Today you’ll learn about how ancient Roman concrete can heal itself, the recent discovery of a virovore, and how a new study looks into whether or not we can control feelings of guilt through the placebo effect.
Today you’ll learn about how ancient Roman concrete can heal itself, the recent discovery of a virovore, and how a new study looks into whether or not we can control feelings of guilt through the placebo effect.
Roman Concrete Magic
Virovore
Placebo Guilt
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Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/roman-concrete-magic-virovore-placebo-guilt
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 ancient Roman concrete can heal itself, the recent discovery of a virovore, and how a recent study looks into whether or not we can control feelings of guilt through the placebo effect.
CALLI: Without further ado, let’s satisfy some curiosity!
[SFX: WHOOSH]
NATE: There are several Roman structures that have been around for thousands of years. Have you ever wondered what makes them so strong? Like why they've been able to stick around? Have you ever thought maybe they were using magic?
CALLI: Curiosity Daily. We talk about science, we talk about psychology. And now we talk about magic.
NATE: Yeah, sort of like it's all right. It's not magic, but it's got. It's got like a sort of magical bit of science to it. So that's good, right? Sure. So, yeah, so concrete has been used for building stuff forever, but the Romans, their concrete was different because of the quick lime that they used in building.
CALLI: Okay, I'm going to stop you right there because we use quick lime today in everything from steel making and in glass production to this is gross but food additives and also. Yeah it's it's in our own concrete. So what is different about theirs.
NATE: All right. So modern concrete is usually made from a combination of limestone, clay, sand, chalk and some other ingredients. The Roman concrete used a white powder called slaked lime, as well as small particles and rock fragments known as Tephra, which came from volcanic eruptions. The main difference between the two: modern concrete starts to crumble in 50 years or less, Roman concrete has stood the test of time for more than 2000 years, and for a long time nobody knew why. Scientists once believed that the concrete was stronger because of a specific chemical reaction between the tephra and the seawater. But new research says that is not the full story.
CALLI: I can't believe I'm going to say this, but I am very interested in the story about concrete. Please explain magical concrete to me.
NATE: So Admir Masic, a chemist at the Massachusetts Institute of Technology started out by gathering some concrete samples from an ancient city wall in a 2000 year old archeological site near Rome. Back in the lab, his team focused on small calcium deposits embedded in the concrete, which are known as lime lumps. Common knowledge dictated that these tiny chunks came from poor concrete mixing. But Masic theorized the Romans were using quick lime in their mix before setting it with water.
CALLI: Huh? Okay. Where are they?
NATE: Probably. You see, quick lime would have reacted when water touched it, sparking a chemical reaction that would create large amounts of heat, preventing the lime from fully dissolving, resulting in lime lumps. And in fact, when Masic’s team tried to recreate their own Roman concrete, they ended up with a concrete that was indistinguishable from the engine samples. So they experimented with it. They added small cracks in the concrete, which would naturally happen as the material aged and then added water to emulate the natural rain flow that would hit the structure and the lime lumps dissolved and re crystallized. This filled in the cracks and it kept the concrete strong like strong, strong.
CALLI: Okay, when you say strong, like how strong are we talking here?
NATE: All right, well, modern concrete can self-heal to a certain extent.
CALLI: It can?
NATE: A little. For example, if a crack that's smaller than a quarter of a millimeter happens in a slab of concrete, the concrete will push itself back together. But anything bigger than that, and you're going to start having decay. But the Roman concrete would self-heal for cracks as big as 0.6 millimeters, which is more than triple the size of crack that modern concrete can withstand.
CALLI: All right. This is all fascinating. And I can't believe I'm saying that, but it really is. But what what's the bigger picture here? Why? Why were they studying concrete?
NATE: Well, Masic hopes this will inspire modern engineers to improve their own concrete recipes and maybe even with quick lime or a more stable compound. He says he already knows of at least one startup concrete company that's interested in his team's research because it makes concrete production way less expensive. And get this, it can also fight climate change.
CALLI: Okay, those are my favorite words. I kind of love anything that fights climate change. But why do all of our segments keep wrapping back to it even when we try not to?
NATE: It turns out a lot of stuff is related to the climate and affecting it. So. And this in particular, I mean, cement production accounts for a whopping 8% of all greenhouse gas emissions. And so a process like this that could potentially slice that number in half could make an absolute huge difference. I think, you know, the old saying when in Rome and owning a construction company and wanting to save the planet by cutting down greenhouse gas emissions, do as the Romans do. Is that is that the phrase?
CALLI: Yeah. Yeah. No. Yeah, you nailed it. You got it.
NATE: Something like that.
[SFX: WHOOSH]
CALLI: You've probably heard of the words carnivore, omnivore, herbivore, all of that. Now, have you ever heard of a virovore?
NATE: I can't say that I have. Carnivore eats meat. Omnivore eats everything, herbivore eats plants. Viro - would that be something that eats viruses?
CALLI: Oh, you got it. Yeah. Okay, so throughout time, creatures of all shapes and sizes have evolved to eat specific diets. You can find viruses just about anywhere, so it's inevitable that some organisms will consume them on accident. But there's a researcher named John DeLong from the University of Nebraska-Lincoln who wanted to know if there were any microbes actively eating viruses.
NATE: Why did he want to know that?
CALLI: Because they're tasty. No, no. All right. Because viruses are actually surprisingly nutritional. They're made up of nucleic acids, nitrogen and phosphorus. DeLong said everything should want to eat them because that diet could actually support not only the physiological growth of a person, but the population growth of a community.
NATE: I do love a good nucleic acid sandwich. All right. So how did you go about trying to find these microbes, then?
CALLI: Well, he went about it in kind of an interesting way. DeLong and his team started out by collecting pond water samples, then isolating different microbes to see what their natural dietary instincts looked like. The team added a large amount of cholera virus to each sample, which is a freshwater virus that infects green algae. And for the next few days, they monitored the microbes and the viruses to see what would happen.
NATE: All right. I guess that seems like it should work. Did it?
CALLI: Yup. There was one microbe in particular known as Halteria that was exclusively snacking on viruses. Halteria are Ciliates, which are single celled organisms that at some stage in their lifecycle have short hair-like structures used for food-gathering known as cilia. All of the Halteria and the other silicates were stored in one freshwater tank together. And over the course of two days, Halteria populations grew by nearly 15 times their original numbers.
NATE: Okay. Are they sure the Halteria was eating the viruses?
CALLI: There were no other food sources in the tank. Plus, chlorovirus levels dropped nearly 100% in the same two day span. And just to make sure it wasn't a fluke, they had a control tank without the virus in that sample Halteria didn't grow at all.
NATE: All right. Just playing devil's advocate here, could it have been other viruses?
CALLI: It's okay. It is impossible for humans to fully control microscopic creatures from entering the water, which is why DeLong team did a follow up test where they tagged chlorovirus DNA with fluorescent dye. Within hours, they noticed that Halteria cells soon began to glow because of the dye from the viruses they consumed.
NATE: All right. Okay. Very cool. So it does seem like these virovores exist. What is their existence mean for us?
CALLI: Okay. As of right now, we don't know. This is the first recorded instance of a creature subsisting solely on viruses that we know about. I can tell you what we think it means. We know that the persistence of viruses in our environment depends not only on environmental factors, but also on grazing by predators. Basically, viruses get stronger because of the way they're consumed. This could potentially change the way we look at predator prey dynamics in the wild because it positions viruses as a hybrid.
NATE: A hybrid of what.
CALLI: Both predator and prey. Viruses are being consumed in finding ways to become stronger. And as they become stronger, we run out of ways to resist the viruses which can kill us or other mammals. Now, this is just a theory for now, and the researchers plan to continue investigating, and that includes the effects virovores have on larger systems like the carbon cycle.
[SFX: WHOOSH]
NATE: If you've ever felt guilty about something like hurting friend's feelings, yelling at somebody, stealing your co-host’s parking spot, don't worry, you're not alone. Thankfully, new research suggests that there is a pill for that. A pill that can eliminate all of those feelings of guilt in one fell swoop.
CALLI: Okay, First off, I just want to clarify something. I apologized for stealing the parking spot. But I do feel kind of bad. So, how do I get the pill?
NATE: Well, there is a study conducted on the topic of guilt recently. We're getting to how you get it. But 112 healthy volunteers between the ages of 18 and 40 took part in the study where they were given questionnaires called state shame and guilt scales or SSGSs, asking them to rank how ashamed they felt about something and how guilty they felt about anything they've done. Next to the SSGS asked the participants to do an exercise purposely designed to make them feel even more guilty.
CALLI: How do you make somebody feel more guilty about something they already did? And like what? What did they make the participants do?
NATE: All right. So each participant wrote a story about a time that they treated someone unfairly. In your case, you could write about the parking spot, you know.
CALLI: Oh, my gosh. Let it go.
NATE: Afterwards, all 112 participants were divided into three groups. One group was given a blue pill that they were told was a drug called phytopharmacon, a drug that allegedly reduces feelings of guilt by making the user feel more calm.
CALLI: Yeah. Okay. That definitely sounds like a pill. I want my.
NATE: Life. Well, the next group received an open label placebo. It was the exact same blue pill, but the group was told that it was a placebo. And researchers told the participants that even though the pill wouldn't help them physiologically, it could benefit them through mind body healing mechanisms.
CALLI: K wait, I think you might have misspoken or I might have misunderstood. You said that they were the exact same pill, right? So then how is it a placebo?
NATE: Because the first pill was also a placebo. Specifically, it's what they called a deceptive placebo. The only difference was that the second group knew the pill was a placebo, but the first group did not.
CALLI: All right. Did the third group take the real pill?
NATE: No. The third group didn't receive any treatment at all. Remember, in studies like these, it's important to have a control group to compare effects. So the third group were the lucky few who didn't have to take the placebo.
CALLI: Let me get this straight. Nobody actually took a pill that can get rid of their guilt. So is phytopharmacon. Whatever this thing is, is it even a real drug?
NATE: Nope. To our knowledge, there are no medicines that can actually eliminate the feelings of guilt. And that was the point of this study to figure out if mind body feeling mechanisms also known as convincing yourself you're okay can be enough to get rid of guilt. After each of the groups received treatment, they're guilty. Feelings were measured using the same questionnaire to figure out what the best way to deal with guilt was. The deceptive placebo, the open label placebo, or no treatment at all.
CALLI: Let me guess. The people who believed they were taking a real drug were better overall.
NATE: Yes, kind of. Because the outcome was actually that anybody who took the placebo showed signs of reduced guilt afterward, meaning that whether the placebo was deceptive or open label, the participants felt way better across the board than anybody who didn't receive the treatment.
CALLI: This has got Shyamalan written all over it. This is ridiculous. Why did the placebo work for both parties then?
NATE: It might help if we talk about what's called the placebo paradox. On one hand, placebos do have effects, especially for pain, and we know how they work because doctors are ethically bound to help patients. It pushes them to prescribe open label placebos, even if they're not technically the necessary treatment. But on the other side, traditional non labeled placebos can be seen as deceptive by patients because they might assume that they're actually being treated. It’s kind of an ethical nightmare for doctors to navigate, which is why open label placebos are necessary. In both cases, however, the patient is taking something they think will improve their health, whether it's a long term fix or a short term fix, that doesn't matter because it's doing something.
CALLI: But in essence, this whole study is about deception, right?
NATE: Yeah, it's definitely not a perfect study. For starters, each participant had a clean bill of health and they weren't actually suffering from known guilt before the experiment, which means we're not sure if this research would even translate to people in clinical practice. Plus, the measures of guilt were only taken 15 minutes after the placebos were given. We have no idea how useful or even what the long term effects of the placebo can really be. And the worst offender here is that the study lumped the effects of deceptive and open label placebos together. So if the goal of the study is to research open label placebos, this undercuts the results a bit.
CALLI: Sure. But that doesn't really take away from the end results, right? Right.
NATE: That's fair. It's quite interesting that open label placebos can even reduce pathological guilt at all because it means they can be used ethically in cases where better treatments are nonexistent. That being said, future studies need to do a wider compare and contrast between types of placebos and provide a longer study time. Maybe you can take one for your burning guilt.
CALLI: Oh, my gosh, Nate, you know what you did? I'm leaving. You can have your parking spot back.
NATE: That's right. It's mine.
[SFX: WHOOSH]
NATE: Let’s recap what we learned today to wrap up. When in Rome, we shall do as the Romans. When mixing concrete… we shall also do as the Romans. A groundbreaking discovery has revealed the ways in which Rome mixed concrete can create more durable yet more cheaply built structures, AND can be a method to fight impending climate change. All it takes is a slightly altered quicklime recipe and voila - we can save the world!
CALLI: Meat, vegetables, a mix of both… and viruses??? Scientists have discovered the existence of the first known virovore, a creature that exclusively consumes viruses for sustenance. It’s not clear what this means for the bigger picture just yet, but some believe that this could completely change the way we look at everything from the food pyramid… to the very dynamic of predator/prey relationships.
NATE: If you could take a pill to get rid of all your guilt… would you? So would the 112 participants who took part in a study on just that recently. But in an interesting twist - the pill doesn’t exist! Instead, the study was looking into the effectiveness of placebos. Specifically, can a placebo help whether somebody knows it’s a placebo or not? The answer, regardless of whether the person was told, was a resounding YES. Future studies need to be performed that further examine the difference in methods, but this looks positive as a means to help people overcome their nagging sense of guilt.