Hey everyone, it's Mango here.

With summer winding down, we are taking a little break, but we will be back with brand new episodes starting September ninth, and we have been working hard on so many fun episodes this summer.

I cannot wait for you to listen to them.

In the meantime, we are re airing our countdown of the twenty five greatest science ideas of the past twenty five years.

This list was so joyous to make.

Mary and Gabe did all this extra research for it.

We pulled in contributors for various places.

We got incredible songs written for the show.

The whole thing is bizarre and delightful and fascinating and joyous, and honestly, I just hope you enjoy it half as much as we enjoyed making it.

Let's dig in.

You're listening to Part Time Genius, the production of Kaleidoscope and iHeartRadio.

Guess What Will?

What's that?

Mango?

I can't believe it, but we are already halfway through our countdown to the twenty five best science ideas from the past twenty five years.

It's crazy.

So twelve and a half in exactly twelve and a half in and I don't know about you, but I feel like these stories keep getting better and better.

I mean that's kind of how a countdown.

Works, but I feel like you should tell people what is coming up next, preview it.

Well, today's episode has five stories, including what Nascar does to our brains, a clock that changed the way we think about time, and our attempt to explain particle physics through music.

Is that even possible?

There's only one way to find out, so let's dive in.

Hey, the podcast listeners, welcome to Part Time Genius.

I'm mungkish Heatikur, and as always I'm joined by my good friend Will Pearson and our palam producer Dylan is over there in the booth wearing his lucky sunglasses.

So I have a good feeling about today's episode.

So in case you're wondering, yes, he does have unlucky sunglasses and we had to ask him to stop wearing them during the show.

Only the lucky sunglasses.

That's right, it was a whole thing.

It was anyway.

Before we get into the countdown, I just want to remind you to subscribe to Part Time Genius on your favorite podcast app, which should be iHeart the iHeart app and if you enjoy the show, which I hope you do, please give us a nice rating and review.

It really helps us out.

And also we actually read the comments.

Someone has to do a show on three D printing and we're planning one in the works.

And this week someone named Elliott wrote the best podcast My name is Elliott, Oh I like that, which is the greatest narrative.

You know, went from how he felt about the podcast to his you know it was good, good stuff.

Well, Elliott, if you're listening messages on our Instagram, so we can send you something fun.

But let's get into the show.

Actually, it just hit me Dylan is probably wearing those glasses because you know what's next on our countdown Mango.

That Dylan is so clever.

Okay, so the first thing we're covering today is NASCAR.

Now, over the years, there have been lots of studies on NASCAR to improve the safety for drivers.

There have been research papers on how the car's bodies and safety measures affect injuries.

NASCAR also a worded a grant to Michigan State University to study everything from heat exhaustion and drivers to figure out better exercises and diet regimen for the athletes, and there have been studies on why fatherhood affects drivers because NASCAR drivers often drop one point six places on average the year after having a kid.

Wow, it does kind of make you wonder like if it's at all related to the fact that they're probably sleeping less.

I think that's probably part of it.

But scientists also hypothesized that when you have a kid, you think about your mortality money, and so you might be less prone to make risky moves on the course.

That makes sense anyway.

The most interesting study I read about was done by this psychologist, Guy Vidioloni from West Virginia University Institute of Technology, and it's a four year study called quote Driving under the Influence of Nascar.

It isn't so much about what happens on the track as it is how the races influence people watching at home.

So according to NPR, Vidilioni looked at all the traffic accidents that took place in West Virginia and then whittled it down to accidents that mimicked what happened on a racetrack.

So these were things like pile ups of multiple cars or accidents where there was aggressive driving and His conclusion was that five days after major NASCAR races, there's a big spike in traffic accidents.

Now, VIDILIONI actually put in a whole bunch of controls to make sure he wasn't just saying something wild.

He wanted to be really conservative about his conclusions, but he counted about six hundred and fifty extra accidents on West Virginia roads in the days after the races, essentially because people were quote acting out NASCAR in their own driving this wild.

Although the thing that stands out to me Mango is like, why is this on the fifth day after a race instead of like immediately after.

I don't think he figured that part out exactly.

Like he theorized that maybe it's because races tend to take place on weekends, and so a Thursday or Friday after tends to be the days that you let loose after a rough week.

But his study is really pointing to the subtle ways that media affects behavior in the real world.

Now, NASCAR is just one example of this.

Another famous case is of the MTV show sixteen and Pregnant, where the reality show actually captured the difficulties for high school students trying to raise kids, and people were really affected by it.

The show led to a five point seven percent reduction in teen births, which apparently was a third of the overall decline in teen births in the country.

Oh wow.

Yeah.

Academics actually sometimes refer to it as the you are what you watch phenomenon, And it's pretty interesting to see, sort of like how MLK talked about the interracial kiss on the original Star Trek being one of the most important moments on television, or how President Joe Biden credited Will and Grace with changing America's perception of gays more than just about anything else.

Yeah, that's right.

So anyway, this whole NASCAR thing won't be a problem ten to fifteen years from now when we're all taking way mos everywhere and getting the chauffeured around and robotic cars.

But until then, all you NASCAR watchers out there, he doctor Villlioni's advice, and be a little mindful of how you're driving the week after a big race.

We want to keep you safe.

Absolutely, all right, Mango, let's say you are a clockmaker.

I'm just going to say that.

Okay, Now, you've built a beautiful time piece that counts hours and minutes.

But now you've got a problem.

You want your clock to count each second with pinpoint accuracy.

So how do you do it?

It turns out you need to crack open the periodic table, because according to the International System of Units, this is how you measure a second.

Quote.

The second is defined by taking the fixed numerical value of the caesium frequency the unperturbed ground state high perfine transition frequency of the cesium one thirty three atom to be nine billion, one hundred and ninety two million, six hundred and thirty one thousand, seven hundred and seventy when expressed in the unit hurtz, which is equal to s the power of negative one.

You got it.

So that is the definition of a second.

Yeah, it's the definition of a second.

I got lost in the reading of it.

But as you may have noticed, it's a little bit complicated.

So the only way to measure it is with an atomic clock.

And the way this work sounds completely made up, but I promise it's actually real.

Basically, an atomic clock is a machine that shoots laser beams at caesium ions, measures frequency at which their electrons jump to different energy levels, and then sends the readings to a place called the International buz Ro of Weights and Measures.

So this is a real place.

It's a real inner governmental organization.

Yeah, and it's actually based in France.

So we've got laser clock sending data to friends.

I guess I'm with you that far.

Okay, I'm glad you're keeping up.

So there are around four hundred and fifty atomic clocks in the world, all sending these readings.

So timekeepers at the International Bureau of Weights and Measures they crunch these numbers from the clocks and then vote on the quote official time, which they publish in a monthly publication that comes out monthly called Circular Tea.

I never thought I'd say this about anything that involves caesium, but uh, that is pretty adorably whimsical.

It is in a way, but it's also pretty serious.

Stuff like this process is how we determine what's called international atomic time.

And a standard atomic clock made with caesium is so accurate it can keep time for about one hundred million years without skipping a beat.

Wow.

But starting in the mid adds, researchers at the National Institute of Standards and Technology or in IST, a federal lab in Colorado, they began developing a new generation of atomic clocks that could make caesium seem outdated.

Actually, so what makes these atomic clocks so special?

Well, they use aluminum instead of caesium, so basically a positive aluminum twenty seven ion.

In two thousand and eight, NST scientists built something they call the quantum logic clock.

Now.

It contains a single aluminum ion cool to nearly absolute zero, shot with an ultraviolet laser, and the aluminum ion acts like the second hand on a clock, so it ticks by jumping up and down between energy levels.

But instead of ticking once for every second, it ticks a quadrillion times per second.

That is a big number, make note.

And it's so accurate it won't lose a second for thirty three billion years.

That's almost triple the age of the observable universe.

That is really hard to imagine.

Yeah, or hard to put to the test, I think.

And this aluminum clock does more than just tell time.

It's even changing our understanding of space time because researchers have used it to test Einstein's theory of relativity.

According to Einstein's theory, gravity affects the passage of time so the stronger the pull of gravity, the slower the time.

And as a result of this, somebody who lives in the mountains of Colorado, where gravity's pull is slightly lower, they'll age faster than somebody who lives at sea level.

Now, the quantum logic clock is so sensitive it actually proved that a person standing at the top of a staircase or someone standing on a stool experienced a faster passage of time.

It showed that each additional foot of height adds about ninety billions of a second to your lifetime.

So NBA players would live longer than jockeys.

I have a dumb question to ask, why do we need clocks to be this accurate.

It's a fair question, but take GPS for example.

GPS isn't just a location tracking technology, it's also a type of clock.

So if you're driving down the highway and the GPS is five seconds late telling you to take an exit, you'd be pretty mad about this.

Right, for the GPS to be useful, it needs to show both an accurate location and an accurate time.

It needs that time to be precise down to the second.

And it turns out that's true for a lot of other technologies as well.

Take telecommunications, satellite networks, radio signals, lots more things like this.

Anyway, it's hard to overstate the importance of this quantum logic clock in the nerdy and wonderful world of time keeping.

Those caesium clocks that impressed you at the start of this segment will eventually end up being obsolete.

And while experiments with other elements are ongoing right now, aluminum is the leading contender to become the ticking heart of what we call a second.

Hey, listeners, do not go anywhere.

We've got to pause for a quick break.

But there is so much weird science right after Welcome back to part time Genius.

When we're talking the twenty five greatest science ideas of the last twenty five years, and we're up to number so it probably won't surprise you to learn that water is the most consumed material on Earth.

But can you guess what comes in second?

Mm?

I'm gonna go with coffee.

You know I might have guessed that too, but know the answer is concrete.

Oh really?

Since the Industrial Revolution, humans have poured nearly nine hundred billion tons of concrete, and nowadays we're pouring the stuff at a breakneck speed, especially in the developing world.

For example, in the time period between twenty eleven and twenty thirteen, China poured more cement than the US did during the entire twentieth century.

Isn't that incredible?

But all that concrete has a big downside.

It's responsible for eight to nine percent of global carbon dioxide emissions.

I never thought of concrete as being such a big pollution problem.

I know, it's not a great thing.

I think of, you know, the sidewalks and things that cars drive on, But I didn't think of it in that way.

Yeah, I didn't realize it either.

But apparently making concrete is an energy intensive process.

So it starts by taking limestone and baking it to temperatures over twenty six hundred degrees fahrenheit.

That kind of heat requires powerful kilns fired by fossil fuels, and that's just to make cement.

To turn cement into concrete, you have to add aggregates like sand, and really lots of it.

As a result, sand mining is a big business around the world.

We've actually talked about this before.

There's even a burgeoning black market for sand, backed by so called sand mafias.

Anyway, this dangerous mix of pollution, mining and mafia's got scientists wondering how to make concrete production more green, Like, what if we supple minute sand with something else, something more sustainable, something that could reduce concrete's carbon footprint.

And it's something that you mentioned just a few minutes ago.

Wait, coffee.

Yeah, so coffee.

Every day, humans drink two billion cups of coffee and most of the coffee grinds just end up in a landfill.

But in twenty twenty three, Australian engineering researchers had an idea, what if we used those ground up beans to make concrete.

So that's what they did.

They scorched coffee grounds to about six hundred degrees, which made the grounds break down into a substance called biochar, which is basically charcoal.

And when they began testing, they discovered that if you replaced just fifteen percent of the sand in concrete with coffee fueled biochar, the concrete becomes thirty percent stronger.

And how does that actually work.

It turns out the biochar retains water better than sand, and as a result, the concrete cries slower than usual, which reduces the risk of shrinking and cracking, helping it maintain its strength.

There are actually two benefits to this discovery.

One, by using spent coffee, it reduces the demand for sand, and two, by making concrete stronger, it reduces the amount of cement required for each bag, and with less cement and sand required, the total carbon footprint of each bag of concrete could drop significantly.

As it happens, a major industry group called the Global Cement and Concrete Association has pledged to go carbon neutral by twenty fifty and thanks to those coffee loving Aussies, they've got a really strong foundation to work with.

It's an incredible discovery and asso pun mego.

I'll take it all right now, mego.

We happen to be living through one of the most polarizing moments in recent history.

IM sure if you've noticed this, But I think one thing we can all agree on is that dinosaurs are really, really cool.

That should be the thing that brings us together.

In fact, that might be some of the firmest common ground we have left at this point.

What do you think?

Yeah, I mean, I'd like to think a little more positively than that, but in general, yeah, I mean, everyone loves dinosaurs.

Exactly, and it's always struck me that even though we're dealing with creatures that are over one hundred million years old in some cases, to this day, we are still finding new things out about them.

And the last quarter century has been particularly generous.

We've on earthed so many new fossils and developed so many breakthrough research techniques that some scientists are now calling this the Golden Age of paleontology.

Huh.

There are way too many of these dino revelations for us to cover today, but singling out just one didn't seem right either, So instead, I thought I would walk us through some of my favorite highlights and they can kind of all share this spot together.

What do you think, I love it like a big heap of dino discoveries is exactly what this science series needs.

Absolutely, I thought you'd approve of this.

So what stuck out to me most is all this research that sort of challenges what we thought we knew about dinosaurs, which for most of us is just what we saw in the Jurassic Park movie.

Sure.

For instance, in one of the most famous scenes of the original movie, we see a t rex chasing after a speed jeep and nearly catching up to it.

So that didn't happen in real life.

That was just a movie, Yeah, exactly.

In fact, she was even closer than she appeared to remember because of that whole mirror.

Yeah, I think we all remember that.

That scene was considered plausible for nearly a decade after the film's release, with many paleontologists speculating that a real t rex could run as fast as forty five miles an hour.

But in two thousand and two, researchers John Hutchinson and Mariano Garcia used some clever math to show that the rex likely had a much slower role than we previously thought.

So, using biomechanical data from the dinosaur's closest living relatives those would be birds, now, the pair was able to extrapolate just how much muscle mass it would take for an animal the size of a t rex to actually be able to run.

As a general rule, no more than fifty percent of an animal's body mass is composed of muscle in only a fraction of that muscle is allocated to the legs.

But for a t rex to run forty five miles an hour, its leg muscles would need to account for eighty six percent of its total body.

Right, some real masks.

Those are monster legs.

It feels like the leg muscles would be up to its eyeballs.

But uh, you know, in that case, there's no room for anything else.

Yeah, it doesn't add up there.

So even though the researchers had poked a giant hole in one of Jurassic Park's best scenes, the filmmakers didn't hold it against them.

In fact, Hutchinson was even hired to consult on one of the Jurassic Park sequels based on the strength of this breakthrough.

That's pretty awesome.

But I'm curious, do we know what a t rex's top speed would be?

Well, the two thousand and two study concluded that t rex would have had a hard time topping twenty five miles an hour, and according to a twenty seventeen study from the University of Manchester, they probably can only reach speeds of around twelve miles a mile, so any faster and the seven ton predators would risk shattering their bones.

Actually.

Wow, so it's almost like at speed that a human could outrun.

At this pace.

Yeah, and remember that's the top speed.

The t Rex was even slower when walking exactly how slow remained a mystery until twenty twenty one, when Dutch researchers built on those earlier findings and used computer modeling to prove that Rex walked at a leisurely pace of between two and three miles an hour.

Now, another point of departure from the Jurassic movies is that the predatory dinosaurs, including t Rex, did not have permanently exposed teeth.

Researchers and artists have long believed that bipedal carnivores have lipless mouths where their upper teeth would hang over their lower jaws, not unlike you know, maybe like a crocodile or something like that.

But according to a twenty twenty three study from the University of Portsmouth, the dinos actually kept their choppers discreetly covered with a pair of thick lizard lips.

Isn't that kind of funny to imagine?

So the researchers found that toothwaar and lipless reptile groups was much different from that of carnivorous dinosaurs, and based on computer modeling, it would have been impossible for a lipless t rex to close its mouth without the lower jaw actually crushing the very bones that supported it.

That is really interesting, And you know, I feel like with all these breakthroughs, they've kind of defanged this idea of a really frightening t rex, right, but like suddenly they're like only strolling around at two miles per hour.

Like they don't have those goofy grins anymore, right, you know, bearing their teeth and a dinosaurs supposed to have feathers, right like on top of everything else, they're fluffy.

Actually, I've got some good news on that front because while many dinosaurs are now believed to have sported feathers, including raptors and a few of the t rex's cousins, the rex itself is thought to have had this smooth, more scaly skin.

The exception would have been juvenile t rexes, whose small bodies may have needed feathers for thermal insulation by the time they reach adulthood, though their forty foot long bodies were so good at retaining heat that they know or needed those downy coats.

So if anything, an adult t rex may have had a stripe of bristles on its back and shoulders, but those would have been used to attract a mate rather than to keep warm.

All right, So that's at least one thing the movies seem to have gotten right.

Yeah, and there's there's still room for improvement on that front too, because while the t rex was scaling, they likely weren't the drab uniform color they're often depicted as you know, you always picture that exact colors.

Recent analysis of t rex fossils have turned up evidence of melanin, the same pigment found in human skin and bird feathers, and that suggests that the rex's skin may have had patches of several different colors, possibly even like a camouflage pattern, which makes sense you think about the stripes and spots of modern predators.

That is crazy, you know.

I kind of imagine like being given like a t rex as a kid and told to color it, and like, you know, you pined with fancy colors, and that seems completely wrong, right.

I also had no idea that melanin could fossilize.

Well, paleontologists didn't eat either until two thousand and eight, and since then discovery has led to all kinds of new insights about the appearance of dinosaurs, including some pretty solid guesses about the exact colors of their skin and feathers now more than anything.

Though.

All the advances we've talked about show us that the dinosaurs weren't the straightforward terrors that we often see in pop culture.

Like any other animal, they live full lives.

That included some quieter moments as well.

I like how you're trying to make it seem like we should all be adopting them from shelters.

I feel like it's the right thing to do.

I would still be a terrified one.

Oh totally.

I mean, you know me, I'm terrified when I see a cat, can imagine a dinosaur?

All right?

Well, because dinosaurs are so cool, we decided today on our Instagram we're going to give away some super special, scientifically accurate dinosaur action figures.

It is important to call them action figures.

I called it a dolt earlier.

Gabe got very like that.

I didn't like it.

He is our resident toy expert, so I'm going to have to lean on that and I will agree to ill at an action figure.

So head over to our instagram at part Time Genius and find out how you can win.

Okay, listeners, you've got to pay for the show with some ads, but uh, we'll be right back after this quick break.

Welcome back to part time Genius, where we're listing out the best ideas in science in the last twenty five years.

Nay, okay, well, so how much do you know about sub atomic particles?

All right, Well, my knowledge of subatomic particles would, if I'm being honest, probably fit inside a sub atomic particle.

Yeah, that's what I thought.

So here's a quick overview that'll help you understand our next great science discovery.

So let's start with protons.

These tiny particles hang out in the nucleus of every atom, and they're made up of even tinier particles called quirks, which in turn are held together with even tinier particles called gluons.

Now, gluons have no mass, but they do carry energy, specifically something called the strong force, and in terms of nuclear physics, it basically means it holds stuff together.

Now stay with me, because I'm sure you know that deep in a tunnel near Geneva there's something called the large hadron particle collider.

And a hadron is any clump of two or three quirks, And what this thing does is it blasts particles like protons at each other at insane speeds, so scientists can find out what happens when they crash into each other.

And even before this technology existed, scientists have been thinking about the outcomes of proton collisions.

So one hypothesis they came up with was that protons might exchange a couple of the gluons that hold them together, creating a super weird, massless little particle made up of only gluons, which they called and this is true a blue ball glue ball?

Is that the actual scientific term, though it is so ah way, In nineteen seventy three researchers put forward a very specific version of this theory.

They said that it was possible for three gluons to briefly stick together after a collision.

Now, at the time, there was no actual proof of this, It was just an idea.

And they call this hypothetical particle the odderon.

All right, so I want to make sure I understand.

So an oduron is what like a triple glue ball?

Yeah, yeah, you know, it's weird.

I had never thought of particle physics involving this much fun vocabulary.

I feel like I might have majored in it if I had known all this.

But all right, So are you going to tell me that someone finally proved this odoron thing is real?

So in twenty twenty one, a group of scientists using the Large Hadron Collider did in fact find evidence of odon.

So yes, when protons collide in this thing, about three quarters of the time they get smashed apart, but about twenty five percent of the time the protons survive intact.

They just kind of bounce off each other.

And because at the point of impact, they exchange gluons, sometimes two, sometimes three, and those gluons keep them together.

So are you still with me here?

I think so?

Right.

So, quirks carry a charge kind of like a positive or negative electric charge, but this is expressed in terms of color, so they can be red, green, or blue, and when you have all three of those stuck together, the charge is said to be white or balanced.

But there's also something called an anti color, which is the property of anti quarks.

Is this like antimatter, Yeah, So the antiquirk is the antimatter evil twin of the quirk, and it's either anti red, anti green, or anti blue.

But what's interesting is gluons have both colors and anti colors, so you could have a gluon that carries red and anti green, which sounds like a very strange Christmas ornament.

A spokesperson for the Oderon experiment told Gizmoto that the math of Vaulteer is quote too hard to explain, but suffice it to say, su Suer has observed frequency differences in proton proton collisions versus proton anti proton collisions, and they realized the difference had to do with changing color balances that could only be explained by the existence of a triple gluon clump.

The odder On I'm trying real hard here, mango, but I gotta be honest.

This is making my head heart a little bit.

I know it is complicated stuff, but it's also an incredible discovery.

But to make the story a little more personal, we asked our pal David Nagler, who is an incredibly talented musician and composer, to write a song about it, Hiding in.

Plain sight Now I'm in the light light because of a proton proton and a proton anti proton condition.

That's the difference between the two.

Three good on stuff like good.

Thanks to the particle physicists for clearing up being decision I'm an a lot, but I'm not that odd and out un.

I'm a real hot rod.

It's not monochromatic light.

I'm red, green and blue making white.

It may seem like a fax, but it's only quantum chromo dynamics.

Folks deep in the particle e Sallerator keeping proton longevity greater.

So I can agree.

The force is.

Strong in me strong.

Autobun, but I'm not that and autorum.

I've got a real hot bond man.

Aut'm not that and auto um.

It's not that b.

And it's.

Wow.

It seems so complicated, but you know what mego.

It also makes me want to dance.

Yeah, the song or the science that you know, all of it.

I'm just feeling good after this.

I couldn't agree more.

And big thanks to David Nageler for helping us out with this.

We'll put a link to his website in the show notes so that you can check out his music.

It's not usually about physics.

Okay, that's it for today's episode, but be sure to tune in tomorrow when our countdown continues with a scientific secret Lurking and home depot, some lively molecules and a medical treatment that began in a really, really gross place.

You won't want to miss it.

And if you'd like to win that realistic dinosaur action figure, head on over to our instagram at part Time Genius to check out today's giveaway contest.

As always from Will, Gabe, Mary and Dylan, thank you so much for listening.