In this episode of Spark Science, we discuss what physicists mean when we say “Energy”. Our guest is a physics professor and Associate Dean of the College of Science and Engineering at Western Washington University, Dr. Brad Johnson. We talk about changing the dialogue of “Global Warming” and thinking about stored energy in the atmosphere.
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>> Here we go.
[♪ Blackalicious rapping Chemical Calisthenics ♪]
♪ Neutron, proton, mass defect, lyrical oxidation, yo irrelevant
♪ Mass spectrograph, pure electron volt, atomic energy erupting
♪ As I get all open on betatron, gamma rays thermo cracking
♪ Cyclotron and any and every mic
♪ You’re on trans iridium, if you’re always uranium
♪ Molecules, spontaneous combustion, pow
♪ Law of de-fi-nite pro-por-tion, gain-ing weight
♪ I’m every element around
♪ Lead, gold, tin, iron, platinum, zinc, when I rap you think
♪ Iodine nitrate activate
♪ Red geranium, the only difference is I transmit sound
♪ Balance was unbalanced then you add a little talent in
♪ Careful, careful with those ingredients
♪ They could explode and blow up if you drop them
♪ And they hit the ground
>> Dr. Regina Barber DeGraaff: Welcome to Spark Science where we explore stories of human curiosity. I’m Reginal Barber DeGraaff. I teach physics at Western Washington University. And I’m here with my cohost, good friend, other Lyndonite, Jordan Baker. How’s it going?
>> Jordan Baker: I’m doing well. I’m sitting in a chair!
>> Regina Barber DeGraaff: Yeah. Good. Well, that’s good. That’s good for our listeners because this isn’t video.
>> Jordan Baker: Right.
>> Regina Barber DeGraaff: Before we get started, I just wanted to ask you, how’s the Upfront doing?
>> Jordan Baker: The Upfront’s doing awesome, not that it’s relevant when this comes up, but we’re doing an improv — improvised musical right now.
>> Regina Barber DeGraaff: Do you sing?
>> Jordan Baker: I do — I can sing. And I am in it sometimes.
>> Regina Barber DeGraaff: If I want to.
>> Jordan Baker: But that’s just a thing that’s going on right now. Check it out. Come by and see it. You should come see it too.
>> Regina Barber DeGraaff: I know. Still — so, for the listeners that have listened to our third show where I say I haven’t seen Jordan do his improv, I still haven’t. Maybe if we get more listeners, I will. Maybe it’ll be like — it’ll be like clapping for Tinker Bell. More listeners, I’ll actually go.
>> Jordan Baker: OK.
>> Regina Barber DeGraaff: OK. All right. Well, today this is kind of a continuation of our episodes in the past. We’ve talked about history of electricity and now, I think when people think of electricity, they think of the word “energy.” Do you?
>> Jordan Baker: Eh. I think — when I think of the word “energy” I think about like energy drinks and stuff. And electricity could go through the body.
>> Regina Barber DeGraaff: While you’re drinking the energy drink?
>> Jordan Baker: Well, I’m just — energy.
>> Regina Barber DeGraaff: Like electrolytes, it’s what plants crave?
>> Jordan Baker: Yeah.
>> Regina Barber DeGraaff: Well, OK. We’ll come back to that. So — but I want to introduce our guest. He is a professor at Western Washington University. I met him when I was very young, older than when I met Jordan. He was my professor for quantum mechanics at Western Washington University. He is still very young, though [laughing].
>> Jordan Baker: I don’t see any gray hairs.
>> Brad Johnson: Good thing this is radio.
>> Regina Barber DeGraaff: Yeah.
>> Jordan Baker: Yeah [laughing].
>> Regina Barber DeGraaff: Is I want to welcome Dr. Brad Johnson to our show. How’s it going?
>> Brad Johnson: I’m doing great. Thanks, Regina.
>> Regina Barber DeGraaff: Have we made you feel somewhat comfortable with our awkward comments?
>> Brad Johnson: I feel completely relaxed.
>> Regina Barber DeGraaff: OK. Good.
>> Jordan Baker: Excellent.
>> Regina Barber DeGraaff: Good. This is how — it’s a good place to start.
>> Jordan Baker: Your toes are beginning to relax.
>> Regina Barber DeGraaff: Yeah. Breathe.
>> Jordan Baker: Breathe in. Breathe through it.
>> Regina Barber DeGraaff: So Brad has — he’s told me in the past that he’s done these kind of outreach town hall kind of meetings about energy and what does the public think when they think “energy” versus what do scientists think. How has that gone for you in the past?
>> Brad Johnson: Well, it’s been a really long story actually. It was one of the ways that I started doing outreach a long time ago. It got started mostly — one time I was driving in my very old, beat up white pickup truck, which only had an AM radio. And, on that AM radio, was Paul Harvey. You guys are too young to know who that is.
>> Jordan Baker: Oh, I know Paul Harvey.
>> Regina Barber DeGraaff: I don’t.
>> Brad Johnson: So I was listening to Paul Harvey and he was doing one of his “rest of the stories” and the rest of the story part is irrelevant. He had a little piece going, though, on the side where he was saying to his listeners, “You know, I was just out this morning playing golf here in Chicago in December in my short sleeves and it was 71 degrees, but I don’t want anyone to worry about global warming because I also know, at the same time, in some place in Eastern Europe — I don’t remember where it was exactly — it was 30 degrees below zero. So, therefore, everything’s OK.”
And it got me thinking about that whole notion of what people think about with that. I started a sort of personal crusade to go out and talk to people about sort of what does it mean when you talk about temperature and the climate and to try and get the emphasis away from the word “global warming” and away from talking about temperature in general, and trying to talk about what’s really going on, and that is the atmospheric energy content and the ocean energy content. Those are the things that really do matter when you’re talking about the drivers of the climate.
And, in fact, the point that I was trying to make in my head when I was listening to Paul Harvey is that, “Gee, you know, those fluctuations that he’s talking about, the larger fluctuations than we’re used to, are exactly the hallmark of having more energy in the atmosphere system than we used to have.” What I realized early on is that people don’t know what you mean quantitatively when you use the word “energy.” And that came up beautifully just a minute ago when you said that energy drink.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: I think that’s part of what I would like to talk about tonight then.
>> Regina Barber DeGraaff: Where do you start then? So you’re in a town hall and like let’s start talking energy. For the general public, where would you start then?
>> Brad Johnson: Well, with this discussion, where I typically start is, “OK. So, you’ve all heard about the temperature and the temperature of the atmosphere and you think about temperature a lot, but temperature is only one place, one way in which we express one of the quantitative features that we call energy.” So I like to go back and start with mechanical because what we call thermal energy is really hard to understand and I hope, as the evening goes on, we can actually get into the nitty gritty of that a little bit. But we like to start with something that’s sort of more or less every day.
And so the way I like to start this is to talk about forces and energy and how they connect together. So forces everyone’s familiar with. You’re walking down the street and someone bangs into you. Or someone throws —
>> Regina Barber DeGraaff: What streets are these? Like Bellingham?
>> Jordan Baker: Yeah.
>> Brad Johnson: Yeah. You know, the crowded streets of Bellingham that you can hardly get through.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: Or a car will hit you or a taxi cab will run you over.
>> Regina Barber DeGraaff: Right.
>> Jordan Baker: Wow.
>> Brad Johnson: Or you’ll get hit by a train. Any of these occur to you and, of course, while this is occurring, you’re thinking about the force, the fact that you were going one way with a particular speed and now you’re going in a different direction with a different speed.
>> Jordan Baker: That’s exactly what I’m thinking about as I’m flying through the air.
>> Brad Johnson: That’s good. That’s good. That’s what you should be thinking about.
>> Regina Barber DeGraaff: And for those who don’t live in Bellingham, Bellingham is very quiet. This is sarcasm.
>> Jordan Baker: Don’t have to worry about getting hit by a cab.
>> Regina Barber DeGraaff: No, you do not. If you see the cab. All right, continue, Brad. Sorry.
>> Brad Johnson: No worries. No worries.
>> Regina Barber DeGraaff: We had one person play this in Germany.
>> Brad Johnson: Wow. That’s amazing.
>> Regina Barber DeGraaff: It is impressive, right?
>> Brad Johnson: I feel nervous now.
[ Laughter ]
Anyway, the point I’m trying to make here is that we can try to get across some of a gut feeling for people what we mean when we use the word “energy.” But let me start here.
First of all, we want to start quantifying some of these words like “force.” So, if you think about going to McDonalds and you buy a quarter pounder, right? When’s the last time you bought a quarter pounder?
>> Jordan Baker: Like 10 years ago.
>> Regina Barber DeGraaff: Really?
>> Brad Johnson: Well you still have the sensation of holding it in your hand in your mind?
>> Jordan Baker: Sure. Yeah. Let’s just say we do.
>> Brad Johnson: Let’s just say, “Yeah.”
>> Regina Barber DeGraaff: Jake would be so disappointed in you. For him it’s been like a month.
>> Brad Johnson: Yeah. OK. So we can ask Jake. But you have the sensation of the quarter pounder in your hand. Well, the weight of that thing here near the surface of the Earth is about one Newton. That’s one of the units we use. And the reason I’m going to use that unit is because one of the units we use for power, which everyone knows, is a watt. When you go and you screw in a 25-watt light bulb, I’d like to give you kind of a gut level feeling for what we’re talking about there.
So if you take your quarter pounder — could be a quarter pounder with cheese — and you hold that thing in your hand and you lift it through the distance straight up, through a distance of one meter. So now you got to think, “OK. I got to think of a meter,” so everyone put their hands out. Right?
>> Jordan Baker: Roughly.
>> Brad Johnson: Yeah. You got to think of a meter stick.
>> Regina Barber DeGraaff: It’s kind of a yard stick.
>> Jordan Baker: It’s a little bit longer than a yard stick. Yeah.
>> Brad Johnson: So you take that you and turn it straight up. OK?
>> Jordan Baker: Got it.
>> Regina Barber DeGraaff: He’s moving his hands a lot, listeners.
>> Brad Johnson: Yeah. And you lift that quarter pounder up that distance, OK? You’ve just done mechanical work and you’ve done the equivalent mechanical work of one joule. OK, not I’m just adding words to that, but the point is you’ve done mechanical work of one joule. Now let’s do the experiment again. Let’s lift the quarter pounder through the distance of one meter straight up and we’ll do it in one second. So one hippopotamus. Right?
>> Regina Barber DeGraaff: Wow. Jordan just did it.
>> Brad Johnson: Jordan just did it.
>> Jordan Baker: There. There.
>> Brad Johnson: OK. So now you’ve just — that was one joule done in one second, which is one watt. So every time you think of one watt, it’s lifting the quarter pounder straight up through one meter in one second. Feel that in your mind. You got to feel that in your tummy. Get that warm feeling going in your tummy.
>> Regina Barber DeGraaff: You work your abs.
>> Jordan Baker: Wow.
>> Brad Johnson: Yeah. You could work your abs to get that warm feeling in your tummy, one watt. I got one watt. So if you think about a 25 watt light bulb — I guess that’s not much of a light bulb — a 75 watt light bulb.
[ Laughter ]
OK?
>> Jordan Baker: It’s you lifting the quarter pounder 75 times?
>> Brad Johnson: Seventy-five quarter pounders.
>> Regina Barber DeGraaff: Wow.
>> Brad Johnson: Right? Through one meter in one second. So that’s how it feels.
[ Laughter ]
>> Jordan Baker: To do the demonstration, you have to get 75 quarter pounders.
>> Regina Barber DeGraaff: Oh, and hand them out to my class? There’s only 38 of us. Oh.
>> Jordan Baker: Oh, no. Some people get two.
>> Regina Barber DeGraaff: Yeah.
[ Laughter ]
>> Brad Johnson: Well you can have a dimmer bulb. Just go with a dimmer bulb.
>> Regina Barber DeGraaff: That’s true.
>> Brad Johnson: Go with the fluorescent bulbs. Those are, you know — the 25-watt fluorescent bulb.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: Now you’re talking.
>> Regina Barber DeGraaff: Right. I would save money. Good idea.
>> Brad Johnson: Save money. Save energy.
>> Regina Barber DeGraaff: Save energy and save money at McDonalds.
>> Brad Johnson: Yes.
>> Regina Barber DeGraaff: Continue.
>> Brad Johnson: So what I’m getting at here is that we’ve used a unit that we hear a lot, but what that unit is is the amount of energy per unit time. So we use the word “energy.” And the energy came in with that word joule. That was the word done to pick up that quarter pounder through one meter. That’s the energy quantitatively speaking.
>> Regina Barber DeGraaff: So just to be clear, though, when you say, “The work done,” that’s another physics term.
>> Brad Johnson: Work is another quantitative word. It’s that force of one Newton times that distance of one meter.
>> Regina Barber DeGraaff: Right. But really we’re talking about the energy it took to do that.
>> Brad Johnson: Yes.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: Because you all know — here’s the second part of this.
>> Regina Barber DeGraaff: You all know.
>> Jordan Baker: Yeah [laughing].
>> Regina Barber DeGraaff: Be careful now. You all know.
>> Brad Johnson: You all know that once you’ve lifted that thing through the one meter and it’s up here and you let go of it, what happens?
>> Jordan Baker: It falls down!
>> Brad Johnson: It’s back! You get back all of that work you just did. And that’s one of the reasons why energy is so fun to talk about. I know you’re having fun.
[♪ Janelle Monae singing Wondaland ♪]
♪ Take me back to Wondaland
♪ I gotta get back to Wondaland
♪ Take me back to Wondaland
♪ She thinks she left her underpants
♪ Take me back to Wondaland
>> Regina Barber DeGraaff: If you’re just joining us, this is Spark Science. I’m Regina Barber DeGraaff.
>> Jordan Baker: And I’m Jordan Baker. Today we’re joined by Dr. Brad Johnson, Western Physics Professor.
♪ The grass grows inside
♪ The music floats you gently on your toes
♪ Touch the nose, he’ll change your clothes to tuxedos
♪ Don’t freak and hide
>> Brad Johnson: Energy is really fun to talk about because energy is conserved — which is another fun word — which is the reason why we have this quantitative business around energy. Because it’s a very important thing that every time you do something, you do some mechanical work or you have these — when we get there — we talk about these thermal processes. Every time we do these things, the total energy is conserved. It stays the same.
>> Regina Barber DeGraaff: You don’t lose it — now, let’s be careful. When we say “conserved” you don’t lose it, you don’t — there isn’t more energy suddenly coming out.
>> Brad Johnson: Right. And there are several ways we can talk about that. One of the ways is you can visualize a bathtub. Right? And a bucket. And the bath tub’s full of water. And if you imagine metaphorically that that water is some substance that we call energy, it’s some mechanical energy —
>> Regina Barber DeGraaff: It’s sparkly see-through water.
>> Jordan Baker: I was going to say Kool-Aid.
>> Brad Johnson: You do a process and you dip some of the water out of that bath tub and you pour it into the bucket. And you say, “Where’s he going with this?” Well, now imagine a pendulum, right, everyone knows what a pendulum is. You tie something heavy to a string and you let it dangle straight down and then you pull it to the side and you let it go. So you visualize in your mind going back and forth and back and forth.
So it’s going really fast at the bottom and then it stops at the top. So what you can picture that are two different kinds of energy. One is what we call the energy of motion. And we use a fun word called “kinetic,” the energy of motion.
>> Regina Barber DeGraaff: Will the game system.
>> Brad Johnson: Like the game system. Kind of. And you have this potential energy, which you can illustrate very easily. All you need to do is pick up a very heavy book and hold it over the head of your sibling or your Jake or whoever you got.
>> Regina Barber DeGraaff: Or your students in 161, which is what you do.
>> Brad Johnson: Right. Yes. That’s what I do. You pick up the heaviest book you can find, which typically in the room is the physics book, and you hold it over someone’s head. You don’t say anything. You don’t do anything. You just simply hold that book over their head. And you watch them. What do they do? What do you think they do, Jordan? What would you do?
>> Jordan Baker: I would just stare up at it, but I can imagine people like kind of squirming and like trying to back away from whatever the impending doom would be.
>> Brad Johnson: Yeah. And why do you think they do that?
>> Jordan Baker: Because they’re scaredy-cats.
>> Brad Johnson: What are they scared of?
>> Jordan Baker: Joules hitting them in the head.
>> Brad Johnson: Work being done on their head! Yes.
>> Regina Barber DeGraaff: He’s already learned.
>> Brad Johnson: Yes. He’s got it.
>> Regina Barber DeGraaff: He’s a great teacher, isn’t he.
>> Brad Johnson: He’s got it. So you’ve got this book here and you know that, if I let go of that book, there’s going to be energy that went from whatever the book’s got just sitting there to all of a sudden it’s crashing in your skull doing work on your bones. Right? All of these words start to fit together.
So there’s something potentially that could happen if I let go of this book. So that’s where we get this notion of potential energy. And that’s what the pendulum has when it swings to the top. It stops.
>> Regina Barber DeGraaff: For a second.
>> Brad Johnson: For just a second.
>> Regina Barber DeGraaff: And then it comes back down.
>> Brad Johnson: And it comes back down. It’s going real fast and what the pendulum does is it continually sloshes the water back and forth from the bath tub to the bucket and back from the bucket to the bath tub. And I’ll call the bath tub its kinetic energy and I’ll call the bucket its potential energy. And the water swings back and forth as the pendulum is swinging so that we have a quantitative measure of this thing called energy, which is the same amount of water going — it’s just going back and forth between the two vessels, the bath tub and the bucket.
And that is why this whole concept is so important. It gives us these great powerful tools to figure things out. That’s the basic idea.
Now, you might say, “OK, but wait. The pendulum will eventually swing and swing, but usually they swing to a stop.” I’ve never once seen one that kept swinging forever.
>> Regina Barber DeGraaff: They die down.
>> Brad Johnson: They die down. And, in fact, those of you are at home that have their string with their heavy object or have their book over their sibling, whatever you got going, you take that string and that heavy object and you let it go and you just let it go and you see what happens. And probably it’ll come to a stop. If it doesn’t, then call me right away. All right?
>> Regina Barber DeGraaff: Because something’s wrong [laughing]. That or you’re on the moon.
>> Jordan Baker: Or you’re on another mystery spot.
>> Brad Johnson: Yeah. Or something — or you’ve discovered something really amazing and I really want to know about it.
So anyway, it swings to a stop. So you say, “Well, wait. Didn’t you just tell me that all of this energy is conserved?” Well, the way to think about that one is that on the way from taking the water from the bath tub to the bucket, a little spilled.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: And then, when it came from the bucket to the bathtub, a little more spilled. And, as I do that back and forth and back and forth and each time a little bit spills, pretty soon all the water’s gone and it’s not in the bath tub and it’s not in the bucket. But it is on the floor.
>> Regina Barber DeGraaff: Well, anyone who’s had a toddler has seen this happen over and over and over again.
So when you talk about this, this idea of potential energy and kinetic energies, where is the biggest hang-up that your students or the public have about that concept? Of this transferring of energy from — this motion — this moving energy to this like stored energy, which is what you were talking? This potential to [inaudible] to transfer energy?
>> Brad Johnson: Well, you know — let me put it this way. During — you know, after a significant amount of time in one of my classes, there are no misconceptions anymore whatsoever.
>> Regina Barber DeGraaff: Really?
>> Brad Johnson: That’s just how it’s been working.
>> Regina Barber DeGraaff: Oh, OK. OK. I had some misconceptions in quantum mechanics when I took it from you, but, you know.
>> Brad Johnson: That’s different.
>> Regina Barber DeGraaff: That’s a different subject [laughing].
>> Brad Johnson: That’s different.
>> Regina Barber DeGraaff: OK. OK.
>> Brad Johnson: No, there are many places — I mean, this is a subject that’s fraught with peril obviously.
>> Regina Barber DeGraaff: It is.
>> Brad Johnson: But the beauty is that there are some really nice mathematics that you can do to make this make sense. And so I encourage everyone out there to learn a lot more mathematics.
>> Regina Barber DeGraaff: Yeah. Absolutely.
>> Brad Johnson: That’s what I would encourage.
>> Regina Barber DeGraaff: So, before we move onto next idea, this idea of losing energy, this dissipation that you’re talking about, the slippage, the water on the floor, what was the weirdest reaction to you holding the book over somebody’s yeah?
>> Jordan Baker: Oh, yeah.
>> Regina Barber DeGraaff: As you were telling this story of holding the book over people’s heads, I want the most extreme reaction to that. Because I can just imagine people sleeping. Because I have people who sleep in the front of the room, which I don’t understand why they do that. But I would just hold it over the guy who’s sleeping. Tell me just a quick one before we keep talking about energy. I’m just curious.
>> Brad Johnson: Well, it really was just — the most extreme one was someone just bailed out of the chair. They just literally couldn’t get out of that chair fast enough and practically killed themselves because these chairs are funny and —
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: So they were bailing out of the chair and fell down and all that. Yeah. I felt bad and so the next time I said, “Well, listen. Next time I won’t use a book. I’ll use a stretchy rubber band,” because you know how —
>> Regina Barber DeGraaff: You point it right at their eye [laughing].
>> Jordan Baker: At their eyeball. Yeah.
>> Brad Johnson: Point a stretchy rubber band at someone, you know, they’re much less likely to react.
>> Regina Barber DeGraaff: Which is another example of this stored potential energy.
>> Brad Johnson: Same thing.
>> Regina Barber DeGraaff: Right? Because you have this elastic — where the more you stretch it, the more you have that stored energy that he was talking about, this potential energy.
>> Brad Johnson: That’s right. Yeah. So that’s — this whole long introduction has been only about, so far, mechanical energy. And so one of the listens we hope to take from this is that the energy changes form, the water goes from the bucket to the bath tub, and those are just the labels on what we’re calling the energy, but the total amount of water was conserved. So now we have to start fishing around for all the different ways that energy gets stored.
[Silence ]
>> Jordan Baker: So we’re just talking about kinetic and potential and thermal energy. All right. What other energies are there that you could name? Top — can you just name as many as you can in five seconds?
>> Brad Johnson: No. I don’t want to go there. I’m going to go there slowly. OK? Always go slow. That’s the —
>> Regina Barber DeGraaff: Especially with physics.
>> Brad Johnson: And that’s — yeah. Dancing and physics, go slow.
So I’m glad you asked that question because what we have been discussing are the two kinds of major forms of mechanical energy. We talked about that being represented by the water in the bath tub or the water in the bucket, but the label “bucket” and “bath tub” were the labels for mechanical and connect. But the water —
>> Regina Barber DeGraaff: Or potential and kinetic.
>> Brad Johnson: I’m sorry. What did I say?
>> Regina Barber DeGraaff: Mechanical. It’s all mechanical.
>> Brad Johnson: Potential and kinetic. Thank you. And that some kind of went on the floor, but it was still water. So one of the things then we go in search of is what other kinds are there.
And there’s this business that we call thermal energy, which is really an interesting and tough subject. That’s one of those things that’s a really hard thing to learn at first. It’s really hard to wrap yourself around and get that warm feeling in your tummy. Sometimes the warm feeling appears in your spleen. We don’t like that. So you have to keep working at it to understand it.
And then there are these other forms like chemical energy, which is very important especially to the fossil fuel industry because that is exactly what that is all about. It’s also important to use as a metabolizing organism. You have all this chemical processes going on.
>> Jordan Baker: Thank you.
>> Brad Johnson: Conversions of energy — yeah. Fine one you are.
>> Regina Barber DeGraaff: Yeah. He does have a high metabolism.
>> Brad Johnson: Yeah. So there you go. So you’re a very good user of chemical energy.
>> Jordan Baker: Yes! I’m efficient!
>> Brad Johnson: Yes. So that’s the idea is that we go fishing around for these things. And once we have a feel for all that, then we have a better idea of what we’re talking about — getting back to what we started with — is this notion of energy content of the atmosphere and in ocean. Because, when I “heat” something, what am I doing? Well, I’m adding energy. And so what kind of energy? Well, I’m adding thermal energy. And there’s lots of ways to do that.
And that’s where it starts to get complicated, but it also starts to get fun and there’s all kinds of fun examples we can talk about with human beings in our every day experience to get our head around some of that stuff. So we’ll talk — if you want to — we’ll talk a little bit about some of that. We’ll talk a little bit about chemical energy. But I’d like to keep coming back to this notion of trying to get away from global warming, temperature change per se, and get to global atmospheric energy content.
[♪ Janelle Monae singing Wondaland ♪]
♪ The music floats you gently on your toes
♪ Touch the nose, he’ll change your clothes to tuxedos
♪ Don’t freak and hide
♪ ‘ll be your secret santa, do you mind?
♪ Don’t resist
>> Regina Barber DeGraaff: If you’re just joining us, this is Spark Science. I’m Regina Barber DeGraaff.
>> Jordan Baker: And I’m Jordan Baker. Today we’re joined by Dr. Brad Johnson, Western Physics Professor.
[♪ Janelle Monae singing Wondaland ♪]
♪ Your magic mind
♪ Makes love to mine
♪ think I’m in love, angel
>> Brad Johnson: So where does the energy in the atmosphere come from? Any idea? You guys?
>> Regina Barber DeGraaff: No.
>> Jordan Baker: Uh, thunder storms.
>> Brad Johnson: Actually that’s interesting.
>> Jordan Baker: Lightning!
>> Brad Johnson: That’s an expression of some of the energy that has come to the Earth from somewhere else. So, when you go out in the daytime — well, maybe not so much in Bellingham — although, little, hasn’t been a problem.
>> Regina Barber DeGraaff: Yeah. It’s been really nice here.
>> Brad Johnson: Yeah. It’s been really nice here lately.
>> Regina Barber DeGraaff: Global warming.
>> Brad Johnson: You walk outside [laughing]. You walk outside and, boom, big yellow bright thing in the sky. OK?
>> Regina Barber DeGraaff: Yeah [laughing].
>> Brad Johnson: So that’s the thing —
>> Regina Barber DeGraaff: I’m the best astronomer ever.
>> Brad Johnson: That’s the thing — yeah, very — you know, it’s one of those astronomic things.
>> Jordan Baker: The sun.
>> Brad Johnson: There you go!
>> Jordan Baker: I got it!
>> Brad Johnson: So that thing is what’s powering the Earth. So the energy that we use here on Earth basically comes from the sun. There is internal energy in the Earth and stuff — there is.
>> Regina Barber DeGraaff: Which we learned from the core, which we talked about in episode three.
>> Brad Johnson: Really?
>> Regina Barber DeGraaff: Yeah. Sorry.
>> Brad Johnson: So the idea is that the Earth is sitting here being bathed in the sun’s energy, but we don’t really have a good feel for what we mean when we say that. So we have to go back to some every day stuff again.
So several ways to do that. One is you think about a campfire. Everybody loves campfires. I mean, who doesn’t like a campfire?
>> Jordan Baker: It’s nature’s lava lamp.
>> Brad Johnson: It’s beautiful.
>> Jordan Baker: You just can’t stop staring at it.
>> Brad Johnson: You can’t stop staring. It makes pleasing sounds. Right?
>> Regina Barber DeGraaff: Smells good if there’s hot dogs in it.
>> Brad Johnson: It keeps the bugs away. I mean, who doesn’t like that.
>> Jordan Baker: Marshmallows catch on fire. And you throw it on your brother [laughing].
>> Brad Johnson: But what’s one of the main features we like? Why do we have campfires at night? What is one of the main features of campfires?
>> Regina Barber DeGraaff: Heat.
>> Brad Johnson: Yeah. Heat.
>> Jordan Baker: Morale.
>> Regina Barber DeGraaff: Morale [laughing].
>> Brad Johnson: Yeah, no. You can’t discount that.
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: You can’t discount that. Because there is a feel-good factor.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: But one of the feel-good factors is that thing where you stick out your hands or maybe some people turn around and they warm themselves. See what I’m saying?
>> Jordan Baker: Warm your tush.
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: Yeah. There’s that warm thing.
>> Jordan Baker: You can say “tush.”
>> Brad Johnson: What are we talking about there? Well, that is another form of energy transfer. So there’s chemical processes going on in that fire that release this energy in the form of light. It makes the temperature of the wood go up. And as things — as the temperature of something rises — we’ll talk about what temperature means in just a second — what happens is, empirically, it starts giving off a lot of light.
Now, the problem with that is you’re thinking, “Well, there are lots of things that are “hot” that I don’t see. What do you mean it’s giving off light?” Well, it’s giving off light that your eyes don’t detect. And a lot of the light that your camp fire is giving off is light that your eyes can’t detect, but your skin detects readily. And that’s exactly what you’re doing is you’re detecting that light that’s coming from the camp fire using the nerves in your skin. That warmth that you feel is the transfer of energy from the fire to your skin by radiation, by radiative transfer.
And that’s a really important concept when you want to think about the atmosphere. That’s one of the most fundamental things that we want to think about when we talk about the atmosphere because that’s the thing the sun is doing. The sun is our big campfire and the Earth is bathing in that campfire light. And so there’s a lot of radiation, a lot of electromagnetic radiation and some other kinds, coming towards us, but it’s mostly that electromagnetic radiation that we’re calling the heat. When you go out in the sun and you feel it on your skin, it’s that same sensation as the campfire. That’s your sensing that light. That is a radiative transfer of energy from the sun to your skin.
And that’s a very important process. That’s the thing that makes the atmosphere “warm” or warms the Earth-atmosphere combination by the absorption of that radiation by the Earth and by the atmosphere and that will then increase, not only the temperature, but all other forms of energy that also occur in the process of the atmosphere and the ocean and the Earth doing its thing. OK? Make sense?
>> Regina Barber DeGraaff: I like how you brought up the electromagnetic radiation. We were just talking about that also.
>> Brad Johnson: Excellent. I was trying to use —
>> Regina Barber DeGraaff: So, yeah. So our listeners, they’re with you.
>> Brad Johnson: They’re well versed.
>> Regina Barber DeGraaff: Unless they didn’t listen to the last show.
>> Brad Johnson: OK.
>> Jordan Baker: Which they did.
>> Brad Johnson: Of course they did.
>> Jordan Baker: I like that you called Earth like a big campfire basically.
>> Regina Barber DeGraaff: Well, the sun.
>> Jordan Baker: The sun.
>> Brad Johnson: Well, right. The sun is our campfire.
>> Jordan Baker: Right. Yeah. Yeah. Yeah. And the Earth is like our body.
>> Regina Barber DeGraaff: Yep. Yeah.
>> Jordan Baker: Our tush.
>> Regina Barber DeGraaff: Well, yeah.
>> Regina Barber DeGraaff: There you go.
>> Jordan Baker: Warmed my — OK. Go on.
>> Brad Johnson: There you go. So let’s think about that atmosphere for a minute. So one of the interesting questions you could ask is, “What if we just took the atmosphere away? What would be the temperature of the surface the of Earth?” Well, it turns out, if you just do this process where you say, “I’m going to let the sun bathe the Earth in its electromagnetic radiation and I’ll let the Earth absorb that until it comes to an equilibrium, meaning that it’s going to give off as much electromagnetic radiation as it’s getting,” if you do that, it turns out that the temperature of the surface is not all that much lower than it is for us now. That the atmosphere does warm the thing, but not by as much as you might think.
And that’s actually an important point because the atmosphere is actually a very, very thin, very fragile thing. To give you an illustration of what I mean, imagine instead of a meter stick — we all know what a meter stick looks like.
>> Jordan Baker: A yard stick.
>> Regina Barber DeGraaff: Yeah. A yard stick. We just went over that.
>> Brad Johnson: So exactly. That was foreshadowing, by the way.
So now imagine a pole vaulting pole only it’s a little bit — just a little longer than the topic pole vaulting pole. Let’s say this pole vaulting pole reaches from downtown Bellingham to downtown Seattle.
>> Jordan Baker: That’s a little bit bigger than just a small — just a little bit.
>> Regina Barber DeGraaff: No. That’s for giants.
>> Brad Johnson: For those of you who don’t live around here, that’s about 100 miles. OK? So, if I took that poll vaulting pole that I just described and I stood it straight up, it would stick out of the atmosphere and into space. Now, of course, there’s no hard and fast boundary there because it’s just the atmosphere is made up of gases that get more and more tenuous and thin as you go up high. But, never mind. When you get that stick that’s only that long — so think about that in your head. That’s not very far. Right?
So if you’re not living around here, picture something that’s important to you that’s 100 miles away and stick a stick between you and that. OK? So you get that picture in your mind.
>> Regina Barber DeGraaff: If you’re driving at six miles per hour, it’s roughly like an hour and a half.
>> Brad Johnson: Yeah. Ish.
>> Regina Barber DeGraaff: Yeah. Ish [laughing].
>> Brad Johnson: So then if you drove that same rate straight up for that same amount of time, you’re out of the atmosphere. So it’s really thin.
Another way to think about that is to compare it. So that little 100 miles compared to the 4,000 mile radius of the Earth itself — so, you see, compared to the Earth itself, it’s this tiny, thin thing. So that whole thing plays together to show us why there’s not an outrageous amount of heating due to that atmosphere being there, but there is some heating of the Earth’s surface environment due to the atmosphere being there.
So what does the atmosphere — so the idea is that, if we didn’t have the atmosphere, the Earth’s surface would come to a temperature which is not all that much different from what it is. OK? And now imagine what is it doing? It’s reradiating that electromagnetic radiation, the heat, away. And now, if it’s reradiating that into a blanket of gases, the gases themselves are going to be just like the Earth. They’re going to absorb some radiation and then they’re going to give some radiation off.
So there’s this interplay between the radiation that comes from the Earth absorbed by the gases in the atmosphere itself and then reradiated back down toward the Earth. So it’s reradiated in every direction. Some comes back down. So there’s this interplay between the radiation of the clouds, the air, and everything else that makes up the — the water vapor — everything else that makes up the atmosphere and the ground itself. And that brings up the temperature of the ground a little bit, that little process. And that’s this greenhouse effect. It’s a little more complicated than that, but that’s this effect.
>> Regina Barber DeGraaff: Right. It’s the trapping that people talk about.
>> Brad Johnson: Yes. It’s part of how it works.
>> Jordan Baker: We’re all using quote marks in the air.
>> Brad Johnson: Yeah. Air quotes. Radio air quotes.
>> Jordan Baker: Yeah [laughing]. You guys got that?
>> Brad Johnson: So there are some good examples of how this works all around you. If you go outside — this is another thing that you can do, but it has to be winter so I apologize for the reference being a winter reference, but —
>> Jordan Baker: Ugh.
>> Brad Johnson: If you go outside on one of those kind of morning’s when it’s been a really clear night, a very clear, cold night, and you go out and you look at your backyard. And there’s a beautiful layer of white frost all over your backyard. Now, if you have a big tree in your yard — maybe it’s in your front yard so maybe I shouldn’t use backyard — but the point is, if you have a big tree in your yard somewhere — now, it’s winter time so it’s a deciduous tree, it doesn’t have any leaves so you can see right through it —
>> Regina Barber DeGraaff: Or, if you don’t have a yard, a park.
>> Brad Johnson: A park. Yeah. Or you can ask about your neighbor’s yard. Whatever. The point is, you go out and you use your observation powers and you look and you see this beautiful layer of white frost on the ground everywhere except in the vicinity right around the bottom of the tree where there is no frost. And so you’re thinking to yourself —
>> Jordan Baker: Ah. Witchcraft.
>> Brad Johnson: Yeah. Witchcraft.
[ Laughter ]
Or something other that’s just as nefarious and that is this radiative transfer thing and that is that the tree itself is radiating. So, as the ground is radiating during the night, it’s radiating into a dark sky. So the only thing it has to trap that radiation is the atmosphere, which doesn’t trap all of it. It only traps a bit. So that’s radiating away, which is a cooling effect for the ground. But, if it radiates into a tree, the tree then captures some of that radiation, some of the radiation from the air, and reradiates it to the ground.
So the equilibrium of all these radiative processes around the tree and the ground make the ground slightly warmer around the tree than it was around out in the open grass where there was nothing there. Even though the tree is not — you could — if you laid on the grass and looked up through that tree, you can still see the sky. So it’s a very interesting effect that it’s actually this radiation between the trunk and the branches and every else that helps keep the ground warmer than the ground that was away from the tree.
So that’s kind of a little mental crutch for how this equilibrium — when I radiate to you, you radiate back to me, and it’s all — we’re all good. Right?
>> Jordan Baker: We’re all good with feeding off each other.
>> Brad Johnson: Exactly.
[♪ Janelle Monae singing Wondaland ♪]
♪ I wander off into a land
♪ You can go, but you mustn’t tell a soul
♪ There’s a world inside
♪ Where dreamers meet each other
>> Jordan Baker: If you’re just joining us, this is Spark Science. I’m Jordan Baker.
>> Regina Barber DeGraaff: And I’m Regina Barber DeGraaff. Today we’re talking about energy with Dr. Brad Johnson.
[♪ Janelle Monae singing Wondaland ♪]
♪ The magnificent droid plays there
♪ Your magic mind
♪ Makes love to mine
♪ think I’m in love, angel
? Take me back to Wondaland
? I gotta get back to Wondaland
>> Brad Johnson: Exactly.
>> Regina Barber DeGraaff: Well, I mean you can just think of a really crowded room.
>> Brad Johnson: Yeah. Or another good example from our everyday experience is, sometimes we’ll walk into a room, especially if it’s a bathroom, some place where you can disrobe a bit and feel this a little bit better, right?
>> Regina Barber DeGraaff: You’re making our listeners do so many things.
>> Brad Johnson: This room — here are some air quotes — “feels” cold. Right? Or this room “feels” warm. And what’s fun is to do the experiment where the air temperature in the room is exactly the same in both rooms, but one room has this feel of cold and one room has this feel of hot. And this is a segue, again, to another thing so stay with me.
>> Jordan Baker: All right.
>> Brad Johnson: So that’s because the surfaces of the walls around you are either shiny or — meaning they’re reflective — or they’re absorptive. And that makes a big difference between this “we’re all good radiation” thing, whereas if a shiny surface is reflecting light, it’s also not absorbing much. So, to make that temperature equilibrium, it’s got to take from you a little more in order to come to the right temperature for you to be radiatively happy. So it feels cold. Whereas a good absorber wall feels warm because that radiation balance between you and the wall happens at a relatively equal temperature.
So, you say to yourself, “This room feels cold,” even though its temperature is exactly the same as the room that “feels” warm.
>> Regina Barber DeGraaff: Right. It’s that transfer that you’re feeling.
>> Brad Johnson: Yeah. It’s that.
>> Regina Barber DeGraaff: So —
>> Brad Johnson: That brings me to the next point about people as a thermometer.
>> Regina Barber DeGraaff: Yeah. I love this too so whatever you’re going to say, it’s like I’m psychic, I know what you’re going to say.
>> Brad Johnson: Awesome.
>> Regina Barber DeGraaff: Yeah. I was just talking to my daughter and she was like three. And she was touching things and she was just like, “This feels cold and this feels hot,” and then we actually had a discussion about thermal conductivity [laughing]. When she was three.
And so that was my intro. You go ahead and talk about thermal conductivity and people as thermometers.
>> Brad Johnson: Yes. So people as thermometers. People are terrible thermometers.
>> Regina Barber DeGraaff: They are.
>> Brad Johnson: When someone says, “Ooh. That’s cold,” they very often don’t really mean the temperature even though they think they mean the temperature. What they mean is, “My body’s losing heat energy faster than it wants to.”
>> Jordan Baker: You make them sound like whiners.
>> Regina Barber DeGraaff: The example I always give in my class, Jordan, which I think you’ll like, is that you’re in your room and your feet are on the carpet and then suddenly your feet touch linoleum in the bathroom. And suddenly you feel, “Oh, my gosh. That area is colder.” But if, like Brad was saying, that whole stuff — if you were actually to have a thermometer to actually like measure the temperature of those substances, they’re the same. It’s just that your foot is losing heat from the tile.
>> Jordan Baker: Right. Sure.
>> Regina Barber DeGraaff: And — sure. Totally.
>> Jordan Baker: Sure.
>> Regina Barber DeGraaff: You got that.
>> Brad Johnson: Absolutely. Well, the classic example is wind chill. And, again, I did air quotes.
>> Regina Barber DeGraaff: Air quotes. “Wind chill.”
>> Brad Johnson: That idea is — there’s a classic experiment that everybody can do at home and that is you take two — three pales of water actually — one that’s as hot as you can stand, one that’s as cold as you can stand, and one that’s just room temperature water. And you soak your right hand in the hot as you can stand water and your left hand in the cold as you can stand water for, you know, as long as you can stand. And then you take them both out of there and stick them both into the room temperature water. And one of your hands will sense that water as very, very hot and one of your hands will sense that water as very, very cold.
This is a beautiful thing. It’s an example of, “Gee. My body was in an environment where it was — heat was flowing into it. It was like ‘Ack. I’m trying to maintain my temperature here. Stop this heat flow in.'” and the other one was saying, “Ah, the heat’s flowing out. I’m trying to maintain my temperature here. Stop the flowing out.” Then, when it got into the — so when your senses got into that neutral temperature water, the fact is they were both losing energy, but one of them thought, “Oh, no. I’m getting energy.”
>> Regina Barber DeGraaff: Yeah, your emotions do sound like Woody Allen.
>> Jordan Baker: Right [laughing]. I like that the hands like have a thought process [laughing]. “Oh, no!”
>> Regina Barber DeGraaff: They do. They do.
>> Jordan Baker: “I’m losing energy!”
>> Brad Johnson: Yeah.
>> Regina Barber DeGraaff: Well, I think that that experiment — a lot of kids do that. Right? In elementary school.
>> Brad Johnson: Yeah.
>> Jordan Baker: It’s usually at sleep overs to like make them wet the bed.
>> Brad Johnson: Yeah. Yeah.
>> Jordan Baker: But, yeah.
>> Brad Johnson: Exactly.
>> Regina Barber DeGraaff: Physics.
>> Brad Johnson: So then — what I was going to say before was wind chill is another really good thing. We got off on the air quotes, but the wind chill thing.
So what the heck is wind chill? OK. So you’ve seen that on the news. It says, “The air temperature outside is 20 degrees, but it — ready — feels like –”
>> Regina Barber DeGraaff: Air quotes.
>> Brad Johnson: “Zero degrees.” And because of the wind. Well, that’s because, of course, it’s not a measure of the temperature in your head, it’s a measure of the energy that you are losing. So when you — if you stood out in the 20 degree air and it was still, you’d lose energy at a particular rate. That would feel cold to you because your body’s losing thermal energy.
Now, the problem is, when the wind begins to blow, you add another component to this where you have evaporative cooling off of your skin and it’s transporting that warm-ish air around you away. So, therefore, you’re going to lose energy at a greater rate.
So what the wind chill “factor” does is it tells you that you are losing energy at 20 degrees with this wind at the same rate that you would lose energy if it were zero degrees. That’s how this whole thing works.
>> Regina Barber DeGraaff: You are so good at this. Like why — I should just talk to you before I teach these classes. Why do we only talk about movies at lunch. I should talk to you about physics. Oh, my gosh.
>> Jordan Baker: Is there a heat chill? Because I lived in northern California and like if you’re driving in a car, all of a sudden it’s like a hair driver. Normally it’s 110 or whatever out and then all of a sudden, yeah.
>> Brad Johnson: Oven fresh air comes in your car?
>> Jordan Baker: Exactly.
>> Brad Johnson: Yeah. There is something called a heat index, but it’s not related to that. There’s something that, if it’s this temperature outside, it’s 90 degrees outside, but the humidity is very high and, therefore, the heat index, what it feels like outside, is actually higher.
>> Regina Barber DeGraaff: Oh, because you’re not getting rid of that.
>> Brad Johnson: Not evaporative cooling because of the vapor in the air doesn’t allow this evaporative cooling process so you actually get — you’re taking in energy at a rate that you would if it were 100 degrees rather than 90. Same basic idea, but — yeah.
>> Regina Barber DeGraaff: This is great.
>> Brad Johnson: So we got these heat indices and these wind chills, but it’s all a matter of we’re not thermometers. We’re heat flow meters. That’s what we are.
>> Regina Barber DeGraaff: We know how much we’re losing and gaining.
>> Brad Johnson: Yes. Yes.
>> Regina Barber DeGraaff: Kind of like how we can only feel acceleration, we can’t feel velocity.
>> Brad Johnson: Can’t feel velocity. Yep.
>> Regina Barber DeGraaff: Wow. I like it.
So we’ve talked about frost on trees. No. Frost on snow. And we’ve talked about —
>> Jordan Baker: Frost on snow?
>> Regina Barber DeGraaff: Frost on grass.
>> Jordan Baker: Frost on grass.
>> Regina Barber DeGraaff: Frost on grass [laughing]. We’ve talked about frost.
>> Brad Johnson: Yes.
>> Regina Barber DeGraaff: And we’ve talked about this idea of heat chill, wind chill, heat index I guess — not heat chill. So how does this all relate to this “global warming?”
>> Brad Johnson: Yeah. The way I can tie this all back together is I think — we pause for a moment and we say, “OK. So we got all these forms of energy, all these places the energy can go.” So it’s important to emphasize that you can add a lot of energy to something actually without changes its temperature. And, in fact, when you add energy to things, the temperature changes at a different amount because of what they’re made out of and things. But there are processes where the temperature won’t change at all.
And a great example of that is when you boil water on the stove. And another thing you can check out at your leisure at home is you take the water and you turn it on and you let it go. And pretty soon it starts to boil. If you have a thermometer that can go that high, you can stick it in there and you can see that, no matter how much you turn your stove up at that point — you can turn it up. You can turn it down. You can do whatever you want — the temperature of that water is not going to change.
>> Regina Barber DeGraaff: As long as it’s boiling.
>> Brad Johnson: As long as it’s boiling. You can just add energy as much as you want.
[♪ Janelle Monae singing Wondaland ♪]
♪ Take me back to Wondaland
♪ gotta get back to Wondaland
♪ Take me back to Wondaland
♪ Me thinks she left her underpants? Take me back to Wondaland
♪ I gotta get back to Wondaland
>> Jordan Baker: This is Spark Science. Today, we’re talking about energy with physicist Brad Johnson.
[♪ Janelle Monae singing Wondaland ♪]
♪ This is your land
♪ This is my land
♪ We belong here
♪ Stay the night
♪ I am so inspired
♪ You touched my wires
♪ My supernova shining bright
>> Regina Barber DeGraaff: So how does this all relate to this “global warming?”
>> Brad Johnson: Yeah. The way I can tie this all back together is, I think we pause for a moment and we say we’ve got all these forms of energy, all these places the energy can go.” So it’s important to emphasize that you can add a lot of energy to something actually without changes its temperature. And, in fact, when you add energy to things, the temperature changes at a different amount because of what they’re made out of and things. But there are processes where the temperature won’t change at all.
And a great example of that is when you boil water on the stove. And another thing you can check out at your leisure at home is you take the water and you turn it on and you let it go. And pretty soon it starts to boil. If you have a thermometer that can go that high, you can stick it in there and you can see that, no matter how much you turn your stove up at that point — you can turn it up. You can turn it down. You can do whatever you want — the temperature of that water is not going to change.
>> Regina Barber DeGraaff: As long as it’s boiling.
>> Brad Johnson: As long as it’s boiling. You can just add energy as much as you want. And you just — all it does is it makes the water go away faster. It turns it into vapor, which is another process if we had time we could discuss. It’s just really fun. I like to talk about people holding hands and all that. But anyway, we can talk about water going into vapor.
>> Jordan Baker: Sounds like camp.
>> Brad Johnson: Yeah.
>> Regina Barber DeGraaff: Well, this idea of phase change is just something that’s really, really hard for a lot of students in our physics classes to get.
>> Brad Johnson: It is.
>> Regina Barber DeGraaff: This idea that energy is actually being added to the system if you’re turning stuff into vapor like you’re saying, but the temperature isn’t changing.
>> Brad Johnson: Right.
>> Regina Barber DeGraaff: And they just — they associate the word “temperature” and “energy” and that’s what you’re trying to say.
>> Brad Johnson: That’s what I’m trying to say.
>> Regina Barber DeGraaff: That’s what we’re trying to get away from.
>> Brad Johnson: Yeah. Trying to get away from that fact because one of the places that you can dump energy, then, is into this phase change, which happens a lot around here. We’ve got a lot of water on the surface of the Earth and, when a lot of that energy comes in, a lot of it goes into “evaporating” in air quotes, bringing the water into the vapor phase into the atmosphere. That’s the connection — one of the connections between the atmosphere and the ocean. So that’s one place.
And then there are these amazing processes that occur on a global atmospheric scale that are just wavelength phenomenon. So everyone knows what waves are. If you go out to a lake and you stand, you know, waste deep in the water and then a boat goes by out on the lake, after some amount of time goes by, all of a sudden this water’s trying to knock you over. You’re going up and down. The water’s knocking you around. That’s the transmission of the energy of the boat pushing itself through the water to you in the form of water waves.
Well, a lot of energy can be going into the atmosphere that can be turned into these wave-like phenomena. And there’s — there are a lot of fascinating things that happen like that. And, if you’re observant, you can go out and see a lot of this stuff in the patterns in the clouds. There are like regular patterns of wave-like activity in the atmosphere that you can see by the regular patterns of clouds. And that’s another place where a lot of the energy goes.
And that brings me back to the Paul Harvey story. That lots of big fluctuations in local conditions temperature, pressure, humidity, all those things that characterize the atmosphere.
>> Regina Barber DeGraaff: Storms.
>> Brad Johnson: Cloud cover. Storms. What we call mesoscale activity, are all dependent on how much energy is in the atmosphere as a whole because the movement and the transmission of energy is what makes that stuff happen. So, if you have larger fluctuations in some of these local conditions, that’s a hallmark of having a lot of energy to push things around. There are these huge wave-like phenomenon that can go on a global scale. And there are many, many examples we can give. I don’t want to spend a whole lot of time on them, but there are lots of great examples that affect us every day in our local weather.
And that’s one of the other things is that local weather is never an indicator of global climate. That’s one of the other things about whenever someone says, “But it was hot here or it rained here,” or whatever, that’s just a local phenomenon that was pushed by a lot of complex dynamics in the atmosphere and in the atmosphere-ocean system that happen to make that happen in that local spot.
But what we’re talking about —
>> Regina Barber DeGraaff: A lot of transfer.
>> Brad Johnson: Yeah. A lot of transfer of energy from one place to another from one form to another. So these waves transfer energy from one place to another without moving anything. So the lake, the waves in the lake got from the boat to you without moving the water. It didn’t take the water and pick it up over there at the boat, drive it over to you, and drop it on you there. It transmitted that energy through the wave motion on the surface of the lake.
And that happens in the atmosphere all the time. It’s a very complex system. This interplay between energy and temperature and potential energy, wave motion, phase changes, the change of water from vapor to liquid or condensing out in the form of a cloud, which is another very interesting, very complicated, horrible thing to study, but — you know.
>> Regina Barber DeGraaff: Well, yeah. I think atmospheric scientists like they don’t get enough respect I think. I mean, there’s so much physics and there’s so much other kinds of science that are just kind of all bundled up in like being a weather person. You know? Like doing atmospheric science. And they don’t get enough credit.
>> Brad Johnson: Yeah. That’s a very hard subject. In fact, I’ve got a small anecdote about that. When I was a graduate student, I had some very hard courses that I would — I knew were coming this one semester. So I was searching around for a course that would maybe be a little easier to try and give myself a break.
>> Regina Barber DeGraaff: Like underwater basket weaving.
>> Brad Johnson: Yeah. Exactly. Only — and I looked in the catalogue and I saw “atmospheric physics.” “Ah, you know, how hard could that be?”
[ Laughter ]
It turned out to be the hardest damn class I ever took in my life because it’s got all of these pieces and parts. And it’s got a lot of different sort of sub-fields of physics that you have to understand really well to understand how they interplay with the other sub-fields of physics like these mechanical waves, or elastic waves in media, or thermodynamics, or phase changes. And all these things that are really hard on their own are now mixing together to drive this system, which is immensely complicated.
>> Regina Barber DeGraaff: Which, as physicists, we’ve kind of all — and in the lower level classes, gotten rid of. Right? All of those interactions and trying to make simplified and — I can just imagine that class being just brutal.
Once we have this good foundation of this idea of energy transfer and where — you know, how thin the atmosphere is and how it’s being kind of “trapped” — again air quotes — so how do you explain this idea of global warming in terms of energy then?
>> Brad Johnson: OK. So —
>> Regina Barber DeGraaff: Why is that happening?
>> Brad Johnson: So the idea is that, if we go back to this notion that we feel comfortable when we’re in equilibrium with something radiatively — so we’re trying — the Earth is trying to become in radiative equilibrium with the sun, the earth atmosphere-ocean system, and the sun are trying to have this radiative equilibrium. So the amount of radiation we receive from the sun, we’re trying to radiate that same amount away. So enough.
We alter the chemical composition of the atmosphere a little bit. We change that radiative equilibrium. So some more gets absorbed by — some more radiation gets absorbed as it gets away from the Earth into the atmosphere, it gets absorbed and then re-emitted. So this changes the local equilibrium, the local temperature, if you will, if you want to go back to that model.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: But what it really does is it keeps some of the energy that came from the sun from going back into space and keeps it here in the atmosphere-ocean system. So the energy content is going up. And there are lots of ways that we can see that happening. There are direct measurements where you go up in a satellite or — sorry — you tell your satellite to tell you —
>> Jordan Baker: I want to go up into the satellite [laughing].
>> Brad Johnson: Yes [laughing]. Tell the satellite —
>> Regina Barber DeGraaff: That’s dangerous.
>> Brad Johnson: How much radiation is the Earth giving off when the sun’s not in the way? So you go to the side that’s opposite the sun. You measure that radiation. We know the radiation coming from the sun. We can see an imbalance there. We can see all of these other phenomenon, the increase in energy in terms of the temperature, for one, which is, you know — that’s a global mean temperature, now, which is a very hard measurement. You have to take a temperature not only at the surface all over the Earth, but at various levels in the atmosphere up into the high atmosphere all over the Earth and average that number.
That’s why that’s a tough measurement. That’s a tough thing to measure. And then you can also measure things like sea surface wave action. Is that increasing? You can measure all of these places where energy can be stored and just kind of take a little measurement of that energy and see if it’s going up. These are all ways that you can get involved in understanding this by taking these basic concepts of energy and saying, “OK. Here’s a place where energy can go. Making the waves on the ocean bigger.” Right? Is that happening?
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: That’s something we can look at.
>> Regina Barber DeGraaff: And that’s why people are talking about this idea where you get more and more extreme storms.
>> Brad Johnson: Yes.
>> Regina Barber DeGraaff: And more extreme weather when you have — in your words, “Higher energy content.”
>> Brad Johnson: That’s right.
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: Because the energy to drive those storms has to come from some place. That’s correct.
>> Regina Barber DeGraaff: Right. Yeah. No. That’s really interesting. And — but bring us back to this idea — I mean, this idea of energy and temperature. So many people inter- — you know, confuse those two things.
>> Brad Johnson: Right.
>> Regina Barber DeGraaff: So tell us —
>> Brad Johnson: So let’s get to the chase.
>> Regina Barber DeGraaff: Help our listeners with that because I think that’s a common thing.
>> Brad Johnson: Yeah. We can cut to the chase there.
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: So what is it that temperature actually is? We’ve been beating around this bush all evening.
>> Regina Barber DeGraaff: Right. Yeah. Let’s wait until now.
>> Brad Johnson: The basic idea is that the temperature, the thing we call temperature, is a quantitative measurement of the average kinetic energy — so there’s that word again — the energy associated with motion of the constituents that make up the fluid or the gas. So, if you think of your gas as being made up of little bee-bees, just as a metaphorical thing for your brain to get around — all those little bee-bees are whizzing around. They’re flying around.
And, if you measured their speeds, they’d have a distribution of speeds. There’d be some faster ones and some slower ones. But, if you take their average, and you take their average kinetic energy, that’s what the temperature is measuring. So that’s one place that, if I excite might basket of bee-bees, that’s one place that energy can go is into making them go faster. That’s increasing their temperature.
Another place it could go is, if the bee-bees get close to one another and they like each other, they may stick together. And, therefore —
>> Regina Barber DeGraaff: Molecules.
>> Brad Johnson: And then those like to run around together. And if you want to break those apart, that takes energy to bust those apart. And that energy didn’t go into making them go faster, temperature, it went into taking them and making them go far apart.
>> Regina Barber DeGraaff: Phase change.
>> Brad Johnson: Yes. So that’s the way that we can discuss the atmosphere in terms of a bunch of bee-bees. And, therefore, yeah, one way — one sink, one place the energy goes is into making the little bee-bees go faster.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: And that’s this notion of temperature. But the problem is that even with the bouncing bee-bees, those bouncing bee-bees can bounce into other things and give up that energy to something else.
>> Regina Barber DeGraaff: Like the wall.
>> Brad Johnson: Right. Like the surface of —
>> Regina Barber DeGraaff: Your container where your bee-bees are.
>> Brad Johnson: Right. Yes. And so all of these places are things you have to worry about. Now, that random motion there is what makes thermal energy so interesting, that whole notion that you have this randomness, that things are just flying around randomly, that the air in this room is contained in this room, but it’s made up of all these bee-bees whizzing around. And so we ask ourselves —
>> Regina Barber DeGraaff: These air bee-bees. We keep on saying bee-bees. We mean air like molecules.
>> Brad Johnson: Yes. Yes. That’s exactly right. And they’re whizzing around the room. So we ask ourselves, “Why are not all the bee-bees over there in the corner?”
>> Regina Barber DeGraaff: I love this. Yes.
>> Brad Johnson: Why are the bee-bees not over there in the corner? Well, there’s no reason why they’re not. There’s no good physical reason why they’re not except it’s very unlikely.
>> Regina Barber DeGraaff: Probability.
>> Brad Johnson: Yes. It’s very unlikely that they’d all be found there at one time. And that’s the reason that they’re spread out the way they are. It’s just the mathematics of randomness. And randomness is a very rich and interesting topic.
[♪ Janelle Monae singing Wondaland ♪]
♪ Take me back to Wondaland
♪ I gotta get back to Wondaland
♪ Take me back to Wondaland
♪ Me thinks she left her underpants
♪ You know I love you, babe
♪ Yes, I need you
♪ Yes, I want to know a love
>> Jordan Baker: We’re talking about energy with physics professor Brad Johnson.
[♪ Janelle Monae singing Wondaland ♪]
♪ I am so inspired
♪ You touched my wires
♪ My supernova shining bright
♪ Hallelujah
♪ Hallelujah
>> Brad Johnson: So. Yeah. Imagine you have a giant bucket with 1,000 pennies in it.
>> Jordan Baker: I’m rich!
>> Regina Barber DeGraaff: Yeah [laughing].
>> Brad Johnson: A thousand pennies. I don’t even know if you can get pennies anymore. Can you get pennies?
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: So. OK. You get 1,000 pennies and you go up to the roof of your house and you pitch those pennies off of the roof, this bucket of pennies.
>> Regina Barber DeGraaff: Jordan did this last week.
>> Brad Johnson: A thousand pennies, just whoosh off the roof. And then you go down and you pick up all the heads. Everything that you see is a head, you put it back in the bucket. You go back up on the roof and you chuck it off of there again. And you go back down and you pick up all the heads. Right?
Well, you’ll find, that on average, you’ll get about 10 throws out of this.
>> Jordan Baker: The heads up.
>> Brad Johnson: The heads up. Yep. This is heads up. I’m going to give you a heads up.
>> Jordan Baker: Just picking up random heads.
>> Regina Barber DeGraaff: Yeah [laughing].
>> Brad Johnson: Let me give you a heads up here. So you — on average you’ll get somewhere around 10 bucket throws out of this exercise. And that means that there’s a penny out there that, every time you do this experiment, it goes 10 heads in a row. OK?
So then what I like to do is challenge you to go take one penny and toss it and see if you get 10 heads in a row. You might want to use the one you just picked up off the ground from this experiment because, hell, it just did it. It just did 10 heads in a row.
>> Regina Barber DeGraaff: Oh, no you don’t.
>> Brad Johnson: Oh, OK. Maybe you don’t. It just did 10 heads in a row so maybe it’s a lucky penny.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: But anyway.
>> Jordan Baker: Is that how you get the lucky penny?
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: Take your penny.
>> Jordan Baker: It’s a process.
>> Brad Johnson: Toss that penny.
[Laughter]
And, man, you’re going to be tossing a long time to find that one time when it does 10 heads in a row. Do you see what I’m saying? There’s this interesting thing about the statistics of numbers versus the statistics of one. And that’s all buried in this mathematics of randomness and there are lots of these kinds of thought experiments, or even actual experiments that you can do to convince yourself that it’s a rich and interesting subject. And there’s a lot to be learned from studying randomness.
>> Regina Barber DeGraaff: Well, and I think a lot of people kind of get this idea, which we’ve been talking about, climate change and these storms and this idea of them being random versus them being part of a process, like you were saying, of energy being increased in our — in the atmosphere.
>> Brad Johnson: Yeah.
>> Regina Barber DeGraaff: And there’s definitely a difference. But, yeah.
>> Brad Johnson: Absolutely. But the atmosphere is a wonderful combination of, you know, mechanics and randomness.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: I mean, it’s one of the richest sort of fields where we can go out and look at that interplay between randomness as a driving force and the physics of what’s going on with a medium like a gas or a fluid. It’s a very, very rich topic, a very interesting and complex topic.
>> Regina Barber DeGraaff: So if you could have your audience take away — so, when they think energy, they should think what?
>> Brad Johnson: Well, they should really have in the back of their mind stored the quarter pounder thing so that they have a good gut feeling for what, you know — what does it mean when I say the sun puts 1,000 watts per square meter on the top of the atmosphere. Think about that for a minute. A thousand watts for every square meter. So go back to your —
>> Regina Barber DeGraaff: That’s huge.
>> Brad Johnson: Yeah. That’s a lot of energy.
>> Regina Barber DeGraaff: Yeah.
>> Brad Johnson: So you go in the back of your mind and you remember those quarter pounders. Right? So you get — start thinking quantitatively about what we say when we say these things. Start connecting it to that feeling you got when you lift your quarter pounder.
>> Regina Barber DeGraaff: Right. All right. And I ask all of our guests this every single time about media and, you know, he they love about TV. Because that’s really all I like to do is watch TV.
So, with all this discussion about energy, as a physicist, what movie would help people understand, or help them make fun of [laughing] misconceptions about energy? Can you think of anything? I know we talk about Real Genius a lot, but I don’t know. And they do lasers. So.
>> Jordan Baker: Them’s lasers.
>> Regina Barber DeGraaff: Yeah. Them’s lasers from the satellites and stuff.
>> Brad Johnson: Yeah. Well, there are probably a lot of movies I could think of if I took the time to think of it. The one that comes across immediately to start thinking about making fun of, for sure, would be The Day After Tomorrow.
>> Regina Barber DeGraaff: Oh, yes.
>> Brad Johnson: Because they tried to take some ideas that were actually very, very reasonable ideas. This notion that the ocean currents control the sort of mesoscopic medium level climate is very, very real. And that if you change the salinity of the North Atlantic, that changes these flows of energy in the water, which could have a very catastrophic effect on the local climates of Northern Europe and, you know, even North America.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: So they take those ideas —
>> Regina Barber DeGraaff: So they’re good to start with.
>> Brad Johnson: They’re good to start with. They’re good, solid ideas. And then they sit down and they go, “Yeah. What if we put a ship in the middle of New York? Yeah! And some wolves!”
[ Laughter ]
And that’s when it gets fun.
>> Regina Barber DeGraaff: Really.
>> Brad Johnson: Yeah.
>> Regina Barber DeGraaff: Right.
>> Brad Johnson: Yeah.
>> Regina Barber DeGraaff: I still need to watch that. Somebody was just talking about that. It had a glacier. Right? In it? There was like The Day After Tomorrow — or am I thinking of a different movie?
>> Brad Johnson: I don’t know.
>> Jordan Baker: I think it might be different. I think it’s on Netflix. You can check it out.
>> Regina Barber DeGraaff: Oh, maybe I should. Maybe we should bring you back after we’ve watched it [laughing]. And then you can talk more about — you wanted to elaborate more on — you were saying randomness and all that kind of stuff.
>> Brad Johnson: Yeah. Randomness is really quite fascinating and I would like people to share that fascination that I have for randomness. Because this notion that things happen randomly and people say that a lot. Well, “that couldn’t just be random.” Well, the structure that randomness can produce is really mind boggling and that’s something that I’d like people to get comfortable with.
>> Regina Barber DeGraaff: Well, I want to end there. And I want to thank you for coming to talk to us. This has been —
>> Brad Johnson: My pleasure.
>> Regina Barber DeGraaff: Very enlightening. And for my own lecture. Completely selfish reasons.
>> Jordan Baker: I will use them for my lectures as well.
>> Regina Barber DeGraaff: You mean your improv.
>> Jordan Baker: Right. Yeah.
>> Regina Barber DeGraaff: You’ll wait for somebody to yell out “energy!” and you’re like, “I got this.”
>> Jordan Baker: Got it.
>> Brad Johnson: Quarter pounder!
>> Jordan Baker: Let me show you something. That was a quarter pounder going down.
>> Regina Barber DeGraaff: Yes. All right. And we’ll never — we’ll — actually we’ll always use air quotes probably more after this.
>> Brad Johnson: Yeah. I apologize for that.
>> Regina Barber DeGraaff: No. That’s all of our faults. Well, thank you again.
>> Brad Johnson: My pleasure.
>> Regina Barber DeGraaff: For talking to us.
>> Brad Johnson: Thank you all. Thank you for having me. I enjoyed it very much.
[♪ Janelle Monae singing Wondaland ♪]
♪ Take me back to Wondaland
♪ I gotta get back to Wondaland
♪ Take me back to Wondaland
♪ Me thinks she left her underpants
♪ Take me back to Wondaland
♪ I gotta get back to Wondaland
♪ Take me back to Wondaland
♪ Me thinks she left her underpants
>> Regina Barber DeGraaff: Thank you for joining us. We just spoke to Western Professor Brad Johnson. If you missed any of the show, go to our website, KMRE.org, and click on the podcast link.
>> Jordan Baker: This is Spark Science. We’ll be back again next week. Listen to us Sunday at 5PM, Wednesday at 9PM, Saturday at noon. If there is a science idea that you’re curious about, send us an e-mail or post a message on our Facebook page, Spark Science.
>> Regina Barber DeGraaff: Today’s episode, Energy and the Atmosphere, was produced in the KMRE Spark Radio Studios located in the Spark Museum on Bay Street in Bellingham. Our producer is Susan Blaze. The engineer for today’s show is Eric Fabruetta. Our theme song is “Chemical Calisthenics” by Blackalicious and “Wondaland” by Janelle Monae.
[♪ Janelle Monae singing Wondaland ♪]
♪ Take me back to Wondaland
♪ I gotta get back to Wondaland
♪ Take me back to Wondaland
♪ Me thinks she left her underpants
♪ You know I love, you babe
♪ Yes, I need you
>> Here we go.
[♪ Blackalicious rapping Chemical Calisthenics ♪]
[♪ Blackalicious rapping Chemical Calisthenics ♪]
♪ Neutron, proton, mass defect, lyrical oxidation, yo irrelevant
♪ Mass spectrograph, pure electron volt, atomic energy erupting
♪ As I get all open on betatron, gamma rays thermo cracking
♪ Cyclotron and any and every mic
♪ You’re on trans iridium, if you’re always uranium
♪ Molecules, spontaneous combustion, pow
♪ Law of de-fi-nite pro-por-tion, gain-ing weight
♪ I’m every element around
♪ Lead, gold, tin, iron, platinum, zinc, when I rap you think
♪ Iodine nitrate activate
♪ Red geranium, the only difference is I transmit sound
♪ Balance was unbalanced then you add a little talent in
♪ Careful, careful with those ingredients
♪ They could explode and blow up if you drop them
♪ And they hit the ground
[End of podast.]