# JP5 AIR COMPRESSION AND EXPANSION

This eighth-grade science lesson is about the formation of clouds. It is the third lesson in a sequence of 19 lessons on weather. The lesson is 53 minutes in duration. There are 25 students in the class.

TimeCaption
00:00:00[ bell ]
00:00:01We will start.
00:00:02Stand up.
00:00:09Straight.
00:00:21Well today... since last class we have been studying water in the air, but do you remember?
00:00:30Starting with a review of last class, what is dew point?
00:00:36What is the dew point?
00:00:41Hey, hey, hey.
00:00:44[ BB: Water in the air. ]
00:00:54What is dew point?
00:00:58Mayumi-san.
00:01:00The temperature at which condensation takes place when the air was cooled.
00:01:03Yes, the temperature is called the dew point at which condensation takes place when the air was cooled. Today, relating to this, clouds which you can see all over the place.
00:01:14[ BB: How clouds are formed. ]
00:01:21We are going to study how clouds form.
00:01:25Where are clouds formed?
00:01:27Dirt.
00:01:28Dirt! Dirt makes clouds.
00:01:31Sea.
00:01:32Sea!
00:01:33Sky.
00:01:34Sky!
00:01:35Mountain.
00:01:36Mountain! Wait a minute.
00:01:37[ BB: Dirt. ]
00:01:38Water vapor.
00:01:39Dirt. What do you mean by that?
00:01:41(inaudible)
00:01:42What?
00:01:43It oozes from the bottom.
00:01:44It oozes from the bottom.
00:01:46Fog.
00:01:47Oh, fog. So, fog and clouds are the same.
00:01:49Wrong! Wrong!
00:01:50The same. The same. You they are the same things.
00:01:52Hmm. We will learn about how the fog is formed after we learn about clouds. When you learn it, you will understand whether fog and clouds are the same or not.
00:02:06What else did you say? Sea.
00:02:09What do you mean by sea?
00:02:13[ BB: Sea. ]
00:02:14Huh? Everything is oozing. From the sea, from the bottom. All you say is, "oozing."
00:02:19The sea means... who said, "sea"?
00:02:24Nobody said it?
00:02:27Someone said it. I will leave it here. What else?
00:02:33Mountains. Sky. Most of them are abstract. Sky. And what was it? Mountains. You listed these things.
00:02:37[ BB:Sky. Mountains. ]
00:02:46What do you mean by sea? What do you mean by clouds are formed from the sea?
00:02:51(inaudible)
00:02:53There is a lot of water-
00:02:55(inaudible)
00:02:56It evaporates and-
00:02:57Clouds are formed at the sea. Then, there must be clouds around here too, right? We can see them right now.
00:03:05Were those clouds formed at sea and floated here?
00:03:12Wrong? We don't know. Then how about the sky?
00:03:20Clouds are in the sky, right?
00:03:24Haven't you seen clouds actually forming?
00:03:27Haven't you seen? No?
00:03:31Today I want you to make clouds experimentally. Not outside, but in the lab.
00:03:42This... this is a tool to take out the air inside. This is a vacuum pump.
00:03:52And inside of this... you can take this out, like this. Inside of this, there is air just like the air around here.
00:04:03And in here, things like oil, Vaseline, was applied, so air won't get in from outside. And you let air out, so what happens to the air inside?
00:04:16Vacuum.
00:04:17Yes, if you say it in technical words, it forms a vacuum. It gets thinner.
00:04:21A state like this happens in nature too. Think about the sky. The upper air. What is the air like far up in the sky?
00:04:32Thin.
00:04:33Thin, right? It's thin. Compared to the air around here, the air in the sky is of course thinner. We produce that state in here. Do you understand what I mean?
00:04:47The air in this glass container becomes thinner. Naturally... I haven't explained this, but there is a balloon in here. This balloon is a little bit inflated.
00:04:59It's not broken. Can you see it? When the air around becomes thinner, what happens to this balloon? What do you think?
00:05:08It inflates
00:05:09Huh? It inflates?
00:05:10It shrinks.
00:05:11Shrinks?
00:05:15When the air inside of this glass container gets thinner, this balloon shrinks, stays as it is, inflates, breaks. Is that all you can think of? Which one do you think it is?
00:05:35Say something. Inflates? Shrinks?
00:05:41I will show you. It may take a little time.
00:05:44Watch carefully.
00:05:49That was a mistake.
00:05:51Now.
00:05:56I am now drawing air from this.
00:06:06Can people in the back see this? What is going on?
00:06:10It is inflating.
00:06:12Can you see that it is inflating?
00:06:18Can you see it inflated more than before?
00:06:20Tama, can you see it? You cannot see? If you cannot see, try to move. Did you see?
00:06:30It is inflating, right? If you wait a little longer, it gets even bigger.
00:06:40Now you can see it is inflating. Did everyone see? Did everyone confirm this? Susumu. You can see it, can't you?
00:06:50What does this mean?
00:06:53The air around this gets thinner means, uh, it gets thinner and this balloon gets inflated. I am going to turn this off and let the air come in.
00:07:05It shrinks, right?
00:07:07This was conducted in nature too, rather it is happening.
00:07:12In short, the air around here goes up. Then, as you saw with this balloon, it grows. In short, the air expands in volume. Can you understand the meaning of "expand in volume"?
00:07:29Huh? Expand in volume. Expand in volume. What does "expand in volume" mean?
00:07:35Grow.
00:07:36Yes, simply said, it grows. It is in a state in which volume increases. When it goes up.
00:07:42And then... when it expanded... I'm sure that you saw it from this, what will happen when it expands.
00:07:48I want you to create the state of this expansion with these one, two, three, four, four types of tools, these and these are the same, and these and these are the same.
00:08:03First, I will explain the procedure. This is a tool with which you can put more air in here. What is happening to the air inside now? I'm putting air in.
00:08:17Simply said, this is a pump. Same as the pump for a bicycle. With this I am pushing the air in. That means, what is happening to the air inside of this?
00:08:27It is increasing.
00:08:28It is increasing. That means... does this container itself expand?
00:08:34It expands a little bit, but when you keep adding the air, this container itself does not change, so what happens to the air inside?
00:08:47Why are you so quiet? What happens?
00:08:51Is it difficult?
00:08:53I'm putting in more air, right? Putting in air. I am putting in more air. That means, if I say it in non-technical words, the air is compressed. Opposite of expansion. Opposite of expansion.
00:09:08Do you understand? I am putting in more and more air. In short, the air is shrinking. I will do the opposite thing now. When I remove this cap, it expands after all.
00:09:27Do you understand? Mirai, do you understand? Don't be spacing out.
00:09:32Do you understand? Do you understand? Tell me whether you understand or not.
00:09:37I understand.
00:09:38You understand, right? When I put air in, it almost bursts. By removing this, the air is released. So this is the same state as when I took out the air with this, because the air expanded.
00:09:54Then what happens inside of this? You saw a little bit. This pattern is one. There are five of them. The other one is the same, but inside of this, candle, no, incense.
00:10:13You put the smoke of incense and do the same thing, then what will happen?
00:10:20You don't put anything to this one. Well, put a little bit of water to both of these. A little bit of water. A little bit.
00:10:27Then, you will do it like this, to this one, you put a little smoke and close it. Then you observe what happens to the inside of this. Okay? These two. And these two.
00:10:39With a round-bottom flask. And this. What is this? This? What is this?
00:10:52A measurement cylinder?
00:10:53Does it look like a measurement cylinder? It goes like this, you know?
00:10:56This cannot be a measurement cylinder no matter how you look at it.
00:11:00This is... a syringe, right? It is also called an enema syringe.
00:11:06It's true. This says a syringe. And below this with a small letters it says an enema syringe. Can you see? It is also called an enema syringe. You do enemas with this, you know?
00:11:19You use this. How do you use this? You put a little water in here, and close the cap. Pull out the piston. People in the back may not be able to see it, but I will do it by putting it down.
00:11:35I cannot pull it out and hold these with two hands.
00:11:36You pull this. What kind of state is this when I pull it?
00:11:42The air inside?
00:11:46When I pull it.
00:11:48It's expanding, isn't it? Do you understand? The volume increases, right?
00:11:52When I push it?
00:11:54Compress.
00:11:55Compress. At that time, what happens to inside of this? Do you understand what I mean?
00:12:01When I pull it like this, it is expanding. When I push it, the inside of this is compressed. Observe the appearance in these cases. Did you understand what I mean?
00:12:13And this. In the same manner, you put smoke of incense a little bit. And do the same. How is it different when you push the piston and when you pull the piston?
00:12:30Did you get the procedure?
00:12:32Who didn't get it?
00:12:36Okay, right? Then there are four patterns, so I will prepare them in the front. That group over there will use this. This group, use this. Group three, use this. Group four, use this.
00:12:47Then, rotate the tools so that everyone can actually use different tools.
00:12:57I would like you to do this for about 20 minutes, so take about five minutes per tool as a group. Should we make a big group? Group one and five. Two and six. Three and seven.
00:13:12Four and eight. Rotate tools among those groups.
00:13:19There is a handout for the record. So summarize things you noticed in this handout. Anything is okay.
00:13:33Give these to the people in the back.
00:13:43You know what you are doing, don't you?
00:13:46Huh? Wait a minute.
00:13:50Give these to the people in the back.
00:14:03Write your name and question number one. Where are clouds formed? And why do you think so? I just explained it to you, so you can predict the answer more or less.
00:14:20Think in your own words and summarize the location and the reason. Within two minutes. After two minutes, we will start the experiment.
00:14:54If you can't think of it, you can discuss it within your group.
00:15:03You don't have to look at the textbook. Write what you think is right.
00:15:09Write the reasons too.
00:15:19Water vapor gathers and-
00:15:22Gathers and-
00:15:23What should //happen?
00:15:25//Happen?
00:15:38You just write what you think.
00:15:41(inaudible)
00:16:02I said you don't have to look at the textbook.
00:16:11Evaporate. Because it evaporates.
00:16:21Can we start now?
00:16:42You are copying mine. You are copying.
00:16:45Can we start now?
00:16:53Two minutes has passed, are we ready? Can we start the experiment?
00:17:00Then people in the front, start the preparation.
00:17:07I prepared the matches for the group who uses incense, so you can light the incense now.
00:17:11You don't need to extinguish it. Since you don't need to put it out, leave it burning.
00:17:20What are you doing?
00:17:22It won't (inaudible).
00:17:29The groups in the back, please do the experiment together with the groups in the front when it's ready.
00:17:40You don't need to light three incenses. One is enough. You should light one incense. Just one for now.
00:17:45Teacher, can I break it?
00:17:46You don't need to break it. Use as it is.
00:17:47Teacher.
00:17:48That's too much. Too much. It should be enough to wet it.
00:17:54The water in the bottle... don't put so much. Don't put it like this. It should be just enough to wet it.
00:18:04This is too much. You wet it once and discard all the rest. The water remaining on the surface of the bottle is enough. This is fine. Don't put so much (that it remains in the bottom.)
00:18:27Ohh!
00:18:29Wow!
00:18:31It broke!
00:18:32Wow!
00:18:34I thought you would do it.
00:18:38Teacher, I didn't do it.
00:18:39I know, I know. It's fine.
00:18:43Listen up! Hey, listen up!
00:18:49This syringe... how did you do before it exploded? Did you press too much? Did you press too hard?
00:18:57I didn't press it.
00:18:58How did you do it?
00:18:59I pressed it normally.
00:19:00You pressed it normally. This one... doesn't have a stopper, so if you press it too much, it breaks. Like this.
00:19:11So if you don't stop at a certain point, it will be like this.
00:19:17Don't do things like this.
00:19:18Teacher.
00:19:19This group, you work with one.
00:19:21Ahh.
00:19:27I think it wasn't unnecessary to put water in. Make sure that this part is not bent.
00:19:37Didn't you put anything inside?
00:19:39We didn't.
00:19:40We didn't.
00:19:41Teacher, can we do both of them?
00:19:42Fine. Both, both. You do the same experiments with that.
00:19:56How is it? How is it? Make sure that it is not bent.
00:20:02Watch the inside when you press and when you pull.
00:20:06Wow! Is this a cloud?
00:20:07When you pull-
00:20:12What happens when you pull?
00:20:13It becomes white.
00:20:15How does it change?
00:20:20When you pull, the air expands, right? What happens at that time?
00:20:25It is formed.
00:20:27What is formed?
00:20:28Clouds.
00:20:30Clouds. I see. Clouds are formed. When you press it? This is smoke.
00:20:35It disappears.
00:20:36Is this smoke from the incense?
00:20:37See teacher? It happens only to one.
00:20:39Why? Both are fine.
00:20:41Like this, right? This is smoke. This is smoke from the incense. Why does it disappear when I press it?
00:20:50That's (inaudible). Hold it. Don't break it. Don't break it. Don't break it.
00:20:57Yes. It's fine that there is no change.
00:21:02Yes. That's it.
00:21:03Isn't it?
00:21:04Write down that there was no change.
00:21:07How did it turn out to be?
00:21:08Yes, no change.
00:21:12This is smoke from incense, right?
00:21:14That's how it turned out? Take this out.
00:21:19You put too much smoke.
00:21:25You need only a small amount of smoke.
00:21:33Try it with this.
00:21:43We put a ridiculous amount before.
00:21:53Hey, you watch this. You watch this.
00:21:55Teacher, do we have to move?
00:21:57This? Smoke of incense.
00:22:00No! We got rid of the smoke of incense, didn't we?
00:22:11Hey watch this carefully. It's not white right now, isn't it? See?
00:22:16Is it supposed to become white?
00:22:18Huh?
00:22:30See?
00:22:31It became white, right? Is this smoke from the incense?
00:22:34No.
00:22:35No, no, no.
00:22:36Think hard.
00:22:38Then you move.
00:22:41Change.
00:22:44Move to a different table. Group one, come here.
00:22:50You put too much water in. You can get rid of all the water.
00:22:54How boring.
00:22:55The group over there, come here. Move to another table.
00:23:02This one is without incense and you just press it. Try it.
00:23:19You watch the change. Did you put the smoke of incense? You have to. This is the one to which you are supposed to put smoke.
00:23:27This one is heavy.
00:23:31Should I put this in it?
00:23:33Yes, yes, yes. All you have to do is to put it in a little bit. Try to put the smoke in a little bit.
00:23:41I'm scared.
00:23:42That's fine.
00:23:49This part is bent.
00:23:57What are you doing by pulling it off?
00:24:01Do it like this. Watch the inside.
00:24:05Can you see?
00:24:06Ohh, I see.
00:24:09Try it.
00:24:10I see.
00:24:11I see why it broke the last time. Because after it was pulled off-
00:24:18This part is bent.
00:24:19When it inhales the smoke-
00:24:20Oh, the color changes.
00:24:21Do you understand? What happens when you pull it? Do it slower. Do it slower.
00:24:24The smoke-
00:24:25Disappears.
00:24:26Smoke? Huh? When you pull it. When you pull it.
00:24:29This. This white one. What is it?
00:24:33Water vapor.
00:24:34Water vapor? You understand that this is not smoke, right?
00:24:39Try to press it.
00:24:41If this were the smoke of incense, when you pull it, it becomes white, but if this were the smoke of incense, when you press it, it should not disappear.
00:24:49So you understand that this is not the smoke of incense. Then what is it?
00:24:53[ tool breaks ]
00:24:54Waa!
00:24:55Waa! Again! Hold it, hold it.
00:25:00Don't put (inaudible).
00:25:02I put (inaudible).
00:25:05Let me do it. Is this the smoke of incense?
00:25:08Teacher, is it okay if the amount of smoke is very little?
00:25:10Yes, it's fine. Is this the smoke of incense by any chance? Smoke?
00:25:13Yes, it's smoke.
00:25:14This is too much.
00:25:15It's the smoke of incense.
00:25:16Too much smoke.
00:25:17Well but-
00:25:23Teacher, this-
00:25:26Is this smoke of incense?
00:25:27Smoke.
00:25:28All of it?
00:25:30Huh? How much smoke was there in the beginning?
00:25:33This much? Well then, you can understand that this is not smoke.
00:25:40This is-
00:25:41Clouds.
00:25:42Clouds.
00:25:43Clouds.
00:25:50I will do it. Watch it. This is not white right now, right?
00:25:56It became white.
00:25:57Wow!
00:25:58It became white when the air got in.
00:26:00It became white when the air got in. What does it mean that the air got in?
00:26:06This is not the case the air got in. Since it was full-
00:26:09The air went out.
00:26:10Yes, the air went out.
00:26:11Went out.
00:26:12It became white when the air went out. What does it mean?
00:26:14I don't know.
00:26:17It is bursting with air.
00:26:19Did you try it?
00:26:20We did.
00:26:21What happened?
00:26:23(inaudible).
00:26:29The air getting in means?
00:26:31What does that mean that the air gets in? That's the point. Okay everyone? Change the table. Move the table. This group, go over there. Move to the next table. Move to the next table.
00:26:50No, move to the next table. This group, go all the way there. I told you to move to the side. You moved in the reverse direction. Oh well.
00:27:06Move to the table where you didn't do the experiment yet.
00:27:10If you moved in the right direction, everything should've been fine.
00:27:13You put too much water in. You can pour off all the water. Okay. Do it now.
00:27:23Didn't you do it with this before? Move to another table.
00:27:31(inaudible)
00:27:43This one too? This one, too?
00:27:45Susumu. Put the burnt matches and things.
00:27:55Okay, that's enough.
00:27:57All you have to do is it put in a little. Okay, okay.
00:28:03Okay. Okay.
00:28:20That's too much.
00:28:22That's what I thought.
00:28:23You can get rid of it. All you have to do is to put in a little bit. It is even stuck at the bottom.
00:28:31(inaudible )
00:28:39Let's put some water in.
00:28:47Wow, this stinks.
00:28:51It's hard.
00:28:53I put a little bit in.
00:28:55No, no. (inaudible)
00:29:07Get rid of the water and try to put the smoke inside of it again.
00:29:11Do you see the change?
00:29:14What happens when you pull it out?
00:29:16It becomes white when I pull it.
00:29:18When you push it?
00:29:19It becomes clear.
00:29:20It's clear, right? What is this white?
00:29:23If you do it like that, it will break again.
00:29:26This is?
00:29:27Water vapor.
00:29:28Water vapor. So what is this?
00:29:29Clouds. (inaudible). You put in too much.
00:29:36When I do this, it expands.
00:29:40Yes, yes, yes, yes.
00:29:41When I do this it compresses.
00:29:43Yes. So in short, when it expands, the clouds are formed, right? When you push it and compress it, the clouds disappear. You see that change, right?
00:29:55What happens when you pull it.
00:29:58It becomes white.
00:29:59It becomes white, right?
00:30:00What happens to the air itself when you pull it.
00:30:06Compressed.
00:30:07When you pull it?
00:30:08Wrong.
00:30:09When you pull it. What happens when you pull it?
00:30:11It expands.
00:30:13It expands. When you press it, it shrinks. It's okay as long as you understand that (the clouds) are formed at that time.
00:30:21Did the group over there do it? Next experiment will be the last one. This is the last change.
00:30:30Wow!
00:30:34Clouds.
00:30:37Takao, that's too much.
00:30:42Yes, it becomes white. Sometimes. I think this one will.
00:30:50Then the last change. This will be the last one. Change.
00:30:57Now nobody should be doing the same experiment.
00:31:01This is the last one.
00:31:11Last one, last one.
00:31:14You put too much smoke in. That's enough. That's enough. All you have to do is put in only a little bit.
00:31:25That's how they broke it.
00:31:27Okay, okay.
00:31:31You can leave it here. Here. And hold it here so that this won't bend.
00:31:39How is it? When you pull it-
00:31:41Ohh! It becomes white.
00:31:43When it is compressed.
00:31:44When it is compressed.
00:31:46When it expands, it becomes white and when it is compressed, it goes back to the original state.
00:31:51Great!
00:31:52We can make clouds.
00:31:53Do you get it? Do you understand that the smoke from the incense does not make it white, Takao?
00:32:00Teacher, why does it become like this when you put incense in?
00:32:02Why is that?
00:32:03Why is that?
00:32:04That's the problem!
00:32:05Why is that?
00:32:08Because it gets hot.
00:32:09Because it gets hot. That's the problem. Why when you put incense-
00:32:15Because it is smoke.
00:32:16Because it is smoke?
00:32:17Why don't you tell us the answer?
00:32:18That's no good. I'll tell you later.
00:32:21Why is it?
00:32:22I won't do it. I'm scared. But I still want to do it.
00:32:31Did you try?
00:32:38Didn't you (inaudible)?
00:32:40No.
00:32:41Oh, you will do it from now.
00:32:54Did you do it?
00:33:04Don't put in too much.
00:33:09Oh! You scared me.
00:33:12Smoke came out.
00:33:45It got wet?
00:34:41Is it enough?
00:34:52Not yet!
00:35:18Ohh!
00:35:46Are you done? Then go back to your seat.
00:35:54Vapor and water.
00:35:59Vapor is from water.
00:36:00Yes.
00:36:02Vapor and air-
00:36:03Then go back to your own seat.
00:36:24Susumu, can you see the blackboard?
00:36:28Okay.
00:36:32Put all the experiment tools in there.
00:36:37You did four types of experiments. I want you to present what you have noticed. First. Number one. In the case when you used a syringe and there was smoke inside.
00:36:53What happened in this case?
00:36:57It became white.
00:36:58Huh? It became white? When did it become white?
00:37:01When you pull it.
00:37:05You pull it. Then it becomes white. And when you press it-
00:37:11It didn't change.
00:37:12Smo- It didn't change?
00:37:13It disappears.
00:37:15Smoke... The thing, which became white, disappeared, right?
00:37:19Did you all have the same result?
00:37:21You confirmed that, right?
00:37:26You cannot see it if I write with too little letters.
00:37:30[ BB: Piston pulled. Piston pushed. ]
00:37:37And piston. P-i-s-t-o-n. Pull and push-
00:37:47Uh, when you pull the piston, it becomes white and when you push the piston, the white thing disappeared.
00:37:55What will happen to the air when you pull.
00:37:57It expands.
00:37:58It expands, right?
00:38:03Expand... expand... expand... expand... how do you write expand in Chinese characters?
00:38:13With the moon radical... Oh, I see. It was written there.
00:38:16[ BB: It expands. ]
00:38:19Dot, dot, dot and another character.
00:38:25What does pressing the piston mean?
00:38:28Compress.
00:38:29Compress. Compress, compress.
00:38:36Like this?
00:38:40Compress-
00:38:42[ BB: It compresses. ]
00:38:44Compress... Uh? I feel something is wrong. Expands and compress? "Contracts" is better? Well, it has become too difficult, so it's okay. Do you understand what to contract means?
00:38:53You don't understand, right? You can understand this better? Then, this is fine.
00:38:58At that time... it becomes white.
00:39:06Uh-
00:39:07[ BB: Pull piston - expands - becomes white ]
00:39:10[ BB: Push piston - compress - white thing disappears ]
00:39:14Well then... Number one, number one point two, when you use a syringe and there is no smoke, what happens?
00:39:21No change.
00:39:22Huh?
00:39:23No change.
00:39:24Was there no change? It did not become white?
00:39:28It didn't.
00:39:29It didn't. In either case... whether you pull the piston-
00:39:41[ BB: Whether you pull the piston or push the piston, there is no change. ]
00:39:53Then... did anyone have a different result? Did everyone have the same results? Everyone's got the same results, right?
00:40:01Then the second type, number one. Pump-type tool. Over there and there. When there is smoke inside.
00:40:10(inaudible)
00:40:11Yes, when you remove the cap-
00:40:13It got white.
00:40:14It got white.
00:40:17Remove the cap.
00:40:25Remove-
00:40:29Removing the cap will cause what to the air?
00:40:35In the same way as this?
00:40:36Expands.
00:40:37Expand, right? When it expands... it got white.
00:40:44[ BB: Remove the cap - the air expands - it becomes white. ]
00:40:57Is this clear?
00:40:59When you are pressing the air in, did the white thing appear or not?
00:41:03It didn't appear.
00:41:04It didn't appear, right? When we are putting more and more air in, the white thing didn't appear.
00:41:08Then type two, number two. Using the pump and there is no smoke in it... what happened to this when you remove the cap?
00:41:21No change.
00:41:22You didn't see any change?
00:41:29In short, this is expansion, too, but-
00:41:43No one has seen the change?
00:41:45Which one?
00:41:49Hmm. Perhaps you are thinking that because this one did not have any changes, this one won't have any change either, but you must have seen a change.
00:42:00A little bit.
00:42:01A little bit. Yes. It changed to white a little bit.
00:42:11So from four experiments, we found out these things, right?
00:42:17When we look at all four of these experiments, can we say that it becomes white when there is smoke or it becomes white when there is no smoke? It's obvious.
00:42:26When there is smoke-
00:42:27When there is smoke, it becomes white. I'm sure that you have noticed already, but this white thing is-
00:42:33A cloud.
00:42:34A cloud. This is a cloud. This white thing. Becoming white, becoming white. These things are actually clouds which were generated in a flask or a plastic bottle.
00:42:50Formation of clouds is, simply said, based on this principle.
00:42:54By expansion of air, the clouds are formed, simply said. Then in nature, how do you think this is done?
00:43:09Before, in the beginning I showed you this experiment. The state of a vacuum. When the air gets thinner, it expands. In the upper atmosphere, compared to the air around here, the air is?
00:43:22//Thinner.
00:43:24Then what happens in nature, what happens to the air around here?
00:43:32It is carried up.
00:43:33It is carried up. First it goes high up in the sky. It goes high up in the sky and?
00:43:41It expands.
00:43:42The air expands. At that time, the clouds are formed.
00:43:46Actually, when expansion of the air, compression of the air, uh... contraction of the air, shrinking of the air happens, the temperature changes. The temperature. What kind of change?
00:44:04It has a lot to do with the dew point which we studied in the last lesson. I will confirm with you one more time what the dew point was. What was it?
00:44:13When you cool the air, condensation, simply said water, is formed. That time, no, that temperature is called dew point, right? That has a lot to do with this.
00:44:26To become white... what is this white substance? You are saying during the experiment, but this is water vapor.
00:44:35In short, when the air expands,
00:44:41The air-
00:44:46Expands-
00:44:48[ BB: The air expands ]
00:44:55Then what happens to the temperature?
00:45:06What happens to the temperature?
00:45:08What can you predict?
00:45:11It increases, it decreases, it stays the same.
00:45:14It decreases.
00:45:15It decreases. Can you understand that?
00:45:19In today's experiment, we didn't change anything in terms of the temperature. So what we found from this experiment is that when it expands, it becomes white.
00:45:30Actually, when the air expands, the temperature decreases.
00:45:37[ BB: The air expands - the temperature decreases. ]
00:45:41The character for "decrease" cannot be this.
00:45:47When the air expands, the temperature decreases.
00:45:50Then... when you put more air in, when you compress the air, the temperature?
00:45:56Rises.
00:45:57Rises. Haven't you experienced that? With a bicycle pump, you put the air in... You have probably never touched the pump. Have you? No? You haven't, right?
00:46:15When you put the air in, if you touch the bottom part, it is warm. That is because the air is compressed and the temperature goes up.
00:46:28Conversely, this is... let me write it here-
00:46:36I feel that the expression "compression" is somewhat inappropriate-
00:46:40In the case of compression, the temperature goes up.
00:46:44[ BB: Compression - the temperature goes up. ]
00:46:47We don't have enough time.
00:46:49In conclusion, when the air around here goes up, it expands, right? Then, when it expands, the temperature goes down.
00:46:57When the temperature goes down, it reaches the dew point which we learned about in the last lesson.
00:47:06It reaches to the state in which it cannot stay as water vapor in the air anymore, it reaches to the state in which it cannot exist as water vapor anymore, then it condenses and becomes clouds which we can see with our eyes.
00:47:18In our experiment, it became white, but you can probably not tell there was a change in the temperature. But this change is happening. The dew point.
00:47:51The clouds are formed. Okay? Did you understand how the clouds are formed? Somehow?
00:47:59Then, the question. Why do we see the differences in formation whether there is smoke or not. Why did we put the smoke in it?
00:48:13The clouds, no the smoke... the clouds are easy to be formed when there is smoke. Then, when you think about this normal air, what is that that works as the smoke?
00:48:26What's in the air? What's in the air?
00:48:31Dust.
00:48:32The water vapor becomes clouds.
00:48:38[ bell ]
00:48:39The bell is ringing.
00:48:41Actually, there are lots of things in the air, such as dust.
00:48:48In technical terms, we call this the nucleus. Nucleus. Do you understand? In the chapter of the atom, I explained a little bit about the nucleus.
00:49:00It has the same function. So as a result, water vapor attaches to these particles and forms drops of water which are visible. Do you understand?
00:49:11We will continue from here.
00:49:15We don't have time to summarize the handout, but write quickly at the section, "Self Evaluation."
00:49:25Teacher, don't we have to write (inaudible)?
00:49:27You can summarize in the next class.
00:49:46Right. Bring the handout in the next class. Keep it. Put it in your notebook.
00:49:55(inaudible)?
00:49:57This? This is not written there. Fine.