Why do things fade in the sun?
Hey. I'm Melissa. I'm
Jam:Jam.
Melissa:And I'm a chemist.
Jam:And I'm not.
Melissa:And welcome to chemistry for your life.
Jam:The podcast helps you understand the chemistry of your everyday life.
Melissa:Okay. Today is very much about our everyday life because it's about the sun.
Jam:Okay. Nice.
Melissa:So today's topic is in honor of our dear friend, Miriam.
Jam:Uh-huh.
Melissa:I mentioned to her that I was trying to decide what we're gonna talk about this week, and she said, why do things fade in the sun, and why does our hair change color in the summer? Nice. She said she was inspired to ask these things because she missed the sun because it hasn't been out for a while.
Jam:I have
Melissa:to say that I do not miss the sun, but in honor of Miriam's sunny disposition, I felt that would be good. And because Even though it's winter and cloudy and a little bit, you know, misty and rainy here right now, it is summer for our listeners in Australia and in the other hemisphere. So they can have a summer themed episode for their summer if they want.
Jam:And for the rest of us, it can just make us think about summer, which for some of us will be something that we miss and look forward to.
Melissa:Not with though. Yeah. So Well,
Jam:thanks for at least doing it for the rest of us. Okay?
Melissa:You're welcome. I'm happy to
Jam:miss the sun or live in the southern hemisphere.
Melissa:You guys are welcome. It's you know, I'm happy to give you a little bit of sunshine in your day. Now before I get to the answer to Miriam's question, Jin, I did want to just take a moment because this is such a common everyday thing that we all see. For you guys at home to just be able to take a minute to think about what you think happens when things are sitting out in the sun and get faded.
Jam:Mhmm.
Melissa:So just take a moment and think about that, and then we'll hop back in with the answer.
Jam:Okay.
Melissa:Okay. So hopefully, you've had a chance to get something in your mind. And now I'm gonna tell you the answer to both of those questions, Why things fade in the sun and why our hair changes color in the summer is actually the same, And that's photo degradation.
Jam:Oh, wow.
Melissa:Big fancy word.
Jam:Yeah. It sounds serious.
Melissa:It does sound serious, but all it means is just light that's breaking something down. So light degrading photo degradation.
Jam:Got it. Got it.
Melissa:So let's talk about what light is. And we've talked about this before, but I think it's beneficial to just revisit it. So light from the sun is quite literally beams of energy. Mhmm. And these beams of energy fall both in the visible spectrum, so that's what we can see, and In the UV spectrum.
Melissa:So we can't see things in the UV spectrum. We've talked about that before too, I think, on the sunscreen episode.
Jam:Right. Right.
Melissa:So these are literally waves of energy coming into our atmosphere and putting energy into things. And we all, I think, know that because we learned about how plants turn energy from the sun into food in biology in, like, 4th grade or whatever. You know, we we know that, but I think remembering that when we talk about the colors fading is important.
Jam:Right.
Melissa:Because when the sun is shining down, it's putting energy into all of our things, not just like plants Or reptiles who are cold blooded. It's also putting energy into the plastic Sandbox that you have sitting in your backyard or your fence or whatever. Mhmm. So those things that have color, it's usually due to pigments. K.
Melissa:And pigments are chemicals with chemical bonds. They usually have alternating double bonds. We've Talked about that before, I think, in the bleach episode. Can you remember the word for that? Those alternating double bonds?
Jam:Oh, man. Dang it. I'm gonna be so mad when you say it, and I can't remember.
Melissa:Conju. I thought you're gonna get it.
Jam:Okay. Oh, conjugation?
Melissa:Conjugation. Yes.
Jam:You you give me, obviously, the most important half of the word?
Melissa:But still, you got it, so that's good.
Jam:I can't believe I didn't remember that because it's the same as, like, Looking at all forms of a verb in a different language or whatever. It's like all the ways that you can conjugate these verbs into the different forms, whether it's about You, me, us, they, that kinda thing. Same
Melissa:word. Never ever realized that that was the same word.
Jam:I think I thought that last time. Maybe you just didn't say it, but it should have helped me remember. So I'm kind of bummed at myself.
Melissa:Well, maybe if you had that, it would have helped you. So maybe for next time, you'll remember. Okay. So those long chains of alternating double bonds conjugated molecules, That's gonna be usually what's responsible for giving you color. So it's just single bond, double bond, single bond, double bond, single bond, double bond.
Melissa:And it kind of acts like an electron highway Where the electrons can move around sort of there. It's nice. It's a it's a nice thing going on there.
Jam:Yeah. Yeah. Yeah.
Melissa:So when those molecules that give most of our stuff color are exposed to light, They'll usually absorb that light and reemit absorb and reemit. The electrons are jumping up and jumping back down, jumping up and jumping back down. But also the energy that we put into molecules is what Breaks molecules. What breaks bonds in molecules? You have to put energy in to break a bond.
Melissa:And since UV light and visible light and even the heat that comes from the sun are all energy, As those things are hitting our pigments with these alternating double bonds over and over and over, it can cause some of those bonds to break. And if maybe one of the bonds in this long chain breaks, then you don't have the same long Chain of alternating double bonds, and the color can change or go away completely.
Jam:Okay.
Melissa:So that's why things fade in the sun is over time, bonds are breaking, you have less Molecules, you have less intact pigments. Uh-huh. And as you have less and less pigments, your color is going to be less concentrated or less vibrant because you literally just have less of the molecules that give color.
Jam:Mhmm.
Melissa:And that is, at least in part, why color fades.
Jam:Woah. Interesting. It's funny because I just like, it's one of the things you know Ever since you're a kid, like, you leave, yeah, like you said, your sandbox or just, like, leaving toys out in the sun or something or, like, the new swing set you got, how it slowly just looks less and less New for a number of reasons, but the color specifically.
Melissa:Mhmm.
Jam:And I think it's just funny because I think of it as just, oh, yeah. There's the sun hits it and just Bakes it kind of. You know? And
Melissa:Oh, yeah. Definitely.
Jam:It just gets lighter. Like, it just I don't really think about it as being, like, Very much a part of the chemistry of something, the molecular makeup of something That is not really what would cross my mind, naturally.
Melissa:Yeah. Absolutely. Well, there's a little more to it, But I actually, if you would, would like for you to take a stab at explaining it back to me, and then I'm gonna talk to you about what else happens When we leave either our hair or our plastics or whatever out in the sun.
Jam:Okay. So
Melissa:that because there's a little bit more That we can talk about.
Jam:Okay. So I think I have a kind of idea of how to think about this this fading in the sun deal. So
Melissa:Okay. I'm ready.
Jam:So it starts out with the sun's, you know, putting out energy all the time. Mhmm. And we love it. That's why we love the sun. Huge fans of the sun over here.
Jam:Glad you exist.
Melissa:Glad Specifically, at Jam's house, not at my house. Uh-huh.
Jam:But you are glad I exist because that's also how we exist and how this planet exists. Even if I'd maybe you would prefer to be behind some clouds all the time, it's still good that it's there.
Melissa:Yes. That's true. I will admit that I know the benefits of the sun. I just think it mostly could do its job from behind the clouds, and we'd still be fine.
Jam:Yeah. Yep. So this energy is coming out of the sun. It actually reminds me a little bit like raindrops. So imagine the The energy is coming out of something that affects a lot of things, both positively and, like we're talking about with fading, kind of negatively.
Jam:It's also like raindrops. There's positive and negative negatives to it. So when the sun's energy hits these items that we've left out, poor items we've left out in the sun. And the energy, goes along these electron highways that also are what gives Those items, the color they have
Melissa:Mhmm.
Jam:And the energy starts to break those bonds because it Requires energy to break bonds, and so a constant just bombarding of energy on these items will speed that Process up in a way that would not happen if they were just staying indoors. Correct?
Melissa:Right. Definitely.
Jam:So it made me think of a similar visual is I've noticed made times when cement gets worn down by rain, which is kinda funny to think about because rain seems so harmless In just one instance, you're just watching, you know, rain fall down and hit, you know, stuff, and it's it's a harmless little raindrop. Just like one second of sunlight seems so harmless. You know?
Melissa:Right.
Jam:But in certain areas, especially, there's an area at our house where the roof converges and there's not a gutter right there. And so The water that comes off of the roof right there is way stronger.
Melissa:Yeah.
Jam:And it hits this part of the cement Much stronger it gets a disproportionate amount of rainfall on that specific spot every time. And so it wears it down in a way that's not the same as other parts of our sidewalk. That's obviously a literal wearing down. But in this case, it's more of a molecular wearing down of just the bonds of the CoServe.
Melissa:I would say a mechanical wearing down for your cement and a chemical wearing down from your Colors.
Jam:And, obviously, sometimes those items that we leave out in the sun get that mechanic worn down too. But Right. That was the closest thing I could grab in my brain that felt similar and is, like, yeah, mechanical versus chemical.
Melissa:I think that's a great example. And, actually, it kinda reminded me when you're talking of how waves do that to sea glass also. Oh, yeah. Glass can get really smoothed down over time, and it is a mechanical wearing down and changing of the qualities of the Glass, but it's a slow over time breakdown of something that seems small and insignificant can cause things to change.
Jam:Yeah.
Melissa:That's a great one. Okay. Are you ready for the for the other applications of this idea?
Jam:Yes. I am.
Melissa:So The same thing, something similar, I guess, I should say, happens to your hair.
Jam:Okay.
Melissa:But it is hair is much more complex than just, one pigment happening, getting some kind of sun energy. You know? Mhmm. Mhmm. Your hair is a lot of different Chemicals.
Melissa:There's proteins. There's pigment. There's all kinds of stuff going on in your hair.
Jam:Right. Right.
Melissa:So one article I read used different shades of hair. They use brown, Blonde red. And they exposed different hair colors to light over a period of time, and they found that the light actually damaged Proteins as well as changing the pigmentation.
Jam:Oh, interesting.
Melissa:So they noted the color visually changing. I think they actually tracked the protein breakdown.
Jam:Mhmm.
Melissa:But the hair changed with exposure to UV light, primarily. UVA seemed to be responsible for hair color changes, and UVB seemed to be responsible for protein damages.
Jam:Okay.
Melissa:They made some guesses as to why, but basically different types of UV can impact your hair differently. But also They noted that blonde hair and blonde hair only change with visible light. Woah. They also noted that blonde hair changed the most, and it seemed that darker hair was more resistant to coloration changes upon exposure to light.
Jam:Interesting.
Melissa:Isn't that crazy?
Jam:Yeah. And for those of you at home who have never seen either of us, I have blonde hair, and most has brown hair. And as happens with a lot of blonde haired people, over time, my hair has become less blonde. But One thing that I have always remembered from my childhood is how much blonder my hair would get in the summer, especially as a kid when I run around outside a ton. And I remember times where I would come back to school at the beginning of the next year, and people would ask if I had gotten it bleached or something.
Jam:Even though they are they argue that I have blonde hair because it would for them, they remembered me from, you know, some point in May. And Mhmm. Then they have a huge gap of time, and they see me in August or whatever.
Melissa:Right.
Jam:It's a little bit of every day that change that happens. But I it's funny because I wouldn't notice it myself, but other people would. That's crazy that it's actually that different from hair color to hair color.
Melissa:Yeah. Because my hair doesn't change colors really. I I don't ever remember thinking my hair changed colors In the summer or any other time of year. But, also, I don't love being outside. Uh-huh.
Melissa:So that could be a big part of it.
Jam:Right. Right.
Melissa:But But it makes so much sense that you as a blonde person would notice because this study noted that blonde hair changed more easily. And I wonder too, they talked about how The different types of UV lights because I think the pigmentation is at the center of your hair Mhmm. But have to go through more layers. So I wonder if if your strand of hair is actually thicker, If it would be more resistant to color change?
Jam:Oh, yeah.
Melissa:So that would be interesting too. I think this was a 2004 study, so I would not surprised if a lot more research had been done. But this was very interesting and fun to read about.
Jam:Yeah. Seriously. Man, I don't get outside, you know, as much as I should now. And so Who knows if, like, my age is part of it? Like, our hair changes as we get older?
Jam:Or if it really is just that Over time, my outside time has decreased, and that's the biggest contributing factor to hair being less blonde. Who knows, dude?
Melissa:Honestly, who knows? And it's funny because she asked specifically why our hair changes color in the summer. Mhmm. And I would contest it's possible that our it's not that our hair changes color In the summer, but just that we are outside in the summer, so we have higher exposure to the sun's light.
Jam:Mhmm.
Melissa:But it I think also the sun is maybe further away Mhmm. In the winter than it is in the summer, I think. And so it could be also that we get more of Those rays at different times of year, or they're more powerful because they have less distance to travel. I don't really know
Jam:Yeah.
Melissa:A 100% about that. That's pure speculation, but I wonder if there's something about The distance of the sun, that also impacts it as well.
Jam:Yeah. I think a lot of the seasons is also how direct it is on our part of the earth.
Melissa:It might
Jam:be that it's further away, but it's just that it's kind of glancing more
Melissa:Yeah.
Jam:Than it is because
Melissa:we're tilted. Right? Yeah. This gets into a part of science so it is fascinating, but that I do not know very much about.
Jam:Yeah. And I have also been fascinated by and even know even less about.
Melissa:But wait. There's more.
Jam:Okay. Nice.
Melissa:So polymers can also Undergo photo degradation. And that doesn't only change their chemical properties, but because those long chains of molecules are so responsible for the the Physical properties of of polymers that we feel. I don't know if physical is exactly the right word there, but
Jam:Mhmm.
Melissa:Exposure To the sun, can actually break down some polymers and make them more brittle. So I read a paper about how that really impacts polystyrene and they're having to put UV stabilizers in The polystyrene. But that made me wonder if exposure to high concentrations of UV light could help us find a new way to break down plastics. Sticks.
Jam:Interesting. Yeah.
Melissa:Just a wonder I had in my brain that I have no capacity to do any kind of research on, but that would be very interesting.
Jam:Yeah. Very much so. Sweet, dude. That's crazy.
Melissa:So that's the power of the sun to change things and Really maim themes. It it really damages things.
Jam:Yeah. Yeah. We really need it, but also, wow, can it do some damage?
Melissa:Yeah. Definitely. Definitely. And it even do damage to my skin, which someone at some point asked What a sunburn is, and I'm gonna have to learn more about that. But it it does play along these lines where we're absorbing too much energy.
Melissa:But I'm not sure why our body reacts the way it does. That's more biology, but I'm happy to learn about that because that's very applicable to me.
Jam:Yeah. Yeah.
Melissa:So that's it. That's all the science facts I have for you today.
Jam:Dude, awesome. That was very cool. Interesting how many things get affected in similar ways, that are kinda everyday. I mean, our the stuff we use, plastic, but also our hair and our Items that we leave in the sun.
Melissa:Right. And if you want to learn more about the sun, check out our episode on sunscreen and About light and bleaching? Check out our episode about how bleach bleaches things.
Jam:Mhmm. And somebody asked about that episode recently. They just said, have you ever done one about bleach?
Melissa:Mhmm.
Jam:And it was, like, yep. We have. We differ a lot.
Melissa:As our library gets bigger.
Jam:Totally. It's it's way more understandable now than it ever has been. Like, just it'd be hard to know which things we already have done because you'd have to swipe through a lot of them. So Never had a chance to ask that. Yeah.
Jam:Because we all remember.
Melissa:Hopefully. Yeah. For now. Someone asked me a question about how something worked that we did an episode on, and I had already forgotten. Oh.
Melissa:So, you know, it just Time. It gets at that memory situation.
Jam:Totally. I was thinking at least we'd remember that we did an episode about it. Even if we forget exactly How it works? We could at least be like, oh, we did that once last year. Go listen to that version of ourselves that knew it.
Melissa:Yeah. I feel like past Melissa does a lot of things or knows a lot of things that present Melissa has long since forgotten. But speaking of past, Do you wanna talk about something that happened in your week, a little week in review?
Jam:Sure. Yes. Absolutely. So this didn't happen, like, this week per se, but just in the past couple of weeks, I'm pretty pumped because I accepted a part time job, basically. You know, I've been doing freelancing for almost a full year now, But I started working now part time for the church that Melissa and I go to and met that.
Melissa:Yay.
Jam:Yeah. So I'm I'm excited about that. It'll give me time with with people, which I'm really looking forward to. And there's also just a consistency to it that Any person who's freelanced for any amount of time will can tell you that that's one of the biggest downsides, especially about being new to it like I have been. And so I'm excited about having some steadiness to stuff that is pretty normal week to week and then Can still freelance as I have time for it.
Jam:So I'm I'm really excited about that. There's a lot of reasons to be excited about it, but I think it'll just feel nice to have some consistency. And, of course, it'll be cool just to for spending time with people in our area to be Basically, a huge part of my job. So
Melissa:Right. Yeah. That's nice. Yeah. And but you're still doing freelance, so people love The sound quality of the podcast, they can still hire you to do stuff?
Jam:Yes. I still am doing freelance. I basically just been taking a short break while I, get accustomed to this part time job. But I my plan is to be Always have some room for some freelance and say yes to things I have room for, as much as I want to. So the nice thing is I I don't have to, like, Say yes to every single thing, which I was doing for quite a while.
Melissa:Right.
Jam:Yes. And even it got me in trouble sometimes too, where I had too much. So now I do not. I have a much lower risk of making that mistake.
Melissa:Well, that's exciting, Jam. I'm very happy for you.
Jam:Yes. I'm I'm pumped too. It's been Cool so far, and I'm still getting used to stuff, but I'm excited.
Melissa:I will say that was not news to me, but even when I hear about things that I I already know are going on in Jim's life. I feel like I get more insight when he shares, on Koji For Life than Even I hear about in our in our friendship life. So Yeah. That was exciting. I didn't know that you are enjoying the consistency so much.
Melissa:That's really cool.
Jam:Yeah. And I think it's fun because, like, You sum we summarize it so much more here, which can be helpful too. It's like a vague a summary of how you're feeling about this and the benefits and and Negatives in some cases or whatever. But yeah.
Melissa:Yeah.
Jam:So, yeah, that's that's what I've been thinking about, and that's what's happening in my world. What about you, Melissa?
Melissa:Okay. Well, it's actually not so different than yours. My job duties haven't changed, but I have been struggling to find And longing for consistency. Uh-huh.
Jam:Uh-huh.
Melissa:I I have to set my own hours. My schedule changes every semester, And that's nice because that means I can work extra on Tuesday and then go drop my car off at the oil change on Monday or whatever. You know? There are nice things about it, But it can be very difficult because I am not inherently extremely disciplined. And that may be surprising for some of our listeners because You mostly know me in this chemistry setting, but I will say it has been a lifelong struggle of mine to find some natural discipline.
Melissa:So I've been really trying to wake up in the morning, go for a short walk, just like a 20 minute walk. It's some Quiet time, my brain to sort of settle and prepare for the day, and then get ready and be out the door by a specific time. So trying to leave the door at 9 o'clock. Mhmm. And that's been really nice.
Melissa:My morning routine has been going well.
Jam:Mhmm.
Melissa:However, I cannot Go to bed on time. So I actually made someone put a lock on my phone to where I can't play on it. It's like, I don't have the password. I cannot get on my phone after 10:30 PM, and last night, I actually fell asleep at 9 o'clock.
Jam:Woah. Nice, dude.
Melissa:So I think just knowing that I don't have the option really takes that away and makes me want to just there's nothing else to do. So I just read until I get sleep and go to sleep, and there's something different about that than looking at your phone. You know?
Jam:Yeah. Yeah.
Melissa:And so that's been really nice, and I'm hoping that I can more consistently have a routine And get my work done in work hours instead of working late because I show up late or whatever. You know? Yeah. I can have a more Steady time. That's my goal for this semester is to get my schedule steadied.
Jam:Yeah. Yeah. Yeah. That's tough, but very cool that it is working kind of well so far, your efforts to rein in that That ambiguity a little bit.
Melissa:Yeah. We're we're about a week in to the walks. I've been walking for a week and really love that. I don't think that that's gonna be hard to maintain. I am worried about bedtime.
Melissa:I've never been good at just going to sleep. Yeah. Once I put down my phone and turn off the lights, I'm out. But I don't wanna miss out on anything, so it's hard for me to stop.
Jam:Yeah. Yeah. Yeah. Just like that nighttime, like, limiting your phone stuff is probably huge. I've heard a lot of people say that, like, looking at a screen before you go to bed, like, that really sends different signals to your brain instead of, like, the wind down kind of signals.
Jam:It's, You know, you're shining a light in your eyes. So that that can have an effect on our ability to wind down and and get a good night's sleep. So that that's a really good idea.
Melissa:Well, I'm really excited about it. So And I'm also really excited that, speaking of light, we got to talk about The sunlight today and that we got to dedicate this episode to Miriam and our Southern Hemisphere listeners. We appreciate you guys.
Jam:And our blondies.
Melissa:And our blondies. Just to you, blondies.
Jam:Well, thank you for teaching us. And, those of us who love the sun can just be have this episode for now while we're waiting for the sun to come back to our part of the world on the northern hemisphere. Melissa and I have a lot of ideas for topics of chemistry in everyday life, but we want to hear from you the things you wonder about, the things you think might be chemistry and probably are, please ask us. If you have any questions or ideas, you can email us on Gmail. You can tweet us on Twitter.
Jam:You can gram us on Instagram, and you can book us right on Facebook at Kem for your life. That's Kem, f o r, your life, to share your thoughts and ideas. If you'd like to help us keep our show going and contribute to cover the cost of making it, go to kodashfi.com/chem for your life and don't at the cost of a cup of coffee. If you're not able to donate, you can still help us by subscribing to our favorite podcast app and rating and writing a review on Apple Podcasts. That also helps us to be able to share chemistry with even more people.
Melissa:This episode of Chemistry For Your Life was created by Melissa Colini and Jam Robinson. References for this episode can be found in our show notes or on our website. Jim Robinson is our producer, and we'd like to give a special thanks to a Heffner and Ian Noll who reviewed this episode.
