Curiosity Daily

Nightlight Plight, Cancer Stinks, Literal Green Energy

Episode Summary

Today, you’ll learn about how that light coming in through your window at night is in fact ruining your sleep, how some diseases—including cancer—can be smelled by dogs and we’re on the verge of being able to smell them with modern technology, and how algae may one day provide the power for our smallest devices.

Episode Notes

Today, you’ll learn about how that light coming in through your window at night is in fact ruining your sleep, how some diseases—including cancer—can be smelled by dogs and we’re on the verge of being able to smell them with modern technology, and how algae may one day provide the power for our smallest devices.

Close your blinds.

What’s that smell?

Get used to algae-power.

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Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/nightlight-plight-cancer-stinks-literal-green-energy

Episode Transcription

NATE: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. Time flies when you’re learnin’ super cool stuff. I’m Nate.
 

CALLI: And I’m Calli. If you’re dropping in for the first time, welcome to Curiosity, where we aim to blow your mind by helping you to grow your mind. If you’re a loyal listener, welcome back! 

NATE: Today, you’ll learn about how that light coming in through your window at night is in fact ruining your sleep, how some diseases—including cancer—can be smelled by dogs and we’re on the verge of being able to smell them with modern technology, and how algae may one day provide the power for our smallest devices.

CALLI: Without further adieu, let’s satisfy some curiosity!

[SFX: Whoosh]

NATE: Calli, what do you do before you fall asleep?

CALLI: I’d love to tell you I’m a big reader every night, but if we are being honest, I watch my favorite youtubers, and then of course re-watch some of my favorite Carl Sagan clips. 

NATE: Ya gotta consume that content, but you might want to think about leaving your phone or tablet in the living room. 

CALLI: Oh come on, on certain nights, falling asleep to that warm glow of a screen feels a bit comforting.

NATE: Well, new research is showing that sleeping with even a single moderately bright light on in your room can have drastic effects on the quality of your sleep, and your health.

CALLI: How much light we talkin’? Book light? Lamp? Night light? DJ’s colored spotlights? Headlights? High beams? High beams from the car behind you as seen through your rearview mirror?

NATE: That last one is the brightest light of all! No, researchers tested this with a one-hundred lux light.

CALLI: Lux? I've heard of lumen but what is lux?

NATE: Lumen is the amount of light that comes out of a bulb, lux is the amount of light that falls on a specific surface. 

CALLI: Ah interesting, so it’s the light that actually illuminates what you are trying to see, not just all the light a bulb puts out.

NATE: Exactly. It's about the same amount of light as an overcast day, or say, having a TV on in a dark room. Or a streetlight outside your window through only a thin curtain. Any of that sound familiar?

CALLI: Any? Try ALL! And I am definitely guilty of falling asleep in front of a screen.

NATE: I think it's fair to say we all are at this point.

CALLI: Ok, so how did they test this? 

NATE: Right, so they had two groups. All the participants in both slept two nights for the study. On the first night they all slept with dim lighting, and on the second night ... one group slept, instead, with that 100 lux moderate light. They tracked both groups during and after their sleep. 

CALLI: What kind of tests were they doing? Did they shake them awake and say, ‘Hey is that light bothering you?’

NATE: An interesting tactic, but that probably would have affected sleep quality a bit. No, they had them wear heart rate monitors while they slept, and when they woke up, they did two tests to see how well they processed insulin.

CALLI: Insulin? Like, the hormone that helps you get glucose out of the blood and into our cells?

NATE: The very same.

CALLI: So what did they find? Please tell me I can sleep in the light. Lizards can, why can’t I?

NATE: Sorry, Calli. When the room was moderately lit, heart rates increased.

CALLI: That’s kind of odd, but why should I care? Maybe my heart is just doing a little workout. While you sleep, I grind. 

NATE: Well that means your autonomic nervous system is working, and it should be shutting down at night. This is what controls your involuntary processes like heart rate, pupil dilation, digestion. It controls your fight or flight responses.

CALLI: Hmm, I guess it would be hard to rest if my body is constantly thinking about sprinting for the door. 

NATE: Totally. And then when you’re not resting at night, the effects carry into your day. Okay, so after the first night of the experiment, which is when the two groups slept in the same, dim light—when they woke up—all of the participants’ insulin resistance was about the same.

CALLI: Good start to the experiment. And by insulin resistance you mean...?

NATE: Good question. It’s actually not something your doctor would typically test for. It’s a measurement used most often in research. It refers to your body’s response to the hormone insulin, which helps regulate your blood sugar. When your insulin resistance is high, your body has a harder time taking the glucose (or sugars) up out of the blood, and if you build up a long term resistance to insulin, that’s the first step on the long road to type 2 diabetes.

CALLI: Ah, got it. So an insulin resistance score is like a golf score. You want a low one.

NATE: Yep! Your doctor would probably be looking at a blood glucose score of some kind. Okay, so the second night the group, who continued to sleep in dim light... their insulin resistance fell, which is good. And it fell an average of about four percent. While the folks sleeping in moderate light ... theirs rose about fifteen percent!

CALLI: That's a big swing. But ... um, what does that mean? 

NATE: Well, put simply, if your insulin resistance is high, your body will need to make more insulin to get the same job done. Plus, over time your cells will become even more resistant, and then even super high levels of insulin won’t be enough to regulate your sugar properly.

CALLI: Right, right. Like how when my little brother wanted to annoy me growing up it worked quickly, and very effectively, then I got used to it, and if he wanted to annoy me later on, he really had to work for it.

NATE: That’s ... sure, yeah, like that. Anyway, the resistance to insulin causes your blood sugar to rise, and over time high blood sugar can lead to diabetes and hyperglycemia.

CALLI: Ok, I’m going home and coating all my windows with aluminum foil, it will be the darkest room in existence, like sleeping in a cave or the hold of a ship. 

NATE: Well, that's not the worst idea in the world, but researchers admit there is still a lot of research to be done before these findings are definitive. This study was just over the course of two nights, and only included 20 sleepers.

CALLI: Ah, so maybe I don’t have to break every screen in my house?

NATE: No, screens can be okay. Maybe just turn them off earlier. Give yourself time to adjust before you head to bed.

 

CALLI: Back to books it is, no more youtube, no more streaming, no more phone scrolling.

NATE: And even if you don’t get better sleep, I think you’ll just be happier. 

CALLI: Thankfully they didn’t study whether or not I can listen to a podcast to fall asleep. I think I need something. 

NATE: When they do that study, I’ll spare you the results.

[SFX: Whoosh]

CALLI: Nate, did you know dogs can smell certain diseases?

NATE: I did! If I remember right, with training they can detect cancers, like prostate cancer, with over ninety-eight percent accuracy!


CALLI: That’s right! Some dogs have also been used to detect malaria, Parkinsons and even Covid-19, and have been a big inspiration for scientists studying our sense of smell. And now, researchers are trying to make machines that share this incredible ability. And they’re not far off, it seems! We may be looking at having the technology that sniffs out certain diseases in the palm of our hands in just a few years.

NATE: That would be amazing, but ... why can't we just train more dogs? Why worry about creating a sensor if we have an adorable, furry solution?

CALLI: Training dogs can be really expensive, and has to be done for each individual dog. Also, believe it or not, not everybody is a dog person. So, scientists have been trying to create a sort of robot nose.

NATE: So how does the nose work? What exactly is it trying to detect?

CALLI: Oddly enough, we don’t know really. With sight, we know there are a small handful of receptors, and we understand how they work, but scent has more than 400 receptors, and we still have a ton to learn about how they interact with odor molecules and each other. We know smell receptors send electrical signals to our brains, but beyond that, we clearly don’t know enough. Dogs have beaten rooms full of $100 million worth of “smelling” equipment. 

NATE: Wow. I never thought about it, but smell is so elusive!

CALLI: Yes! And because of that, DARPA—which is the Defense Advanced Research Projects Agency, who essentially funnels research, money, and talent toward advancing science for the benefit of the US Military—has sponsored competitions specifically looking for advanced smelling technology. These competitions often attract talented scientists and big investment in cutting edge areas of science and technology.

NATE: What kinds of cutting edge things have scientists tried in order to win the DARPA prizes?

CALLI: Researchers first tried to send the electrical signals coming from the smell receptors to a circuit board instead of the brain.

NATE: What does that mean? How do you do that?

CALLI: Well, first they had to grow a whole bunch of them in a lab! They used smell receptors grown from human cells, and spread them across a circuit board. They then monitored an electrical current sent through the board for responses to different smells.

NATE: Wow. A lab-grown nose.

CALLI: Essentially, yes. Though, almost immediately the system was overwhelmed by how many different molecules there were to smell.

NATE: What did they do next? I’m guessing either decrease the number of molecules, or increase computing power?

CALLI: Or! You could try not to smell all the individual molecules. They decided to try to capture the overall smell, the essence. This sort of thing is more about how the molecules interact with each other rather than identifying individual molecules.

NATE: Wow. How did they think to do that?

CALLI: They were copying what dogs do! Research has shown that cancer-sniffing dogs don't smell particular molecules, or biomarkers, but rather can detect that a sample is particularly “cancery.”  So, they took a smell and recorded the overall electrical pattern the receptors created. Each smell did in fact create a unique overall pattern that the computer could learn to recognize. 

NATE: Learn to recognize? Are we training computers…like training dogs?

CALLI: Exactly like training dogs. They exposed the machine, which researchers call Nano-Nose, to a variety of smells and allowed it to learn what to look for.

NATE: And this worked?!

CALLI: Yes! The Nano-Nose, looking for smells rather than molecules, could in fact pick out different individual odors. Better than dogs even!

NATE: No way!

CALLI: For real. The Nano-Nose could pick up odors in smaller concentrations than the dogs.

NATE: That’s incredible.

CALLI: Agreed. Though, this was in a controlled environment. Under normal circumstances, the dogs would almost certainly win out. The real world is a lot more confounding when it comes to scents and smells. But the technology is moving along well. The system was originally about the size of a desktop computer, but researchers think it could shrink enough to fit into our smartphones within five years or so. 

NATE: Each of us with our own smell-o-phone? 

CALLI: Exactly. And this could help with real world detection of illness at early stages.

NATE: Is this going to change targeted ads though? Am I going to start getting Old Spice commercials after a particularly smelly workout? 

 

CALLI: Privacy is certainly a major concern, especially as we incorporate this potentially intimate technology onto things we carry every day. But some researchers say the potential for life saving results means we need to seriously consider incorporating the tech into our lives.

NATE: Well they better train it to sit and roll over too if they really want me to buy in.

CALLI: (laughs) People might take a few extra looks if you start petting your phone Nate.

[SFX: Whoosh]

NATE: Calli, brace yourself. This story is about how pond scum has super powers.

CALLI: Pond scum…? Nate, what do you mean?

NATE: Algae, also known as pond scum, may help provide the answer to one of our biggest problems with the ever-growing Internet of Things.

CALLI: Internet of Things?

NATE: Yeah, I know. Sounds ridiculous, but that’s a real term! It refers to the network of little devices that don’t, like, surf the web or anything, but use the internet or a much smaller network to communicate with nearby control devices or each other. Lightbulbs connected to bluetooth, smart thermostats and refrigerators, some speaker systems, mostly smart home stuff, but also some minor home health devices like a wearable heart monitor.

CALLI: Ah, very cool. So, wait, how does pond scum fit into all this?

NATE: Well researchers just used blue-green algae, or synechocystis, to power a microprocessor, continuously for more than a year, with nothing more than ambient light and water. 

CALLI: They used aglae? To power an electronic device? This is science fiction.

NATE: It's not science fiction, it's biophotovoltaics! The science of using biological microorganisms to harness power!

CALLI: Like a potato battery!?

NATE: Kind of! But, the potato isn’t really providing energy as much as a way for electrons to move back and forth freely. 

CALLI: So what exactly did they do?

#NATE: Well, the researchers made a device ... it's about the size of a double-A battery and made from common, inexpensive, and mostly recyclable materials. Inside the device there is algae and an aluminum electrode. As the algae photosynthesizes, the electrode translates this process into energy we can use.  

CALLI: Well what can it power? 

NATE: In this experiment, researchers powered an Arm Cortex M Zero Plus microprocessor. It doesn’t sound like much, but this is a small chip found in a lot of Internet of Things devices, like it’s probably in your smart watch or fitness tracker. Using the algae power, it was able to carry out basic calculations.

CALLI: Wow, so it worked. Algae powered the microprocessor. How much energy does that take? 


NATE: It consumed about point-three microwatts per hour. 

CALLI: Less than a single microwatt per hour doesn’t sound like much power.

NATE: Right, though, that’s part of what excites the researchers! The growing field of Internet of Things devices requires power, but not a ton of power. And even though they don’t need much power, there are a lot of things in the Internet of Things. The impact of getting enough lithium to make batteries to power all these devices would be really expensive, AND bad for the environment. These literally-green power sources could provide the small amounts of power that these devices need ... cheaply, reliably, and without a massive environmental impact. 

CALLI: I mean that's awesome, but what about when the sun goes down? 

NATE: That's one of the coolest things! Researchers found the algae still processed power, even without light. They think this happens as algae processes its food after photosynthesis. Even in the dark it's doing work and making power. 

CALLI: Ok but was this in a lab? You know, with super specific conditions?

NATE: Not even close! It was a semi-outdoor environment with natural light and temperature fluctuations.

CALLI: Semi, outdoor?

NATE: In simpler terms, it was on a window sill!

CALLI: Ah.

NATE: Even with these conditions, researchers were really surprised by how consistently the system worked. They expected big pauses or shutdowns, but the device hummed along for more than a year. 

CALLI: Are these going to be replacing all of our solar panels soon? 

NATE: Not quite. Photosynthesis isn't very efficient. The algae gets just point-two-five percent of the energy in sunlight whereas we can get up to twenty percent in solar panels. The big difference is that they are cheap to produce and environmentally friendly. It makes them a great solution for things that need power, but just a little bit. 

CALLI: So where will we see these things? Other than The Internet of Things.

 

NATE: This system could be really useful for off-grid or remote locations where even a small amount of power can make a big difference. And if you needed more power, you could daisy chain a few of them together. 

CALLI: Oh this sounds like a great solution to a common problem, and think about how much we can lower our lithium needs!

NATE: It turns out all we needed to go green was to go blue-green. 

[SFX: Whoosh]

NATE: Let’s recap what we learned today to wrap up.

CALLI: Sleeping with a light on in your room can affect the quality of your sleep, and how well your body operates the day after. New research is showing that even a moderate amount of light can raise our heart rate and keep our autonomic nervous system from fully resting.

NATE: Cancer-smelling dogs are helping researchers better understand, and recreate, our sense of smell. Within a few years each of our smartphones could have a sense of “smell” capable of detecting illnesses like cancer and malaria at early stages.

CALLI: Researchers successfully powered a microprocessor from an unlikely source, algae. This breakthrough is raising hopes for cheap, environmentally friendly power for many of our small devices.