How Do Airplanes Fly? What Neil deGrasse Tyson got wrong about Bernoulli | StarTalk 

One of the great challenges in this world, is knowing enough about a subject to think you're right...but not enough about the subject, to know that you're wrong...

As a pilot, listening to Tyson's explanation of lift was like listening to fingernails on a blackboard... Also, anytime anyone says that natural phenomenon "wants" to do something, it's time to change the channel.

How in the world does someone like tyson not understand the time/distance fallacy? This was proven wrong decades ago

I've listened to the first set 30 seconds you are the clear winner

Neil gets A LOT of things wrong.

Tyson is NOWHERE as smart as he thinks he is.

A man who truly loves the sound of his own voice.

I went to engineering school with guys like NDT - so eager to teach and or sound smart that they have to sound authoritative in everything, regardless of how little understanding they have of whatever topic they're wandering through at the moment.

Tyson’s greatest work was Cosmos where he was reading from a script written by people who actually knew what they were talking about.

"Astrophysicist to the Stars" Neil deGrasse Tyson wanders into the weeds to find a rake. Steps on it.

Tyson is living proof you should never rely only on social media for accurate information.

Listening to Tyson talk, it boggles the mind how anyone ever took him seriously.

Tyson is perhaps the most annoying explainer on RU-vid and I am not alone in my observation

Tyson ain't no Sagan, that's for sure...

Dunning-Kruger would be proud of their theory!

NDT is evolving into Cliff Clavin from Cheers.

Neil is one of those giant heads who claim to know more than he actually does. I was a fan of his for a short time until I realized he’s not as smart and knowledgeable as he thinks he is.

NDT needs to turn off his ego and watch this vid.

DeGrasse isn't just in the wrong lane here, he's on the wrong highway!

From the outside, it appears that Mr Tyson's self worth is wrapped around being the smartest person in any room he enters. And it doesn't seem like that meshes well with the final quote in this video.

Tyson also said that helicopters fly by creating downward thrust! 🤣 The man is almost as big a hack as Bill Nye

Thanks for clearly explaining how he is wrong. Neil has his finger in every aspect of science, philosophy, etc. He's full of himself and he really believes he knows about everything in this universe.

I'm gonna correct one thing - he wants us to think he knows it all. I wish he'd stick to topics he really knows, but he likes the sound of his own voice, so I know he won't stop.

The primary purpose of an aircraft carrier's angled deck is to allow landings and launches simultaneously.

Magnar, well done! I too watched the Neil deGrasse Tyson video (due, in part, to his celebrity status), only to find myself muttering “no, no, no ….”. Thanks for putting together such a well researched, technically correct, exposé of three common misconceptions in aeronautics.

Neil is wrong about so many things but is also incredibly arrogant and can simply gaslight or ignore anyone who callenges him. Being immune to challenge is why the contents of his mind are weak trash despite being given advantage above most of humanity in terms of time and resource/people access. Neil is one of the most disappointing failures to capitalise on an incredible silver platter I'm aware of.

I love it when you can ‘see’ the low pressure envelope above a wing when planes are close to landing in wet humid conditions. That cloud above the wing.... now you see me, now you don’t. The same conditions also show the powerful vortices coming from the outboard tips of the trailing edge flaps. When lift and wake air turbulence become visible.

I used to like Neil’s science descriptions. Then I saw him give a keynote live at a technical conference in San Francisco. I forgot what topic he was talking about, but the number and level of bombastic arguments and assumptions was counter to what I learned from my scientific mentors. (Three of them are notable enough to have Wikipedia articles.) But upon watching this (and I’m only at 11:30 ), my level of Picard facepalming has reached a new level. How does he get these cowpies past his fact-checking team?

Your shirt is indeed cooler! More people should see this video.

Honestly, as a huge fan of Carl Sagan, Neil deGrasse Tyson is regular disappointment.

You are just closer then Neil but there is still road ahead. Like solve Navier-Stocks and there will be the answer

I respect Dr. Tyson, but it surprised me when he stated that a helicopter cannot glide if its only engine stops. I fly single-engine airplanes and helicopters, and I'd rather be in the latter when the engine quits.

Thanks for confirming what I have known as a pilot for years. Interesting to note, I still, on occasion have to correct certified flight instructors during bi-annual reviews, that bernoulli alone is not sufficient. In fact, there are still manuals out there that still teach it incorrectly.

Neil seems to be getting careless. Air does not "want" anything. It is a group of molecules under pressure due to gravity. I assure you, air does not want anything, just as water does not "seek its own level". It is water. Water seeks nothing. Words matter, Neil. 🙂

I heard the bit about the air going a longer distance and wanting to "catch up" 50 years ago when I was 12. Seemed wrong to me even back then. Thanks for finally setting the record straight.

Tyson is one of those people who, while obviously very knowledgeable about many things, is also full of hubris and seems to want to always be the smartest guy in the room. I've known several people like him - smart but overly confident about what he actually knows.

My high hopes were crushed as well after I saw ND Tyson's video. Aero Engr here. Kudos on your rebuttal. Well done!

Neil DeGrasse Tyson, and most others, also forget that you can build a plane with thin flat wings and it will still fly. Inefficient, yes, but I build balsa models like that for fun.

Tyson is a science _popularizer,_ just like Carl Sagan was. Nothing more.

As always captain, you correct misled people. Being always looking for the truth and do research is key to good pilots. Thank you for your wisdom 🙏

What really scares me is that I have never taken a single class in aerodynamics... yet I still knew many of the things he said were wrong. Particularly the part about all airports and aircraft carriers have more than one runway are they are never at 90 degrees... you know... because I have eyes.

A perfectly flat panel, with no curvature, generates lift. Small wooden children's toy airplanes use flat sheets for wings, and they fly just fine. Properly curved airfoils can increase lift efficiency. Cantilevered wing tips can help with reducing vortices, thereby reducing stall speed. There are optimal designs for these also. Long thin wings are more efficient than short fat wings at generating lift, but long thin wings are more susceptible to turbulence. Each blade in a jet engine is a type of wing.

Arrogance and ignorance are never far apart.

On another explainer, Tyson said that airplanes taxi in the air above the airport, and not on the ground. Chuck Nice was visibly disturbed by Tyson's explanation, because even Chuck knew that aircraft taxi on the ground….on taxi ways.

The character Sheldon Cooper on the Big Bang Theory is smarter than Neil.

Neil deGrasse Tyson is a pop spokesmodel for science. He doesn't acrually do science.

This dude loves hearing his own voice.

Using the definition of NASA: "Lift is a *mechanical* force. It is generated by the interaction and contact of a solid body with a fluid (liquid or gas)" then, in a *strictly mechanical sense* only the lower part of the wing is able to generate lift in steady horizontal flight. By definition, no force is able to get a "grip" on the upper part of the wing (the outside surface which is in contact with surrounding air) and *pull* the upper part of the wing upwards. There is no pulling force on the upper part of the wing. However, because of the angle of attack and the fact that the wing is not moving through a vaccum but through pressurized air, the upper part of the wing is able to decrease the ambient static air pressure exercised by Earth's atmosphere, therefore less air molecules are hitting against the upper side of the wing pushing it downwards, but this is not lift as lift would be directed upward, not downward. So at all times, air is only pushing against the upper part of the wing pushing the wing down and that's why those diagrams here: 8:56 are wrong as they depict force vectors pulling the upper side of the wing upwards. There is no mechanical force pulling the upper part of the wing upwards. However, there is a force resulting from static air pressure pushing at all times against the upper AND lower part of the wing. So the lower part of the wing is able to push the wing upwards as the upper side of the wing it is no longer pushed down as much because of aerodynamic effects (angle of attack, wing shape, air speed and so on). The wing moves upwards because of the aerodynamically created influence on the effect the surrounding static air pressure has on the wing (greater on the lower part) + the aerodynamically generated force of lift on the lower part. On the upper part, there cannot be any aerodynamically generated force of lift, only an *aerodynamically generated local reduction of the effect of static air pressure pushing downwards against the wing* (because of Bernoulli) therefore diminishing the downward push of the static pressure on the upper part of the wing. Therefore not every surface on the wing produces lift, but every bit of the surface influences how air moves around the wing and how the airflow is bend. Also, in case you don't understand this argument: if you buy a vaccum suction cup holder, once installed on a window pane, it actually does not suck on the window to stay put. The part facing the window pane can be compared to the upper wing, the part facing you can be compared to the lower wing. So the "vaccum suction cup holder" remains put because static air pushes it against the window pane (that would be lift) the only difference is, in order to create it, there is no need for airflow because the surface facing the window is hermetically sealed of and the lower static pressure is permanently maintained so there is no need for dynamic airflow over a curved surface at an angle of attack in order to create a local reduction of static air pressure hitting the wing. Now, it would be foolish to say the inner part of that suction cup holder created "more lift than the outer part" - as no force is pulling the inner surface against the window pane, only the outside static air pressure is pushing the suction cup against it.

As noted by others - if “Equal transit time” were correct then inverted flight would be impossible, as would flat high-speed wings that have no curvature. Holding angled cardboard out a car window forces it upward.

Several years ago I was looking through a graduate level aeronautics textbook where the author was discussing lift via Bernoulli & upper/lower path length. He concluded that a Cessna 182 would have to accelerate to over 400MPH to lift its own weight if this were the mechanism that enabled a wing to generate lift. It is amazing that this myth is still being taught by the FAA and was a multiple choice answer on the airman 3rd class written test.

Who even takes Tyson seriously?

Neil is wrong a lot in the most confident ways possible. 😂

Neither of you are correct, even your video contradicts your statements. Freeze the screen at 4:31 and take a thorough look at it. It was not the air above the wing that became faster (see the uppermost smoke line at the very top of the screen matching the one right above the wing), but the air below the wing has slowed down due to the pitched position of the wing. In this specific experiment the pitched position of the wing was a more substantial factor than the wing profile. You can fly even with a completely flat shaped wing if it is pitched as it will create a pressure delta on its own.

If Bernuoulli effect is dominant in producing lift, then upside down flight would be impossible.

A simple experiment I was shown in the 1960s, long before I gained my humble private pilots license, involved 2 pieces of paper. Take a sheet of, let’s say, copy paper and hold it horizontally, like a mouth organ, but just under your bottom lip. If you blow across that paper, even quite gently, the sagging sheet will lift to be horizontal in both directions, left to right and front to back. A more dramatic experiment is to hold 2 sheets of paper vertically, close together and up against your lips. When you blow between them, fairly hard, you will be rewarded with the noisy report of the 2 sheets flapping wildly against each other. These are but 2 examples of Daniel Bernoulli’s principle at work. Oh. another example, I experience it every morning, is the way a shower curtain is drawn inwards by the water rushing past it, same principle. Smart man that Dutch born Swiss mathematician/physicist! The other factor keeping aircraft airborne is that the wings push the air down, via the angle of attack, not unlike a water skier’s skis. This is well illustrated by the slight drop in altitude noticed when an aircraft moves out of ground effect immediately after it leaves the end of the flight deck of an aircraft carrier. This is more pronounced with lower powered planes.

The problem with Neil is he's always talking to someone that can't challenge his perceived intellect.

Sir I agree with you cause neil thinks the sun is white yet the sun radiates at 5800 to 6400 Kevin just like a yellow sun and a white sun radiates at 10000 to 12000 Kevin making Earth into Mercury and Europa and IO at Jupiter the new Earth and Earth would not be a life capable planet anymore...yours very truly Alfonso Cantu USMC

Neil DeGrasse Tyson gets many things wrong outside of his own field of expertise. A typical example of the Dunning-Kruger effect.

Neil is a celebrity not scientist...

Only one of those three should be recommended, and that is Doug. The only video people should watch is his. Prof Babinsky uses a simplification that has existed in the literature since the 1920's, and it only captures the flow around the leading edge. He explains none of the transient effects that are important. It is as bad as all of the others, Coanda or Bernoulli, and it equates to "just look at this one part, and ignore everything else". It is very Wizard of Oz. Prof Fidkowski make the common engineering mistakes, talking about inviscid lift and does not address some key aspects. Doug's video, his book, and his articles in The Physics Teacher are amazing. He makes it clear that to calculate lift you are solving the Reynolds-averaged Navier-Stokes. The work by Prof Tianshu Liu from WMU makes it very clear that the Navier-Stokes are needed, given viscosity is fundamental for the generation of lift. That is, the Navier-Stokes are the fluid equations we have with viscosity (unlike Euler). So, Magnar, I am sorry to say that you are also incorrect because what NASA have is incorrect. In 2D, where most of the fundamental airfoil data comes from, flow does not accelerate downwards, it returns horizontal, and you can show the lift force as a the pressure difference between the upper and lower surface on the wind tunnel, which is what NASA measured back in the 30's and 40's to characterise all the NACA airfoils. So, while Newton's 2nd law, which must include pressure and viscous forces, will show a momentum flux across an airfoil, it will not be equal to all lift. In fact, this was shown by Prandtl back in 1919. The most important point is that lift generation is a transient effect, where by viscosity if the fluid results in a vortex being shed at the trailing edge, which due to conservation of angular momentum results in a bound vortex around the airfoil. This is what makes the flow over the top faster, and the flow under slower, this then equates to lower pressure above and higher pressure below, which is the lift force.

The first time I heard this on Start Talk it made me question everything I ever heard or will hear out of Neil's mouth. I am merely an aviation enthusiast and I knew he got it waaaay wrong.

Um yeah, as an airline pilot I can honestly say Neil is a total 🤦‍♂️. His 30 degrees makes absolutely no sense. I love how he says “oh airports can just switch runways around”. You have a large amount of airplanes in the sky flying a certain route geared for a specific runway. And then you have airplanes taxing on the ground for a specific runway. So it’s a major PITA for controllers to flip runways around. Neil gets so many things wrong.

Finally! someone else who knows about the Babinski principle.

I had not listened ot Tyson's explanation previously, but it sounds like a simplified Physics class that ignores the complications of the real world. It reminded me of the joke told to me by one of my Physics professors in college to stress that point: "Physics is the study of frictionless elephants whose mass can be neglected". The forces on the air do indeed act to "keep it at one parcel", but real-world forces like friction and the energy imparted as the wing moves through it prevent this from happening. Terms get complicated depending on the frame of reference that is being used (ie. whether the wing acts on the air, is with an aircraft, or the air acts on the wing, as in a wind tunnel). At least Tyson discussed angle of attack and its effect on lift. Some drawings used to explain lift show the airfoil at an angle of attack that produces either no lift or sometimes even a net downward "lift".

Airports also consider prevailing wind directions. So runways at a 30° angle may be the best if the winds almost never are at 90° from the first runway.

Tyson tries WAY too hard to be the successor to Carl Saga. Unfortunately for humanity, Neil is not even close to Sagan's knowledge and ability to explain complex notions in simple and ACCURATE terms to lay people. To be so wrong on these subjects, leads him open to science doubters attacks. Too much ego is a bad thing.

DeGrasse Tyson’s greatest accomplishment is that he met Carl Sagan. This second is that he makes a buttload of money talking, not doing, about cosmology and related stuff. The third and most annoying “accomplishment” is that he thinks he knows everything and cannot shut up long enough to learn. This is a problem with some mediocre academics…they leave their silo of actual expertise and get it wrong as often as anybody else. He is not Carl Sagan, who was an active scientist and gifted sharer of his knowledge. The original series on PBS “Cosmos” was so much better than the CGI version with deGrasse Tyson. I really don’t understand why people listen to him when he strays far from his education/expertise. Is it because it’s the USA and they need a black expert? 😅

It is interesting that two of the world's leading astrophysicists, Tyson and Kraus, rockstars of their field, think they can bang on about everything. I especially dislike their hubris, the emphatic way they pronounce their opinions. A real scientist is careful and uncertain - because science is a set of hypotheses which are only correct until we find something better. In consequence, I have no time for such people - because if they are wrong about a subject I do understand, they might well be wrong about everything.

Thank you for your clarification on this issue. Good Job.

Great video explaining most important aspects There is one other thing Coranda effect . The tendency of a fluid to stay attached to a convex surface

@Aerodynamics Seems like at first you say Tyson is wrong but then you show some slides and whilst commenting the slides (generating lift under positive angle) you "forget" Tyson was explaining the same. Tyson is right all the way, and your video has no point or fact to weight vs what has been said by Tyson. Fun fact: Convair F-102, Dassault Mirage III and few others are relying only on the angle of the wing to produce lift. You may be a pilot but physics is not your strong side.

Dunning Kruger owns Tyson. He gets so much wrong compared to more talented physicists, because he believes his own hype and is relatively poor at professional scientific critical thinking. He's a good communicator, but makes a very high rate of mistakes every time I see him talk (relative to high quality physicists who typically have excellent critical thinking skills and a much lower rate of self delusion).

I was working on my pilot licenses while in college pursuing my civil engineering degree. My hydraulics professor was the first engineer I had heard who was so perplexed at how many otherwise credible people had the flawed "understanding" of Bernoulli and lift. To this day, from the FAA publications down, that misunderstanding continues. It's hard to understand why it has not been corrected after having been explained by so many sophisticated aerodynamic experts like those Magnar refers to at the end of his video.

And this is why he needs to stay in his lane. My home airport of Plant City Municipal Airport(KPCM) only has one strip and 2 runways. There are airports that can have 2 strips and only 3 runway, not 4 like you would think, because one end is not used for takeoff or landing due to obstacles(but usually due to rich people). Also, where I used to work at Igor Sikorsky Memorial Airport(KBDR) has 2 strips and 4 runways(used to have 3 strips and 6 runways), and the two remaining strips are RWY 6-24 and RWY 11-29.

as a kid in elementary school, one day an airline pilot came to the school to teach the class about how planes work. She used the equal transit time explanation to show how lift works, and unfortunately by the time I had learned that that wasn't entirely accurate, I had already been sharing that incorrect information for years.

I own and operate my own aircraft so I know the only thing that makes an aircraft fly is .... money and paperwork! .... go on, someone tell me I'm wrong.

Normally, when people put on a video on a subject that they are not familiar with, they do research on the topic and learn the terminology and theories. Neil deGrasse Tyson does non of that. He just assumes he can explain, fails to use the right terms and makes anyone who heads him misinformed. I understand if someone gets one or two things wrong, but those people have some familiarity on the topic, just not a complete analytical understanding, but this guy just fails.

I know it's going to be a good day when I start with The Grass getting disproven.

I recently saw him talk about landing the space shuttle. He claimed that NASA discovered that putting linear grooves in the runway would straighten out the shuttle when it landed. The Dept. of Transportation had been putting grooves in the highways and freeways before NASA even existed. They do this to help the road shed water when it rains to avoid hydroplaning. I've driven on these surfaces for almost 50 years and I can tell you that a grooved surface does NOTHING to keep a vehicle going straight.

As an engineer, I think you are splitting hairs to debunk NDGT. He is trying to educate a lay audience at a level that a non scientific audience can grasp. And he does that extremely well. If you want to argue with his science, look for the papers he writes, critic them with other scientists.

Neil deGrasse Tyson is getting on my nerves. There are definitely topics he knows a lot about... but certainly not ALL topics. Yet he speaks so confidently, making those that don't know believe every word he says. He is so enamoured with the sound of his own voice, that he doesn't realize he is way out of his depth. This is embarrassing.

Tyson is so annoying. He never listens to anyone in a conversation. When others talk you can see he can't wait to jump back in. He literally goes blank when others are talking and interrupts constantly. People say how much he brings science to the masses. Really? For every person he gets interested in science he turns off another with his arrogance. I once saw him say he was watching a football game and that he did quick math on a play to determine the Coriolis effect or something. Totally ridiculous stuff. Brian Cox is much better at breaking things down for people and I have seen him be very modest and say he doesn't know about a certain subject and actually listen to others talking.

Thank you for this wonderful explanation

The best explanation I’ve seen is lift is the force generated by the difference in pressure between the upper and lower surfaces of the aircraft.

Neil will always be a space cadet. Best description of lift I have seen yet. Never thought of it as a hybrid principle between Bernoulli and Newton.

I watched Tyson's series about Cosmos, that was nice. And then, suddenly, he told things, showing that he did not have a clue about Relativity. So, I stopped watching him.

That’s what you get with pop physics. The physics version of Richard Dawkin’s pop evolution.

Wel, holding your hand out of your car window is still a good analogy for a wing. A poorly designed wing but a wing none the less. You do not need an airfoil shape to achieve flight. A cinder block will fly and be controlled with enough thrust. The airfoil shape is more efficient at creating this effect of being sucked up like a noodle by the lower pressure air as this air is sucked down into the upper shape or surface of the airfoil. It's bernulis principle. It's a half Venturi shape layed on a flat surface instead of bent into a circle. A ram air engine of sorts. Sucks its way up and pushes that air downward. It's some wormhole stuff.

The sound of Neil’s voice close to the wing is enough to create lift.

It's actually a little bizarre that NDT got this so wrong. I mean if he thought for a moment and recalled - for example - that many airplanes regularly fly inverted (and that most airfoils don't look like his example and many are close to symmetrical about the chord line) he'd have to realize that his explanation was flawed. And don't even get me started by the "up the flaps on the tail wing" part. Sigh. Thanks for the video Magnar!

I used to like Neil deGrasse Tyson. As time moves on though I just can’t listen to his patronising voice anymore, raising his volume to boom over other people if they dare to attempt to say something. Also, as time has gone by, he has become more and more incorrect in the things he says, while all the time being so cocksure that he is right. He can often be quite infuriating. 🙆🏼‍♂️

I'm afraid he started this video with a gigantic mistake: Neil Degrassi Junior High knows very little about anything.

Runway directions are chosen by monitoring wind conditions for a period before aerodrome construction which @gcpgrey did a video on. They aren't at 90 due to laziness . Nzch has it because wind commonly goes north south (02/20) but occasionally off the mountains (27/11).but klas doesn't have 90 diff. This is because analysis shows common wind directions.

As a sailing instructor I sometimes had students who knew all about Benoulli's theorem. When I pointed out that a sailboat's sail has no thickness, I was met with disbelief. "How dare you question Benoulli!" Newton's law of motion explain airfoil lift nicely. Those infatuated with Benoulli have to resort to Newton when challenged on the inconsistencies.

deGrasse Tyson is a celebrity scientist. That pressure leads him to have opinions (which they are) about things he's not really qualified to explain. Everyone has limits.

Neal fancies himself a know-it-all, but he sure as hell knows absolutely nothing about aerodynamics or aircraft control surfaces. That was painful.

I love Neil's enthusiasm, even when he misses the mark a bit.

A lot of lift is deflected air, although they dont bounce off the wing. You can see it when a skydiver flies under a string of helium ballons while landing. It sucks the ballons to the ground after the parachute goes under. Tyson is still wrong, its just more complicated than even pilots think.

This video is not necessary. Anybody who would watch a video about this subject already knows NGT is little more than a smooth talker.

Neil de Gasse Tyson is full of himself. He’s got a big mouth to match his ego size. He’s the great pretender. A slick smooth slippery salesman selling his limited understanding of science instead of selling used cars.