Bill Nye The Science Guy S01 E01 Flight

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Bill Nye The Science Guy S01 E01 Flight

this is the sky I know what you’re saying you’re saying well there’s nothing there what do you mean there’s nothing there there’s enough to fly on want to see it again things fly pretty cool huh science rules inertia is a property Bill Nye the Science Guy brought to you by air without air you ain’t flying air pressure makes things fly that’s it from June bugs to giant Jets they all fly because of air pressure and you’re saying well how can air make that much pressure I mean it’s not like it has a test tomorrow or anything and besides air is so light and well airy when it’s air pressure that lets us breathe and it’s air pressure that makes the wind blow without air pressure nothing could fly take a look at this it’s our plastic airplane of science this airplane is flying even though I may not be going anywhere maybe know the feeling we air moving over the wings is creating what scientists call maybe a scientists like you calls blip yeah it’s like when you lift something up like maybe when you lift up a 400-ton jumbo jet or a plastic airplane of science now where does the lift come from well it comes from moving air when the wings are tipped up a little bit the moving air creates differences in air pressure the air going underneath the wings is going a little more slowly than the air going over the top now when air is moving this way it pushes this way it doesn’t push so much up or down so there’s a little higher pressure under the wing then on top and that difference in air pressure creates lift now this thing that happens with air that when it’s moving this way it pushes this way and not so much sideways is named after a Swiss guy named Verne ooh so we call it the Bernoulli effect when the wings curved on top it doesn’t need to be tipped up as much to get lift it doesn’t need as big of an angle of attack airplanes fly because their wings develop differences in air pressure when they’re curved on top or given an angle of attack so airplanes are held up by something we can’t see invisible air pressure not that bad when we throw the plastic airplane of science differences in air pressure created on the wing develop lift huh lift is what makes flying disks wide and kites check this out ordinary balloon now some of the air we breathe the air that surround us all the time is now inside the balloon I’ve used the power of my lungs to force molecules into the balloon the more molecules in the balloon bouncing around the greater the pressure and that pressure causes the balloon to expand air pressure [Applause] daizy’s this one well we’re gonna have to work on that see air pressure gives these balloons their shape without air pressure we’d have something like like this although watching balloons fly around not that bad here’s another experiment you can do that shows what air pressure can do get two pins a little nice big bowl like this now get a heavy book you can use a balloon to lift the book you can do it with air pressure set two pencils on the table like this place the balloon between the pencils with the open edge of the balloon hanging over the edge now put the book on the pencils

just blow into the balloon you’re lifting the books with air pressure from your bread pressure inside they’re powerful dice yeah it’s pretty good day for parasailing ah that was great hey whoa here’s the parachute this is the front and this is the back between there we get high pressure so on top we get slightly lower pressure and that difference in air pressure that’s where the lift comes from that’s a Boeing 727 a classic jetliner it’s full of people kids dogs and choice of chicken or beef it weighs almost a hundred tons hundred tons that’s a lot of tons to get off the ground differences and hair pressure even though we all know there’s thousands of airplanes taking off and landing every day it’s still a pretty cool thing to watch we can bill bill oh hey I didn’t know you guys are up there go ahead rewind it give me camera what no Jew no no three that’s great okay now check out the airplanes wing look at its shape there that’s important because this is a plane gets going some of the air is gonna go over the wing and some of the air is gonna go under it just like the plastic playing of science back to you in the booth the x’s are going over the top fast and the olds are going underneath not quite as fast ready to take – it’s the same air just traveling at different speeds which creates a difference in air pressure the faster X’s can’t push down as hard as a slower O’s push up the O’s pushes filling up when the plane gets going the air on top zips right over the wing which creates an area of low pressure so you’ve got high pressure underneath and low pressure on top to create lift the X’s and O’s get back together at the back of the wing ready for Bill take bill with air moving over wings we can develop differences in air pressure that can be used to create lift now how do you think we get air moving with engines big engines that’s how we get air moving let’s keep the shower moving this is a simulator room and the one we’re going to fly in today is 767-200 so go ahead and walk on in hi my name is Susanna Darcy and I’m a test pilot for the Boeing Company then I’m ready to fly us captain on the Boeing 737 the five seven six seven and 747-400 this is a simulator that’s used for all the training for airline pilots and test pilots they’re getting their ratings on 767 pulling back right here beautiful we’re flying there’s a positive rating you tell me gear up these are the throttles and how the throttles work is like an accelerator on a car it’s the control column and when you pull back we go up and when you push forward the airplane will go down probably most people with not called pilots Scientifics but on the other hand you need a lot of math and science there’s 50 feet airplane starts to flare automatically right there a touchdown come up and peel the brakes on altitudes or our numbers headings remember so an airplane is really just a fun application of mathematics perfect are you sure you haven’t done this before consider the farmer you me err everything is made of molecules little pieces of stuff and when things like air molecules get moving they can exert pressure here take a look at the molecule machine of science see the little balls they’re moving like moving air molecules and they exert a pressure

on this paper disk see now what would happen if I move the paper disk up real fast well take a look see the molecules spread apart they expand they want to exert a pressure in the direction they’re going along the tube they don’t exert as much pressure this way or this way and that’s Bernoulli’s principle yeah it’s the same pressure you feel when you’re riding your bike excuse me I’m gonna generate a little wind here in the lab you feel pressure you don’t feel as much pressure on the back of your head now this pressure is called dynamic pressure the pressure of moving air so the same thing happens on an airplane wing suppose we had an airplane wing like the plastic airplane wing of science C as air goes over it the air going under the bottom exerts a little pressure on the bottom but the air going over the top doesn’t exert as much pressure this way this way this way or this way so we get C lift it’s all done with molecules see ya here’s an easy experiment you can try at home that shows you the difference between high and low air pressure all you need is some string tape a straw and two ping pong balls hung up like these take the straw and blow air between the balls what do you think will happen okay so you have your ping pong ball set up what do you think is gonna happen now you might think that the air going between the balls would push them apart but when you try it they get closer together that’s because the fast-moving air has lower sideways air pressure than slow moving it so the faster air going between the balls makes the pressure on them drop since the air on the outside of the balls has higher pressure it moves the balls closer together this is called the Bernoulli effect named after the Swiss guy who discovered this principle of pressure the Bernoulli effect is what makes birds airplanes and kites fly Switzerland is also known for chocolates Swiss cheese and cuckoo clocks Bernoulli he was onto something huh what I do for a living is I’m an air traffic control specialist seven one six wait for takeoff the airplanes have to talk to us at all times when the time they push back off the gate until they land again they’re talking to an air traffic controller our job involves science every day when 2201 zero moments ago I decided to be an air traffic controller in the sixth grade and I got fascinated in in flight and just different scientific formulas and then I found out that I had to know about the clouds and precipitation and science became my favorite subject in school in fact it was my best subject scientist if you find out what you want to do at a young enough age then you can strive for it when you get old and then anyone can achieve a goal if you strive for it and push for it hard enough Wright brothers first to fly an airplane with an engine Charles Lindbergh first person to fly alone across the Atlantic Amelia Earhart first woman to pilot a plane across the Atlantic what do these three have in common famous fliers true stories this week on the Johnny lift show this looks like an ordinary wing doesn’t well it is no ordinary wing only it’s really small and scientists test wings not in the wild anything can happen world of the outdoors but in here this is a wind tunnel but tato remember when we were flying our plastic airplane of science it didn’t make any difference whether we were flying it in front of a fan or flying it with a toss the wings lift the same way see planes take off and land toward the wind that way whether they’re speeding up to take off or slowing down to land there’s already air moving over the wing so airplanes can get big and complicated and sometimes look a little weird so we always want to make sure they fly the way we want them to so it’s easier and I dare say a lot less expensive to test wings and airplanes in here than it is to go just build one and see what happens these big ones fly great and they were all tested as models some people are afraid that airplanes can’t fly I guess because the air they fly

through is invisible well so is the air we breathe for crying out loud I mean it’s just air now we humans have figured out ways to make pretty good winds and they develop differences in air pressure and differences in air pressure that creates flip now in order to get lift you have to have the wing moving you have to have the air moving it’s kind of like having your face in front of a fan huh they’re like when you’re riding a bike you feel the wind on your face the pressure of moving air that’s what we call dynamic pressure airplanes fly anyway a human on a bicycle is a very efficient machine there’s airplanes now that you actually get in and pedal for power this is the gossamer albatross it was the first human powered airplane to fly across the English Channel it was pedal powered by Brian Allen don’t kid yourself pedaling hard and long enough to keep an airplane like this flying is no easy task but wait there’s more you also get a wing with an angle of attack and lift isn’t that amazing [Applause] and I have made a quarter of a million up with it look out for wine all right you see how that happened we got that one all done there it is air pressure Wiz flips this is science we got all up up in the air that we made it their their flight there the father the flight cool wings will maintain lift as long as they have an angle of attack look in here not bad huh helicopter rotors work just like airplane wings instead of flying straight through the air though they also spin in a circle they develop differences in air pressure and that develops lip they work great helicopters have wings that spin here’s how you can make your own helicopter you’ll need a piece of cardboard like a cereal box a pair of scissors some tape and a pencil anyway here’s what you do cut your helicopter rotor blades of science like this notch it in four places here here here and here bend it at the end of the wing in opposite direction tape it to your pencil and you’re ready to go take your helicopter and spin it see it flies it works just like a real one here’s another type of helicopter cutter piece of paper like this fold these two flaps down like this now I put a paper clip on the bottom and watch it fly helicopters science ravenson butterflies common ones the sky they can sail through the air – with [Applause]

wait things over lastly air above them ooh so fast Bradley their losses slow creates high pressure to lift and go [Applause] now you know how birds bats butterflies and airplanes fly basically it’s three things what air has pressure to to get things to fly we want differences in air pressure those differences in air pressure come from Bernoulli’s principle remember the swiss guy as molecules of air go this way they don’t exert as much pressure this way or this way remember the Bernoulli’s principle the swiss guy with the cheese 10:3 when you give a wing an angle of attack then Bernoulli’s principle comes in and makes low-pressure on top and high pressure on the bottom and that creates slip well I got some serious angles of attack to develop gotta fly Bill Nye the Science Guy see ya produced in association with the National Science Foundation