The full moon is bright, beautiful, and reappears in the sky like clockwork. Many cultures use the full moon to mark the passing of time and organize calendars around the moon’s cycle. So why does the full moon also have a reputation for causing mischief and mayhem? In this episode, we’ll learn where some of these beliefs come from and investigate whether the full moon actually does affect humans and our behavior. We’ll also hear about folklore tied to the full moon and examine how the moon’s phases work. All that plus a brand new mystery sound!

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CHARLIE: You're listening to Brains On where we're serious about being curious. Brains On is supported in part by a grant from the National Science Foundation.

MARC: Woo hahahaha. After months of work, it's finally time to fire up the Sock Cloner. Never again will I be plagued by missing socks eaten up by the dryer. Just one final touch.



What? What happened? Everything was working perfectly yesterday.

WOMAN: Have you seen Archibald?

MARC: Who's Archibald?

WOMAN: He's our office spider, remember? Big, beautiful brown eyes, round belly, eight long, hairy legs and a mischievous personality. I haven't seen him since I brought him breakfast this morning.

SANDEN: You guys. The 2D Verbum Ink Replicator and Scribatron 3,000 is jammed.

WOMAN: Oh Sanden, for the last time, it's just a copy machine. You can call it the copy machine.

MOLLY: What is going on in here? I'm about to record an episode.

WOMAN: Everything is going wrong. Technology is breaking. Beloved spiders are missing.

SANDEN: And my Sock Cloner died. (CRYING) It never even really lived.

MOLLY: I wonder what's up?


SANDEN: Oh no. We're doomed.

MOLLY: What was that alert?

SANDEN: It's my Sky Tracker app. Tonight's moon, it's fa- fa- fa- fa- full.


SANDEN: So. That's what's behind this madness, Molly. I'm telling you, Molly, you should just cancel your recording session and go home. All of us should leave right now. Lock ourselves in our bedrooms, get under the covers, and don't come out until the morning.

MOLLY: Sanden come on, I'm sure there's a perfectly logical explanation for the missing spider, the copier jam, and Marc's technical difficulties--


MOLLY: I'm just going to go check on that.


You're listening to Brains On from APM Studios. I'm Molly Bloom. And here in the studio I've got Charlie from Eagan, Minnesota. Hi, Charlie.

CHARLIE: Hi Molly.

MOLLY: So Charlie, you sent us a great question that inspired today's episode.

CHARLIE: Yeah I wanted to know, why are there so many stories about the full moon? I have noticed sometimes people talk about the moon like it's a powerful thing or even sometimes scary.

MOLLY: What were they saying about the full moon?

CHARLIE: They were saying something close to you don't go trick-or-treating too late in the night because it's a full moon tonight. And then I'm like, it's literally just the moon. It's not some powerful old magnet spinning around our Earth trying to haunt us. It's just lighting up the night sky so we don't have a horrible trick-or-treating.

MOLLY: So you were like, it's just a moon. I don't understand why everyone is having all these feelings about it. So that's why you wrote this question to us?


MOLLY: Awesome. So I have a question for you.


MOLLY: Why do you think people have so many ideas about the full moon?

CHARLIE: Maybe because they're scared of it or something.

MOLLY: Yeah but why do you think they are scared of it? Like you said, it's just the moon. Why are they scared of the full moon?

CHARLIE: Maybe because they don't know a lot about it. Maybe because they've never been on it before. The main thing of fear is because you don't know all about it.

MOLLY: That's very wise. So yeah, you think maybe if they knew more about the full moon they wouldn't be scared of it.


MOLLY: Full moons are just one phase of the moon. You know how the shape of the moon changes throughout the month? Sometimes we see a bright full circle, other times we see half a circle, or even a little sliver of moon. And sometimes we see no moon at all.

CHARLIE: These are all different phases of the moon. The moon isn't actually changing shapes. It's just the light on the moon that changes.

MOLLY: So why does this happen? Well it has to do with how the moon circles the Earth.


The Earth is constantly spinning.

CHARLIE: Picture someone spinning a basketball on their finger.

MOLLY: Exactly. The Earth spins like that. It takes one day and one night, about 24 hours, for the Earth to fully spin around.

CHARLIE: Now next to the spinning Earth is the moon. As the Earth does its daily spin, the moon looks like it's in the same spot.

MOLLY: This means as the Earth spins, everyone on the planet gets a chance to see the moon.

ADORING FANS: Moon over here. It's the moon, oh my gosh. Oh my gosh, it's so gorgeous. I love you, moon.

THE MOON: Hello my adoring fans. So nice to see you again.

ADORING FANS: Moon it's me, it me. I love you so much. Will you sign my calendar?

MOLLY: Now the moon circles around the Earth.

CHARLIE: But the moon's no speedster. It takes about a month to make it one lap around our planet.

MOLLY: So that means every day when it's your part of the planet's turn to see the moon, it's moved a little bit.

ADORING FANS: Um, where did the moon go? It's dark now.

THE MOON: Yoo hoo. I'm over here now.

ADORING FANS: Moon! You just moved a little, moon. Please don't ever leave us.

CHARLIE: It's this movement that causes those phases we talked about earlier.

MOLLY: The moon is a big, beautiful chunk of rock. It doesn't create light, even though it looks like it's glowing.

CHARLIE: The glow of the moon is actually just light coming from the sun.

MOLLY: The sun is always in the same place, and the moon is moving around the Earth. So depending on where the moon is on its trip around the Earth, the light on it will change.

CHARLIE: Imagine the sun is a big spotlight, and the moon is a big, beautiful head with a big, beautiful face. And that big, beautiful face is always looking at the Earth.

THE MOON: Can you blame me? Look at that beautiful Earth. So gorgeous. It's where my devoted fans live, after all.

MOLLY: When the moon is on the side of the Earth farthest from the spotlight, the moon's face is pointed toward the sun.

CHARLIE: This is when the moon is full.

MOLLY: In other words, the moon will be fully lit up.

ADORING FANS: Moon you are glowing. Moon you look so good. What's your skincare routine?

THE MOON: Thank you so much. My skin care, lets see. A lack of oxygen, a lots of dust, and exfoliation from meteors crashing into my face.

CHARLIE: But as the moon keeps circling the Earth, it starts to inch its way into shadow. Eventually some light will shine on just one side of the moon, so only half of its face will be lit up.

ADORING FANS: Whoa moon. Oh moon, what happened? I see half of you.

THE MOON: Let's hope it's my good side.

MOLLY: Eventually, the moon will travel around the planet until it's directly between Earth and the sun.

CHARLIE: This is called the New Moon, you can't really see the moon at all.

MOLLY: That's because that big spotlight is now shining on the back of the moon's head. Its face isn't getting any light at all. So that means we can't see it.

ADORING FANS: Moon, oh my gosh. Where did you go? Moon don't leave us. Moon!

THE MOON: All lies. I'm still here. I'm just in shadow. But hang on, as I circle some more, I'll come back into the light and you'll see more of me. Just wait a few days, my dearies.

MOLLY: The moon will gradually move to be more and more in the light every night until eventually, it will have circled back to the spot where its opposite the sun and fully lit up.

CHARLIE: And then we're back to a full moon. The whole thing takes about 29 days.



THE WEREWOLF: Ah woooo. Hello, friends and foes. It's time for some moon myths. Our first lunar legend is all about, well, well it's about me, the werewolf. There are stories of shapeshifters all around the world. Tales of humans turning into all sorts of creatures. One of the earliest stories about werewolves comes from ancient Greece.


There was this finicky fellow named Lycaean and he was a bit of a trickster. Lycaean was so mischievous he tried to trick Zeus, the King of gods. As you might imagine, this did not go over well. Zeus was so fed up he turned Lycaean into a wolf.


Woooooooo! And the story of werewolves kept popping up all over Europe. Some Nordic legends said humans could transform into wolves by wearing a wolf pelt. Others in France and Italy believed the transition only happened during the full moon. But just to be clear, real wolves don't howl at the moon. They just howl at night because they're nocturnal animals not because of the moon. Although, it's very fun. Have you ever tried it? Ah woooooo! Wow. That was incredible. In fact, I think I'm going to go howl some more. Catch you later. Ah woooooo.

Ba ba ba ba ba ba ba ba ba ba ba Brains On.

MOLLY: All right, back to our original question. Why are we so obsessed with full moons? For starters, they're bright and beautiful and they also happen very regularly.

CHARLIE: Yeah there's a full moon once a month. It's like clockwork.

MAGGIE ADERIN-POCOCK: The regular cyclical nature of the moon means people tap into it, in terms of a calendar.

MOLLY: That's Maggie Aderin-pocock. She's an author and space scientist.

CHARLIE: And total moon fan.

MAGGIE ADERIN-POCOCK: The moon is just mesmerizing. If I've had a hard day, with my daughter going to school and me working, and especially during lockdown. Just catching a glimpse of the moon we're just totally relaxed me.

MOLLY: Maggie says humans have used the moon to tell time for thousands of years, which makes sense because it's sort of like a giant clock in the sky that everyone can see.

CHARLIE: Yeah the word month even comes from an Old English word for moon.

MOLLY: Like we talked about earlier, everyone on Earth gets a chance to see the moon every day. If you're seeing a half moon in Argentina, you'll also see a half moon in Alaska. And if it's full in Rwanda, it's full in Romania too. Researchers recently found an ancient moon calendar in Scotland. It was made about 10,000 years ago by nomadic people, or people who traveled from place to place throughout the year.

CHARLIE: But this calendar wasn't like the ones we used today.

MOLLY: Picture a big open field, like somewhere you'd play soccer or baseball, and on that field there are 12 large holes dug in a long line.

CHARLIE: The line of holes is curved, kind of like the letter C.

MAGGIE ADERIN-POCOCK: And each one of the pits represents one of the phases of the moon. This was done very early on where people were thought to be nomadic. But they took the time to actually dig out these pits. So the moon must have played an important role in their lives.

MOLLY: Lots of cultures still use moon calendars today. Like the Jewish calendar, which uses cycles of the moon and the sun to measure time. In the Islamic calendar, the new crescent moon marks the beginning of each month. And lots of Asian cultures have big celebrations for the Lunar New Year.

CHARLIE: The moon has played an important role for tracking time in lots of different cultures. But it's also been the focus of many myths and legends.

MOLLY: Some of those stories are kind of dark or scary. And Moon Expert Maggie says these ideas go back thousands of years. Ancient philosophers like Aristotle and Pliny the Elder thought a full moon could affect our mood, even unleash our dark side.

MAGGIE ADERIN-POCOCK: These guys thought that it's the water in our bodies. So we understand that the moon has an effect on the tides. And so I think they believe that the moon has an effect on the water in our bodies, sort of almost releasing or letting out the alter ego.

CHARLIE: That's why the word lunatic has luna in it. That's the Latin word for moon. Some ancient people thought the moon could make you go a little loopy.

MOLLY: We know today that even though the moon controls the tides in the ocean, it doesn't affect the water in our bodies. This is just one of many moon myths out there.

CHARLIE: Hundreds of years ago, doctors in the Middle Ages thought the moon could make you sick.

MOLLY: And in England in the 1700s, people caught committing a crime during a full moon could argue for less punishment because, well, they said the moon made them do it.

CHARLIE: We've been fascinated by the moon for centuries, probably because it's so noticeable. And it even helped us keep track of time.

MOLLY: Right. Those creepy moon stories most likely come from that fascination. But there may be another reason too.


Huh, It's a message from Sanden.

CHARLIE: Do you think he found Archibald?

MOLLY: I don't know. It just says, come to the Brains On Theater right now, in all caps.

CHARLIE: There's our Brains On Theater. Does it have popcorn?

MOLLY: Yup and slurpees. And those fancy seats that recline all the way back so you can take a nap through the boring parts. It's on a 37th floor.



CHARLIE: Hi Elevator. Floor 37, please.


ELEVATOR: Thank you. Be hung. Swing set. And teachers.

MOLLY: Elevator? Are you all right?


ELEVATOR: Sixteen down going fishing.

MOLLY: Ah nuts. Looks like we're going to have to take the stairs.

CHARLIE: To the 37 floor? Ugh.


MOLLY: While we're climbing we might as well listen to the mystery sound. You ready, Charlie?


MOLLY: All right. Here it is.


Whoa. Whoa. What a sound. What do you think?

CHARLIE: Maybe it's probably one of those things where you suck up water through this tube and then you squirt it out and it goes coming out so fast.

MOLLY: Oh that's a good guess. I definitely heard some splashing at the end.


MOLLY: I have no idea what this was either. So I thought it was like a slide whistle that was full of water. But I don't think that's correct.

CHARLIE: Yeah I heard it I heard a whoop sound in it. So.

MOLLY: I like your guess. Well we will hear it again, have another chance to guess, and hear the answer after the credits. So stick around.


The moon is just one of an endless number of cool things in space.

CHARLIE: Yeah you've got alien planets, black holes, asteroids, and tons of stuff we haven't even discovered yet.

MOLLY: Space is so cool that we're doing a whole episode about neat space facts and we want you to be in it. Record yourself singing a jingle about space.

CHARLIE: A jingle is a short, catchy song about something.

MOLLY: Charlie, would like to give it a try? Do you have a space jingle you'd like to share?


MOLLY: Let me hear.

CHARLIE: (SINGING) Asteroids, asteroids, imagine if you were the moon. If you were, it would be kind of cool. Except the unfun part probably would be the asteroid smashing into your face. That wouldn't be fun. And now I'm done with this song about space.

MOLLY: Oh yes. Nicely done. Send us your jingle at or you can send us a question like this one.

CHILD: Why do we have nightmares?

CHARLIE: Hear the answer by subscribing to our Moment of Um podcast.

MOLLY: And stick around for the Honor Roll and the answer to the Mystery Sound at the end of the show.

CHARLIE: Keep listening.


THE WEREWOLF: Moon Myths back again. Ah wooo! This one is about the moon goddess from ancient China. There was once a woman named Chang'e. And she wanted to be forever young. So she stole the magical elixir of immortality.


Perhaps that elixir was carbonated because Chang'e floated all the way up to the moon. In some stories, Chang'e is also joined by a fluffy white rabbit. Some even say can see the shadow of the rabbit when you look at the full moon. Pretty moongical or magical. It's a work in progress. That's all for now. Ciao-oooooooooo.



CHARLIE: We. Made. It.

SANDEN: There you are. What took you so long?


We had to take the stairs. Elevator wasn't working.

MOLLY: Which was just a coincidence, maybe, the speakers need a new battery. Whoo, I am hungry.

SANDEN: Yeah well, good luck getting the popcorn machine to work. The kernels just rattle and rattle but they never pop. I'm sure that's just a coincidence too, huh?

CHARLIE: Oh man. I was really excited for popcorn. Oh well. What movie are we watching. Duck, Duck, Ghost?

SANDEN: Oh. Too scary. No, have a seat. I have something much more fun than a movie, a PowerPoint presentation.


CHARLIE: Really, PowerPoint?

SANDEN: Slide one. Reason Sanden is right about the full moon. You'll see there's an animated GIF of me high-fiving myself. Slide 2. In 2007, a police department in the United Kingdom decided to put extra officers on duty when the moon was full. They believed there was more crime on those nights.

MOLLY: Actually, that's a myth. Lots of research has shown there isn't a link between the full moon and crime.

CHARLIE: And if there are more officers on patrol on full moon nights, there's probably a higher chance they'll see more crime.

SANDEN: Well. Next slide. One study published in 2011 found almost half of the hospital workers surveyed believe the full moon affects human behavior. They say when the moon is full more people go to the emergency room and more babies are born. Additionally, doctors at--


Molly, I'm not done with my presentation. Can't your phone call wait?


MOLLY: I'm calling Jean-Luc Margot. He's a professor of Astronomy and Planetary Sciences at UCLA. And he has studied exactly what you're talking about now. Hey Jean-Luc.


MOLLY: Sorry to bother you so late. I'm at Brains On headquarters and everything is going wrong. The copy machine is jammed, our pet spider is missing, Elevator couldn't understand a word I was saying.

CHARLIE: Don't forget about Marc's Sock Cloner.

MOLLY: Things are just not going our way today. I know there must be a logical explanation, but Sanden is convinced it's the full moon.

SANDEN: I made a whole presentation. Look at my next slide, I included a photo of a kitten.

MOLLY: Yeah, he was just talking about medical workers and the superstition some of them have about the full moon. You've studied this, right? Here let me put you on speaker.

JEAN-LUC MARGOT: Right, there's a pretty common belief among health care workers that there are more births, human births, on a full moon. And if you talk to health care professionals, very often they will swear to you that they've observed this, that there is no doubt about it, that there's more babies are born on a full moon.

CHARLIE: This one should be pretty easy to investigate. You just have to compare birth days with the moon calendar and see if there are more babies born during the full moon.

JEAN-LUC MARGOT: And when you do that analysis, you find that there's absolutely no correlation with the phases of the moon, right? So there are no more babies born on the day of the full moon than any other day during the lunar cycle.

CHARLIE: Some doctors also think more people show up at the emergency room on full moon nights.

MOLLY: It turns out that's also a myth. Hospital records show there aren't more people coming to the emergency room during full moons than any other part of the month.

SANDEN: But so, why do people keep blaming the moon then?

MOLLY: One idea is something called confirmation bias. It's when we look for information that confirms what we already believe and ignore everything else. Sometimes we do this without even thinking about it.

CHARLIE: Like thinking the moon jammed the copier tonight, even though it jammed pretty much every week.

JEAN-LUC MARGOT: Right. And this is how it could work in the case of hospital admissions or human births at the hospital. Is that you drive to work and you notice the beautiful full moon, right? And then there are a number of admissions to the hospital or a number of births. And you say, oh dear, you know, this confirms my theory that there's more births on the full moon. And what you don't realize is all the other days when you drive to work and there's not a full moon. But there's an equal number of births or an equal number of admissions to the hospital. And you just don't make that association.

MOLLY: Confirmation bias is super common. Even scientists have to be really careful about it when they're trying to figure something out.

CHARLIE: It's their job to come up with a hypothesis, which is like an educated guess about what's happening.

MOLLY: But they have to look carefully at all possible causes. If they're too focused on the idea they started with, they might miss something really important.

CHARLIE: This happened when a group of scientists was studying car accidents.

SANDEN: Oh I was just about to get to car accidents. Researchers found that there were more of them when the moon was full.

MOLLY: That's what they found the first time they did the study. But then later they realized they had made a mistake.

JEAN-LUC MARGOT: People had forgotten to look at days of the week. And they did a study over a period of a few weeks where it turned out that the Saturdays fell roughly on the days of the full moon and they observed a larger number of accidents. Well, the reason for the increased number of accidents was not related to the full moon but it was related to the fact that maybe people go out more on Saturday nights.

CHARLIE: So the scientists did the research again.

MOLLY: But during a month where the full moon happened mostly on weekdays.

CHARLIE: And they realized the full moon wasn't actually causing more car accidents.

MOLLY: This might help explain all the spooky stories about the moon. Once we got the idea in our heads that the moon causes trouble, we kept looking for evidence to prove that and created a case of confirmation bias.

CHARLIE: Yeah, other nights might have just as much trouble.

MOLLY: But we notice when it happens during a full moon and that might influence the stories we tell about it.

SANDEN: OK but there must be some behavior that the full moon is responsible for, right?

JEAN-LUC MARGOT: Absolutely. So the moon controls the tides. And you can easily imagine that if you're a marine creature, the tides are going to affect your behavior. So I live in California and there's this species of fish called the grunion. And the grunion has a very interesting reproductive behavior. They come out at high tide to lay their eggs. And then the eggs develop for a couple of weeks. And then at the next high tide, the babies sort of swim out to sea.

CHARLIE: Because if they lay their eggs above the highest tide, which happens when the moon is full, they know they'll be safe in the sand.

SANDEN: I knew it. The full moon does do something. The grunion is, oh-fish-ally my new favorite fish.

MOLLY: And the moon also affects our sleep. A team of Swedish scientists found that people actually sleep 20 minutes less when the moon is full, even in a room with no windows.

CHARLIE: And they aren't sure why. So it's possible that the moon is somehow linked to our biological clocks.

MOLLY: But there's no evidence that the moon is to blame when things go wrong, like broken popcorn machines and loose spiders.

SANDEN: OK. But what about the 2D Verbum Ink Replicator and Scribatron 3,000 and Elevator and the Sock Cloner. Can a full moon cause technology to break?

JEAN-LUC MARGOT: No. There's absolutely no evidence that the full moon can cause electronics to malfunction or break.

MOLLY: See, something else must be going on. Think of it like a mystery that we still have to solve.

SANDEN: All right.

CHARLIE: Thanks for clearing that up, Jean-Luc.

JEAN-LUC MARGOT: Oh you're welcome. It was my pleasure.

MOLLY: Back to Elevator.

CHARLIE: Elevator, back to the studio please.


ELEVATOR: Pine needles, underwear, Carrie, gunga doors.

MOLLY: OK. Before we jump to conclusions, let's think. What else could be going on?

SANDEN: A web.

MOLLY: No Sanden, there is not a web of conspiracies affecting Brains On headquarters.

SANDEN: No, I mean a spiderweb, down there in the corner.

CHARLIE: It's Archibald. It looks like he's caught a bunch of little yellow bugs.

MOLLY: That's where Elevator's speaker is. And those aren't bugs, they're popcorn kernels.

SANDEN: And scraps of paper from the 2D Verbum Ink Replicator and Scribatron 3,000.

CHARLIE: Also known as the copy machine. And is that a sock?

MOLLY: I think we found our culprits.

ELEVATOR: Brains, brains, brains.


THE WEREWOLF: I've got one more moon myth for you. And hold on to your witch hats, black cats, and vampire bats because this one is a doozy. It's about a moon eating monster from Siberia.


Picture this, a giant dragon-like head with wings so big they covered the entire night sky. Eek! And let me tell you, this beast had an appetite to match that wingspan. He would chomp on the moon piece by piece until it slowly disappeared.


But since the monster was just a floating head, with wings, no stomach he had trouble digesting.


So all those tasty moon morsels had to come back up and return to the sky. How pleasant. Although, I must say moon morsels do sound kind of enticing. I wonder if they tasted cheesy? Wow, I'm hungry.


Perfect timing. My pumpkin bread is ready. My dear friends, I must feast. But thank you for listening to these moon myths. What a treat. Ta-ta. Ah wooooooooo.


MOLLY: Humans have been interested in the full moon for thousands of years.

CHARLIE: And we've probably told stories about it for just as long.

MOLLY: We've used the moon to keep track of time and have blamed it for everything from lunacy to sicknesses.

CHARLIE: But a lot of that might be confirmation bias. That's when we think evidence proves our case. But something else might be the real reason.

MOLLY: Still, a full moon seems to affect our sleep and it definitely affects the tides.

CHARLIE: That's it for today's episode of Brains On. This episode was produced by Molly Bloom, Anna Goldfield, Nico Gonzalez-Whistler, Ruby Guthrie, MarC Sanchez, and Anna Weggel.

MOLLY: This episode was sound designed by Rachel Breeze and mixed by Anna Haverman. Our editors are Sanden Totten and Shahla Farzan. Our executive producer is Beth Perlman and our production coordinator is Lauren Humbert. Special thanks to Amy Limmer and Vicki Kreckler. The executives in charge of APM studio are Chandra Kavati, Joanne Griffith, and Alex Schaffert.

CHARLIE: Brains On is a nonprofit, Public Radio program.

MOLLY: Your support means the world to us. An easy way is to tell your friends about us.

CHARLIE: Friends, have you heard about this super amazing podcast?

MOLLY: You can buy our books.

CHARLIE: They're so excellent. is the place.


MOLLY: All right Charlie, are you ready to go back to the mystery sound?


MOLLY: All right, here it is again.


CHARLIE: Probably a rocket or either the thing I said where you can like squirt water out of it.

MOLLY: That's really.

CHARLIE: Like after you suck it back up.

MOLLY: It's kind of like a tube.


MOLLY: All right. Are you ready for the answer?


MOLLY: All right here it is.

ENOCH: Hi. I'm Enoch.

NOAH: And I'm Noah. And that was the sound of water coming out of the pipe that you get your water from at the campground.

MOLLY: Oh. So is a pipe. That's where you get your water at a campsite.

CHARLIE: So did I guess it?

MOLLY: You were close I'm going to say. Because there was water coming out of a tube. But it wasn't a squirt, you know, tube. It was where people get their water at a campsite.

CHARLIE: At least I was very close.

MOLLY: You were very close. That was a very hard one.


Now it's time for the Brain's Honor Roll. These are the incredible kids who keep the show going with their mystery sounds, drawings, questions, and high fives.



We'll be back soon with more answers to your questions.

CHARLIE: Thanks for listening.

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