Today, you’ll learn about the benefits of shading rooftop gardens with solar panels, caffeine’s dark secrets, and how the first image from the James Webb telescope promises a great run for Hubble’s successor.
Today, you’ll learn about the benefits of shading rooftop gardens with solar panels, caffeine’s dark secrets, and how the first image from the James Webb telescope promises a great run for Hubble’s successor.
The sun really can feed you.
Caffeine: the ultimate chicken or the egg dilemma.
“The invisible addiction: is it time to give up caffeine?” by Michael Pollan
“Caffeine: How much is too much?” by Mayo Clinic Staff
“Caffeine - Uses, Side Effects, And More” from WebMD
“How and When Did Humans Start Consuming Alcohol?” by Sedeer el-Showk
“Coffee and caffeine consumption and depression: A meta-analysis of observational studies” by Longfei Wang, Xiaoli Shen, Yili Wu, and Dongfeng Zhang
A picture might be worth more than a thousand words.
Follow Curiosity Daily on your favorite podcast app to get smarter with Calli and Nate — for free! Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/solar-salads-cursed-caffeine-webbs-first-photo
SOLAR SALADS, CURSED CAFFEINE, WEBB’S FIRST PHOTO
Follow Curiosity Daily on your favorite podcast app to get smarter with Calli and Nate — for free! Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
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 the benefits of shading rooftop gardens with solar panels, caffeine’s dark secrets, and how the first image from the James Webb telescope promises a great run for Hubble’s successor.
CALLI: Without further adieu, let’s satisfy some curiosity!
[SFX: Whoosh]
NATE: Calli, I’m super excited, it's almost time to start filling my vegetable planters.
CALLI: Oh I love this time of year, there is nothing better than bringing in fresh veggies. Saves money, saves time going to the grocery store.
NATE: I love to do it! And share them. But what if I told you that your vegetable garden might not just be the solution for the occasional afternoon hunger pang. That it can have a mutually beneficial relationship with clean energy technology, and help fight against rising urban temperatures?
CALLI: You’re talking about using cucumbers to get us out of a pickle?
NATE: Researchers are now exploring the benefits of using rooftops to simultaneously harvest crops, and electricity. The method is called agrivoltaics You’ve got your rooftop garden ...
CALLI: Ah, I've heard of this, wouldn't that be a green rooftop? Those buildings covered in plants?
NATE: It's similar, but then you put solar panels up above it. The solar panels provide some well-needed shade.
CALLI: Shade? I thought plants love the sun, and where can you get more of it than on the roof?
NATE: That's just it, there might be too much sun. Most plants can’t handle it. So, in a normal rooftop garden setting, you have to be exceptionally careful about which varieties you choose. When the plants get more sun than they can handle, they stop photosynthesis and ... instead ... start doing something called photorespiration… That's where they break down oxygen rather than carbon dioxide.
CALLI: I didn’t even know they did that.
NATE: It's an inefficient process that slows down their growth... On top of that, the panels help block some of the wind. Roofs are often windy places. Because of this, most green roof designers choose hearty, sun-loving succulents.
CALLI: Well what do the other picky, non-prickly plants like?
NATE: If you think of a forest, big trees often shelter smaller plants on the ground from strong winds, and provide intermittent shade. And it turns out, most plants prefer a bit of shade. The growth of Leafy greens increases, and pepper plants can triple their production with some shade.
#CALLI: So then how do we get sun and shade and wind protection?
NATE: Agrivoltaics! If you plant gardens and farms beneath rooftop solar panels, then you get all in one.
CALLI: And having plants beneath them doesn't mess with the solar panels at all?
NATE: Believe it or not, it can actually make the panels work more efficiently. The plants respirate, and sort of “sweat.” They release water vapor that rises and cools down the solar panels.
CALLI: And cool panels are better than hot ones?
NATE: Hot solar panels are less efficient at creating energy, so the relationship really is symbiotic. Some researchers are even looking at using semi-transparent solar panels that would let some light through, great for plants that prefer less sunlight, but don’t want total shade either.
CALLI: Well I wanna start growing plants and power on my roof? What do I need?
NATE: Might be tough. The roof needs to be flat, and it needs to be strong enough to support the weight of panels, planters, plants, and a lot of dirt. It also needs to be highly waterproof. You don't need plant water seeping into your home.
CALLI: That's actually a lot of requirements.
NATE: Totally, that's why researchers are finding that it makes more sense to do agrivoltaics on new buildings with strong roofs rather than trying to retrofit existing buildings. They’re even suggesting that governments subsidize these roofs as they decrease greenhouse gas production from food transport, generate green power, and lower urban temperature.
CALLI: I haven't heard someone talk about temperature this much since Sean Paul. But why would we want lower urban temperatures?
NATE: Well, cities are filling up, and heating up. Basically, all that man-made stuff, concrete, glass, working machines, and air conditioners. Cities can be about twenty degrees hotter than the surrounding rural areas. If you shade the buildings with their own green roofs, it reduces the effect. The plants use the energy of the sun instead of spitting it back out into the city.
CALLI: So the real question, the meat and POTATOES of the issue if you will, is how much food can we actually produce under these panels?
NATE: Researchers found that in a city like Denver, using agrivoltaics could produce as much as five thousand pounds of food per acre.
CALLI: Holy guacamole!
NATE: Calli, you’re on fire today. Maybe not in a good way! Anyway, lots of research to go, but agrivoltaics is a promising new field.
CALLI: I’m all on board. If there are two things I love, it's a good salad and some green energy. Why not mix them together and throw in some more comfortable cities?
NATE: Solar salads coming up!
[SFX: Whoosh]
CALLI: Nate, do you drink coffee?
NATE: You know ... I actually don’t.
CALLI: You’re better off than me, I need that stuff every morning.
NATE: I just use my zest for life and love of science to get me going in the morning.
CALLI: [laughing] That's good, because research is showing that the world’s addiction to caffeine might actually be making us less productive, and may be the cause of the sleepiness many of us consume caffeine to combat. Now, that’s not to say it doesn’t have scientifically proven positive effects as well, but it’s not all upside.
NATE: I’ve never been a coffee drinker, but I have always wondered, what exactly does it feel like?
CALLI: I love it. Not only is it a nice morning ritual, but it also helps me feel awake, more alert, and focused on the tasks at hand. Studies have found that people who consume caffeine can better remember information, improve their physical performance, increase their focus, fend off sleepiness, and even decrease the risk of depression!
NATE: All that sounds kind of incredible.
CALLI: So those benefits are most recognizable in people who don’t normally consume caffeine. That’s because the more you drink caffeine the more you become accustomed to its effects. You can even develop a chemical dependency.
NATE: Right, yeah. I’ve heard of caffeine withdrawal.
#CALLI: It’s similar to withdrawal from other addictive chemicals. Now, it’s important to note that we’re talking about if you’re drinking more than four-hundred milligrams of caffeine a day ... more than four cups of caffeinated coffee. The withdrawal from that kind of thing can give you headaches, fatigue and ... even more insidious ... stress, decreased motivation and confidence, even dysphoria.
NATE: Dysphoria? Sounds like a new show on “HB-Oh-no.” But what is caffeine doing in the brain?
#CALLI: (Laughs) Caffeine doesn’t actually give us more energy, it helps us feel ... less tired. A chemical called adenosine accumulates in our brain over the course of the day. It makes us gradually feel tired, and prepares us to go to bed at the end of the day. Caffeine blocks the uptake of adenosine in the brain, preventing us from feeling tired. That is, of course, until the caffeine is metabolized and all that adenosine floods back into the brain.
NATE: Is caffeine one of those drugs we kind of evolved with? I know there is evidence of alcohol consumption in pre-human primates.
CALLI: Like, they would find some fruit that fermented in the sun. Naturally-occurring alcohol.
NATE: Yeah, exactly. Is it that old?
CALLI: Not even close. It's relatively new. Coffee production popped up in east Africa around the 15th century, and trade spread it across the Arabian peninsula. Europe got its first coffee shop in 1629 in Venice, England got its first in 1650, but it didn't take long for these numbers to sky rocket. Coffeehouses became places not just for a morning buzz, but for the exchange of ideas! Michael Pollan author of, “Caffeine” even posited that the industrial revolution likely wouldn't have happened without caffeine. Once we had indoor lighting, we still had to stay up to work. Coffee allowed us to work through the night and focus on the mundane and repetitive tasks that machinery required.
NATE: If we are supposed to feel tired at night, and then don’t, that can’t be good for our body’s natural rhythm.
CALLI: When researchers started looking at the main reason most people drink coffee, to wake up or stay awake, they found that our solution, caffeine, might actually be the biggest cause of the problem.
NATE: Well that doesn’t sound helpful at all.
CALLI: Researchers found that the quarter life of caffeine, when 25% of it is still working in your body, is 12 hours. That means that that 9am coffee is still keeping you awake, blocking adenosine uptake in your brain, until 9pm. It could be a big source of insufficient and low quality sleep.
NATE: Which would mean you’d wake up feeling tired and groggy…
CALLI: ...and reach for that cup of coffee to fix it. It's a perfect loop: making the problem, solving the problem, making the problem. In the in-between we get insufficient sleep, which, over the long term can be a big factor in developing Alzheimer's, strokes, heart failure, anxiety, and depression.
NATE: Would you try quitting? I know I sleep great.
CALLI: The Mayo Clinic has a few tips for limiting, or eliminating caffeine intake. Figure out how much caffeine you take in a day, read labels to make sure none is sneaking through unexpected places like “health” drinks, then gradually start cutting back. Try eliminating one caffeinated drink a day until you’re off, or ... limit your caffeine intake after noon. And if you’re really trying to stay off the stuff, look for caffeine-free pain relievers, as many pain relief drugs including caffeine.
NATE: It might not be easy but if you can get better sleep you might be a bit happier.
CALLI: Totally, and then I could get that real boost when I needed it. In the meantime, I still love my morning brew, I’ll just skip that second cup after noon.
NATE: You’ll see, in no time at all, all you’ll need is a good science story to wake you right up!
CALLI: (laughs) Well you’ll have to forgive me the next few days. I have a feeling that cup of excitement is gonna come with a splash of grouchiness.
[SFX: Whoosh]
CALLI: Nate, today, I’m bringing our listeners an incredible update on the James Webb Space telescope.
NATE: That’s awesome. What is it?!
CALLI: NASA recently got the first test image from the James Webb Space Telescope ... for those who don’t know, Webb is the new ten-billion-dollar telescope that launched at the end of last year ... and the clarity blew their minds! It’s WAY better than expected! We’re looking at ten or twenty years of gorgeous photos that will help unravel the story of the origin of the universe.
NATE: I’ve been so excited about this telescope. I am a huge fan of Hubble and I know this is a big step up.
CALLI: Absolutely. While Hubble orbits a few hundred miles from Earth’s surface, the James Webb Telescope orbits the sun. It’s nine-hundred-and-thirty-thousand miles from earth. That’s over a hundred-and-fifteen times the diameter of the earth away.
NATE: Oh dang, well remind me who James Webb is that he gets his own name plaque out past the moon?
CALLI: He was the former NASA administrator who led the Mercury and Gemini programs, as well as much of Apollo. And the telescope bearing his name is equally as ambitious as he was in his career. It uses 18 hexagonal beryllium mirrors calibrated to work as one. This huge complex mirror collects the light, reflects it to a second much smaller mirror, which reflects it again toward the telescope's instruments. It has a diameter of six-point-five meters. Compare that to Hubble’s single two-point-four meter mirror.
NATE: How do you get 18 mirrors to work as a single one?
CALLI: That's what is so important about this first image. They won’t use this image to make new observations about the universe. Webb’s got those nearly twenty mirrors, and now, because of this image, they know the images they get will work perfectly. The process is called fine phasing. They used this image to check every parameter of the mirror alignment.
NATE: Wow, I guess that makes sense. Like one of the printer test sheets with a little of each color and all that.
CALLI: Yep! Only in this case, the clarity they found means all the mirrors are properly adjusted within nanometers. The multiple mirrors are working in combination to create a single, supremely sharply focused image. Scientists say the focus is as sharp as the laws of physics allow. They’ve achieved the “diffraction limited alignment” of the telescope.
NATE: Ah I’ve heard of this, it's when you optimize light wavelength, lens power, and the distance to the objects you’re looking at. It's like the perfect prescription glasses.
CALLI: Yep! And that level of focus is far better than scientists even allowed themselves to hope for.
NATE: So what will this allow us to do?
CALLI: Well there is still a lot of work to go. Like, they’ve gotta turn all the cool instruments on! Spectrographs and cameras, so they can record the incredibly wide range of information Webb is equipped to gather. We can expect full high-res images and data later this summer. Webb can see stars and galaxies more than 100 times too faint for Hubble, by looking at a wider range of wavelengths.
NATE: Oh wow. So what fascinating thing did we look at first?
CALLI: That's actually pretty funny, the first image is a star that researchers say is, well, pretty boring. It's in the Milky Way about two thousand light years away. Scientists used a red filter to create a greater visual contrast between the star and the blackness of space beyond it.
NATE: Ah so it was just the lucky one to get chosen, like when my business card got me a free week of sandwiches from one of those drawings.
CALLI:...Something like that. But what really got the scientists excited was what they saw around the star: an array of beautiful distant stars and galaxies in the background. It kind of gives you an idea of just what we are going to be able to see over the lifespan of this telescope, for the next 10-20 years.
NATE: Will we be able to explore those background galaxies? Bring them to the foreground?
CALLI: When the telescope is fully operational, scientists and researchers say we should be able to see stars and galaxies billions of light years away. This should give us light from just a few hundred million years after the birth of our universe. It should wildly change, and potentially expand, our understanding of the birth of the universe and our place within it
NATE: Man, if all this optimism is coming from just the first mechanical images, then I can’t wait to see what’s to come when it’s fully operational.
CALLI: Me either! And, I’ll bring more updates when it is!
[SFX: Whoosh]
NATE: Let’s recap what we learned today to wrap up. A new scientific field, agrivoltaics, may provide the solution to our urban food and electricity problems. Combining food plots and solar panels may increase the efficiency of both and help lower rising urban temperatures.
CALLI: Many of us rely on the caffeine from coffee and tea to increase our wakefulness and focus. Research is showing, though, that this solution to our problems, might actually be the source of them
NATE: The first image from The James Webb Space Telescope is here, and it is spectacular. The clarity of the image is better than scientists and researchers allowed themselves to hope for, and suggests that the next 10-20 years will include unprecedented imagery of the depths of space.