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1º ESO/BILL NYE EXPLAINS SEASONS - Contenido educativo

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Subido el 7 de marzo de 2021 por Alicia M.

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Ah, the seasons. It gets cold in the winter, flowers bloom in the spring, we get lots of sun in the summer, and leaves fall in the fall. 00:00:00

See, the Earth's seasons affect every living thing on Earth. That's right, seasons affect the way everything grows and changes every year. 00:00:15

The reason we have seasons on Earth is because the Earth is tilted. 00:00:26

Now let's say that this is the Earth, 00:00:30

and there's an imaginary line going through the middle of it called the Earth's axis. 00:00:32

It's tilted, and it stays tilted as the Earth goes around the sun 00:00:36

at 100,000 kilometers an hour. 00:00:41

That's a billion kilometers every year. 00:00:43

Now not only is the Earth going around the sun, but the Earth is spinning. 00:00:46

And when you're on the part of the Earth that's toward the sun, it's daytime. 00:00:50

And when you're on the part of the earth that's away from the sun, it's nighttime. 00:00:53

Now, the seasons work in kind of the same way. 00:00:58

When the part of the earth that you're on is tilted toward the sun, it's summertime there. 00:01:01

So when it's summertime here at Nye Laboratories, on the other side of the world, it's wintertime. 00:01:05

In places like South America and Australia. 00:01:10

Hey, Bill, your shoe's untied. 00:01:13

Oh, thanks. 00:01:14

Then, when the part of the earth that we're on is tilted away from the sun, it's wintertime here. 00:01:17

And it's summertime on the other side of the world. 00:01:22

Isn't that wild? 00:01:25

All because the Earth's axis is tilted. 00:01:27

That's the reason for the seasons. 00:01:30

Why are the North and South Poles the coldest places on the Earth? 00:01:33

Well, please consider the following. 00:01:38

Let's say that this heat lamp is like the sun, because it's hot. 00:01:43

And let's say that this globe is like the Earth, because it looks like the Earth. 00:01:47

Anyway, we've mounted thermometers on the Earth like this. 00:01:52

See? 00:01:55

Now, the one at the equator is just about off the scale. 00:01:56

And the one at the south pole is right around the room temperature mark. 00:02:00

And the ones in between are somewhere in between. 00:02:04

That's because the heat is hitting the one at the equator almost straight on. 00:02:09

Whereas at the poles, it's just barely grazing by. 00:02:14

And then somewhere in between, well, it's somewhere in between. 00:02:17

You see, it's not that the equator is closer to the heat. 00:02:20

It's that the heat is hitting it more straight on. 00:02:23

See, if the Earth were sitting like this, 00:02:26

then this thermometer would be the hottest and this one would be the coldest. 00:02:28

Anyway, that's why the very warmest places on the Earth are right around the equator, 00:02:32

tropical rainforests and jungles. 00:02:37

And the very coldest places are at the poles 00:02:39

because they're the ones that the energy from the heat lamp just barely grazes by. 00:02:41

I mean the energy from the sun. 00:02:46

I mean, well, anyway. 00:02:47

Thank you for joining me. 00:02:49

Do you notice, though, that the axis about which the Earth turns is not straight up and down. 00:02:51

It's tilted to one side at an angle of 23.5 degrees from the perpendicular. 00:02:56

This has a lot to do with why we have different seasons, as we shall see. 00:03:01

Let's say that this plastic globe of science is like the Earth, 00:03:06

and we have two solar panels mounted on it. 00:03:10

Now, solar panels convert light directly into electricity. 00:03:13

So right now, these two panels are making enough electricity 00:03:18

to run these two little motors. 00:03:22

Now, right now, both motors are going about the same speed. 00:03:24

Now, notice that we have one panel in the northern half of the Earth, 00:03:27

the northern hemisphere, 00:03:31

and one panel in the southern half of the Earth, the southern hemisphere. 00:03:33

They're both receiving about the same amount of light. 00:03:36

But let's say it's summer here at Nye Laboratories 00:03:39

in the northern half of the Earth, the Northern Hemisphere. 00:03:43

That means that the Earth would be tipped toward the Sun 00:03:46

about like, look, the motor in the Southern Hemisphere 00:03:50

is just barely moving, and the motor 00:03:58

in the Northern Hemisphere is spinning like crazy. 00:04:00

Now let's say it's six months later, 00:04:02

and the Earth has gone around the Sun 00:04:04

so that its axis is tipped this way. 00:04:06

Now look, it's reversed. The one in the south is going wild, and the one in the north is 00:04:10

slowed way down. See, what that means is that this panel in the southern hemisphere is receiving 00:04:16

more light, more energy from the sun than the one in the northern hemisphere. It's just 00:04:24

like the Earth's seasons, right here with the Solar Panel Plastic Globe of Science. 00:04:28

Using a flashlight, you can see for yourself that direct rays are concentrated on a smaller 00:04:35

area than planted rays. This is why direct rays produce more heat. 00:04:39

Subido por:: Alicia M.
Licencia:: Reconocimiento - No comercial
Visualizaciones:: 199
Fecha:: 7 de marzo de 2021 - 18:21
Visibilidad:: Público
Centro:: IES LA SENDA
Duración:: 04′ 45″
Relación de aspecto:: 4:3 Hasta 2009 fue el estándar utilizado en la televisión PAL; muchas pantallas de ordenador y televisores usan este estándar, erróneamente llamado cuadrado, cuando en la realidad es rectangular o wide.
Resolución:: 480x360 píxeles
Tamaño:: 14.65 MBytes