot of energy,
can't wiggle around a lot, then it clicks together to form a solid.
Now heat that stuff up, give it energy, make those atoms wiggle and jiggle and zoom.
If they have enough energy to overcome the power of those bonds,
then they will break open that crystal lattice and they will slide around.
And that's how they become a liquid.
melting is, is breaking down the crystal lattice so that the atoms are more loosely bound to
each other. They're still connected. There's still some bonds there. It's not totally a gas.
Gas is when you give up all connection to each other and they're all just a bunch of independent
molecules or atoms. So liquid is when you break those strongest bonds and now you have very
weak bonds so the atoms can flow over each other. Is it just that like some percent of the bonds
have broken or that bonds of a certain type have broken? Like all the hydrogen to oxygen bonds have
broken, but the carbon and hydrogen bonds haven't broken yet? Or does it depend on the molecule that
you're talking about? It depends on the molecule, but it also depends on the type. And so, for example,
after the bonds are broken, there are still some bonds there, but they're weird, very soft
intermolecular bonds. You know, you can have like a bond between this water molecule and that water
molecule because of its polarity. Like maybe they're overall neutral, but it's got a little bit more
negative on this side and a little bit more positive on that side. And that can attract the neighboring
atom or they can organize themselves that way. It's sort of a loose bond. Whereas when they're
tightly bound, then they use a different kind of bonds. You know, the electrons can like literally
be shared among them. In some kind of lattice is like in metals, the electrons just flow freely,
right? You can't even really say which atom they're connected to. They just like flow all around
the whole thing of really complex energy level structures for those electrons because they're really
just shared. It's like one really big atom or one super molecule. You know, you and I might both know
more chemistry than we've been letting on.
Secrets coming out today.
That's solid state physics.
Okay.
All right.
I was getting worried there.
Okay.
So it really is about the strength of the bonds.
If atoms are capable of making very strong bonds,
then it requires more energy to break them,
higher temperatures to break them.
So stronger bonds between the atoms mean a higher melting point.
If they're already very, very loose bonds between the atoms,
like the atoms don't like the bond at all,
or they use none of the very strong categories of bonds,
then the melting point is going to be lower
because it doesn't take a lot of energy to release the atoms.
So we're going to take several steps towards the understanding.
The first one is melting point is determined by the strength of the bonds.
Stronger bonds, higher melting point, weaker bonds, lower melting point.
Okay, I've got that general concept.
Can you give me a little bit more information about what makes for a strong bond?
Yeah, so basically you're asking like, well, what makes the bond stronger,
what makes the bonds weaker?
Why does it depend on the element?
what determines that? And the answer there is the electron structure. The electrons are the things
that do the bonding. And so the electron structure is what determines whether the bonds are strong
or whether the bonds are weak. For example, one of the most important thing is have the electrons
filled up their shells. Like the electrons form these shells around the atom. You know,
there's the first energy level, the second energy level. If that outermost energy level is
filled, then the electrons in the atom are pretty happy and they don't want to go anywhere.
If, however, they're not filled, you have like four out of eight or seven out of eight,
then that atom is happy to take another electron or to share another electron with its friend,
so together they have filled shells.
So, for example, if you have hydrogen, hydrogen can have two electrons in its outer shell,
but it's only got one.
So it likes to find another hydrogen, so together they have two.
They can share those two in a bond.
So those two electrons are shared between the two protons,
and that thing is really bound together into H2.
Aw.
I know.
It's very cozy.
It is.
Actually, what if they hate each other?
What if they're like, oh, my God, this guy never does the dishes?
Oh, I get that.
I get that.
But they can't get away from each other.
Well, you've got to turn up the heat so that they can escape.
Oh, melting is like chemical divorce.
Wow, fascinating.
We are liberating these atoms.
You've heard of women's liberation.
Now we're doing proton liberation.
I thought it was electron liberation.
There you go, yeah, electron and proton, yeah.
Oh, okay, got it, yeah.
So there's a few things that affect whether these bonds are strong or not.
One is, are the shells filled, right?
So do you have a complete outer shell?
It's like a set of armor, it's hard to penetrate,
or do you have an incomplete outer shell,
in which case the atom likes to bond?
And we're going to go through some examples later on.
You'll see that these patterns emerge in the periodic table.
The other is how closely is it holding on to those electrons?
Because the electrons can be like really far out
and it's sort of a distant outer shell, very weakly held,
or they can be, like, really tightly held
if the atom is very, very powerful.
It has, like, a lot of protons in it.
It can really hold those electrons close.
So that also determines this.
So we're sort of like two dimensions here
to determine whether the bonds are strong
or whether the bonds are weak.
Is it filled shells?
Is it not filled shells?
So filled shells means harder to form bonds.
Not filled means easier to form bonds.
If the electrons are close,
it's harder to form bonds.
bonds with them because they're held tightly by their nucleus and the electrons are not
close. It's easier to form bonds. This is reminding me of the fun conversation that we had in
response to a listener question about why life tends to be carbon-based instead of silicon-based.
Yeah. Silicon, not silicone. I always mix those two up. In Orange County, it's silicone mostly,
actually. Yeah. Well, I live in Virginia. We're, anyway, we don't need to go there. And the answer
ended up depending on a lot of these questions. Yeah. But you're putting your finger
a really important trend, which is that as you go across the periodic table, elements in the same
column tend to have the same electron structure. They have like one extra electron or two, or it's
totally filled, or it's not. So the rows in the periodic table reflect the energy levels. And then as
you march along the columns, you have the same pattern of the electrons filling up. So as you go from
left to right in the periodic table, you're filling up that outer shell. And so, for example,
the last column in the periodic table all have their last one all filled up because it's
the last one. And so that whole column are folks with very filled shells. That's why they're
called the noble gases. They don't like to interact with anybody. And that's why they're all in the
same column because they're the same electron structure, which is why they have the same kind of
behavior. And like the first column, all are noble gases plus one. So they all have one extra
electron, one lonely electron in its own last shell really dying to do something with.
this friends. And so that's why those are all very active, for example. They like to react
and interact. So the electron structure really determines all these properties and the
periodicity of the table. Now, I remember sitting in chemistry in high school and being like,
all right, I think maybe I have finally memorized how many electrons are supposed to be in each one
of these shells. But why are there shells in the first place? Yeah. And I never got a
satisfactory answer. And maybe that's why I never could love chemistry until this moment, Daniel,
because I'm going to ask you, can you tell me, why are there even shells?
And do they sell them by the seashore, right?
Yeah, so the answer is, of course, the underlying physics, quantum mechanics.
Like, let's start with a simple atom like hydrogen.
Hydrogen has a proton and it has an electron.
Where could that electron be?
Well, quantum mechanics says, use the Schrodinger equation.
And Schrodinger equation says, well, there's a bunch of solutions for where the electron
can be, a bunch of places where everything is copacetic and the wave function is happy.
but there's a ladder of solutions.
It's not a continuous state of solutions.
Like, let's zoom out and take a classical example
where we have intuition, the orbit of a planet.
Where can a planet orbit the sun?
Well, classical mechanic says,
if you have a certain radius,
you need to be moving at a certain velocity
in order to have a stable orbit.
Cool, but every radius has a velocity.
Like, you could orbit the sun at literally any place.
There's an infinite number of available radii.
Once you pick a radius, you have to have the right velocity,
or you'll fall out of orbit or you'll zoom out of the solar system,
but you could pick any radius, any solution works.
Around hydrogen, that we like to think of these as like planetary orbits
and there's lots of misleading popside diagrams that convince you so,
these are not orbits, right?
These are solutions to the Schrodinger equation,
and there's a ladder of solutions.
There's a finite number.
It's like number one, number two, number three.
The quantum mechanics dictates that.
And an intuitive way to think about why there are a discrete number of solutions
is to think about how the wave function fits around the atom.
It goes around the atom.
It has to reinforce itself.
So when you go around, you have to come back and basically be in the same part of the wave.
And so you can fit like one wave or two waves or three waves.
But you have like 3.7 waves, then it's going to interfere with itself.
And it's not going to be a stable solution.
So you want a stable solution of the electron around the atom.
You have to fit a certain number of wavelengths of the wave function around the atom.
So that's why you have a discrete number.
That's what causes the shells.
And then it gets much more complicated if you have more protons and multiple electrons.
When you get all the way up to like mercury, it's a mess.
So does it have to be waves because electrons aren't point particles?
They're actually waves.
And that's where the wave thing comes in.
Yeah, exactly.
You have the wave function, which is a complex value thing.
And it is really the thing that tells you where the electron can be.
And so when the electron is in its lowest state, you shouldn't think of it like, oh, it's orbiting at a certain radius.
it's got a probability distribution, and that's the minimal stable configuration for that state.
Okay. All right. Got it. Chemistry is awful. That's what I think.
The other crucial piece of physics is that electrons have this weird behavior where you can't have two of them having the same state.
They just will not share. They're like grumpy siblings. You cannot put two of them in the same bed.
You need to have different rooms or they need to have something different.
So the first state, you can have two electrons because one can be spin up and one can be spin down.
The second layer has more energy so they can wiggle in different ways.
There's different patterns to have their energy is distributed.
So there's more options there.
But quantum mechanics tells us that we can only have one electron per unique energy level.
And as the shells get bigger, there's more options for the electrons for ways to differentiate themselves.
So you can have two in the first one.
And then I don't even remember the numbers, and I'm not going to guess.
But it gets very complicated.
But there are quantum mechanical answers for why there are a certain number of,
of electrons allowed in each shell as to do with the poly exclusion principle and the number
of ways you can distribute the angular momentum solutions in each energy level.
In my head, at some point, the number of electrons in the shells as you added shells
started being the same.
But I took chemistry when I was, gosh, that was over 30 years ago now.
So that's just a bad memory, right?
It's the number of electrons in each shell gets progressively higher the farther you get
from the center.
Yeah.
Okay, all right.
But the shells then start overlapping.
And, you know, sometimes like the highest energy subshell from level four is actually
higher energy than the lowest energy subshell from level five.
So level five fills up before the last level four fills up.
And the ordering starts to get really, really nasty, which is why electron configurations
are hard.
I'm feeling angry.
Why is it like that?
All right, all right.
Let's give ourselves a chance to release the anger.
And when we get back from this commercial break,
we'll take another peek at the periodic table
and look for patterns and melting points.
I'm Dr. Joy Hardin Bradford.
And in session 421 of Therapy for Black Girls,
I sit down with Dr. Ophia and Billy Shaka
to explore how our hair connects to our identity,
mental health, and the ways we heal.
Because I think hair is a complex language system, right?
In terms of it can tell how old you are, your marital status, where you're from, you're a spiritual belief.
But I think with social media, there's like a hyper fixation and observation of our hair, right?
That this is sometimes the first thing someone sees when we make a post or a reel is how our hair is styled.
You talk about the important role hairstyles play in our community.
the pressure to always look put together and how breaking up with perfection can actually free us.
Plus, if you're someone who gets anxious about flying, don't miss session 418 with Dr. Angela
Neil Barnett, where we dive into managing flight anxiety.
Listen to therapy for black girls on the iHeart Radio app, Apple Podcasts, or wherever you get your podcast.
I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast.
Here's a clip from an upcoming conversation about exploring human,
potential. I was going to schools to try to teach kids these skills and I get eye rolling from teachers
or I get students who would be like it's easier to punch someone in the face. When you think
about emotion regulation, like you're not going to choose an adaptive strategy which is more
effortful to use unless you think there's a good outcome as a result of it if it's going to be
beneficial to you because it's easy to say like go you go blank yourself right? It's easy. It's easy
to just drink the extra beer. It's easy to ignore to suppress seeing a colleague.
who's bothering you and just, like, walk the other way.
Avoidance is easier.
Ignoring is easier.
Denial is easier.
Drinking is easier.
Yelling, screaming is easy.
Complex problem solving.
Meditating.
You know, takes effort.
Listen to the psychology podcast on the Iheart radio app,
Apple Podcasts, or wherever you get your podcasts.
And here's Heather with the weather.
Well, it's beautiful out there, sunny and 75, almost a little chilly in the shade.
Now, let's get a read on the inside of your car.
It is hot.
You've only been parked a short time, and it's already 99 degrees in there.
Let's not leave children in the back seat while running errands.
It only takes a few minutes for their body temperatures to rise, and that could be fatal.
Cars get hot, fast, and can be deadly.
Never leave a child in a car.
A message from Nitsai and the Ad Council.
We're siblings.
Like, you fight, you disagree.
It's really hard to be in a partnership.
Yeah, you judge each other.
You lead differently, and we've gotten to that edge.
Hey, I'm Simone Boyce, host to the Bright Side,
and this week I'm joined by Hollywood Power Sisters, Aaron and Sarah Foster.
They open up about navigating the judginess of Hollywood,
dealing with rejection and the pressure of running a business with your sibling.
And yeah, they're spilling the tea on season two of their hit Netflix series.
Nobody wants this.
I feel like the overall consensus was like, people were just obsessed with this,
will they, won't they?
Like, that's the thing, right?
It's just intoxicated.
You want to be able to sustain that for as many seasons, but you also have to, like, marry them off eventually.
I don't know what you think this is for.
You'll marry them off, Aaron?
Well, I don't even know if they're staying together, Sarah.
Y'all, this conversation is honest, hilarious, and everything you didn't know you needed this week.
Listen to the bright side on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts.
And we're back.
Okay, so at the beginning of the show, we talked about where you find electrons, how they fill up the shells, and how that impacts bonds between atoms.
Now we're going to take a look at the periodic table because we're really interested in melting points to try to figure out why mercury is weird.
So let's look for patterns in the periodic table to see what we should expect mercury to be doing in terms of melting points.
Yeah, and there's a lot of really interesting stuff to dig into here.
and a lot of it can be explained by chemistry,
but mercury sticks out like a sore thumb.
And so we're going to walk you through a couple of the trends
that explain what's happening in the periodic table,
but they can't completely describe mercury,
and they're not actually enough to make mercury liquid at room temperature.
So there's a little bit of physics we're going to need at the end
to give you that complete explanation.
Chemistry is never enough.
Chemistry is never enough.
So let's keep in mind that we're thinking about the electron structure
of these elements, whether or not, for example, they have a filled shell.
And so let's like walk across the middle of the periodic table.
So you have SC, which is Scandium, right?
And then the next one is titanium.
And it goes all the way across the copper and then to zinc.
And if you look at the melting points here, they start pretty high.
Like scandium melts at 1,500 Celsius.
And then they go down to zinc, which melts at only 400 Celsius.
Now that's pretty high.
You don't want to get into like a hot tub of zinc.
But it's a big difference.
It's like more than a thousand degrees difference.
Why does scandium melt at a really high temperature and zinc melts at a really low temperature?
Because zinc is the end of this chunk of the periodic table.
It's completed a shell.
So zinc has a complete shell, which means it's not as likely to bond.
It's not as easy for it to bond, which is why it has a lower melting point than all of its friends next to it.
Like copper right next door to zinc has a melting point of more than a thousand degrees C.
whereas zinc, again, is just 400.
And you see the same behavior in the next row.
Silver, which is right next to cadmium, cadmium is just under zinc.
Silver has a melting point of about 1,000 C and cadmium of about 300.
So just this one step over, you add one proton and one electron,
melting point drops precipitously.
And the reason is that you've filled up this shell.
Now these atoms can't form the same kind of strong bonds
where they're sharing electrons with each other.
And so it's much easier to break them apart.
So that's why zinc and cadmium and mercury, which is also in this column, have much lower melting points than their friends, copper, silver, and gold, which are right next to them in the periodic table.
They're more stable, and because they're more stable, it's easier to make them liquid?
It's easier to make them liquid because their bonds are weaker.
It's not about the stability.
These aren't like radioactive elements.
It's just like, do they like to click together?
And zinc and cadmium and mercury all have a completed last shell.
It's the S2, the 4S2, the 5S2, or the 6S2.
They've completed that little sub-shell, and so it's harder for them to form bonds.
Like copper and silver and gold, the ones next door to them, are missing one electron
relative to our friends, zinc, cadmium, and mercury.
So they'd like to fill in that last shell.
And if they meet another atom of their type, like two silver come together, they can
complete that last shell together.
And so they can form this kind of strong bond by sharing electrons.
It's harder to break them apart.
Mercury can't do that.
Cadmium can't do that.
Zinc can't do that.
So they can't form the same kind of strong bond between the atoms.
And so it's easier to break them apart, which means a lower melting point.
Got it.
Okay.
Thank you.
So now we're comparing these two columns, right?
Column 11 has a higher melting point and then column 12, zinc, cadmium, and mercury.
But still, mercury looks weird.
like zinc and cadmium melt at 300, 400 C.
It seems like a very respectable temperature for a metal.
Mercury melts at negative 39C.
Like mercury has a crazy low melting point.
To make mercury solid, you have to get it to negative 39 Celsius.
That's very, very cold, right?
And it's a huge jump.
And if you're saying, all right, well, this column is all colder than the other one,
still within the column, zinc and cadmium have a higher melting point than mercury.
So what makes mercury so much lower than zinc and cadmium?
Well, there is a trend there that we would expect.
As you go from top to bottom in the column, you're getting heavier and heavier nuclei, right?
Like, Mercury has more protons than cadmium, which is more protons than zinc.
And that's the other effect we talked about.
Mercury holds onto its electrons more tightly than cadmium or zinc because it has more protons.
Say you're an electron floating around the atom, there are more protons.
pulling you in, binding you tightly to that atom if you're mercury than if you're cadmium
or if you're zinc. Does that make sense?
Kind of. So if you're mercury, though, you also have more electron shells. And so your
outer shell, which would do the bonding, is farther away from your heavy nucleus. They're
farther away. What does that do?
Yes, exactly. And this is my frustration with chemistry is that you can often tell
yourselves these intuitive stories and then somebody can come along with another.
intuitive sounding story that also makes sense. And you're like, huh, hmm, I don't know, which one of
this is right. You know, and the answer is that it's complicated. But overall, the fact that you have
more protons wins. And so it pulls these things in. And, you know, the way to think about it is like,
yeah, these things can all be neutral. You have an equal number of protons and electrons.
And the electrons don't like to be on top of each other. But still, these protons are very
powerful in pulling them in. And each electron is having basically just a relationship with the protons,
not with the other electrons.
It's not like the power of those protons is shielded by the other electrons.
Instead, it's now pulled in by 80 protons, right?
So it's a very powerful force.
I think that one wins.
But hey, chemistry experts out there write in and tell me if we got that wrong.
Okay, so Mercury really wants to be a liquid.
And we know that because it has a full shell and it's really big.
But even knowing those two things, Mercury wants to.
to be a liquid at temperatures way lower than what we would have expected.
So where do we go next to try to understand that?
Yes, so we're at the limits of chemistry here.
Chemistry tells us, yes, mercury should be lower than gold, for example, in the same way,
zinc should be lower than copper, and it is.
And chemistry tells us, yes, mercury should have a lower melting point than cadmium or zinc
because it's a bigger atom and it holds these things in.
And that's all cool.
But if you run the calculations and you take all that into account, chemistry predicts
that mercury's melting point should be 82C.
But the measured value is negative 39C, more than 100 difference.
So, like, yes, there are these trends that suggest mercury should have a low melting point,
but they suggest it should still be solid at room temperature.
To get mercury even lower to get that melting point down below room temp
and even down below zero C, you need to do something else.
Chemistry is not enough to make mercury liquid.
Come on chemistry.
Get better with your predictions.
This isn't physics.
So you might think, well, is quantum mechanics wrong?
Because chemistry is determined by quantum mechanics.
We just told you about all the shells and the shorteninger equation and all this stuff, right?
So is quantum mechanics wrong?
Well, quantum mechanics by itself is not wrong, but it's not the whole story, right?
We know that quantum mechanics doesn't describe the entire universe because quantum mechanics, for example, can't describe gravity or black holes or the beginning of the universe.
We have another theory in physics that helps us explain what happens when things go
really, really fast, or when things get really, really massive, that's relativity.
All the calculations we've been doing, all the explanations we've been giving are chemistry
based on quantum mechanics that assumes that relativity is not a thing.
If, for example, assumes that there's no limit to how fast things can go, or that there are
no black holes.
We're essentially ignoring relativity and doing pure quantum mechanical calculations.
And most of the time, that's fine.
Relativity is not really relevant.
We're not doing chemistry around a black hole.
We're not doing chemistry near the speed of light, so it works.
But, you know, sometimes it doesn't.
And that's what's happening here is that we've been ignoring the relativistic effects on the electrons of mercury.
And that's because everywhere there's mercury, there's actually a tiny black hole next to it.
Is that right?
No?
No.
Okay.
No.
But you know where you can get your mercury?
At the flea markets, I went to as a kid.
No, in H.G. Wells.
Oh, grown.
No, that was great.
No, it was not great, but thank you anyway.
Yeah, so what's happening here is not that there's a black hole next to every bit of mercury,
although I love the theory.
I don't know if you heard it, that maybe every electron actually is a black hole.
Could we tell anyway?
We'd like to talk about that on the podcast another time.
No, what's happening here is that electrons are actually relativistic around mercury.
Mercury is so powerful with this nucleus.
Those 80 protons have such a strong hold on the electron.
that the electron velocities start to approach the speed of light.
They're not going at like 99% of the speed of light,
but whereas electrons around hydrogen go about 1% of the speed of light,
electrons near Mercury move almost 60% of the speed of light,
which is close enough for these relativistic effects to start to matter.
So that suggests to me then that everything with 80 protons are more
should also have these relativistic effects.
Is that true?
From there on out, we need relativity to understand.
understand the melting points of atoms?
Yes, absolutely.
And there's another guy under Mercury in the periodic table,
Copernicium, which is a crazy synthetic chemical element,
which means we need to make it.
It's not like found naturally in the wild.
And people suspect that the relativistic effects for copernicium are even stronger than
for mercury.
Mercury is something that's all over the place, so it's well studied and easy to play with.
But turns out doing these calculations, including the relativity in our calculations,
is very hard, which is one reason.
why only a couple of years ago
were people able to do this calculation
and predict the relativistic
corrections to the original quantum
mechanical calculations. Say that again
this time in English.
So you can go out and measure
the melting point of mercury, right? You put it on
the table, you heat it up, you see it melt, you
cool it down, you see it solidify. That's the
measured value. Then you can
go and say, I'm going to predict
what it should be based on my understanding
of what's happening. And they can do
calculations and they do these calculations
like we referenced earlier a number of 82C.
That comes from using quantum mechanics to predict the strength of these bonds
and understanding like at what temperature those bonds would break.
So you're using quantum mechanics to predict the bonds,
and from that you can get the temperature.
So that's the predicted value of mercury.
Now, if you go in and you say, well, I'm going to tweak quantum mechanics
because I'm going to do quantum mechanics not by itself.
I'm going to include relativistic effects in my quantum mechanics.
Then you're changing what's going on in your predicted mercury,
which changes the prediction.
of the bonds, which changes your prediction for the melting point.
And so when we see a difference between our prediction and our observation, we know something
is wrong.
So we go back and tweak our predictions to make it right.
And, you know, in principle, we should always be using relativity to get everything right.
But most of the time, it's irrelevant.
You want to calculate when that train is going to go from Cleveland to New York.
Relativity doesn't have any fact, right?
So you can ignore it.
Also, relativity is a huge pain.
Like, it's nonlinear.
It's complicated.
It's not easy to do.
So most of the time, if you can't ignore it, you should.
But when you discover that your non-relativistic calculations are not up to the task,
when they're getting the answer wrong, that's when you've got to go back and do your homework
and include the physics in your calculation because it turns out it's necessary.
Beautiful.
Okay.
All right.
So now we've got electrons moving super fast.
And now we're incorporating relativity.
What is the jump from there to understanding why melting point is affected?
Yeah. So first we should clarify which part of relativity we're including, because folks might be thinking, Daniel's been telling us that quantum mechanics and relativity can't play nice together. Like, that's the whole goal of modern physics has come up with quantum gravity and understand the Holy Universe and blah, blah, blah, and string theory. That's right. Daniel has been telling us that.
And that was not a load of baloney. That's all true. That refers to our failure to unify quantum mechanics with general relativity, theory of gravity and curvature and all sorts of crazy stuff.
which we have not been able to do.
But we have, and it's been decades and decades since we've done this,
unified quantum mechanics into special relativity,
the theory of what happens when things go near the speed of light
and incorporates the fact that light is always the same for all observers
and that nothing can go faster than light.
Special relativity, which is just like flat space,
but includes things like time dilation and length contraction
and maximum speeds and weird velocities and stuff,
that's special relativity that we have been able to merge with quantum mechanics.
have relativistic quantum mechanics that allows us to do these calculations, or quantum field
theory also has special relativity built in. So special relativity and quantum mechanics do play
very nicely together. Oh, that's great. Okay, and so when they're playing together,
why does them playing together change multiple points? Yeah, great question. And since this paper came out,
there's been a lot of coverage of this result in popular media, and I read all of them, and they're all
wrong.
What?
They all get the physics wrong.
Yes.
Let's take a break.
And when we come back,
you're going to tell us how we get it right.
I'm Dr. Joy Hardin-Brand-Bradford.
And in session 421 of therapy for black girls,
I sit down with Dr. Ophia and Billy Shaka to explore how our hair connects to our identity,
mental health, and the ways we heal.
Because I think hair.
is a complex language system, right, in terms of it can tell how old you are,
your marital status, where you're from, you're a spiritual belief.
But I think with social media, there's like a hyperfixation and observation of our hair,
right, that this is sometimes the first thing someone sees when we make a post or a reel is how
our hair is styled.
You talk about the important role hairstylists play in our community,
the pressure to always look put together, and how breaking up with perfection can actually
free us. Plus, if you're someone who gets anxious about flying, don't miss session 418 with
Dr. Angela Neil Barnett, where we dive into managing flight anxiety. Listen to therapy for black
girls on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. I'm Dr. Scott Barry
Kaufman, host of the psychology podcast. Here's a clip from an upcoming conversation about exploring
human potential. I was going to schools to try to teach kids these skills and I get eye rolling.
from teachers or I get students who would be like it's easier to punch someone in the face.
When you think about emotion regulation, like you're not going to choose an adaptive strategy
which is more effortful to use unless you think there's a good outcome as a result of it
if it's going to be beneficial to you. Because it's easy to say like go you go blank yourself,
right? It's easy. It's easy to just drink the extra beer. It's easy to ignore to suppress seeing
a colleague who's bothering you and just like walk the other way. Avoidance is easier. Ignoring is
easier, denial is easier, drinking is easier, yelling, screaming is easy. Complex problem solving,
meditating, you know, takes effort. Listen to the psychology podcast on the IHartRadio app, Apple Podcasts,
or wherever you get your podcasts. And here's Heather with the weather. Well, it's beautiful out there,
sunny and 75, almost a little chilly in the shade. Now, let's get a read on the inside of your car. It is hot.
only been parked a short time, and it's already 99 degrees in there. Let's not leave children
in the back seat while running errands. It only takes a few minutes for their body temperatures
to rise, and that could be fatal. Cars get hot, fast, and can be deadly. Never leave a child
in a car. A message from NHTSA and the Ad Council. We're siblings. Like, you fight, you disagree.
It's really hard to be in a partnership. You judge. Yeah, you judge each other. You lead differently,
and we've gotten to that edge. Hey, I'm Simone Boy.
host to the Bright Side, and this week I'm joined by Hollywood Power Sisters, Aaron and Sarah Foster.
They open up about navigating the judginess of Hollywood, dealing with rejection, and the pressure of running a business with your sibling.
And yeah, they're spilling the tea on season two of their hit Netflix series. Nobody wants this.
I feel like the overall consensus was like, people were just obsessed with this, will they, won't they?
Like, that's the thing, right? It's just intoxicating. You want to be able to sustain that for as many seasons, but you also have to like marry them off eventually.
I don't know what you think you'll marry them off, Aaron?
Well, I don't even know if they're staying together, Sarah.
Y'all, this conversation is honest, hilarious,
and everything you didn't know you needed this week.
Listen to the bright side on the IHeartRadio app,
Apple Podcasts, or wherever you get your podcasts.
Before the break, Daniel was telling us that he's been reading a bunch of
Popsai articles that attempt to merge quantum mechanics and special relativity and that all of
their explanations are wrong.
So let's talk about the wrong explanations first.
Yeah.
And these are not just Popsai articles in like, you know, science news.buzz or something.
I hate science news.
Dot buzz.
People are constantly forwarding the articles from sites with names like that and being like,
is this true?
And I'm like, man, why are you even reading that site, you know?
But there's some pretty venerable places that have put out press releases.
and articles about this that get it wrong.
And they all repeat the same nonsense.
They all repeat this business about how electrons,
when they approach to speed of light,
gain mass, become more massive.
That's the heart of their explanation.
And number one, that's not true.
Things do not gain mass as they approach the speed of light.
This concept of relativistic mass is outdated.
It's not appropriate.
It was Einstein's mistake.
We talked about it recently in the podcast.
We can dig in it again.
in a moment. Also, it doesn't really explain why mercury has a lower melting point. You
know, electrons having more mass doesn't answer this question. I actually reached out to a chemist
here at UCI to ask him about this, and he said, quote, most chemists know little about
relativity, and I suspect that makes them more likely to swallow the pop-side buzzwords.
I'm surprised any chemist was willing to talk to either of us, given our reputations.
Well, maybe he's not a listener to the podcast.
Oh.
So let's unpack that for a minute.
Why do I say that it's not true that electrons increase their mass?
Because you hear that everywhere, right?
And it's a very popular thing to say because it sounds weird.
It's one of these things that people say a lot because it has an impact on your mind,
but it doesn't really actually make sense.
It just sounds cool.
And we talked about on the podcast why that doesn't really make sense and why
relativistic mass isn't even a useful concept.
It doesn't make sense because if mass depends on,
velocity is three directions, right? It's a vector. You get a velocity in one direction, another
direction, a third direction is three dimensions of space, three dimensions of velocity. If mass depends on
velocity, then mass also has three dimensions. Then you would have like a different mass in each
direction. It's weird. It doesn't make any sense. It's not what we think about as mass. And mostly
it's misleading. People think that something weird and mystical is happening. Like as the
electron is approaching the speed of light, it's growing and mass like it's getting more stuff
to it in some weird way.
That's not what's happening at all.
What's happening instead is that as electrons approach the speed of light relative to an object,
our intuition about the relationship between energy and velocity fails.
Down here at very low velocities at the surface of the earth, when we're running around
at low speeds and driving, and what we think are high speeds were really pretty slow
compared to the speed of light, we think that as you add,
energy, velocity goes up to, and they go up together, right? But what happens as you approach
the speed of light is energy can keep going up. There's no limit to energy, but a velocity is
limited to the speed of light. And so as you add energy to something, its velocity doesn't go
up by as much. And so that sounds sort of like, oh, when it's getting more massive because
it's harder to get it to go faster, right? It's really just a relationship between velocity and
energy that gets more complicated near the speed of light. So it's not like a useful thing. It's
We can just use energy.
Energy contains all the same information as relativistic mass.
And energy is not as misleading.
It doesn't give people the impression that, like, the electrons getting more stuff to it somehow.
So it's not a useful concept and it's misleading.
And in this case, it doesn't explain why mercury would have a lower melting point.
You know, having more mass would mean it would take more energy to get you to higher velocities,
but these things are moving at very, very high velocities.
So that would imply they have even more energy, which would push them out from the center
and would be easier for them to nab by other atoms.
And so it sort of goes in the wrong direction as far as I understand it.
All right.
So I am definitely not going to be reading science.
Dot buzz, or what was it, science news.
Because they clearly got this wrong.
And, you know, you mentioned that everybody was talking about it.
You know, when my daughter came home from school and was like electrons increased their mass as they approach the speed of light,
I was like, I'm so disappointed.
pointed in you, Ada. But so what is the right explanation? So there is an explanation. It's not like
as simple and as compact a story as the electron gets weirdly massive. The answer is that to figure
out where the electrons go, you have to solve the equations. And the equations depend on a lot of
stuff. And the solutions to those equations, you know, the energies that the electrons are happy to be
at are different if you include relativity than if you don't. And if you include relativity,
you get electrons with smaller orbits, right?
They're still moving at very, very high speeds,
but they have tighter orbits.
They're closer to Mercury.
Essentially, they have lower energy
than without relativity.
And so they have tighter orbits
at these very high velocities.
And because they have tighter orbits,
Mercury is able to hold onto these electrons
even more tightly than its friends
in the same column, zinc and cadmium, for example.
And so if you turn off relativity,
then it relaxes a little bit and these electron orbitals get larger.
If you turn on relativity, then the electron orbitals shrink a little bit.
And I went back to that chemist and I asked him,
hey, do you have an intuitive explanation for what's going on here?
Like, is there a nice little story in the same vein as like,
hey, electrons get more mass, but actually correct?
And he said, look, chemistry is complicated.
The answer is no, there isn't a nice simple explanation.
It's just that when you include these effects,
the first order relativistic correction,
if you're doing perturbation theory, is to reduce the energy of this shell.
And it turns out to be a really hard calculation, which is why people only recently
were able to do it.
You have to model a bunch of atoms altogether to figure out the bonds between them and
all of the electrons around those atoms.
And this is a really hard thing that you need really powerful computers, and then adding
the relativistic pieces means every time you want to move your system forward in time,
you have to do a bunch more complicated calculations.
Like relativity makes everything harder.
Like not only is it harder to think about it, but it's also harder to get our computers to predict.
It's like more steps in each calculation, more multiplications and divisions and square roots and all sorts of really weird stuff.
But it's these relativistic effects which push the prediction from chemistry down below room temperature.
So there's a recent paper, and they predict that the melting point of mercury should be negative 23C.
So without relativity, they predict 82C with relativity.
predict negative 23C. Now, the real value is negative 39C, so they're still not getting it right.
There's still more to understand there, probably second, third order relativistic corrections,
more detailed, accurate predictions. But they have gotten it down below room temperature,
and so this, we're convinced, is the explanation for why Mercury is a liquid of room temperature.
It's relativity.
So that is super cool. So Mercury has an atomic number of 80, and it's got,
a really low melting point but why doesn't everything past 80 also have a really low melting
point it still feels like mercury is anonymous relative to everything else yeah well it sort of does
like if you keep going you know lead for example has a melting point of 320 that's not that high
it's a lot lower than silver and gold and that's because it's really heavy and it has these
relativistic effects but also it doesn't have a complete shell so it's much higher than mercury
because it doesn't have a complete shell.
If you get all the way over to the end of the periodic table,
you have like Xenon, its melting point is like negative 100C,
and radon is like negative 70C.
These things are gas at room temperature.
So you see those effects as you move down the periodic table,
melting points are shrinking,
and one of these reasons is relativity.
But it's not the only thing that's happening, right?
Okay, so it's the combination of the shells being filled,
how tightly those shells are held,
by the nucleus being heavy
and the fact that that
heavy nucleus is causing the electrons
to move faster and now you have relativistic effects.
And all three of those things come together with mercury
to impact its melting point more than anything else.
So like, for example, if you move to tin,
10, yes, still has that relativistic effect going on,
but now you have one electron in the outer shell
and so it's wanting to react to stuff
and so now you're in a different world altogether
and that's why it doesn't have such a low melting point.
I think maybe you're thinking about thallium, which is the next one over for mercury.
And it looks like tin, but it's actually a TL.
But yes, otherwise.
Yes, exactly.
Yes.
And so that's why thallium is like 350 degrees higher melting point than Mercury, because
it's got this one extra electron, which we're very happy to bond with other thallium atoms.
My annual eye appointment is next week.
And so maybe in a few weeks I'll be able to read the periodic table.
But even if it was TI, that wouldn't be 10.
And tin is S-N, right?
Because it's got some weird Latin name.
Oh, how embarrassing.
How embarrassing.
But you're right that there are relativistic effects all over the bottom of the periodic table.
For example, gold.
Why is gold beautiful and gold colored?
Whereas silver, which has the same electron structure and is one above it in the same column,
is basically colorless.
It's, you know, silver.
The answer is relativity.
The color of an element depends on the photons it will emit and absorb,
which depend on the spacing between the energy levels and relativity changes those energy levels in gold much more than they do in silver, which makes it gold colored.
Without relativity, gold would look like silver.
Oh my gosh.
I know.
So much cool stuff happening with relativity.
People always say relativity is beautiful.
Now you know why.
It's gold.
People are always saying that.
Like it's common on T-shirts and stuff like that.
People are saying that.
You're being ironic, but I'm not.
Relativity really is beautiful.
I do think it's beautiful.
I do.
And this has been super cool.
So how recent is this incorporation of special relativity into our understanding of what's
happening in the periodic table?
Is this something, I think I'm remembering you said we've kind of known about it for a while
but haven't been able to calculate it until recently?
Like how recently have we started incorporating this stuff in there?
So, you know, we've known about quantum mechanics for about 100 years and relativity for about
100 years.
They were merged together into relativistic quantum mechanics.
only a few decades after the birth of both those theories.
So that's been for a long time.
But in order to do this calculation requires a lot of computing.
So it was only about 10 years ago that people were able to do this calculation
and predict the melting point of mercury more accurately than 82C.
And so, yeah, this is a pretty recent calculation.
It's a cool time to be alive.
It is a cool time to be alive.
But while mercury is amazing and gorgeous and fascinating, please don't play with it.
don't drink it, don't throw it at your sister.
You probably don't want to put a vial of it on your neck.
Though it turned out pretty well for you, Kelly.
That was probably one of the less dangerous things kids like me were doing in the 90s
when we were sort of free ranging around our neighborhoods.
All right, well, I'm going to get my special Relativity as awesome t-shirts
because you've convinced me.
And I look forward to talking to you next week.
That's good.
And so for those of you folks out there keeping track,
Relativity has now explained two totally different kinds of Mercury,
both the orbit of the planet Mercury and the melting point of the element, Mercury.
Relativity is all over it.
Ah, you know, actually, when I read your intro, I thought to myself,
I don't know the story about how relativity predicted Mercury's orbit.
Should that be another episode?
Is there a 30-second version, or should we do a future episode?
Future episode, let's do it.
Future episode, locked in.
All right, thanks for listening.
If you want to get in touch, please send us an email,
at Questions at Danielandkelly.org.
We can't wait to hear from you.
Thanks for staying with us for this chemistry episode.
Daniel and Kelly's Extraordinary Universe is produced by IHeart Radio.
We would love to hear from you.
We really would.
We want to know what questions you have about this extraordinary universe.
We want to know your thoughts on recent shows, suggestions for future shows.
If you contact us, we will get back to you.
We really mean it.
We answer every message.
Email us at questions at danielandkelly.org.
You can find us on social media.
We have accounts on X, Instagram, Blue Sky,
and on all of those platforms,
you can find us at D&K Universe.
Don't be shy.
Write to us.
Get fired up, y'all.
Season two of Good Game with Sarah Spain is underway.
We just welcomed one of my favorite people
an incomparable soccer icon
Megan Rapino to the show
and we had a blast. Take a listen.
Sue and I were like riding the lime bikes
the other day and we're like
we're like people ride bikes
because it's fun.
We got more incredible guests like Megan in store
plus news of the day and more
so make sure you listen to Good Game with Sarah Spain
on the IHeartRadio app,
Apple Podcasts or wherever you get your podcasts.
Brought to you by Novartis,
founding partner of IHeart Women's Sports Network.
Tune in to All the Smoke podcast, where Matt and Stacks sit down with former first lady, Michelle Obama.
Folks find it hard to hate up close.
And when you get to know people, you're sitting in their kitchen tables, and they're talking like we're talking.
You know, you hear our story, how we grew up, how I grew up.
And you get a chance for people to unpack and get beyond race.
All the Smoke featuring Michelle Obama.
To hear this podcast and more, open your free Eyeheart Radio app.
Search All the Smoke and listen now.
Here's Heather with the weather.
Well, it's beautiful out there, sunny and 75, almost a little chilly in the shade.
Now, let's get a read on the inside of your car.
It is hot.
You've only been parked a short time, and it's already 99 degrees in there.
Let's not leave children in the back seat while running errands.
It only takes a few minutes for their body temperatures to rise, and that could be fatal.
Cars get hot, fast, and can be deadly.
Never leave a child in a car.
A message from Nits and the ad council.
Have you ever wished for a change but weren't sure how to make it?
Maybe you felt stuck in a job, a place, or even a relationship.
I'm Emily Tish Sussman, and on She Pivots, I dive into the inspiring pivots of women who have taken big leaps in their lives and careers.
I'm Gretchen Whitmer, Jody Sweetie.
Monica Patton.
Elaine Welteroth.
Learn how to get comfortable pivoting because your life is going to be full of them.
Listen to these women and more on She Pivots.
Now on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.
This is an I-Heart podcast.