Name: 雲はなぜ起きているのか？ (Why Do Clouds Stay Up?)
Uploaded: 2021-01-14T08:15:41.000Z
Duration: 6 min 29 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

People have been looking at clouds since people
have been… people. Those billowing shapes

might have been our first art or characters
in our first stories. We still love to pick

out shapes, like bears, fish, flying saucers,
faces, elephants. Some clouds even fly through

Which is weird because clouds are full of
so much water that they can easily weigh as

There's lots of different kinds of clouds,
but in the most general weathery terms, clouds

are big fluffy piles of water vapor that live
overhead. As warm, humid air rises through

the lower atmosphere, it expands, cools, and
some of it condenses into very tiny liquid

Just how that water vapor rises, though, depends
on the type of cloud. If the wind pushes it

up a mountain like it's on a ski jump, we
might get lenticular clouds. Humid jet engine

But maybe the easiest cloud to understand
is everyone's favorite fluffball: cumulus.

So how do you keep the weight of a hundred
elephants in the air? Buoyancy! Warm air is

less dense, so it rises, just like inside
of a lava lamp.

Cumulus clouds appear over dark pavement,
fires, sunny hillsides… any source of warm

updrafts. As the water vapor in that air is
carried up, it cools, so its molecules slow

down, and some of them stick together, forming
droplets that we can see.

We still have an unanswered question though:
After the wind carries them away from the

warm updraft, why don't clouds fall back
down?

Because of condensation! You know how when
sweat evaporates off your forehead, you feel

cooler? That's because water moving from
liquid to gas takes some heat with it. Condensation

So as the water in a cloud condenses, it heats
itself from the inside, staying aloft like

Da Vinci called them “bodies without surface”,
which is why we can't live on them. But

Lt. Col William Rankin did just that… accidentally
anyway. As he was piloting his fighter jet

over the top of a massive cumulonimbus cloud,
the engine caught on fire. He ejected and

fell from 47,000 feet straight into a 9 mile
tower of lightning, thunder, ice, and rain,

carried up on 70 mph updrafts and barely conscious.
He suffered from frostbite, bloodied from

the pressure change, bruised by hail, drowned
by rain. What should have been a ten minute

parachute ride down to the ground instead
took him 40 minutes.

He was definitely not on cloud nine. He was
in it.

In the 1896 edition of the International Cloud
Atlas, cumulonimbus, the world's tallest

and most powerful clouds, were placed at entry
#9.

Unlucky pilots aren't the only living things
inside clouds. Scientists found that living,

airborne bacteria make up as much as 20% of
cloud condensation nuclei.

Not only are they home to airborne ecosystems,
clouds are in some ways very much alive and

evolving themselves. Just take a few minutes
and stare up at a fluffy cumulus, as its edges

billow and die. The rain that falls from them
will one day rise again to become new clouds.

LIVE TO GFX
It might be because they're so alive that

their names sound like biological species.
Cirrocumulus stratiformis! Cumulonimbus capillatus

Actually those sound like Harry Potter spells.
Undulatus asperatus!

The greatest cloud photo of all time wasn't
taken looking up at the clouds, but looking

down on them. When Apollo 17 astronauts brought
this image back to Earth, it became the symbol

of a new environmental movement, demanding
a new appreciation of our fragile planet.

29% of its surface covered by land, 71% covered
in liquid water, but so many clouds. There's

a lot that scientists still don't know about
clouds but they are definitely important and

they look cool. Like Gavin Pretor-Pinney says,
they are nature's poetry writ large for

What's a sunset without the clouds? It's
just a disappearing circle. I mean, a plain

Clouds are what puts the “pale” in this
“Pale Blue Dot”. I like that.

I've got some homework for you this week.

Gavin Pretor-Pinney is the founder of the
CIoud Appreciation Society and author of this

book, The Cloudspotter's Guide. This book
will completely change the way you look at

the sky, I can't even sit by the window
on planes anymore, because it's too overwhelming.

Gavin wrote about a trick that I'm challenging
all of you to do: go outside and lie on your

back so you can look up and behind you at
the clouds. They become the landscape, and

the ground becomes the sky.
If you see anything cool, take a picture and

I only scratched the surface of the cloud
world today, but there's a link to this

book down in the description, it might be
the best book on clouds out there. I've

also included a link to the International
Cloud Atlas, so you can learn to identify

all those puffy white things in the sky, and
also a link to a video about Lt. Col William

Oh man, look at all these clouds, there's
a stratus cloud, there's a nimbus cloud, those

are great. And a Cumulonimbus, whoa watch
out for that one. You guys are totally putting

字幕リスト動画再生

雲はなぜ起きているのか？ (Why Do Clouds Stay Up?)

conscious

overwhelming

fragile

evolve