Learn about whether parasites can turn us into zombies, why awkward silences are so awkward, and why bubbles form in boiling water.
Learn about whether parasites can turn us into zombies, why awkward silences are so awkward, and why bubbles form in boiling water.
Could parasites turn us into zombies? By Cameron Duke
The Science of Awkward Silences by Anna Todd
Why do bubbles form in boiling water? by Ashley Hamer (Listener question from Abu)
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/could-parasites-turn-us-into-zombies
[MUSIC PLAYING] ASHLEY HAMER: Hi. You're about to get smarter in just a few minutes with Curiosity Daily from curiosity.com. I'm Ashley Hamer.
NATALIA REAGAN: And I'm Natalia Reagan. Today, you learn about whether parasites can turn us into zombies. Why awkward silences are so awkward? And why bubbles form in boiling water?
ASHLEY HAMER: Oh, that was awkward. Let's satisfy some curiosity.
[SWOOSH]
Zombies aren't real. There are no known viruses that reanimate the dead. But before you get too comfortable, I want to talk brain parasites. These three brain parasites don't exactly turn people into zombies. But they do have some freaky mind control powers.
The first one I want to talk about is Toxoplasma gondii. This is a parasite that takes over the brains of mice, and makes them sexually aroused by the scent of cat urine. Not good, if a mouse wants to avoid being eaten. Cats take advantage of the easy meal, and end up infected. Once the parasite is safely inside the cat, it lays its eggs, which end up in the cat's poop.
Ultimately, Toxoplasma wants to infect mice and cats. But because cats are adorable enough to make humans clean their litter boxes, Toxoplasma can make its way into the human brain too. While Toxoplasma doesn't affect human brains as severely as it does mouse brains, there is some evidence that it can affect people's personalities. Some studies show that Toxoplasma affects risk taking behavior. And others, link Toxoplasma infections to mental illnesses like, schizophrenia.
Other parasites, like the ones in the genus Trypanosoma, have more intense effects on human behavior. The infection starts with the bite of the tsetse fly carrying the tiny parasite in its gut. Once a human has been bitten, these little microscopic organisms mature in blood and lymph turning into hook shaped worms before entering the brain. First, they hit the hypothalamus. This causes sleep disruption and headaches. If the infection goes untreated, it continues on to produce other effects, like aggressiveness, speech impairment, motor weakness, and loss of appetite. Ultimately, these symptoms give way to lethargy and a coma, which is why some call Trypanosoma infections sleeping sickness.
But neither of those two parasites comes close to the zombification, the rabies virus is capable of. Like the others, rabies infects the brain. Specifically, it targets the hippocampus, amygdala, and hypothalamus. These are all regions that play roles in emotion and memory. Rabies generally begins by triggering a hyperactive fear response that leads to aggression.
Often, victims begin to fear water. Because rabies has paralyzed the swallowing muscles in the throat. This leads to dehydration, which concentrates the virus in the victim's saliva. Rabies transmits itself to others by literally manipulating its hosts into biting other people. But there are no documented cases of human to human rabies transmission. Probably, because human teeth make terrible weapons.
But here's the good news. There are medications available to treat Toxoplasma gondii and Trypanosoma. And while there's no cure for rabies, there is a vaccine. So consider that zombie apocalypse averted.
NATALIA REAGAN: Well, don't I feel comforted?
[LAUGHS]
[SWOOSH]
Hey, Ashley. You know what I just love?
ASHLEY HAMER: What?
NATALIA REAGAN: Frogs.
ASHLEY HAMER: Oh, neat.
NATALIA REAGAN: Well, that was kind of unbearable, wasn't it? We've all had those moments where we say something strange. And all we get in return is a long, awkward silence. Why is that silence so painful? Scientists have looked into the question. And it seems to come down to the fact that we're social creatures with one ultimate fear, rejection from the group. Ashley you rejected me.
ASHLEY HAMER: I'm sorry, Natalia. Come on back.
NATALIA REAGAN: OK.
[LAUGHS]
According to a 2011 Dutch study published in the journal, The Experimental Social Psychology, awkward silences are particularly uncomfortable if they disrupt the conversational flow. The study authors reason that a conversation that flows well provides a perception of consensus between the speakers, which gives them a sense of belonging and social validation. But a disruption signals a problem with that consensus, and could be a sign of impending social rejection. I mean, think about my earlier conversation with Ashley. I clearly said something she didn't expect. And probably, didn't agree with.
ASHLEY HAMER: I'm sorry. I love frogs. They're adorable. I take it back.
NATALIA REAGAN: Sure, you do, Ashley. Sure, you do. To look into how this works, the researchers measured volunteers reactions to conversations where one person made an insensitive or inappropriate remark. Some participants read or watched a conversation where the remarks were followed by an obvious silence. For others, the conversation flowed easily after the awkward remarks. Sure enough, participants who witnessed the conversations with awkward silences reported feeling more anxious, rejected, and less self-assured than the other participants.
The researchers repeated their experiment again a few years later. But this time instead of measuring rejection, they tested whether the awkward silence could actually make people change their attitudes to fit group norms. They used a pretest to figure out which participants had a high motivation to belong to a group, and which participants didn't. Then everyone listened to a conversation where someone expressed an opinion that was followed by an awkward silence. In a survey afterward, those with a high motivation to belong were more likely to disagree with the opinion that led to that awful awkward silence. The silence made them change their minds to fit in with the group.
Fluid conversations can help us feel a sense of unity, belongingness, and a shared reality in a social situation. But when you take that away, it can feel downright excruciating. But it might be good to remember, that not all silence is rejection. Sometimes people are distracted, or processing what you've said, or trying to think of a good response, or they're just on video chat, which is awkward enough as it is. Right, Ashley, who I'm currently video chatting with?
[LAUGHS]
ASHLEY HAMER: I'm assuming that I'm not leaving an awkward silence. But yes, absolutely, I agree with you.
[SWOOSH]
We got a listener question from Abu in India, who writes, "I recently bought loose leaf green tea and was searching for the perfect way to steep a cup. They said that boiling water at 100 degrees Celsius ruins the flavor. And you've got to turn the stove off once bubbles form. And a few of them come up, when the water is roughly 80 degrees Celsius. I've been looking at bubbles to turn off the stove at the perfect moment for the past few days and started wondering, how and why these bubbles form?"
I love this question. Because I don't think I've ever thought about it before. I mean, bubbles are just air, right? Wrong. There is so much going on in a pot of boiling water that I never even realized. For instance, boiling water has not one, but two types of bubbles. Each of them comes from an entirely different process.
So when you put a pot of water on to boil, the first thing that'll happen is that small bubbles will start to cling to the sides of the pot. These bubbles are made of air. See, water is full of dissolved air. I mean, that's the whole reason fish can breathe after all. But as the temperature of the water goes up, the solubility of those gases goes down. All that nitrogen, oxygen, and carbon dioxide come out of solution. And that's what forms those little bubbles on the sides of the pot.
But as the water gets closer to boiling, a different kind of bubble forms. You know, how the water on the surface of the pot starts to steam? That's water vapor, where water molecules get so excited that they start spreading out and turn into a gas. That doesn't just happen on the surface. It happens deep in the pot too.
As little pockets of water get hot enough to turn into vapor, it creates a bubble, which rises to the surface and lets the vapor escape. Eventually, those little bubbles join forces into a rolling boil. That happens at 100 degrees Celsius at standard atmospheric pressure. But if you lower the atmospheric pressure, by say climbing a mountain, it'll take less heat to make that water boil. That's because there's less pressure weighing down on the water. So those bubbles have an easier time forming.
So if you're at sea level, bubbles are a pretty good indicator of temperature. But if you're not, you might want to get a thermometer. Thanks for your question, Abu. If you have a question, send it in to podcast@curiosity.com, or leave us a voicemail at 312-596-5208.
NATALIA REAGAN: I have a question, Ashley.
ASHLEY HAMER: Yes, Natalia.
NATALIA REAGAN: Is it true that a watch pot never boils?
ASHLEY HAMER: Scientifically, it is not true. In my experience, I think it's absolutely true.
NATALIA REAGAN: Good to know. Thank you.
[SWOOSH]
Before we recap what we learned today, here's a sneak peek at what you'll hear next week on Curiosity Daily.
ASHLEY HAMER: Next week, you'll learn about, how the return of wolves improved life for every animal in Yellowstone, how some bacteria in your gut produce electricity, a new theory for why we experience the uncanny Valley effect, the door to hell, which is a giant fiery pit, that's been burning since 1971, and more. So now, let's recap what we learned today.
NATALIA REAGAN: We learned that while there isn't a virus that can reanimate dead folks, at this moment, it's 2020, so anything can happen. There are parasites and one virus that can alter our brains behavior in some pretty scary ways. This includes Toxoplasma gondii, a parasite that can make mice, against their better judgment, get extra friendly with cats. And therefore, well, die.
I also called this parasite the kitty litter culprit. Since it can affect humans too. Since the parasite is in their kitty poop. And the rabies virus can also make people behave differently by triggering fear responses that can turn into aggression. This is why we don't pet rabbits, squirrels, or people.
ASHLEY HAMER: I'm always very impressed by parasites. Just like the cancer thing where it's just like you have to respect it. The way that they can tap into our behaviors and figure out a way to make more of themselves by changing the way we act, really needs to be respected. It is very impressive.
NATALIA REAGAN: Are you saying that, if I dress up like a giant tapeworm, you're going to respect me more?
ASHLEY HAMER: Yes, please do that. Halloween's coming up.
NATALIA REAGAN: I know what I'm going to have to do, yeah. Actually, tapeworms are some of my favorite parasites. Just learning about them, and the little scolex that attaches to the colon and things like that, and just-- yeah, the platyhelminthes. They're just really interesting worms. I mean, again, it's like that will to survive. It's impressive.
ASHLEY HAMER: Yeah, it's a tough life. They have to get really good tools for a living. And we also learned that awkward silences are awkward. Because at our very core, humans are social. And we want to belong in a group. So when something you say leads to a prolonged silence, it's often interpreted as a feeling of rejection.
And new research shows that awkward silences can actually inspire others to change their opinions to avoid those awkward silences and fit in more with the group. So maybe you can use those awkward silences to inspire good. I mean, I've definitely heard of people doing this. Where if someone says something that you feel is offensive maybe to someone else in your group who can't speak up for themselves, a good response is just not to say anything at all, and make the situation awkward.
NATALIA REAGAN: Yeah, it's an interesting call. Because that's my first thought was that social shaming for saying something inappropriate, whether it's homophobic, racist, bigoted of some sort. I generally would hope people would call it out. But if you can't call it out for whatever reason, definitely, don't cosign with it. And by not cosigning a long, awkward silence, coupled with a searing look, and maybe a strongly worded email afterwards.
[LAUGHS]
Lastly, we learned that bubbles form in boiling water, because water is filled with lots of different gases. Fish have got to breathe, right? And the solubility of the gases go down when the temperature goes up. So bubbles begin to form as the water warms up. Then as the water gets hot enough to turn into vapor, pockets of water vapor turn into bubbles that rise to the surface and escape. That's your classic rolling boil.
ASHLEY HAMER: My mom's a big fan of poached eggs. And when you make poached eggs, you have to get it probably to the same temperature that Abu was talking about. That it's like not quite boiling. And she always called that, smiling water. She always said, that's what they call it in French, smiling water. I don't know if that's true. But let me see. Let me look it up.
NATALIA REAGAN: That's sweet. I like that. Yeah.
ASHLEY HAMER: Yeah. Google will not confirm that smiling water is a thing. But it's a thing for my mom.
NATALIA REAGAN: It's something for Ashley's mom. And I like it. I think it's sweet.
ASHLEY HAMER: Yeah.
[SWOOSH]
NATALIA REAGAN: Today's stories were written by Ashley Hamer, Anna Todd, and Cameron Duke. And edited by Ashley Hamer, who's the managing editor for Curiosity Daily.
ASHLEY HAMER: Scriptwriting was by Natalia Reagan and Sonja Hodgson. Today's episode was edited by me, Ashley Hamer. Our producer is Cody Gough.
NATALIA REAGAN: Have a great weekend. And join us again Monday to learn something new in just a few minutes. Was that awkward enough, Ashley?
ASHLEY HAMER: That was pretty awkward.
[LAUGHS]
And until then, stay curious.
[MUSIC PLAYING]