Did you spare a kite when you were a kid
It's a piece of paper, a piece of mackerel and a tail with two ribbons. You're running against the wind, you're sweating, and the kite is shaking. You stop, it's falling again. You run again, it's up again。
What i couldn't figure out was why i had to run against the wind. Isn't it safer to run
I tried to run. Turns out the kite was dragged to the ground like a dead fish. My dad's in the back and he's like, "reverse the wind! Reverse the wind! I'm running against the wind. I thought the kite was perfect -- it was just for me。
Then i learnedPhysicsI didn't know until i knew itRaiseI don't know. And today you're flying the same thing on your wings as a kite。
The kite flew on the basis of the air flowing over the kite's surface。
The kite is tilted. The wind comes from the front and hits the kite. Two things happened:
First, air pressure on the wind gets high. The wind hit the kite, it was blocked, the air squeezed together, and the pressure increased。
Second, the back wind air pressure gets low. Winds go around from both sides of the kite and meet in the back. 'cause the path's getting longer, the flow's fasterBernoulian doctrineQuick local pressure。
The result is high pressure in the front and low pressure in the back. Back and forth, push the kite up. That's the lift。
Translation: the wind pushes you from the front, smokes you from the back, and you're carried up by the push plus。
What's more, why do you have to run against the wind? Because kites need relative wind speed. The wind comes from the front, you run against the wind, the speed of the wind relative to the kite = wind speed + your speed. The more speed, the greater the lift. You run the wind, the wind blows from behind, the kite hits, there's no lift, of course。
You think you're running, you're actually making wind for kite。
The first time i knew that, there was one thought in my head: when i was a kid, i was sweating all over the air, and i was giving a piece of paper as a human drummer。
Year 2000HistoryThe kite is an old chinese invention
How long has a kite been in china? At least 2000 years。
It's been said that during spring and autumn, the ink was made a wooden bird, "three years, flying and losing." this is the earliest kite prototype. Luban then flew three days and three nights with bamboo and paper。
Han shin used kites for military purposes when he arrived in handy. Rumor has it that he used a kite to measure the distance when he attacked uyung palace. In the north-south era, kites became a means of delivering information。
Since then, kites have changed from military use to civilian entertainment. Song dynasty's "tokyo dreams" documentary says, "the peaks are competing." the kites were already doing very well — dragons, phoenix, butterflies, acupunctures。
When did the westerners get something like that? In the eighteenth century, european talent began to study aerodynamics of kites. In 1783, the french mongolfier brothers invented hot balloons. In 1899, the wright brothers used the kite doctrine to test their wings — they did a double-wing kite, which they turned with wire control. That's the basis of the later leyt vehicle。
The chinese played a kite in 2000. The wright brothers invented the plane。
And even better, the kite's principles are a direct source of aviation engineering:
2000 years ago, a piece of paper and a few bamboos were being taught today to boeing and airfarers。
Why is a kite counterintuitive
Because normal people think, "how can you fly when the paper is so light?"
But the kite tells you, the lighter things, the easier to fly. The greater the ratio of lifting power to weight, the easier it is to lift。
What's more counterintuitive is that the kite is not blown up by the wind, but by the wind。
You take a piece of paper and throw it up, and it floats down. But when you fold the paper into a kite shape, and it leans towards the wind, it flies. The difference is that paper paper doesn't produce the shape of lift, and kite does。
It's like you're holding your hand out of the window: flat. Wind's coming up. But with your hands down, the wind pushes you down, and your hands up. That's the lift -- your hand turned into a kite。
Today, this idea is used in countless places:
A piece of paper before 2000 was taught today in airplanes, racing cars, sailboats, drones。
Do you spare a kite? What was the worst? I used to fly a kite, the line broke, and the kite flew up to the tree, and i climbed the tree enough, and the branch broke, and i fell into the mud, and the kite was still on the tree, and my dad said, "you're a kite, and the line broke." have you ever broken a line in your kite? Or has anyone made a kite themselves? The type of paper? Let's talk about you and the kite
# history # physics # kite # lift # benuli # wisdom # knowledge # childhood memories
