Why do planes fly?
Update: 2024-12-12
Share
Description
Daniel and Kelly dig into the surprisingly controversial question of why airplanes stay in the air.
See omnystudio.com/listener for privacy information.
Comments
Top Podcasts
The Best New Comedy Podcast Right Now – June 2024The Best News Podcast Right Now – June 2024The Best New Business Podcast Right Now – June 2024The Best New Sports Podcast Right Now – June 2024The Best New True Crime Podcast Right Now – June 2024The Best New Joe Rogan Experience Podcast Right Now – June 20The Best New Dan Bongino Show Podcast Right Now – June 20The Best New Mark Levin Podcast – June 2024
In Channel
United States
00:00
00:00
1.0x
0.5x
0.8x
1.0x
1.25x
1.5x
2.0x
3.0x
Sleep Timer
Off
End of Episode
5 Minutes
10 Minutes
15 Minutes
30 Minutes
45 Minutes
60 Minutes
120 Minutes
Transcript
00:00:00
Join I Heart Media Chairman and CEO Bob Pittman for a special episode of The Hit Podcast, Math and Magic, Stories from the Frontiers of Marketing.
00:00:09
As he interviews the iconic and prolific Martha Stewart in front of a live audience, in celebration of her 100th book.
00:00:17
"Did you ever think you were gonna wind up writing 100 books?"
00:00:20
"Yeah, you did?"
00:00:22
"Yeah, it's just a minor goal."
00:00:24
Listen to Math and Magic on the I Heart Radio app, Apple Podcasts, or wherever you get your podcasts.
00:00:30
"Hey, I'm Jay Chetty, and my latest interview is with Wiz Khalifa."
00:00:35
"The craziest part of my life, I can go from performing in front of 40,000 people to either being an industrial or being in the plane or being back in the bed all by myself."
00:00:47
"He is a multi-platam selling recording artist, Minnie Mogo, and an actor, which am I the one?
00:00:52
The only one."
00:00:53
Listen to On-Purpose with Jay Chetty on the I Heart Radio app, Apple Podcasts, or wherever you get your podcasts.
00:01:00
"Yo, what up?
00:01:01
It's your girl Jessalarius, and I think it's time to acknowledge that I'm not just a comedian.
00:01:06
It's time to add uncertified therapists to my credentials.
00:01:09
Because each and every Wednesday, I'm fixing your mess on carefully reckless on the Black Effect Podcast Network.
00:01:14
Got problems in your relationship?
00:01:16
Come to me.
00:01:17
Your best friend, Akton Chetty?
00:01:18
Come to me.
00:01:19
Thought you was the father, but you not?
00:01:21
Come to me.
00:01:22
I can't promise I won't judge you, but I can guarantee that I will help you.
00:01:25
Listen to carefully reckless on the Black Effect Podcast Network.
00:01:28
I Heart Radio app, Apple Podcasts, or wherever you get your podcasts.
00:01:32
AT&T, Connecting Changes Everything.
00:01:36
Hi, I'm Ed Zitron, host of the Betrothline podcast, and we're kicking off our second season digging into text elite and now they've turned Silicon Valley into a playground for billionaires.
00:01:49
From the chaotic world of generative AI to the destruction of Google search, Betrothline is your unvarnished and, at times, unhinged look at the underbelly of tech, brought to you by an industry veteran with nothing to lose.
00:02:02
Listen to Betrothline on the I Heart Radio app, Apple Podcasts, wherever else you get your podcasts from.
00:02:07
Hi, I'm Danny Shapiro, host of the Hit Podcast Family Secrets.
00:02:12
How would you feel if when you met your biological father for the first time he didn't even say hello?
00:02:18
And what if your past itself was a secret and the time had suddenly come to share that past with your child?
00:02:25
These are just a few of the powerful and profound questions we'll be asking on our 11th season of Family Secrets.
00:02:32
Listen to season 11 of Family Secrets on the I Heart Radio app, Apple Podcasts, or wherever you get your podcasts.
00:02:45
They say that any technology sufficiently advanced is indistinguishable from magic.
00:02:50
Well, there's one technology that people have lusted after for thousands of years that we now rely on, even find routine.
00:02:58
I'm talking, of course, about flight.
00:03:00
It's been only a hundred years since people were able to leave the ground and fly to the air and return safely.
00:03:07
Now it's so routine that people sleep through it, but imagine what that would seem like to someone from a thousand or ten thousand years ago.
00:03:15
It's essentially like magic.
00:03:17
Of course, we know it's actually not its science because we can understand it and we can break it down.
00:03:23
We can explain it.
00:03:24
We understand why planes fly.
00:03:26
Right?
00:03:27
Do we?
00:03:28
Could we actually explain it to visiting ancestors from the deep past?
00:03:32
Or is it still some kind of black magic, even for modern humans and the best aeronautical engineers?
00:03:38
So today on Daniel and Kelly's extraordinary universe, we'll be asking an old question, why do planes fly?
00:03:45
Hi, I'm Kelly Wiener Smith, and my favorite way to travel is by train.
00:04:03
Hi, I'm Daniel Weizen.
00:04:05
I'm a particle physicist, which means I have to fly around the world to get to the biggest particle accelerator.
00:04:10
And what is your worst flight experience?
00:04:15
My worst flight experience is traveling with my own six-month-old baby.
00:04:20
We had a bassinet and we got her to sleep in the bassinet and we thought, oh, this is going to be great.
00:04:25
Then the sewerless came by and said, oh, there's some turbulence.
00:04:27
You have to take her out and put her in a seat and buckle her in.
00:04:31
And we said, no, she's sleeping.
00:04:33
And she said, sorry, it's the rules and everyone around us went, oh, no.
00:04:38
And they were right because she screamed for the rest of the eight-hour flight.
00:04:42
Oh, no, that's horrible, I'm so sorry.
00:04:45
When you finally get your kid to sleep and something wakes them up on a plane, it's the worst.
00:04:49
It's the worst.
00:04:50
And everybody knew it was the worst and we all knew there's nothing we could do.
00:04:53
But hey, you know, them's the rules.
00:04:55
How about you?
00:04:56
What's your worst travel experience?
00:04:58
It also involves playing with my child.
00:05:00
She was probably about six months old around there also.
00:05:04
And I brought a change of clothes for her.
00:05:05
I was totally prepared for her.
00:05:07
She was sitting on my lap and we were about to take off.
00:05:10
And right as the plane started moving forward, she had a blow out poop on my lap.
00:05:16
And so it smelled horrible, but you can't get out of your seat until you retruising altitude.
00:05:21
So everybody was like giving me dirty looks and covering their noses.
00:05:25
And it took like 20 minutes before we were allowed to get out of our seats.
00:05:29
And then, you know, I had to change her in the airplane changing room, which is like so tiny.
00:05:34
I thought she was going to fall off the little tray.
00:05:36
And anyway, I brought a change of clothes for her, but I didn't assume I'd have poop on my pants.
00:05:40
Oops.
00:05:41
Classic parenting mistake.
00:05:42
Exactly.
00:05:43
So I smelled horrible.
00:05:44
The whole flight and people kept looking at me and it wasn't a lot of fun.
00:05:48
But then's the brakes.
00:05:50
You got to leave the house with kids sometimes.
00:05:51
You just got to look back at those people and say, "Hey, who's going to pay for your social security?"
00:05:56
Right?
00:05:57
Somebody's got to make the next generation.
00:05:58
That's right.
00:05:59
And it's me.
00:06:00
Medan poopy pants.
00:06:01
I'll get a little like badge that says that.
00:06:07
Now whenever I see a parent with a kid, I'm like, "What can I carry for you?
00:06:10
How can I help?"
00:06:11
Like I offered to help out all the time.
00:06:13
Yeah, exactly.
00:06:14
The big lesson I learned is never judge.
00:06:16
And you never end somebody else's family.
00:06:18
You don't know what they're going through or what they're struggling with or how much they slept last night.
00:06:22
Just help and smile.
00:06:24
Yep.
00:06:25
And kids are always at their worst because they're always the tiredest and they're not used to it.
00:06:28
And so, anyway, yes, don't judge.
00:06:30
But planes are wonderful.
00:06:32
I needed to get from place to place and I needed to get there quickly.
00:06:34
And actually, I wouldn't have wanted to take my daughter on a long train ride for the journey that we were going on because it would have been days.
00:06:40
But I was flying to London the other day and we had kind of talked about why do planes fly and you said it's complicated.
00:06:47
And while I was above the Atlantic, I thought, "How complicated."
00:06:51
How will we understand this?
00:06:54
I hope the answer is really well.
00:06:55
So, I'm looking forward to today's conversation.
00:06:57
Good.
00:06:58
Well, this question actually came to me from a listener, Tom Johnson from Ohio, wrote to me and asked if we could explain why planes fly because he looked into it a little bit and he was kind of confused.
00:07:10
So he wanted a clear explanation for why it is that planes stay in the air.
00:07:15
And if you have a question that you want to ask us, we would be happy to answer them.
00:07:19
So send us an email at questions@danielandkelly.org.
00:07:23
When I told Tom that we were going to answer his question on the pod, he said, "My wife is absolutely going to roll her eyes tonight when I tell her over sushi."
00:07:31
Which made me wonder, Tom is in Ohio, where is he getting his sushi?
00:07:35
Probably, they have it flowing in.
00:07:37
So even his sushi relies on airplane wings.
00:07:40
Yeah.
00:07:41
And I lived in Ohio for a decade or more and I can tell you that when sushi has to fly that far, it's not great.
00:07:47
You're too far from the ocean at that point.
00:07:51
You're saying nobody should fly to Ohio for sushi?
00:07:53
No, I'd say that.
00:07:54
I'm going to go on the record saying you shouldn't fly just to Ohio for sushi.
00:07:57
Ohio has got other things going for it.
00:07:59
You should have Ohio pride, you know?
00:08:01
Maybe I know you're transplanted Virginian, but like you come from Ohio, a good thing about Ohio, for example, is it made you.
00:08:07
You know, I was actually born in New Jersey, which isn't even hard to defend, but I do actually love New Jersey.
00:08:15
And I will defend New Jersey, but, you know, Ohio was a very safe place to grow up where I grew up.
00:08:21
And so that's fine.
00:08:22
And I think Ohio has made the most astronauts.
00:08:25
And so, you know, we all would make jokes about, you know, what is it about Ohio that makes you want to get as far as possible away from this planet?
00:08:31
And I'm not sure if Ohio is still winning an astronaut production, but it was at some point.
00:08:36
All right.
00:08:37
Well, let's stop flying around the issue and get to the question.
00:08:40
I was wondering what people out there thought about how planes stay in the air, how wings work, what stories they had been told, and what they understood about this question.
00:08:49
So as usual, I went to our bank of volunteers to ask them, why do planes fly?
00:08:55
If you would like to play for a future episodes, please don't be shy right to us to questions at adangelandkelly.org.
00:09:00
In the meantime, think about it for a moment.
00:09:03
Why do you think planes fly?
00:09:06
Here's what a bunch of listeners had to say.
00:09:08
I believe nobody really knows.
00:09:10
I would be glad to learn otherwise.
00:09:13
I know that I've read in my schoolbook that the air takes a longer way on the top of the wing than on the bottom of the wing.
00:09:19
And therefore, we have a sort of suction going on that pulls the wing up.
00:09:24
There's fly because they want to and because of the differential air pressure.
00:09:29
Forces the air to take a longer path to go over the wing versus under the wing.
00:09:38
And this differential in the path length reduces the pressure on the upper surface of the wing.
00:09:46
And that provides lift.
00:09:48
There's some confusion surrounding the Bernoulli effect and the air flow speed over the top and bottom of the wings.
00:09:57
There's a lift, which means that the air going over the curved part of the wing takes longer with the air going underneath the wing, so the lift is created there.
00:10:06
Takes longer for the air to go over the top of the wing.
00:10:09
The aerodynamics of that wing shape causes low pressure to form over the top of the wing and high pressure to form under the wing.
00:10:19
So it wasn't it to do with Leonardo da Vinci came up with the original idea to base planes on the updraft from wings of birds.
00:10:30
Planes fly because they can't swim.
00:10:35
I think that light planes, such as paper planes, can maintain fly just because of aerodynamics.
00:10:42
That heavy planes need engines to generate pressure difference, but I am not entirely sure how this works.
00:10:49
So we have to have thrust greater than drag and lift greater than gravity.
00:10:54
A higher pressure below and a lower pressure above.
00:10:59
Top of the wing is curved, so the air has to travel further.
00:11:03
I thought that planes flew because their motion forwards caused air to flow over the wings and created a force that pushes up on the wings.
00:11:14
So I think planes fly because of the way that the wind dens around the wing.
00:11:23
Planes fly because the lift that they generate is greater than the gravitational pull.
00:11:29
The air has a longer way over the wing than under the wing.
00:11:34
Top of the wing because of its shape, it makes a suction, so it sucks the plane up.
00:11:40
I'm not actually completely sure why plane flies, but I know I've been in them and they tend to do that and I hope they continue to do so.
00:11:48
I love that the answers were a combination of people who clearly sort of know what the answer is and like gave good answers and then people who are hilarious.
00:12:00
As they can't swim made me laugh out loud, so bravo.
00:12:05
You know I love that approach.
00:12:06
You don't know the answer, tell us a good joke.
00:12:08
Yeah, absolutely.
00:12:09
And then that would be one of the keys to life I think.
00:12:13
I want to see that more in my physics exams, you know, when somebody doesn't know how to solve this quantum mechanical problem, hey, write me a good joke, I'll give you some points anyway.
00:12:21
You won't give points for people.
00:12:22
Sure, absolutely.
00:12:23
I used to regularly have a question on exams that was just a random New Yorker cartoon and then the question was write a physics related caption for this cartoon.
00:12:32
Oh, nice.
00:12:33
I love that you're encouraging creativity.
00:12:35
I had an exam where I could get five extra credit points if I drew a parasite and you'd think that that would be great, but I was like, I hate this because I don't even do nice stick figures.
00:12:44
That's why I've married an artist.
00:12:45
He takes care of all of it.
00:12:47
But the good thing is there's a stage of parasites where they essentially just look like a circle and so I just sit up, there's a medicine carrier says done and I didn't get full credit.
00:12:57
All right, so where do we start?
00:13:00
So the beginning of the question of why planes fly goes all the way back to the Wright brothers in 1903.
00:13:07
You know, the Wright brothers, they were engineers, they were not physicists.
00:13:10
And so while the Wright brothers made a plane fly, they actually didn't understand it at the time, like they had no principles, they had no theory, they had no real reason to think their plane was going to fly,
00:13:23
they just kind of made it work.
00:13:25
And then they were showered of course with awards and fame and all sorts of stuff, which led some people in the physics community to get a little bit resentful.
00:13:33
So if they had no idea, why did they pick the design they picked?
00:13:36
Is it because they were building on things that other people had made that maybe they understood what they were doing?
00:13:42
And so they just sort of tinkered with that.
00:13:44
Yeah, engineering is a lot of tinkering, right?
00:13:45
So let's try this.
00:13:46
Let's try that.
00:13:47
And sometimes things work.
00:13:48
And then later you figure out why that thing floats or why does this thing fly?
00:13:53
And that's essentially what happened with the Wright brothers.
00:13:56
And they won this fancy award from the Aeronautical Society and one physicist Colonel Fullerton wrote it and said, quote, I think it was a mistake of the Aeronautical Society giving the right to metal for their contribution to Aeronautical science.
00:14:07
I agree with they're having the metal, but it should have been for what they have done.
00:14:11
In other words, they didn't understand it.
00:14:13
They didn't actually advance Aeronautical science.
00:14:16
They just sort of like made it work and they left open the question of like, why does this work?
00:14:21
I feel like there should be a metal for the moment when you're about to like push your plane off the cliff and you're like, we don't understand what's going on, but he flew.
00:14:30
The Wily Coyote Award or something.
00:14:33
Maybe it's a subset of the Darwin Award, yeah.
00:14:36
And this turns out to be really important politically because this is just before World War I, right?
00:14:41
And so World War I is beginning and we have nations trying to figure out like how to make planes fly, how to make them stable.
00:14:50
And nobody really understood like why some things work, how to make them better.
00:14:54
But if you don't have like a model for why planes fly, it's pretty hard to improve their performance.
00:15:00
And so just before World War I, you had all these folks in Britain and then also on the continent, trying to understand the theory of flight so they could take advantage of it militarily.
00:15:09
Hmm.
00:15:10
Okay.
00:15:11
So the Wright brothers didn't have a theory and nobody else had a theory either.
00:15:14
So everyone was just tinkering to see how it worked and that it worked for the Wright brothers did the fact that it worked for the Wright brothers give insights into why it would work like did their design work because it took advantages of some physics principle that became obvious after the fact to the physicists.
00:15:31
It certainly isn't obvious after the fact because people are still to this day arguing why planes fly.
00:15:38
And it's fascinating that the divide in the field, we're going to dig into this really goes back to the split that happened in World War I where you had the sort of like mathematical battle between the scientists you had the British trying to figure it out and you had the Germans trying to figure it out and they took different approaches and those approaches still live on and do battle in science today in modern aeronautical engineering.
00:15:59
The Germans took this approach of thinking about air as a fluid flowing over the wing and analyzing the velocity and thinking about the pressure but the British didn't like that approach.
00:16:07
It made some approximations that made them uncomfortable and they're like using Newton's forces Newton of course being British.
00:16:12
And so to this day, we have two competing theories for why planes fly and how they work.
00:16:18
It's fascinating to me that we still haven't figured this out.
00:16:20
You're right.
00:16:21
We had a working example about a hundred years ago and that definitely helps.
00:16:24
Right.
00:16:25
It rules some things out.
00:16:26
It inspires experiments.
00:16:28
So having a working example is useful but it doesn't always tell you exactly why something happens.
00:16:33
So are these theories, which I'm sure we'll get into the details of in a second.
00:16:37
Are they different enough that that resulted in the British and the Germans having planes that had different shapes during World War One or do both theories sort of predict that the same plane shape is good.
00:16:50
Yeah, they make different predictions about what's important in the shape of the wing, which is fascinating.
00:16:56
And I found this quote from a historian David Bloer who said, on the eve of the Great War, none of the British workers in the field of aerodynamics had any workable account of how an airplane could get off the ground,
00:17:07
but you know, makes it pretty hard to optimize the performance of your war planes and pretty scary to get into a war plane on top of all the reasons that it's scary to get into a war plane.
00:17:17
Exactly.
00:17:18
And later on, we'll hear about Albert Einstein's personal design for an airplane, which really didn't work very well.
00:17:25
So let's dig in.
00:17:26
Should we start with the Germans or should we start with the British?
00:17:29
So the German story is the one that most people have heard about.
00:17:32
It's this theory of fluids and flow and Bernoulli's equations and all this kind of stuff.
00:17:37
So we should start with there to make contact with what most people think about when they think about flight.
00:17:41
All right.
00:17:42
Let's do that.
00:17:43
So the usual story for why plane flies has to do with the shape of the wing.
00:17:48
And so aeronautical engineers call this an airfoil.
00:17:50
It's rounding in the front and it's pointing in the back.
00:17:53
It's sort of like a long, thin teardrop, right?
00:17:56
And the idea that you're usually told is that the shape of this wing creates a pressure difference that you have lower pressure above the wing and higher pressure below the wing and that creates lift because higher pressure below and lower pressure above basically pushes up on the wing.
00:18:13
And it's the shape of the wing that's crucial in creating these pressure differences, which is what creates lift.
00:18:18
So that's the usual story for why planes fly that comes down to this particular shape of the wing.
00:18:24
So you've got this curved edge moving towards the air quickly.
00:18:29
Why does that shape not create the same amount of pressure on the top as it does on the bottom?
00:18:35
Because that shape is like symmetrical, right?
00:18:37
Is it because when it goes over, it has more space to sort of spread out?
00:18:40
So the shape is not actually symmetrical, right?
00:18:43
Typically, it's like flat on the bottom and more curved on the top.
00:18:47
And so the shape is not actually symmetrical, which is why the Bernoulli story tells you that it pushes up.
00:18:52
Bernoulli is a guy in the 1700s who is thinking about fluid flow and mostly about like water through pipes and pressure and volume and like fluids are still something we're struggling to understand,
00:19:03
but Bernoulli had a simplified view of it, which Oiler actually came through later and proved all of his equations for him.
00:19:09
But Bernoulli's principle tells us that faster moving fluids have lower pressure and slower moving fluids have higher pressure.
00:19:16
So if the shape of the wing is the moves through the air, makes the air go slower under the wing and faster above the wing on this curved shape, then that'll generate lower pressure above the wing and higher pressure below the wing and that gives you lift.
00:19:30
And that feels easy to test, right, because you just flipped the wing over and it should do the opposite, right?
00:19:36
Like it should send you plummeting downwards.
00:19:39
Yes, already you're identifying a problem with this, but before we take this explanation to part, let's do a little bit more to support it because you're right, it kind of is easy to test and you can do a simple test at home.
00:19:50
You can just like take a piece of paper and blow air above the piece of paper.
00:19:54
And what you see is the paper goes from being sort of droopy to being flat.
00:19:57
So it's sort of like lifts up and it's like a classic symbol at home demonstration, which you're doing is you increasing the velocity of the air above the paper, which in theory lowers the air pressure above the paper,
00:20:09
which provides lift because now the pressure is higher below the paper and lower above the paper.
00:20:14
And you know, this story of like the air moves faster over the wing and slower below the wing is also verified in lots of other experiments.
00:20:22
Like you can do these smoke tests where essentially you put a wing in a wind tunnel and instead of just blowing air over it, you blow smoke over it, smoke just being like a bunch of particles.
00:20:32
And you can track those particles and you can measure the velocity.
00:20:35
So basically measure the velocity of the air around the wing, see what happens, right?
00:20:39
Don't just like talk about it, you know, in your salons while you're smoking cigarettes or whatever, actually figure it out.
00:20:45
And this is verified.
00:20:46
Like wind tunnels and smoke tests tell us that the air does move faster over the top of the wing than below the wing.
00:20:52
And so this seems like it all sort of comes together, but as you identify, there are some important limitations to this explanation of why planes fly.
00:21:02
So when you get a window seat near the wing and you look out, it's easier to see like it's bunching up and it gets a little bit like kind of white ish, is that pressure forming?
00:21:13
Like are you sort of bunching up the air molecules to the point where they're visible or something else happening there?
00:21:18
Or am I imagining it and this is like an episode of the Twilight Zone?
00:21:22
Nobody else sees that Kelly, yeah, exactly.
00:21:24
It's just you.
00:21:25
That was such a great episode.
00:21:27
I love that.
00:21:28
No, I think what's happening there is you're seeing more water vapor.
00:21:31
There are definitely changes in the air pressure below and above the wing.
00:21:34
And as you know, water is very sensitive to pressure with the vapor point and all this kind of stuff.
00:21:39
So what you're seeing there is not the air itself, but water vapor forming, which can show you just like any smoke tests can show you where the air is flowing.
00:21:46
So that is pretty cool.
00:21:47
That sounds obvious now that you say it, but now I'm like, why did I ask that?
00:21:51
Oh, whatever.
00:21:52
That's fine.
00:21:53
Okay.
00:21:54
So we decided now we're going to talk about the limitations.
00:21:55
Has anybody flipped the wing the other way and then saw what happened?
00:22:01
Did that plane still fly?
00:22:03
So planes fly upside down all the time, right?
00:22:06
Big problem with this explanation is that it predicts that the asymmetry of the wing is crucial, right?
00:22:11
That the curve even on the top compared to the flat bottom is really important for making lift.
00:22:17
And so it predicts if you flip that over, planes should like crash to the ground, right?
00:22:20
And upside down wing should have anti lift or should have a net force downwards.
00:22:26
But we don't see that happening, you know, you can fly planes upside down all the time.
00:22:30
Everybody who's been to like an aeronautic show has seen old-fashioned planes or new planes, they can fly upside down.
00:22:37
So Bernoulli's equation doesn't answer this question.
00:22:40
This can't be the complete story of why wings provide lift because it gives the wrong explanation or upside down planes.
00:22:48
So you mentioned that Euler figured out all of these equations to support Bernoulli.
00:22:54
Does it turn out that Euler's equations were missing some important factor?
00:22:58
Because the equation said it should work, but then it doesn't work.
00:23:00
So what was missing in the equations?
00:23:02
Oh, yeah, great question.
00:23:03
And this really goes to the heart of what's going on here.
00:23:06
There's nothing wrong with Bernoulli's equations.
00:23:08
And I'm giving Euler credit only because Euler came along and like did all the math Bernoulli had like these leaps of insight and like, oh, I think this and that and the other thing.
00:23:16
And then Euler came along and actually like dotted all the eyes and crossed all the tees.
00:23:20
And I think Euler would have gotten credit for these equations.
00:23:23
If he hadn't already gotten credit for like 80% of everything in mathematics, so much of stuff in mathematics, but like Euler just let somebody else take credit for it because he's already got everything else named after him,
00:23:34
which is amazing.
00:23:35
So there's no problem with Bernoulli's equations, but there are always a simplified description.
00:23:40
Like Bernoulli's equations describe fluid flow and they make some assumptions.
00:23:43
Like, you're talking about a fluid as if it's incompressible.
00:23:47
For example, or you're talking about as if it's not made of microscopic particles.
00:23:51
That's not true, right?
00:23:52
Air is made of microscopic particles, it is compressible.
00:23:56
That doesn't mean that the equations don't apply.
00:23:58
It means that they apply in some limited sense.
00:24:00
It also might just be the wrong story, it might not provide the answer, the explanation.
00:24:05
You know what we're looking for is an answer to a question which is macroscopic like, we see the wing go through the air, the wing goes up, we want to know why.
00:24:14
That's sort of like a human question, right?
00:24:16
It's not a mathematical question.
00:24:17
It's not like there's a prediction and number of retronic calculate.
00:24:21
We want like a story that tells us why this is happening, and that's a little bit more slippery than just mathematics.
00:24:28
It's something to do with cause and effect and understanding, and you know, at the heart of science is coming up with these stories, but it's not always easy, especially when we're zooming out from a microscopic universe to try to tell a story macroscopically.
00:24:41
It's like economics, you know, you can ask like, why do prices go down?
00:24:45
Well, I have this theory of inflation, I have a theory that involves prices and supply chains, whatever, the theory can be correct, but it doesn't always apply because the conditions that assumes aren't always relevant,
00:24:55
and it doesn't always answer the question that you're asking.
00:24:58
I feel like the next time I get on a plane, I'm going to think to myself, I wish it were simple.
00:25:04
I don't wish we'd really understood this, but plates tend to stay up, so that's good.
00:25:09
So we've established that the Germans got everything wrong, and one more one.
00:25:13
Wait, was that where we're one or where we're two?
00:25:15
This is where we're one.
00:25:16
We're talking about you.
00:25:17
And while they got it wrong both times.
00:25:18
Sorry guys.
00:25:19
Hey, I'm Jay Shetty, and my latest interview is with Wiz Khalifa.
00:25:32
The craziest part of my life, I can go from performing in front of 40,000 people to either being an address room, being in the plane, or being back in the bed,
00:25:43
all by myself.
00:25:44
He is a multi-platin' selling recording artist, Minnie Mogo, and an actor.
00:25:48
Did you feel like a big break was coming?
00:25:54
I didn't know what that big break looked or felt like, but I knew that what I was doing was working.
00:25:59
The gang banging and the drug selling, that's not really for me, but the looking cool, the having girls, the making music, I'm like, I like that part of it.
00:26:08
I was that experience for you, losing someone so close to you that you love.
00:26:12
I am grateful that I was able to have the last moments that I had, and to be able to prepare for it.
00:26:19
It was something that I'm still dealing with.
00:26:21
Listen to On Purpose with Jay Shetty on the I Heart Radio app, Apple Podcast, or wherever you get your podcast.
00:26:28
One of the steward has been a household name for over four decades and still isn't done.
00:26:34
Join I Heart Media Chairman and CEO Bob Pittman for a special episode of the hit podcast, "Math and Magic," stories from the frontiers of marketing, as he interviews this icon in front of a live audience to celebrate her 100th book,
00:26:49
Martha the Cookbook, 100 Favorite Recipes, with lessons and stories from my kitchen.
00:26:54
Did you ever think you were going to wind up writing 100 books?
00:27:01
Yeah, you did.
00:27:02
Yeah, it's just a minor goal.
00:27:03
This intimate and wide-ranging conversation between friends covers the pivotal decisions in Martha's career, the philosophy that has guided her, and the source of so much of her creative inspiration.
00:27:13
They actually looked at the July issue that I had proto-typed and they said, "This is fabulous.
00:27:18
What would you do next July?"
00:27:19
And I said, "Well, living is a limitless subject matter."
00:27:22
Listen to "Math and Magic" on the I Heart radio app, Apple podcasts, or wherever you get your podcasts.
00:27:29
Y'all, what up?
00:27:30
It's your girl, Jessalarius.
00:27:31
And I think it's time to acknowledge that I'm not just a comedian.
00:27:34
It's time to add uncertified therapists to my credentials, because each and every Wednesday I'm fixing your mess on carefully reckless on the Black Effect podcast network.
00:27:43
Got problems in your relationship?
00:27:45
Come to me.
00:27:46
You're best friend acting shady.
00:27:47
Come to me.
00:27:48
I can't promise I won't judge you.
00:28:06
But I can guarantee that I will help you.
00:28:08
As a daughter, a sister, a mother, and an entrepreneur, I've learned a lot in life.
00:28:12
So I'm using my own perspective and experiences to help you fix your mess.
00:28:16
Tell me your situation and let's fix it as a family.
00:28:19
Listen to carefully reckless on the Black Effect podcast network.
00:28:22
I Heart radio app, Apple podcasts, or wherever you get your podcasts.
00:28:26
AT&T, Connecting Changes Everything.
00:28:33
Hi, I'm Ed Zitron, host of the Betrothline podcast, and we're kicking off our second season digging into how Texel Lee has turned Silicon Valley into a playground for billionaires.
00:28:43
From the chaotic world of generative AI to the destruction of Google search, Betrothline is your unvanished and at times unhinged look at the underbelly of tech, from an industry veteran with nothing to lose.
00:28:54
This season I'm going to be joined by everyone from Nobel-winning economists to leading journalists in the field.
00:28:59
And I'll be digging into why the products you love keep getting worse and naming and shaming those responsible.
00:29:04
Don't get me wrong, love.
00:29:06
I love technology.
00:29:07
I just hate the people in charge and want them to get back to building things that actually do things to help real people.
00:29:13
I swear to God, things can change if we're loud enough, so join me every week to understand what's happening in the tech industry and what could be done to make things better.
00:29:21
Listen to Betrothline on the I Heart Radio app, Apple Podcasts, or wherever you get your podcasts.
00:29:27
Check out Betrothline.com.
00:29:28
Hey, what's up?
00:29:32
This is Ramzes Jock.
00:29:33
And I go by the name Q War.
00:29:34
And we'd like you to join us each week for our show, Civic Cypher.
00:29:37
That's right.
00:29:38
We're going to discuss social issues, especially those that affect black and brown people, but in a way that informs and empowers all people to hopefully create better allies.
00:29:46
Think of it as a black show for non-black people.
00:29:49
We discuss everything from prejudice to politics to police violence, and we try to give you the tools to create positive change in your home, workplace, and social circle.
00:29:57
Exactly.
00:29:58
So your black, Asian, white, Latinx, Indigenous, LGBTQIA, plus you name it.
00:30:04
If you stand with us, then we stand with you.
00:30:07
Let's discuss the stories and conduct the interviews that will help us create a more empathetic, accountable, and equitable America.
00:30:14
You are all our brothers and sisters, and we're inviting you to join us for Civic Cypher each and every Saturday, with myself Ramzes Jock, Q Ward, and some of the greatest minds in America.
00:30:24
Listen to Civic Cypher every Saturday, on the Our Heart Radio app, Apple Podcast, or wherever you get your podcast.
00:30:31
Okay, so we know that when a plane flips over, it doesn't go crashing to the ground.
00:30:45
What was he getting wrong?
00:30:46
Bernoulli.
00:30:47
So Bernoulli's story is very nice, and it's very simple, and there's lots of it that's correct.
00:30:52
As you say, it doesn't explain some things, it doesn't explain why planes can fly upside down, and it also doesn't explain something really crucial at the heart of the story, which is why is the air moving faster over the top of the wing than the bottom of the wing?
00:31:06
Like we said, the wing is asymmetric, it's curbing on the top, and it's flat on the bottom.
00:31:11
But why does that make the air go faster over the top?
00:31:15
And you often hear this pop-side explanation, which is completely wrong, which is that it's a longer trip over the top of the wing, so the air has to go faster in order to like meet its air particle partners at the back end of the wing.
00:31:28
Why would it have to?
00:31:29
Exactly.
00:31:30
Why would it have to?
00:31:31
It doesn't have to.
00:31:33
It's nonsense.
00:31:34
But you hear this all the time, I was taught this myself, you know, that like when air particles hit the front of the wing, if one goes above and one goes below, then to meet up again at the back of the wing,
00:31:44
the one that takes the longer route would have to go faster.
00:31:47
And it's an example of like it's a compelling story, but it doesn't actually make any sense because they don't have to take the same time.
00:31:54
It's fine.
00:31:55
The universe doesn't like crash or implode or hit a seg fault or something if the air particles don't meet up again.
00:32:01
Yeah, right.
00:32:02
They're not like buddies.
00:32:03
They don't have to get to the same spot at the same time.
00:32:05
Yeah.
00:32:06
Alright, so that doesn't have to happen.
00:32:08
So that doesn't have to happen.
00:32:09
That's not the explanation for why air moves faster over the top.
00:32:12
And so the Bernoulli story sort of lacking that explanation, like why is there this pressure difference?
00:32:18
And it opens this door to this question of like, well, do the speed differences cause the pressure differences or is it the pressure differences that are causing the speed differences?
00:32:27
Because Bernoulli's equation doesn't give us causality, it just says lower pressure higher speed.
00:32:32
It doesn't say the lower pressure is caused by the higher speed.
00:32:35
It could also be the higher speed is caused by the lower pressure.
00:32:39
So that tells us that we need more to the story.
00:32:41
Bernoulli's story can't describe completely UI planes fly because it doesn't tell us why planes fly upside down and it doesn't explain why we see air going faster over the top of the wing, which is something we definitely see happening.
00:32:52
Alright, so I know we're about to talk about another explanation, but does looking at birds help at all?
00:32:59
Because they have, you know, different kinds of wing shapes and they've kind of figured it out over evolutionary time.
00:33:04
This isn't going to give us the pressure answer, but does it give us some insights into like how these wings should be shaped?
00:33:11
I'm getting off track, but I just looked at a picture of a bird in my office and now I have to ask.
00:33:15
It does.
00:33:16
And bird wings work with similar principles to airplane wings, except of course for the flapping part.
00:33:21
But for gliding, they do fasteningly insect wings are even more complicated and insect flight is not something we understand like at all.
00:33:29
It's really kind of incredible.
00:33:31
We should do a whole nother episode about why insects fly.
00:33:34
And if you're ever feeling depressed, there are some slow-mo videos of insects trying to take off and it is the most clumsy, amazing thing I've ever seen.
00:33:43
It blows my mind that they ever get off the ground and it makes my daughter laugh so hard she pukes a little.
00:33:47
So I knew a guy who did these experiments where they put an insect on a pin and like glued it to a pin and then they showed it videos.
00:33:55
So it was like thought it was flying and they would like try to take videos of its wings moving to understand it.
00:34:00
It's kind of incredible.
00:34:01
All right.
00:34:02
This has been an amazing tangent.
00:34:03
I've had a lot of fun.
00:34:04
Let's go back to World War One, which is less fun.
00:34:06
So I think we've talked about the shortfalls in Bernoulli's explanation.
00:34:10
Are we ready to move on to what the British folks were thinking?
00:34:14
Yeah.
00:34:15
So across the English channel, we had folks that are working on a completely different theory and not a completely different theory just because they disagreed scientifically with the best approach.
00:34:23
Remember, there's a war here and so they're not going to collaborate.
00:34:26
They're not going to be like going to the same conferences and sharing their ideas.
00:34:30
It's sort of like when evolution splits.
00:34:31
You know, you get all these weird animals off on an island and they diverge into their own crazy direction and get weird pouches for their babies or whatever.
00:34:39
That's what happens when you work in isolation, you get competing explanations.
00:34:43
And so we have this fascinating sort of social experiment where you like isolated two groups of scientists and asked them to solve the same problem and they took very different approaches.
00:34:51
So was it like allopathic speciation where they weren't encountering each other at all anymore?
00:34:57
And that's why they come up with different theories because there was no crosstalk or was it some Patrick's speciation where the ideas could have flowed between each other but they were still deciding to stay segregated.
00:35:06
Was it nationalism or did they just not know?
00:35:08
Is what I'm wondering.
00:35:09
I think it started with nationalism, but then it developed into sort of tribal camps.
00:35:14
And the Germans criticized the British and the British criticized the Germans, you know, even after the first war, when these guys could have gotten together and had like a global unified theory of flight, they continued working in their own direction because they were invested in it.
00:35:27
You know, this guy's advisor told him that the German approach was nonsense and the German guy's advisor told him that the British approach was shy, you know, or whatever.
00:35:35
And so...
00:35:36
Do you speak German?
00:35:37
I do not speak German.
00:35:40
I speak Danish, which is sort of Germanic a little bit, but you know.
00:35:43
Yeah, cool.
00:35:44
You do not speak German.
00:35:45
Anyways, so the British across the English channel didn't like the German approach, didn't like thinking about errors of fluid because they were like, "This is too idealized.
00:35:53
You can't explain what's really happening."
00:35:55
The Germans thought, you know, ideal fluids are fine approximation, but the British didn't like it.
00:36:00
And you know, any time you're making an explanation in science, you're going to be making approximations.
00:36:03
It's just a question of what approximations you make, they're always shortcuts.
00:36:08
Nobody can completely describe the full complexity of the universe in their equations.
00:36:13
It's always a simplification, and there's an arc to that.
00:36:15
Choosing a simplification that captures the essential details of what's happening in reality so you can provide a useful explanation while dismissing all the irrelevant complexities that you don't need to worry about.
00:36:28
Which is why, for example, we can talk about how a ball flies to the air and often ignore air resistance and ignore the quantum effects and ignore everything else that's happening, the tug of Jupiter on that ball because we judiciously choose what approximations to make.
00:36:43
So that's what's happening here is two subjective approaches.
00:36:46
And the British were focused not on this ideal fluid approach, but instead on using just a simple approach with Newton's law.
00:36:52
They were just thinking about the forces.
00:36:54
How do forces act differently on the top and the bottom based on that tear drop shape?
00:36:58
Yes.
00:36:59
So the Newton's approach basically ignores the tear drop shape and it says, "The shape of the wing isn't actually important.
00:37:04
What's crucial is the angle of the wing into the wind."
00:37:08
So they're thinking, "Hey, the wing is tilted a little bit," and so as the wing is moving through the air, the wind gets bounced basically off the wind and goes down.
00:37:18
So you have wind flowing onto the wing and you have an angle and then it bounces down and so the wing goes up.
00:37:24
And like anybody who's ridden in a car and put their hand out at an angle knows that you can feel a lift, right?
00:37:29
Your hand basically flies.
00:37:30
And your hand is not a tear drop, it's not an airfoil, it's not like carefully, Germanically engineered to get lift, it's just your hand, you know, but still you can get lift.
00:37:40
This is a simple application of Newton's theory, like action reaction.
00:37:44
The wind gets pushed down by the angle of the wing, the aeronautical engineers call it the angle of attack, and so the wing gets pushed up very simple.
00:37:53
So if that's true, then you could adjust wing shape to be even better at flying by making it bend even more so that you're stopping even more air as you go.
00:38:03
Did the British try that to prove how much better they were?
00:38:07
I wish you'd been around in the aeronautical society, so clear with your questions.
00:38:12
So what you're describing is actually what you see in an airplane when you take off.
00:38:16
If you're paying attention to the wing, modern airplanes actually have a changeable shape, right?
00:38:21
They have these flaps and these levers right so they can change the shape of the wing.
00:38:25
And during takeoff, they do just that, they push down the back of the wing, so it's more of a curvy shape, but like grabs the air a little bit more, so you get more lift during takeoff.
00:38:35
And then when you're flying, they make it flatter.
00:38:37
So what you're cruising, you get less lift, but you also get less drag, drag is the force that pushes the wing backwards.
00:38:44
So you want upwards force lift without as much backwards force drag.
00:38:48
So what you're seeing is exactly what modern airplanes do is they make it curvy or when you take off to get more lift.
00:38:55
Very cool.
00:38:56
I was reading about programmable matter and I think one of the proposals was to have matter that responds to the environment and makes those changes on its own without you needing to do anything, but I am glad we have more control over the process right now.
00:39:08
I'm not ready to have us let go of that control yet.
00:39:12
And the nice thing about this explanation is it explains why planes can fly upside down.
00:39:16
They fly upside down because they have the right angle of attack.
00:39:19
It doesn't matter the shape of the wing at all.
00:39:22
It just matters that the airplane wing is at the correct angle.
00:39:26
So if you fly your airplane upside down, you can do it as long as the wing is angled into the air at the right angle.
00:39:32
So does this completely explain everything that's never how our podcast episodes end?
00:39:38
So what is it missing?
00:39:41
So this is a beautiful story of the limitations of science because both explanations explain something, but neither of them tell the complete story.
00:39:50
So for example, there's a couple of things that the British Newton's theory force explanation doesn't describe.
00:39:56
Number one is what's going on on the top of the wing, right?
00:39:59
This just focuses on the bottom of the wing, but we see that the pressure is lower on the top of the wing.
00:40:04
The Newton's theory approach says all the lift comes from below that you're getting this force from the wing that's hitting it from below.
00:40:10
But we see this lower pressure above and it turns out as we'll talk about later, that contributes maybe even more to the lift, the low pressure above the wing than the high pressure does below the wing.
00:40:20
And the Newton's theory cannot explain this.
00:40:23
That's number one.
00:40:24
And it can't explain why there's low pressure above the wing, right?
00:40:27
Just like the other one.
00:40:28
Yeah, exactly.
00:40:29
Number two is that if you do these smoke studies, we see that the wing affects the flow of the air, not just below the wing.
00:40:36
It's like the influence of the wing on the air is larger than just the wing.
00:40:41
If the air begins to flow up above the wing before it hits the wing, this is upwash in advance of the wing and is downwash after the wing.
00:40:50
So it's not just like you have a paddle and it's being hit by molecules and it's getting pushed up.
00:40:55
There's a complicated interplay here between the wing and the flow around it and the air itself applying pressure on itself.
00:41:02
So you can't ignore the sort of fluid effects of the air if you want to completely describe what's happening.
00:41:08
Yeah.
00:41:09
I'm describing all of that.
00:41:10
I thought, oh, man, it really feels like fluid dynamics should have explained that so maybe the German example should have worked.
00:41:16
Why does the fluid example not work then with all of that complicated stuff happening?
00:41:21
So the fluid example does explain some parts of it.
00:41:23
And so where we're going to go in the end is this like weird hybrid of the British German theory in order to have the most complete explanation of why it happens.
00:41:32
But what we're doing right now is sort of examining like the failure of the individual one.
00:41:36
Then the fluid approach can describe the flow of the fluid around the wing.
00:41:42
But the British approach, though simple and satisfying, can't describe all of this stuff.
00:41:46
Okay.
00:41:47
Spoiler alert.
00:41:48
Yeah.
00:41:49
So one thing it fails to describe is the sort of holistic flow of the air around the wing.
00:41:53
The other is stalling.
00:41:54
And the Newton's force approach, the only reason you're flying is the angle of attack and the greater the angle, the greater the force.
00:42:01
Right?
00:42:02
And flies knows that if you have too great an angle, you're going to stall.
00:42:07
Like if your plane is pointed too far upwards, you're not going to get lift anymore.
00:42:12
And what happens technically, what we see in wind tunnels is that if the angle of attack is too great, then as the air flows over the top of the wing, it doesn't merge smoothly with the air flowing below the wing.
00:42:24
And you get this like weird turbulence.
00:42:26
They call it a separation region because the air doesn't nicely reconnect.
00:42:31
And when you're going through a fluid, turbulence is a problem, you want to minimize turbulence.
00:42:36
And so if the angle is too large, this is like gap between the air flows as they come off the back of the wing and they don't merge nicely.
00:42:44
That's called the separation region between these flows and that creates the stall and you lose your lift.
00:42:48
So you can't explain that also with the Newton's explanation, you need some fluid theory to explain that.
00:42:55
Slightly tangential, we haven't discussed propellers.
00:42:58
Do propellers and jet engines play any role here or is that just in like, that moves us forward and all of the uppiness comes from the wings?
00:43:07
Yeah.
00:43:08
So basically engines just provide forward velocity so that the wings attack the air.
00:43:14
All the propellers are a subtle point because propellers have a particular shape which is related to the shape of a wing, right?
00:43:20
Because it's converting motion in one direction to air velocity in the other direction.
00:43:24
So the shape of a propeller is related to the shape of a wing.
00:43:28
But for the question of why planes fly, you can think of it just like something pushy, right?
00:43:32
The pushy bit that gets the plane moving through the air.
00:43:35
Yeah.
00:43:36
Okay.
00:43:37
So you got the pushy bit but we don't understand what's happening around the wings yet.
00:43:39
So how do you move from figuring out that both the German and the British explanation are failing in some way to figuring out the answer to what's going on?
00:43:50
Is this like where we are?
00:43:51
We just don't know or are there more experiments you can do to figure it out?
00:43:54
So what you shouldn't do is ask the world's smartest physicist Einstein to weigh in on this very practical engineering question.
00:44:01
Well, let's find out what he had to say after the break.
00:44:06
Hey, I'm Jay Shetty and my latest interview is with Wiz Khalifa.
00:44:16
The craziest part of my life, I can go from performing in front of 40,000 people to either being in a dress room, being in the plane, or being back in the bed all by myself.
00:44:28
He is a multi-plotive selling recording artist, Minnie Mogo, and an actor.
00:44:32
What's your mother want?
00:44:33
The only queen!
00:44:34
Did you feel like a big break was coming?
00:44:37
I didn't know what that big break looked or felt like, but I knew that what I was doing was working.
00:44:43
The gang banging and the drug selling.
00:44:46
That's not really for me, but the looking cool, the having girls and making music, I'm like, I like that part of it.
00:44:52
I was that experience for you, losing someone so close to you that you love.
00:44:56
I am grateful that I was able to have the last moments that I had and to be able to prepare for it and it was something that I'm still dealing with.
00:45:05
Listen to On Purpose with Jay Shetty on the I Heart Radio App, Apple Podcast, or wherever you get your podcasts.
00:45:12
Martha Stewart has been a household name for over four decades and still isn't done.
00:45:17
Join I Heart Media Chairman and CEO Bob Pittman for a special episode of the hit podcast, Math and Magic, Stories from the Frontiers of Marketing, as he interviews this icon in front of a live audience to celebrate her 100th book.
00:45:32
Martha, the cookbook, 100 favorite recipes with lessons and stories from my kitchen.
00:45:38
Did you ever think you were gonna wind up writing 100 books?
00:45:42
Yeah, you did?
00:45:43
Yeah, it's just a minor goal.
00:45:45
This intimate and wide-ranging conversation between friends covers the pivotal decisions in Martha's career, the philosophy that has guided her, and the source of so much of her creative inspiration.
00:45:57
They actually looked at the July issue that I had prototyped and they said, "This is fabulous.
00:46:02
What would you do next July?"
00:46:03
And I said, "Well, living is a limitless subject matter."
00:46:06
Listen to Math and Magic on the I Heart Radio App, Apple Podcasts, or wherever you get your podcasts.
00:46:12
Hi, I'm Ed Zittron, host of the Better Offline podcast, and we're kicking off our second season, digging into how Tex Elite has turned Silicon Valley into a playground for billionaires.
00:46:22
From the chaotic world of generative AI to the destruction of Google Search, Better Offline is your own varnish, and at times unhinge look at the underbelly of tech, from an industry veteran with nothing to lose.
00:46:33
This season I'm gonna be joined by everyone from Nobel-winning economists to leading journalists in the field, and I'll be digging into why the products you love keep getting worse and naming and shaming those responsible.
00:46:44
Don't get me wrong, though.
00:46:45
I love technology.
00:46:46
I just hate the people in charge, and want them to get back to building things that actually do things to help real people.
00:46:53
I swear to God, things can change if we're loud enough, so join me every week to understand what's happening in the tech industry, and what could be done to make things better.
00:47:01
Listen to Better Offline on the I Heart Radio App, Apple Podcasts, or wherever else you get your podcasts.
00:47:06
Check out BetterOffline.com.
00:47:07
Yo, what up, it's your girl, Jocelyn Arias, and I think it's time to acknowledge that I'm not just a comedian.
00:47:16
It's time to add uncertified therapists to my credentials, because each and every Wednesday I'm fixing your mess on carefully reckless on the Black Effect podcast network.
00:47:24
Got problems in your relationship?
00:47:26
Come to me.
00:47:27
Your best friend, Acton Shady.
00:47:29
Come to me.
00:47:30
Thinking about cursing that one's think on to y'all at the next family gathering, do it.
00:47:34
But come to me before you do, because I cast all mine out before.
00:47:37
Do you want to fight your coworkers?
00:47:39
Come to me.
00:47:40
Baby, daddy, man, because you got a boyfriend?
00:47:42
Come to me.
00:47:43
Thought you was the father, but you not?
00:47:45
Come to me.
00:47:46
I can't promise I won't judge you, but I can guarantee that I will help you.
00:47:50
As a daughter, a sister, a mother, and an entrepreneur, I've learned a lot in life.
00:47:54
So I'm using my own perspective and experiences to help you fix your mess.
00:47:58
Send me your situation, and let's fix it as a family.
00:48:01
Listen to carefully reckless on the Black Effect podcast network.
00:48:04
I heart radio app, Apple podcast, or whatever you get your podcast.
00:48:08
AT&T, Connecting Changes Everything.
00:48:15
Jenny Garth, Janet Kramer, Amy Robock, and TJ Holmes bring you, I do part two, a one-of-a-kind experiment in podcasting to help you find love again.
00:48:24
If you didn't get it right the first time, it's time to try, try again, as they guide you through this podcast experiment and dating.
00:48:30
Hey, I'm Janet Kramer, as they say, those that cannot do, teach.
00:48:34
Actually, I think I finally got it right, so take the failures I've had, the second or even thirder, whatever, maybe the fourth time around.
00:48:42
I'm Jenny Garth, 29 years ago.
00:48:44
Kelly Taylor said these words, "I choose me."
00:48:48
She made her choice.
00:48:49
She chose herself.
00:48:50
When it comes to love, choose you first.
00:48:53
Hi, everyone.
00:48:54
I'm Amy Robock.
00:48:55
I'm TJ Holmes, and we are not necessarily relationships, experts.
00:49:00
If you're ready to dive back into the dating pool and find lasting love, finally, we want to help.
00:49:06
Listen to I Do Part Two on the I Heart Radio App, Apple Podcast, or wherever you listen to podcasts.
00:49:20
Alright, so for most of the Daniel led episodes, we have to walk through a What Did Einstein Think, because he just provided so many good insights into so many things.
00:49:34
So let's figure out what did Einstein think about this?
00:49:36
Yeah, so Einstein, he's a smart guy, he developed relativity.
00:49:41
He struggled and failed to integrate quantum mechanics into it, so it's not like he solved every problem he attacked, but he was a smart guy, and he was German, and this is a relevant question for the Germans at the time.
00:49:53
And he was interested in this, and he wrote, quote, "There's a lot of obscurity surrounding these questions, and open puzzles like this, you know, they attract smart people."
00:50:01
Like, oh, maybe I can figure this out.
00:50:02
Maybe there's an insight, a moment of clarity that will just untangle this whole mess.
00:50:08
And so he thought about flight from the German point of view, and he actually designed his own wingshape, sort of a weird variation on the air force.
00:50:17
Because Einstein, remember he was not just a clever physicist, he worked in the patent office.
00:50:21
And so he had seen lots of inventions, he had a practical mind also.
00:50:25
So he designed his own wing, and he took it to a German aircraft company.
00:50:29
And you know, he was an esteemed famous scientist at this point, so they thought, okay, sure.
00:50:33
So they worked with him, they collaborated with him, they built the plane, and they sent it on a test flight.
00:50:39
And the pilot came back and said he would never fly the thing again, because it, quote, flew like a pregnant duck.
00:50:44
I feel like whenever a question sort of tiptoes into biology and Einstein is involved, you want to back away.
00:50:52
So, you know, I think maybe most of us know that ducks can't get pregnant, they carry eggs, but they don't get pregnant the way we do.
00:50:59
And also like, you know, he married his cousin, which I think is a bad idea, also from a biological perspective.
00:51:04
But anyway, okay.
00:51:05
So Einstein was great at everything, but not at designing wings.
00:51:08
Yeah, exactly.
00:51:10
And so fast forward 50 years or so, what are people talking about today in terms of why planes fly?
00:51:16
I went across campus here to a colleague at UC Irvine, he's a professor of aeronautical engineering here, and he studies lift.
00:51:24
He works on this problem.
00:51:26
I asked him, what is the simple explanation for lift?
00:51:28
And he said, quote, this is not settled in the aeronautical engineering community.
00:51:33
Please don't laugh.
00:51:34
So here we are laughing, it's hilarious, you know, like, you guys still haven't figured this out more than a hundred years after their right brothers.
00:51:43
But yet still so much money is main off like, so it's nice to know you don't have to have everything worked out before you commercialize something.
00:51:49
But let's not over sell it.
00:51:50
It's not that we don't understand why planes fly.
00:51:54
It's that we don't have a compelling, simple explanation at the sort of zoomed out level.
00:52:00
And again, there's always a difference between like the micro physics.
00:52:03
Can you model what's happening with individual air molecules and the shape of the wing and come up with a simulation in which planes fly?
00:52:11
Absolutely.
00:52:12
We can, and we do.
00:52:13
This is why, for example, Boeing can design their airplanes on the computer and be confident that they will fly.
00:52:19
They don't need to use wing tests anymore and build a bunch of models to experiment.
00:52:23
Because we have accurate simulations for what's going on in the micro physics level, it's just that when you zoom out and now you want to tell a simple story about what's happening, there are competing ways to do that.
00:52:33
And all of them ignore some details and so none of them are completely satisfactory.
00:52:38
So when he says this is not settled, he doesn't mean we don't know why planes fly in a sort of micro physics point of view.
00:52:45
He means we don't have a nice compelling one sentence explanation for why this happens.
00:52:51
The way we can, for example, like a ball flying through the air.
00:52:54
Why does a baseball fly into parabola?
00:52:56
We know the answer is when you have constant acceleration, you get parabolic motion.
00:53:00
Simple one sentence answer.
00:53:01
That's what we're lacking for flight.
00:53:03
We have a very complex thing that's happening with micro physics and it's when we're struggling to come up with a simplified explanation at the macroscopic level.
00:53:12
Do engineers care?
00:53:14
So if you can make a simulation on a computer that tells you everything you need to know, like our engineers still interested in this question or has this completely moved to the realm of like physicists who never see the light who are studying it in their offices.
00:53:28
Like, yeah, do they care what the answer is anymore or do physicists care only?
00:53:31
Absolutely.
00:53:32
They care because engineers want simple working models.
00:53:36
You know, when they want to model how a plane is going to fly, they don't want to have to go back to describing every single particle.
00:53:42
They want simple sets of equations that let them work quickly and easily.
00:53:46
The same way, for example, we'd love to be able to predict a hurricane without modeling every single rain drop.
00:53:51
Currently, we have the technology and we're building these incredibly powerful computers just to model wind and pressure and predict the weather.
00:53:59
We'd love simple equations to be able to do that, rather than having to use incredibly detailed computation.
00:54:06
And so anytime we can summarize complexity with simple math, we definitely win.
00:54:11
So people are definitely working on this and trying to find a complete holistic approach that captures all this behavior that lets us do important engineering without simulating all of the tiny micro physical details.
00:54:22
Absolutely.
00:54:23
Yeah.
00:54:24
People care.
00:54:25
And I want to go on record that I apologize for implying that physicists don't go outside.
00:54:30
What is this outside thing you're talking about?
00:54:32
I was going to ask you about that.
00:54:33
I have heard about this, but I've been too shy to ask.
00:54:35
You told me you've been hiking.
00:54:36
I know that you're maybe even more extreme than I am in terms of outdoor adventures.
00:54:42
No, I do love going outside.
00:54:43
That's why I live in California.
00:54:44
It's amazing here.
00:54:45
The fall right now is absolutely incredible.
00:54:49
Okay.
00:54:50
So we've talked about a lot of different ideas, a lot of things we know and we don't know.
00:54:53
I know the answer at the end is that it's complicated, but is there a simple ish kind of way to summarize where we are right now in our understanding?
00:55:02
Yeah.
00:55:03
So I think the simplest way to describe it is that both the Bernoulli and Newton stories help, but they're both limited.
00:55:09
And the limitation is that they're trying to tell a story in terms of like simple causes and simple effects.
00:55:14
The air flows and it bounces off the wing or the pressure is lower above the wing because the velocity is higher.
00:55:20
And the real story is that the cause and effect are not so simple.
00:55:23
There's lots of things happening here and they are interplaying together.
00:55:27
So it's not so easy to disentangle the cause and the effect.
00:55:30
There's a lot of things at work here, pressure and velocity and forces all in this fantastic harmony that's making the wing go up, which is why none of these simple stories are satisfactory.
00:55:41
And we can, we have a slightly more complex story to explain why planes fly that involves all of these aspects sort of working together, but you know, humans like simple stories ball goes down because of gravity,
00:55:53
this kind of thing.
00:55:54
We don't have that simple, a cause and effect.
00:55:56
I'm always amazed by things that work so well where when you scratch the surface, we really don't understand.
00:56:03
Like, I was talking to someone who uses deep brain stimulation to treat epilepsy.
00:56:08
So like when somebody has a seizure, they're having like an electrical storm in their brain.
00:56:11
And sometimes they have electrodes implanted into the center of their brain and they essentially just get their brain zapped.
00:56:17
And that helps.
00:56:18
And so I reached out to an expert and I was like, why does zapping someone's brain with electricity stop the epileptic seizure and they're like, we don't know.
00:56:27
Just like I am a little nervous getting onto a plane here and why does the plane go up?
00:56:31
We don't know.
00:56:32
I also would not want to hear, why are you shopping my brain?
00:56:34
We don't know.
00:56:35
But in both cases, it works and it seems to work reliably.
00:56:39
So we get by.
00:56:41
So true, I think for most pharmaceuticals, right, we're like, well, it does have this effect.
00:56:44
We don't really understand.
00:56:45
That's right.
00:56:46
So biochemistry of it.
00:56:47
But hey, keep taking it, you know.
00:56:49
That's right.
00:56:50
Yes.
00:56:51
We all muddle along.
00:56:52
And I'm not an anti-vaxxer at all.
00:56:53
I just mean this is sort of the way science is.
00:56:54
You always understand science at some level.
00:56:56
You don't always need to understand the micro physical explanation in order to make it work.
00:57:01
And that's actually a huge gift.
00:57:02
Otherwise, we couldn't do anything.
00:57:04
If we needed to understand like the nature of quantum gravity before we made a bowl of chicken soup, we'd never have chicken soup.
00:57:10
We'll never understand the world.
00:57:11
It's lucky that the world can be understood without knowing all the details or science would be impossible.
00:57:17
It's lucky you can tinker with the world without understanding it.
00:57:19
Yes, that too.
00:57:21
So we do have a story we can tell about why planes fly.
00:57:24
And I think the best way to think about why a wing goes up is to focus on pressure, pressure above the wing and pressure below the wing.
00:57:31
Fundamentally, a wing goes up because pressure grows below the wing and pressure falls above the wing.
00:57:37
And both of these are contributed to by the Bernoulli and the Newton story.
00:57:41
Got it.
00:57:42
Okay.
00:57:43
We managed to summary something in like care for sentences.
00:57:46
But we can also dig into it in a little bit more detail.
00:57:48
You know, like, why does pressure grow below the wing?
00:57:51
Well, Newton tells us to focus on the angle of attack, right?
00:57:53
And that's correct.
00:57:54
The wing goes through the air and the angle of attack pushes down on the air and the air pushes back.
00:58:00
And this is pressure.
00:58:01
Just like if you're scooping up snow with a snow shovel, right, there's going to be increased pressure.
00:58:05
The snow is going to get compacted.
00:58:07
So why does pressure form below the wing, not that controversial?
00:58:10
It's the angle of attack.
00:58:11
That's crucial.
00:58:12
And as long as you go like this, and you just don't look at the top part of the wing.
00:58:15
And so I'm covering the top part of my eyes and you don't think about the top part of the wing that everything is good, but we don't understand what's happening above.
00:58:21
Is that right?
00:58:22
Well, above the wing, we can also think about the pressure.
00:58:24
The Newton story can't explain what's happening.
00:58:26
But if you think about in terms of fluid, you can, right?
00:58:29
So what's happening above the wing?
00:58:30
Initially, if you just like shoot air above the wing, then it wants to flow straight back, which effectively creates like a vacuum underneath.
00:58:37
The angle of the attack working together with the shape of the wing creates this low pressure zone above the wing, because the air needs to go down to flow onto that, right?
00:58:46
So that's exactly what happens is you create this low pressure zone, which is like a vacuum.
00:58:50
It pulls the air into it, and that's pulling the wing up.
00:58:54
So you have low pressure above the wing, created by the shape of the wing and the angle of attack, which creates low pressure above it.
00:59:01
And so these two effects work in harmony.
00:59:04
You have a force from below, and you have like suction from above.
00:59:08
So wings go up not just because the air below them is pushing them up, but the air above them is sucking them up into the sky.
00:59:15
So the Germans got the top right and the British got the bottom right?
00:59:18
Is that right?
00:59:19
I feel like there's so many times where I hear that there's a debate and there's people on this side and people on that side.
00:59:24
And five years later, the answer is almost always, oh, they were both right and it's some combination of things.
00:59:29
But okay.
00:59:30
Cool.
00:59:31
And so mostly this comes from the shape of the front of the wing, right?
00:59:34
Now, the shape of the wing is important because you want to minimize drag, right?
00:59:38
The Newton folks tell you, the shape doesn't matter.
00:59:40
All that matters is you get the force from the bottom.
00:59:42
But what you want is to create low pressure on the top without creating a lot of drag and without creating this turbulent zone, which gives you a stall.
00:59:50
So that's why you have this shape.
00:59:52
You have this shape in the front of the wing to give you this uneven pressure distribution.
00:59:56
So you get low pressure, but not so much that you get a stall.
00:59:59
And then you have this smooth ending.
01:00:01
So the flow comes together nicely without creating turbulence at the end.
01:00:05
So the shape of the airfoil and the angle of the attack is optimized to give you smooth flow, low pressure above the wing and to minimize drag, which is important if you want to take off.
01:00:17
I feel like the next time I get on a flight, I'm going to appreciate it all, much more having a better sense of how this all works.
01:00:23
But in terms of coming to this explanation, the experts still are arguing about how to summarize this.
01:00:29
I've given you sort of a summary version of it, but I'm sure there are aeronautical engineers out there who have differing opinions and are going to write into us with their theory for why planes fly,
01:00:40
or at least for how to describe it.
01:00:42
Our original listener, Tom Johnson, wrote in because he saw this video from the Smithsonian Air and Space Museum that explained it in terms of just Bernoulli, right, the Bernoulli explanation of low pressure on top.
01:00:54
And he wasn't satisfied with this.
01:00:56
And he wrote to me and he said, quote, I contacted the Smithsonian about this video, voicing my concerns, and I was told unequivocally that it's their policy that Bernoulli makes planes fly.
01:01:07
I wasn't aware that physics cared about policies, but I guess I'm mistaken.
01:01:12
That's amazing.
01:01:14
Institutions are fantastic.
01:01:16
Exactly.
01:01:18
And so again, you know, while the micro physics is clear about what's happening around the wing and you can track these individual particles, we still do struggle a little bit coming up with a simple explanation.
01:01:28
It turns out pressure is important and velocity is important and the forces are important.
01:01:33
So none of the sort of classic simple explanations can describe everything that's happening around a wing.
01:01:38
You need a more complex, a fuller description of what's happening to explain all the phenomena.
01:01:42
Why planes can fly upside down?
01:01:45
Why the pressure goes down above the wing, all this kind of stuff.
01:01:48
So in the end, the British and the Germans have to work together.
01:01:51
Oh, I mean, that's better in the end.
01:01:54
So those plane wing shapes, so I'm thinking of other instances where you've got like things moving through the air.
01:02:01
So we've got like wind turbines and then you've got racing cars.
01:02:05
They don't want to go up.
01:02:06
They want to go down.
01:02:07
So they do the whole shape and reverse like how has this information been used in other contexts?
01:02:11
Yeah, exactly.
01:02:12
So formula one cars, they have a wing in the back, but that wing pushes the car down so that it maintains friction because they need friction in order to go forward, right?
01:02:21
So wheels have to get pushed onto the ground so the wheels can grab and then when they turn the wheels, the car goes forward.
01:02:27
If the car lifts up above the ground, then it can't move forward anymore.
01:02:30
So they designed it in order to generate downward pressure.
01:02:33
So they have a crucially a different angle, right?
01:02:36
But they also think about the foil and they do really complex modeling because you know millions of dollars mean microseconds and that's the difference between winning and losing.
01:02:45
So yeah, absolutely.
01:02:46
They invert all of this theory in order to get a wing that can push down.
01:02:50
The crucial thing there is the angle of attack, right?
01:02:52
And then wind turbines, they don't want the wind turbine to go airborne, but they want it to spin as fast as it can, which feels like maybe some of the principles we talked about today could help that happen.
01:03:04
Yeah.
01:03:05
How does this plan to wind turbines?
01:03:06
Yeah, exactly.
01:03:07
Well, it's the same principle essentially.
01:03:08
You have air flow across the propeller and you want to convert that to a sideways force, right?
01:03:14
So you want to force up relative to the propeller.
01:03:17
You don't want the whole propeller to fly above the ground, right?
01:03:20
But you wanted to spin around the axis.
01:03:23
And so again, the angle of attack and the shape of it ensures a force that turns it and smooth flow around it because you don't want turbulence at the back of your propeller blade.
01:03:33
Yeah.
01:03:34
So each one of those is essentially just a little wing.
01:03:36
Very cool.
01:03:37
I'm guessing that we weren't racing cars before we had planes.
01:03:41
So probably the plane stuff came first.
01:03:43
Yeah.
01:03:44
Cars were pretty slow until kind of recently, like you could wind big car races by driving it like 45 miles an hour for me.
01:03:52
That's not so cute now.
01:03:54
It's much harder to die at that speed.
01:03:56
Why would you watch that?
01:03:57
Exactly.
01:03:58
But it's really fun to think about how we explain the world around us and how challenging it can be to explain some things.
01:04:06
It makes me really grateful for the times that we can find a very simple explanation.
01:04:12
And wonder like why that's possible sometimes and not other times.
01:04:15
Is it because of the way that we think about the world or is it just something about the way the world works?
01:04:20
You know, alien scientists have a better theory for why wings work because they started off from a completely different point of view mathematically or scientifically or is everybody struggling to describe some complex behaviors?
01:04:32
Are these things just inherently complex or is it just our language that's making them a challenge?
01:04:37
I wonder if part of that is there some percent of explanations that we have that we feel good about that are actually wrong if you look at them more closely, but the stuff works anyway.
01:04:47
Yeah.
01:04:48
And then I wonder if some other stuff just there happens to be a metaphor that we're familiar with that makes it easier to understand and there's just not like a ready metaphor for some of the more complicated things.
01:04:56
Yeah.
01:04:57
And sometimes we accept an explanation even though it's nonsense, like the air has to go faster over the top of the wing to meet it partners.
01:05:05
Like a lot of people go, "Oh, yeah, that makes sense," but it doesn't actually make sense.
01:05:11
And fundamentally, all of science is quote unquote wrong if you zoom in far enough.
01:05:17
Everything is just an approximate description.
01:05:19
Not like scientists are lying to us or we're promoting nonsense, but everything is an approximation, even like describe an electron as a fundamental particle.
01:05:28
Yeah, probably it's not, probably it's made of something smaller.
01:05:31
We just haven't seen it yet, but our theory works so far.
01:05:34
We've never been able to make an experiment where it breaks.
01:05:37
And so all of science is a work in progress in that sense.
01:05:40
Not just like do we have the best explanation for it, but how far can we push this until we see it break?
01:05:46
And seeing it break is an opportunity, right?
01:05:48
It's not a disaster.
01:05:49
It's a chance to learn something deeper about the universe to come up with a more accurate description or to poke through reality to another level and see how it works underneath it all.
01:06:00
So it's just part of the journey of science.
01:06:02
I feel like it's a great time to be in science.
01:06:04
There's still so many fundamental things left to understand.
01:06:08
At the same time as we're gaining all this new technology that allows us to address questions in different ways.
01:06:13
We have all these new tools.
01:06:14
Can't wait to see what we learn in the next couple decades.
01:06:16
Yeah.
01:06:17
And it's not just like what's inside an electron like weird abstract fundamental stuff that you'll ever see.
01:06:22
It's stuff right in front of you.
01:06:23
Stuff you can see with your eyes, you know, tornadoes and hurricanes and airplanes and fluid flow.
01:06:29
All this stuff is complex and unsolved.
01:06:31
So smart young people with energy out there, go out there, figure it out.
01:06:35
It's lots less to do.
01:06:38
So thank you very much to Tom Johnson for sending us this question.
01:06:41
If you have questions about the way the world works or why you can't understand it, please write to us to questions@danielandkelly.org.
01:06:48
We'd love to hear from you.
01:06:53
Thanks, Tom.
01:06:58
Daniel and Kelly's extraordinary universe is produced by iHeartRadio.
01:07:02
We would love to hear from you.
01:07:03
We really would.
01:07:04
We want to know what questions you have about this extraordinary universe.
01:07:09
We want to know your thoughts on recent shows, suggestions for future shows.
01:07:13
If you contact us, we will get back to you.
01:07:16
We really mean it.
01:07:17
We answer every message, email us at questions@danielandkelly.org.
01:07:22
Or you can find us on social media.
01:07:24
We have accounts on X, Instagram, Blue Sky, and on all of those platforms, you can find us at D and K Universe.
01:07:32
Don't be shy, write to us.
01:07:36
Join iHeart Media Chairman and CEO Bob Pittman for a special episode of the Hit Podcast, Math and Magic, Stories from the Frontiers of Marketing.
01:07:46
As he interviews the iconic and prolific Martha Stewart in front of a live audience in celebration of her 100th book.
01:08:00
Listen to Math and Magic on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
01:08:06
Hey, I'm Jay Shetty, and my latest interview is with Wiz Khalifa.
01:08:11
The craziest part of my life, I can go from performing in front of 40,000 people to either being an address room,
01:08:21
being in the plane, or being back in the bed, all by myself.
01:08:29
Listen to on purpose with Jay Shetty on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
01:08:37
Yo, what up, this is your girl, Jessel Aries, and I think it's time to acknowledge that I'm not just a comedian.
01:08:42
It's time to add uncertified therapists to my credentials, because each and every Wednesday I'm fixing your mess on carefully reckless on the black-effect podcast network.
01:08:50
Got problems in your relationship?
01:08:52
Come to me, your best friend, Achton Shetty.
01:08:54
Come to me.
01:08:55
Thought you was the father, but you not?
01:08:57
Come to me.
01:08:58
I can't promise I won't judge you, but I can guarantee that I will help you.
01:09:01
Listen to carefully reckless on the black-effect podcast network.
01:09:04
iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
01:09:09
AT&T Connecting changes everything.
01:09:15
Hi, I'm Ed Zitron, host of the Better Offline Podcast, and we're kicking off our second season digging into text elite, and now they've turned Silicon Valley into a playground for billionaires.
01:09:26
From the chaotic world of generative AI to the destruction of Google search, Better Offline is your unvarnished and, at times, unhinged look at the underbelly of tech, portier by an industry veteran with nothing to lose.
01:09:38
Listen to Better Offline on the iHeartRadio app, Apple Podcasts, or wherever else you get your podcasts from.
01:09:43
Hi, I'm Danny Shapiro, host of the Hit Podcast Family Secrets.
01:09:49
How would you feel if when you met your biological father for the first time he didn't even say hello?
01:09:54
And what if your past itself was a secret, and the time had suddenly come to share that past with your child?
01:10:02
These are just a few of the powerful and profound questions we'll be asking on our 11th season of Family Secrets.
01:10:08
Listen to season 11 of Family Secrets on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
01:10:15