Stuff You Should Know - Why do leaves change colors in the fall?

Episode Date: November 27, 2012

Ah, autumn - arguably the most beautiful time of the year, thanks to the vibrant colors trees put on display as they close up for the winter. Ever wonder why and how trees change color in the fall? Chuck and Josh have it down pat and explain it here. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Flooring contractors agree. When looking for the best to care for hardwood floors, use Bona Hardwood Floor Cleaner. The residue-free, fast drying solution is specially designed for hardwood floors, delivering the safe and effective clean you trust. Bona Hardwood Floor Cleaner is available at most retailers where floor cleaning products are sold and on Amazon. Also available for your other hard surface floors like Stone, Tile, Laminate, Vinyl, and LVT. For cleaning tips and exclusive offers, visit Bona.com slash Bona Clean. The War on Drugs is the excuse our government uses to get away with absolutely insane stuff. Stuff that'll piss you off. The cops, are they just like looting? Are they just like pillaging? They just have way better names for what they call,

like what we would call a jack move or being robbed. They call civil acid work. Be sure to listen to the War on Drugs on the iHeart Radio app, Apple Podcast, or wherever you get your podcasts. Welcome to Stuff You Should Know from HowStuffWorks.com. Hey buddy, if you don't mind if I plug my Movember page real quick. Please do. I am growing a moustache this month for Movember for cancer research, specifically male prostate cancer research. That's right. And you can donate to my team, which would be pretty cool, because you know, you get a free podcast and it'd be nice to throw a little money toward cancer research.

Chuck's being nice here. Give him some money. He's growing out facial hair to help a charitable organization engage in really important scientific research. That's right. And you can go to mobro.co slash Charles Bryant. And that's my page. Or just go to the Movember site, type in Charles Bryant in the search bar, and look for the picture of me. There's only a couple of us out there. Chuck's wearing a red shirt. That's right. Yeah. So what is that again? That's mobro.co slash Charles Bryant. Yes, thank you in advance. Yeah, that's nice Chuck. All right, let's get to it. Hey, and welcome to the podcast. I'm Josh Clark. There's Charles W. Chuck Bryant in audio and video Chuck. We're just hanging out doing some recording doing our thing. I guess this is episode number

5 million 82. That's right. Yeah. Before we get started, I wanted to point out Josh that on the way in about 20 minutes ago in a parking deck, I saw what was probably an $80,000 Mercedes with a license plate that said Rush Band. Oh, yeah. Have you seen that? Yeah, I'm trying to figure I've seen it many times. I'm trying to figure out, are they talking about Rush? I think so. Or Rush Limbaugh. Oh, yeah. The first time I saw it, I was like, all right. And I was like, oh, I wonder which one. Jeez, now I'm doubting myself. And then that was Rush the Band, which I thought, well, it's obviously a guy, first of all. It would have to be. And it's obviously a guy that's some sort of CEO here in the building because maybe his car was pretty sweet.

Yes, but also consider this. It doesn't have a reserved spot. Yeah, that's true. Could be Elise. Rush Limbaugh fan. I don't know if you would say Rush. Do people call him that? I would have put LMBH FN. No, people would definitely call him Rush. All right. Yeah. He could also love that drug that used to be legal called Rush that you buy at head shops in the 80s. Maybe he just loves that. Yeah, he stocked up on it. What is that stuff? Is it I have no eradicated or did it convert into something that we like, like PCP, something we know by another name? I don't know. But, and boy, we're segueing already, but this is a short one. So I guess it's all right. I did see an internet thing yesterday where this artist took like every

drug you could think of and drew a self portrait. It was pretty interesting. I got to say, like, from the weird, like fun psychedelic mushroom one to which one was it that was just horrifying? It was just like fuzzy scribbling. Methamphetamines? No, that one was pretty scary, too. But that was one that was just like weird. Oh, it's probably Robotussin. No, but he did do that. He drank officer. Yeah, you should do none of this, by the way. Right, people, even if you are an artist. Yeah, you know who makes the best art? Clean, non addicted human beings who get high on, you know, a nice spring day. And they're not getting high during that spring day. They're getting high from the spring day. That's what I meant by that. Sure. Let's talk about days. Let's talk about fall

instead of spring. Yeah, that's a great autumn. You want to? Autumn is my favorite season, Josh. Same here. As it is a lot of people because here in Atlanta, which is like living in the middle of a forest, an urban forest. It is. It's like the most heavily wooded state in the union, I understand. Is it really? That's what I hear. Well, this article here gives a lot of due to New England, which is no slouch, obviously, but Georgia and the Southeast Man, the Rocky, er, the Rockies. They moved over. The Blue Ridge Mountains, just gorgeous. Smokies? Smokies, like vibrant reds, yellows, orange. It's just like unbelievable. Right. I saw an article, I think it was on MSNBCR as a Today Show article. And it was like places other than Vermont,

New Hampshire and Maine that are good for, I hate this word, leaf peeping. I thought that was made up and I had to look it up and it's not. Yeah, it's real. Yeah. It's the most disgustingly folksy word I've ever heard in my life. But that's what it's called. If you go and look at leaves as they change color, you're a leaf peeper. No, you're not. Some people call you that. I think you have to associate with that thing. Oh, like you might have a t-shirt that says that? Yeah. Like leaf peeper at work? Or leaf peepers do it with their eyes open. Nice. Thanks. Nice. In the woods. Yeah. So, yeah, if you are into that kind of thing, some people might call you a leaf peeper. And you probably are a veteran of New Hampshire's,

Vermont's and Maine's autumns. Yeah. But like you're saying, the Smokies are nice, the Appalachians are nice. Yeah. Out West apparently has some really good leaf peeping. Oh, yeah? Yeah. Utah? I'm sure, yeah. Utah, Colorado. And Arizona maybe, in the right spots? Probably. Yeah, probably. Northern Arizona. As long as like you have some sort of maybe like an elm, a good maple out there. Yeah. It's going to be worth standing and gawking at for a certain period of time. If you go a little further up in Idaho, you're going to hit the Snake River. And if you hit the Snake River, you're probably going to run into a Native American of the Shoshone tribe. Okay. This is like their central location, or it was their ancestry.

The Shoshone, if you ask them, especially if you asked them a few hundred years ago, I'm sure, why the leaves turn color, say like red or yellow, they would tell you a little story about the Great Bear. Yeah. You've heard this one, right? I have. Do you want to tell it? Well, apparently the lore says that the color came from above and after they killed the Great Bear in the sky. Which is why? You know, for a hunt for the pelt. Oh, gotcha. The blood splashed down and turned the leaves red. Yes, Chuck, which makes a lot of sense, except there's plenty of times when you see a tree that's turned bright yellow. What is that? What's to explain that, Shoshone? Well, they would say that it comes from the bear's fat

splashing out of the pot when they are cooking it. Yes. Which is thought a little gross. It is, but it's practical. Sure. Yeah. So that's one explanation for why leaves turn color. And after reading this article, I found that science isn't 100% sure what's going on there. They have a pretty good idea, but they're not 100%, especially when it comes to turning red. Yeah, you can't crawl inside of a leaf. You can't walk up to one and ask it, right? Oh, you're red. Yeah. Like the walls of this room. Yeah, these walls talk back, and they say disturbing things. But you're right. They don't know for sure, but they have some pretty good guesses. And it all starts with photosynthesis.

And chlorophyll. Yeah. Do you remember photosynthesis? I looked it up to refresh myself. Yeah, that's one of the neat things, because it's one of the very first science things you'll learn as a kid. Yeah, like that word's been with me since I was a tyke. Yeah, chlorophyll, photosynthesis, and go ahead, give the first grade version. Okay. Well, chlorophyll is a pigment, and plants, it's green, and it's green because it absorbs red light and blue light. And so the only light that's left is green, and that's the light that we see. It doesn't absorb that. Yeah. So since it's a pigment, it can absorb light and do crazy things with it. And in the case of a plant, it converts the light energy into chemical energy in the form of

adenosine triphosphate, ATP. Wow. So what's just happened is it's captured light and taken that light and turned it into a chemical. So it's stored energy, which is pretty cool. Agreed. A little further down in the leaf, you take a little water. Yeah. You got the ATP. Yep. Combine it with some CO2. And then all of a sudden, you got glucose. And if you have glucose, what were you going to say? I thought you were going to say chicken pot pie. You have the beginnings of a good chicken pot pie. Okay. Like you can't make a chicken pot pie without ATP. Yeah. That's just the start. So you have all this glucose, and you're ready to make some chicken pot pie. Before you make that, the plant is going to use

it to fuel cells. It's food. It makes its own food, right? That's pretty neat in itself. That's photosynthesis. So photosynthesis is carried out in the presence of lots of light, right? Right. And during the right kind of weather when there's a lot of light. So summertime. Yes. Summertime comes to an end though. The days start to go a little shorter. That's right. It gets darker earlier. Yeah. Air dries out a bit. Yeah. And the plant says, you know what? I'm kind of done making my own sugars for a while. I'm going to just live off my fat like a great bear in the sky. That's right. And so it stops making chlorophyll. Yeah. And chlorophyll is not the only thing going on in the leaf. Obviously you have your green.

But there are also other pigments like keratin and xanthophil. Yeah. Xantho means yellow in Greek. And that is what gives keratin egg yolks their cover. The keratin cover. Their color. Their cover. It's a cover color. The shell gives it the cover. Sure. Yeah. It's what gives it the color. And they're always in leaves. And they also help absorb the sunlight. They're not the star that chlorophyll is. But they do transfer chlorophyll for photosynthesis. Right. They help. Yeah. And so the plant always has I guess keratines and what is it? Xanthophil? Xanthophil. But it doesn't always produce chlorophyll. So when it's substituting chlorophyll, the Xanthophil and the keratines go, hey, look at us.

I think it's always chlorophyll, right? No, it's substituting chlorophyll. But it's always there at some point. Or are there some leaves without chlorophyll at all? Oh, no. It depends on the time of the year. Okay. That's what I thought. Right. So the plant will stop producing chlorophyll and the keratines and the Xanthophil will take over. Yes. But yeah, I believe that there's always chlorophyll or every plant has an ability to make chlorophyll, right? Yeah. For photosynthesis. I think so. Because that's how it eats. Yeah. Yeah. The war on drugs impacts everyone whether or not you take drugs. America's public enemy number one is drug abuse. This podcast is going to show you the truth behind the war on drugs. They told me that I would be charged for conspiracy

to distribute 2200 pounds of marijuana. Yeah, and they can do that without any drugs on the table. Without any drugs, of course, yes, they can do that. And I'm the prime example of that. The war on drugs is the excuse our government uses to get away with absolutely insane stuff. Stuff that'll piss you off. The property is guilty. Exactly. And it starts as guilty. It starts as guilty. The cops, are they just like looting? Are they just like pillaging? They just have way better names for what they call like what we would call a jack move or being robbed. They call civil answer for that. Be sure to listen to the war on drugs on the iHeart radio app, Apple podcast or wherever you get your podcast. Hey witches, I'm Ilaria Baldwin and I'm Michelle

Campbell Mason and together we host the new iHeart radio podcast, which is anonymous. I am a health uncomfortable because I have an identity separate from that. He is a husband, okay? Alec is a husband and he can be Mrs. Ilaria Baldwin. Come to the coven where we don't hold back and we don't shy away from tough topics. We are going to go really deep into women's relationships with each other. So bring your brooms and join us as we tackle why women are pinned against each other and what we can do to stop this vicious cycle. Consider this your invitation to witches anonymous because witch please, we're in this together. Listen to witches anonymous on the iHeart radio app, Apple podcast or wherever you listen to podcasts. So you've got the red or you've got the yellow

and you have the orange leaves explained. Bam. There's no chlorophyll any longer. Right? That's right. And we should probably talk about that period of hibernation. What goes on? There's another step that goes on. Yeah, a couple of things happen. The leaf is going to form a layer of separation. Jennifer calls it cork like cells. Yeah. At the base of the leaf. I like that. Seals it off from the tree. It's like a little stopper, I guess. And then the tree stops producing the chlorophyll and well, that's pretty much it. Like no more chlorophyll. We've got a barrier between the, I guess, the end of the branch and the leaf. Yeah. So the tree doesn't dry out when it loses all its leaves. Exactly. And here's where we get into the red, where the red comes from.

Right. Something called pigment called anthocyanin. And that is a flavonoid. So the flavonoid family. And depending on the pH, it can be responsible for reds, purples and blues and all sorts. It's like what makes a plum purple, for instance. Yeah, or grape or grape blueberries, grape, or blueberry blue. Yeah. There's more than 300 distinct anthocyanins. Right. And apparently, they're really, really good for you. Like loaded with antioxidants. Yeah, yeah. That's why probably why blueberries are so good for you. Yeah. Well, exactly. It's a superfood. But one of the things I found that it said that it was, it's one of some of the strongest physiological effects of any plant compound on the planet is found in the anthocyanin. Nice. Yeah, it's pretty crazy. Well,

they don't, not all plants produce anthocyanins. Yeah. Not all plants that do produce anthocyanins produce it all the time. I try to get a list. Oh yeah. Of just trees, but I'm sure it's out there. I just couldn't find it. I would say a lace leaf Japanese maple that will be at the top of the list. That was for having it? Yeah. Sure. That's all I got. Okay. But so, I mean, if you are a leaf peeper or you're somebody who others might call a leaf peeper, it just sounds so dirty. I know. It's a terrible word. Any kind of peeper is just, I don't know. Sure. Todry. Yeah. Because, you know, peeper. Yeah, exactly. If you are into looking at fall leaves, we'll say that. Thank you. Then you probably know that some years there's really great reds, other years there's not.

I felt like last year we didn't have that many. Yeah, it seems like I don't remember seeing reds for a while now. Agreed. And science is not 100% certain what's going on, but what they think happens is anthocyanins are created by a plant to recover sugar. Yeah. During times when there's a period of stress that the plant's going through. So, if you have a very wet summer into autumn, you're probably not going to see any reds. If you have a very dry summer into autumn, you will usually see reds. And the reason why is because apparently these sugar stores in the leaves are just kind of dry. They're dried up. They've turned into sap. So, the plant produces anthocyanins to go in and recover it to get it all loosened up so it can suck it back out into its trunk

before those cork-like cells cut it off. Yeah, it's sort of like there's a timetable and they know that they're going to be cut off from that supply soon. Yeah. So, it just really tries hard there at the end. To get every last bit out. Every last bit. And the anthocyanins are a red pigment. So, when it sends it into the leaves, that's what they think is going on. They said that the best predictor that they found for a nice brilliant red display in the autumn as summer turns into autumn, warm sunny days. So, there's lots of sugar production going on. Yeah. And then cool nights that slows down the ability of the tree to suck the sugars that were produced that day out of the leaves. So, there's a bunch stuck in there. And dry too, right? Yeah. That's kind of what we've got

going on now. Yeah. Hopefully, we'll see a lot of reds. I think my favorite, the reds are nice, but I don't know what tree it is, but it's one particular tree that has those yellow. Like it just glows? Oh, yeah, man. It's just like so yellow. It's blinding. It's a type of maple. Is it? I think so. Like there's a couple. There's one that like really glows that's a maple. And then there's another that's maybe the oak. I can't remember. I've seen them. I feel like we talked about this. Am I having deja vu? It was the time we went leaf peeping. We talked at length about this. That's right. Yeah. I forgot. We brought our little flask of apple cider. Yeah. Walked through the woods. Yeah. It was a heck of a peeping trip. That's right. So, I guess that's pretty

much the end of it. Yeah. Science has explained the yellow and the green and the orange and the red. Pretty sure about the red. Pretty sure about the red. Yeah. They're not 100% convinced. Yeah. I wish I had something else to add, but I think this is just one of those that, you know, this fall you can tell your friends, you see that tree? You know what's red? Well, that's what we're doing here. Yeah. Oh, also, if you are into looking at leaves as they change color in the fall. Yeah. If you're one of those people. Who doesn't? Well, some people, you know, like get in their car and drive places. Yeah. But who is just like, ah, shut the shades. I don't want to see that stuff. People who hate art. Rush fans. Right. Depending on the kind of rush

they're talking about. Yeah. If you are into that though, there's an app. If you also are into smartphones and you own one, you can download a free app called a leaf peeper. I'm not saying this, but it's a P E E P R. Um, and it's free. And it's like this color coded map of the United States by region. Oh, cool area. And it shows, um, where the leaves are green, um, turning, moderate, uh, fading and gone. So you can kind of track the leaves as they. Oh, that's cool. Yeah, it's pretty neat. And you can take pictures and post it to your favorite social media site. Well, I think I was going to call for that anyway. I think if you live in a place that you think rules the roost, uh, post your pictures on our Facebook page. Yeah. And, um, I will do the same.

We will do battle Georgia against the world. Okay. Cause I think we have some of the best. You're going to go do some leaf peeping. I'll see bits and leaves. Sure. It seems like something you should do. Like wearing like shorts and hiking boots and nothing else. Your leaf peeping. Yeah. I mean, Emily and I will usually try and take one drive up in the mountains. You know, maybe, uh, pasties while your life. I can't wait for the video. The war on drugs impacts everyone, whether or not you take America's public enemy. Number one, this drug abuse. This podcast is going to show you the truth behind the war on drugs. They told me that I would be charged for conspiracy to distribute a 2,200 pounds of marijuana. Yeah. And they can

do that without any drugs on the table. Without any drugs. Of course, yes, they can do that. And I'm the prime example of that. The war on drugs is the excuse our government uses to get away with absolutely insane stuff. Stuff that'll piss you off. The property is guilty. Exactly. And it starts as guilty. It starts as guilty. Cops. Are they just like looting? Are they just like pillaging? They just have way better names for what they call like what we would call a jack move or being robbed. They call civil asset for it. Be sure to listen to the war on drugs on the iHeart Radio app, Apple podcast, or wherever you get your podcast. Hey witches, I'm Ilaria Baldwin and I'm Michelle Campbell Mason. And together we host the new iHeart Radio podcast, which is anonymous.

I am a health and wellness expert. I am an author. I am a mother. I am a wife. Although I feel like putting that in my bio makes me slightly uncomfortable because I have an identity separate from that. He is a husband. Okay. Alec is a husband and he can be Mrs. Ilaria Baldwin. Come to the coven where we don't hold back and we don't shy away from tough topics. We are going to go really deep into women's relationships with each other. So bring your brooms and join us as we tackle why women are pinned against each other and what we can do to stop this vicious cycle. Consider this your invitation to witches anonymous because which please we're in this together. Listen to witches anonymous on the iHeart Radio app, Apple podcast, or wherever you listen to podcasts. Let's see if

you want to learn more about things like leaves changing color. I love stuff like that. I love earth science. Yeah, me too. I love your science. I think is what it is. I've grown to love it. Yeah. You can type in earth science in the search bar at howstuffwords.com and it'll bring up stuff like this. And I said stuff like this, which means it's time for listener mail. This is an oldie but a goodie. It's about Sherpas. And I think now's a good time to point out that I'm not sure if Sherpas has fallen off the list. But if you get our material from iTunes, you're only going to get 300. 301. But we have many more available. And if you type in your favorite search engine like Google, let's say stuff you should know RSS feed, it will bring you to a page

with all 450 plus shows. Yes. Or you can listen right there. Or some people use like a Stitcher or I think there's some other various podcast apps that like list the whole thing. Right. So we've been getting asked lately like, Hey, what about the sarcopenia? Where's that one? Or where's this one? They're all there in the vault. That's right. And stuff you should know RSS. All for free still. Yeah. Get them. Get them all. Collect them all. All right. So this is about Sherpas. And if you have not heard that one, it's an old one. You should go listen to it. Did you like that one? That was one of my least favorites. Oh, really? All right. Don't listen to it. Dust does not recommend. Guys, I recently listened to the Sherpa episode from a ways back

and found that I had an interesting story regarding Sir Edmund Hillary's ascent. I was born in Canada, but my mother and her family are all from New Zealand. Oh, yeah. My uncle Allen Sares lives just north of Auckland currently. And it's one of the most interesting people I know. He made his career in sports photography primarily for horse racing. He got a start in the field thanks to Sir Ed. This is the story as told to me by my uncle a little over 10 years ago. When Hillary was training for his ascent, he could be seen from time to time hiking on the road side all decked out in his climbing gear in order to be well used, well used to the weight or well used. One day my uncle then in his mid 30s passed him, stopped him and said,

can I take your photo? Sir Ed, already well known locally, was happy to oblige. My uncle never distributed any of the prints. Was he wearing like a camisole or something? What? He didn't distribute the prints? Right. Oh, no, I don't think that's anything like that. I got you. You just held on to him. But when word came back that Hillary had succeeded in the ascent, my uncle rushed to develop as many copies of the photo as he could. My uncle never distributed any of the prints. Weird. Yeah. But when word came back that Hillary has succeeded in his ascent, my uncle rushed to develop as many copies of the photo as he could. He stuffed them into envelopes addressed to many of the world's newspapers along with a note asking for whatever

recompense they felt the photo was worth. That's a great business model. Just send pictures and say hey, pay me a little something. Hey, Rupert Murdoch, let's use the honor system. Many papers ran the photo though and there were no photos as there were no photos of the ascent available until after Hillary had descended and his own photos were developed. My uncle died bitter and penniless. Thankfully, the strategy worked for my uncle and he became well known for sports photography in the 1950s and 60s in New Zealand. Yeah, the horse thing, that's right. He is now 97 years old and has no, in no way has slowed down. Wow. In fact, he has just finished a book on his career as a naval intelligence officer in WW2 that is due to be published next year. Cool.

He was also a successful track and field athlete in New Zealand, winning a silver medal in 1938. This guy sounds pretty awesome. In what are now the Commonwealth Games. Yeah, that's fantastic. We'll plug the book when it comes out. Yeah, for sure. Send it. I could not stop thinking about this story while listening to podcasts on purpose. He also tried to track down a copy of the photo, but it had been unable to find it. Best regards, Anthony Zellermeyer. Well, thanks a lot, Anthony. Yeah, that's a great letter. 97, man. Keep going. Seriously. Wow. If you have a family member that you're very proud of for good reason. Yeah. For like eight good reasons. We want to hear about that person. Also, don't forget Chuck's call out.

Like he's putting the smack down on your neck of the woods. It doesn't even have to be in the United States. Europe's got some great leaves. Asia has some great leaves. Basically anything that's above or below the tropics, probably going to have some good leaf color. It falls like in Japan. It's nice. Yeah, seems like it was maples. Yeah. Over there, they just call them maples. We want to see pictures of your hometown trees showing their greatest colors, right? I agree. Also, if you're a member of the Shoshone Tribe, write in and say hi. I agree. You can tweet to us at SYSKpodcast. You can join us on facebook.com slash stuff you should know. Or you can send us an email to stuffpodcast at discovery.com.

For more on this and thousands of other topics, visit howstuffworks.com. For what they call, like what we would call a jack move or being robbed. They call civil acid. Be sure to listen to the War on Drugs on the iHeart radio app, Apple Podcast, or wherever you get your podcasts. I'll see you in the next video.