Unexplainable or Not: Beach day!

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It's time for another episode of Unexplainable or Not, the game show where we finally get some answers.

This week, our guest is Sam Sanders.

He's the host of Intuit, Vulture's podcast all about pop culture.

You might also know him from Vibe Check or It's Been a Minute.

Welcome, Sam.

Thanks for having me.

So happy to be here.

I'm like insanely nervous because

I'm good at some things.

I'm not particularly good at science things,

but I love to talk.

Well, this is great.

I mean, hopefully makes our job easy.

So as a recap of the rules here, Unexplainable or Not is a game show where you have to guess what we know and what we don't.

You're going to hear three stories about scientific mysteries, and you're going to hear them from me, our producer, Bird Pinkerton.

That's me.

Hi.

And our science editor, Brian Resnick.

Hey.

Hello.

But one of these three mysteries has recently been solved.

After you hear all three of them, you're going to get a chance to guess which one you think scientists have actually figured out.

If you get it right, we're going to tell all our listeners exactly why Intuit is the greatest show in the world.

And it has so many reasons, by the way.

Oh, you're too sweet.

But if you get it wrong, you got to tell everyone you know why Unexplainable is even better.

Yeah.

Best show you've ever heard.

I would sing the praises of your show either way.

You accept?

I accept.

This week, in honor of you and your last name, and I apologize for this in advance,

we're talking about sand.

Let's do it.

Let's do it.

All right.

So it's not just because of your name.

Sand is actually surprisingly mysterious.

There's this like scientific joke that sand is more complicated than quantum mechanics and general relativity.

It's like potentially the most.

After looking through these mysteries, like kind of, it's kind of wildly complicated.

Okay.

So we've got three different potential sand mysteries for you.

And I'm going to go first.

Okay.

Here's the question.

What makes sand squishy?

Before we get into it, I'm wondering, like, when's the last time you were at a beach?

Every few weeks, I'll take my dogs out to

a dog beach in Huntington Beach, which is like an hour south of LA.

There's a mile strip of the beach where all the dogs can be off-leash.

So it's like dog beach heaven.

On occasion, they have like costume days for certain breeds of dogs.

So like the second time I went there, it was like dress your pug up day on the beach.

It was the best pug.

Oh gosh, too many to even like think through.

The ones who were superheroes were like iconic, but all of them were just so sweet.

It's one of my favorite places in the world, I might say.

Amazing.

And your dogs probably really love running around on the beach just because it's squishy and it doesn't hurt that much.

And at a basic level, scientists know why this is.

It's because sand is basically like a bunch of little particles moving past each other.

But the real mystery here is that scientists can't predict just how squishy a kind of sand is going to be.

You might think that that's kind of like, okay, like, who cares?

Why would it matter how squishy sand is?

But I mean, you're in California, like, think about the erosion and the landslides that are happening on hillsides when they just kind of like fall into the beach.

And it's really hard to predict when some, you know, quote unquote hard sand is going to turn into soft sand.

So, I talked to this physicist, Karen Daniels, from NC State, and she told me she's working on essentially like a grand unified theory of sand.

Okay.

To start, she told me that, like, we know rounder, smaller grains are squishier.

So, if the individual grains of sand are rounder and smaller,

yeah, it allows them to kind of move past each other a bit easier.

You can think about like moving your fingers through a jar of marbles or something, or like the little like bubble gym thing at McDonald's.

Is it like that kind of?

Yeah, exactly.

If it's small and more round, things aren't going to get caught on each other.

But if they're like jagged and harsh, they could get caught in each other and basically make it behave more like a solid.

Gotcha.

But the issue is when it gets even smaller, something like sugar, humidity can affect it and it can start clumping.

Oh, yeah.

It's a rock.

So knowing the individual grains, the type of grains isn't enough.

It's about how they behave together.

Karen told me this is basically called emergent properties.

It's sort of like why it's so hard to predict the weather or where clouds are going to move because it's just made up of so many little particles.

And because this is so hard to predict, people come to Karen and they're like, look, we have this type of powder or sand or something, and we're using these machines.

And we just need to know how much is it going to squish?

Is it going to break our machines or not?

And no one can predict that yet.

So she's basically like, I just have to step on it and figure it out.

I love that.

That's what she says.

She says, I got to put it down.

I got to step on it and I measure how much it squishes.

I could do that.

Right.

I mean, that's like the type of science that a lot of people can do, right?

But the problem is, like, she can't just step on everything.

So, this is why she really wants to come up with this universal theory of sand.

So, basically, she takes a bunch of grains of stuff.

It's not sand, but they're more like the size of marbles, just so it's easier to measure.

And rather than stepping on it all, she uses all these fancy types of equipment to measure it and kind of figure out exactly where every single grain is, how it's oriented, whether it's moving, what pressure is being placed on it.

And if she can basically get a census, essentially, of every single grain, she can then start to predict without having to step on everything.

So she's been able to do this in her lab.

It's been really successful, but she hasn't done this in the real world yet, which is obviously much smaller sand, many more variables.

But she is about to.

She's about to go out and do a real experiment to predict how much sand can squish and hopefully develop a universal theory of sand.

Or has she done it already?

Bird raises a good point.

This could already be solved.

I want to say

it's already been done.

You think it's been done?

If you're saying that she's already said, I can just step on this stuff and she's already working on the sand and this is her life's work, I feel like I believe in her and she's done it.

Okay.

Keep that in mind.

Okay, I'm I'm scared.

I don't know if I'm right or wrong.

Just, you know, you don't have to make your final call yet.

Just file that away.

Okay.

We got two more potential mysteries for you.

And next up, we got a sand mystery from reporter Bird Pinkerton.

All right.

Hi, Sam.

Hi.

So, Sam, my mystery is about sand castles.

Oh.

The worst Beyonce song ever.

Sorry, neither here nor there, but it's triggering for me.

And I love her.

Okay.

Well, my mystery is about sandcastles, and it's about why Beyoncé made the song Sandcastle.

It's specifically about the force that holds sandcastles together and sort of what is the tiniest sandcastle that you could make with that force.

Oh.

This force, we actually understand a lot about it kind of regular size.

So I'm assuming you built a sandcastle at some point in your life.

Yes, but I never had the patience to make a really good one.

But like, if you were going to describe like the basic ingredients of sand castle building, it's like sand and what?

A little bit of water.

Exactly.

Yeah.

And so basically the sort of force that holds these wet grains together is called capillary forces.

And to explain what that is,

have you ever put like a flat-bottomed glass at the bottom of a wet sink?

Yes.

So what happens when you then try to like lift

glass?

Yeah, it's a little stuck.

Yes.

Sam, you're acing all of these questions.

Yes.

10 out of 10 on our science quiz.

In the scientific terminology, sometimes water be glue.

That's what it is.

That's what it is, right?

Yes.

And so the reason that is what it is is that...

Basically, when you have two solid surfaces, so in this case, it's the glass and it's the sink,

and then you have like a really thin layer of water between them, it ends up making kind of a bridge almost.

It has like this hourglass shape where it's widest where the water is attached to the glass and the narrowest in the middle.

Basically, it's this weird property of water where it curves and bends.

And that curving and bending overall is what creates that stickiness.

It sounds beautiful.

Is it pretty?

I mean, little hourglass water.

Compelling.

It's got a nice figure, sure.

Okay.

And so this force is basically how your sand castle works.

Gotcha.

It's sort of like these tiny grains of sand have these tiny little bridges going in between.

Bridges of water kind of keeping them connected.

Exactly.

And it's also important for like building material, soil structures, stuff that's a lot less compelling than sand castles or, you know, a lot more economically relevant, whatever.

And we have known about this force overall for over a hundred years.

Gotcha.

But the mystery here is what happens when things get small?

Like Like the size of like a single atom or a molecule, things can sometimes start to get like a little wacky.

And we're actually building at this point stuff at molecule size, like all these nanotechnologies in medicine where they're like, we use laser tweezers and like tiny tools for manufacturing, again, for medicine.

Like it's good to know how stuff is functioning when it's small because we are making small things, yeah.

At small sizes.

But does this break down or change when it gets small, right?

That's our mystery.

And to figure this out, you would basically have to build the world's tiniest sand castle.

Like it would no longer be sand because sand is actually so cute.

That's really cute.

Like a like a sand castle of molecules, essentially.

Yeah.

And so it turns out that building a sand castle of molecules is hard and complicated, right?

There are barriers to learning.

Can you build the world's smallest sandcastle using these capillary forces?

I think it's a mystery we have not solved yet.

Okay, okay.

It's a lot harder to build a nano sandcastle than to step on different kinds of sand.

Seems totally reasonable.

Yeah.

I've stepped on sand, never built a tiny sandcastle.

There you go.

All right.

So we've got squishy sand, we got tiny sand castles, and then we have one final potential mystery, and it's coming from our science editor, Brian Resnick.

Hey, hello.

My mystery is about glass, which is related to sand.

Glass is molten sand, silica

that's been hardened really quickly.

It's solid, it's clear, it does amazing things, it's everywhere in our world.

But glass is super mysterious, and there's so many questions around glass.

I had to talk to three physicists about this, but a lot of them boil down to like, why is glass a solid?

And what is glass anyway?

So, to explain the weirdness of glass, it's first helpful to think about what typically separates liquids and solids.

So, when water is a liquid, the molecules of water are all disordered.

They're all like they can swish around, they can move, they're all kind of on top of each other.

It looks like they're having a fun time raving at a party.

Whoa, whoa, whoa, stop.

I love that.

Whenever I'm drinking a glass of water from now on, can I just imagine it's like a rave?

Yeah, they're going, you know, they're swishing around they're you know dancing they're grinding up on each other i don't know um never mind um no keep that in keep that in yeah

so when the temperature cools down those water molecules they're not dancing anymore they actually line up in a very strict order.

They crystallize.

They become solid because they are in this geometric repeating structure.

And

this is how a lot of solids work.

They're crystals.

That's typically the the difference between solids and liquids.

Glass,

glass is weird because if you took a picture of glass on a molecular level, it looks like a liquid.

It looks like everyone's in a rave.

It looks like all the molecules are disordered.

And yet it's a solid.

Yeah.

So this is a huge mystery.

And we have the start of an explanation, but it does not solve for the problem.

This is a real simplification.

So the idea is it's like something like a traffic jam.

So we're out of the rave now.

We're driving home.

I shouldn't strain the note of it.

Keep it going.

Keep it going.

So the idea is like you're flowing in a liquid, so you're driving through traffic.

And then imagine if all the cars on the road just stopped and like really suddenly.

You're not going anywhere.

So like the opening of La La Land when they're on the 405 and all of a sudden all the cars stop and it's the musical.

Yeah, I don't, I don't recall.

That's basically glass.

Or like just that moment in like a flash mob where everyone freezes, but they're all dancing, maybe.

That's glass.

Yeah, yeah, yeah.

That's glass.

Glass is the flash mob of the particle world.

That's jazz.

That's glass.

Well, maybe one car can move at a time and try to.

But basically, glass is kind of this liquid that has been kind of flash frozen.

But the problem is, like, it still doesn't make sense because if you take a picture of that glass, it still looks like a liquid.

So what allows the liquid to flow, but this glass is suddenly like solid.

Solid.

And so scientists think there's like a prize to be won here.

Is there some order in the glass that we can't see just by looking at it that explains why it kind of holds itself together, why it doesn't move very much?

It's kind of similar to what Noam was describing is you can't predict the properties of a glass.

You kind of just have to test them.

So if you want to like, you make a new type of glass, like you can't predict how it's going to break.

You just have to like try to break it.

New glass, yeah, and break it.

Yeah.

So, scientists think if they can understand the secret order that makes glass glass, maybe they can invent new types of materials.

Like, you can, if you understand what creates a glass with a certain property, you can make a glass that's harder to break or maybe breaks in a different way.

So, that's the question.

Like, why is glass solid?

And can we understand glass well enough to, you know, really manipulate it and make new things the world has not seen before.

So here's my thinking.

Glass is everywhere.

Yeah.

And there are all different types of glass, which leads me to believe that someone has figured out at least a little bit of this.

So that's three potential mysteries, Sam.

Yes.

Or at least they all were mysteries at one point.

And one of these mysteries has recently been solved.

Recently been solved.

And you'll have a chance to guess after the break.

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I don't like sand.

It's coarse and

rough and irritating, and it gets everywhere.

We are back from the break.

It's unexplainable or not.

Sam, welcome back.

Thank you.

We got three potential mysteries here.

Mystery one, why is sand squishy?

Mystery two, what's the tiniest sand castle we can build using capillary forces?

And three,

what's the deal with glass?

So without making your final guess, what are you thinking when you think about all three at the same time?

I still kind of feel like

the

how and why and which sand is squishy or not.

I'm like, that's an easy solve.

Step on it.

I think building a nano sand castle seems kind of hard.

I think the thing with glass is like, as a layperson, I would have just assumed already that we know all there is to know about glass because we use it everywhere.

But what if that's not the case?

What if?

Basically, the more I talk through this with y'all, the more I am perplexed.

I do not know.

You're not allowed to Google it either.

Okay, I'm not going to Google.

It honestly might be tough to Google.

Yeah, like, what are the search terms here?

Mini sandcastle, not Beyonce.

The mystery that has been solved recently is

how small can you make a little bitty nano sandcastle with the capillary water?

Final answer?

I don't know.

Yeah, okay.

I don't know.

I'm so scared.

I don't know why I'm so scared.

Okay, so here is your answer, Sam.

So, you know, there is a paper published just to tell people why the sandcastle could stand.

Wait, did I get it?

Sam got it?

Yes.

Do I receive an honorary PhD?

I have not been this nervous on a microphone in years.

So Bird is going to just tell you the actual reveal of her mystery here.

Yeah.

I spoke to this researcher, Chan Young.

I'm a research fellow at the departments of physics and astronomy in the University of Manchester.

And she did help solve this question, but it didn't exactly involve building like a tiny sandcastle.

They did build a different tiny thing.

What did they build?

Basically, if you remember from before, right?

So you have this thin layer of water, it ends up bending, kind of making this sticky force.

We've known this for like 150 or so years.

And the paper that Chan was referencing, right, was written by this guy named Lord Kelvin, who we hear a lot from in these game shows, weirdly, as Tan puts it.

He's like a very brilliant scientist, and you have no idea how many science and technology terms is named after him.

But when he wasn't doing like absolute zero and generating new electricity and a whole bunch of things, he wrote an equation to kind of describe these capillary forces.

This was back in like the 1870s.

So, this force works because water bends.

But when things get so small that you only have like one molecule of water,

one molecule of water can't bend, right?

It's just it's in its shape.

Yeah.

And the equation that Kelvin wrote doesn't necessarily allow for that.

And so Jen and her team were sort of thinking like we actually don't know what would happen at this scale.

Gotcha.

So they decided to figure out how to build not a sand castle, but a

very, very, very narrow tube.

0.34 nanometers.

A sand tunnel.

A sand tunnel.

For all sand people to walk through.

Yeah.

But specifically to allow water molecules through.

So like a single layer of them that was like one to two molecules thick.

So this tiny tunnel is a way to test that the force is still sort of working the way the equation would predict that it would because the stickiness of this like capillary force can kind of like pull water up a tube.

They were so delicate and so hard to make.

So this work takes more than three years time

to finish.

And again, they assumed here that the equation Kelvin wrote was going to kind of fall apart when you got to this single molecule.

So we would also expect, okay, it won't work.

But to what degree it won't work, we don't know.

We just wanted to figure out how bad would it not work.

And they basically like add water.

They're watching the molecules of water.

waiting to see this force sort of break down in some way.

But surprisingly, it didn't.

It just kind of seemed like the equation that Kelvin wrote about capillary forces, it worked.

It worked.

It held up.

She says she was really surprised.

It's just, you are fascinated by how nature does this.

So what this means, she did confirm, is that if you built a tiny sand castle at a nanometer scale, not with grains of sand, but with like tiny, tiny sand particles, water molecules would hold that sand castle together.

So theoretically, you could build the world's tiniest sandcastle.

I love that.

I love it.

That's going to get me through the rest of the week.

If the world can sustain the world's tiniest sandcastle, you can do anything too.

It's inspirational.

It's rather inspirational.

It is inspirational.

Be the nano sandcastle you wish to see in the world.

I don't know.

So, Sam, one last thing before you go, go: it's become kind of a tradition on our game shows that I will write a song about the revealed mystery.

Normally, it's like this kind of upbeat, bouncy thing.

Um, but I don't know, like, thinking about tiny sandcastles got me a little bit existential.

It's very emo.

So, here's the idea of a tiny sandcastle.

Here's the song.

I'm just gonna play it for you now.

Okay.

Oh, my God.

All my life,

I've been building sand castles

trying to build something stable when

everything

always scrumbles

Oh I love it

But as I got older my dreams seemed a lot harder and harder I said castles got smaller and smaller And when they got small enough I started to wonder if they'd hold together at all.

Now I'm building the smallest sand castle in the world.

So small, they're technically not sand

castle.

Lord Calvin's idea was more right than he knew.

Small castles lead to small

victories.

All my life,

Yo,

all my life I've been building sand castles.

That's heavy.

Yeah, you're okay, mom.

I like that.

Now I got to hear Beyonce singing this song.

Yeah, maybe she can take it on tour.

Submit it.

I don't know that Beyonce's sand castles are getting much smaller as her life is.

They're getting bigger.

They're getting smaller.

She's getting like the biggest sandcastle in the world.

Yeah.

So, Sam, because you won, congratulations again.

We have to tell everyone we know how great Intuit is, that it's the greatest show in the world.

Oh, wow.

That's not going to be hard to do that.

It's a wonderful show.

Wait, can I do it?

Can I do it now?

Yeah, Bert, just go.

Okay, I love Intuit because it feels like it is a show where you don't do a ton of

hand-holding in a way where I feel spoken down to, but I never come out of the show confused or not feeling like I understood it.

And I have so many culture geists that I have not submitted because I am too shy.

Oh, don't be shy.

You just made my week.

Thank you so much.

Everyone should listen.

That's it for the show, Sam.

Thanks so much.

Oh my God, this was so much fun.

Thank y'all for having me.

I'm a very big fan.

I love listening to this show.

You make me smarter without making me feel dumb.

So thanks for that.

And

it was really good to have won something this week.

That felt nice.

Thank you to our presenters, Bird Pinkerton.

You're welcome.

And to Brian Resnick.

You're welcome.

And thank you to our audience for joining us.

If you have a mystery or a solved mystery you want us to tell on an upcoming game show, let us know.

You can write us at unexplainable at vox.com.

We read all the emails.

Unexplainable is a part of the Vox Media Podcast Network, and we'll be back next week.

That's it for Unexplainable or not.

This episode was reported by Bird Pinkerton, Brian Resnick, and me.

Meredith Hodnott handled the editing with help from Andy Nguyen.

I did the producing and the music.

Christian Ayala was on mixing and sound sound design, and Serena Solon hit the facts.

Thanks so much to Sam Sanders for playing our game this week.

Go check out both of his excellent shows.

Intuit is an amazing, approachable, fun show all about pop culture, and Vibe Check is basically your favorite group chat come to life.

Special thanks this week to Camille Scalier, David Waits, Mark Etiger, and Stéphane Douadi.

If you have thoughts about this episode or ideas for the show, please email us.

We're at unexplainable at vox.com, And as always, we'd love it if you leave us a review or a rating.

Unexplainable is part of the Vox Media Podcast Network, and we'll be back next week.

All my life,

I've been building sand

castles.

This month on Explain It to Me, we're talking about all things wellness.

We spend nearly $2 trillion on things that are supposed to make us well.

Collagen smoothies and cold plunges, Pilates classes, and fitness trackers.

But what does it actually mean to be well?

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And is all this money really making us healthier and happier?

That's this month on Explain It To Me, presented by Pureleaf.

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