Today, you’ll learn about the good, the bad, and the ugly of shark repellents, how human’s thirst for groundwater is literally changing the tilt of the Earth, and how hairy moles might offer a clue to fighting hair loss.
Today, you’ll learn about the good, the bad, and the ugly of shark repellents, how human’s thirst for groundwater is literally changing the tilt of the Earth, and how hairy moles might offer a clue to fighting hair loss.
Shark Week continues all week long on Discovery. For the latest, head to SharkWeek.com.
Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/shark-deterrents-earth-axis-tilt-hair-loss-reversal
Shark Deterrents
Earth Axis Tilt
Hair Loss Reversal
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[SFX: INTRO MUSIC/WHOOSH]
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 good, the bad, and the ugly of shark repellents, how human’s thirst for groundwater is literally changing the tilt of the Earth, and how hairy moles might offer a clue to fighting hair loss.
CALLI: But guys first, can we celebrate that this is our 200th episode of “Curiosity Daily!” I can hardly believe that!
NATE: It’s so cool and exciting so thank you to all of our loyal listeners! This would not be possible without you!
CALLI: Now, without further ado, let’s satisfy some curiosity!
[SFX: WHOOSH]
NATE: Here’s a scene for you to imagine: you’re in the woods on a hike, and suddenly you start getting bitten by mosquitos. What do you do?
CALLI: Pull out the bug spray, obviously.
NATE: Now imagine that instead of the woods, you’re in the ocean, and instead of mosquitos…it’s sharks and there’s no boats anywhere to be found.
CALLI: Wow, you took that to a dark place real fast.
NATE: That’s the scenario that lots of new companies are trying to get you to imagine so they can sell you all new, handy-dandy shark repellent!
CALLI: You’re talking about shark repellent during shark week? How dare you!
NATE: I know, I know. The good news is that shark attacks are incredibly rare. According to the Florida Museum of Natural History’s International Shark Attack File, in 2022 there were only about 108 reported shark-human interactions.
CALLI: That IS good news.
NATE: Especially when you consider the millions upon millions of beach goers each year. That’s a miniscule fraction! And of those 108, only 57 were unprovoked - and a few of them might not have even involved a shark. Obviously, those are only the reported incidents. But still that’s pretty good news!
CALLI: Okay. What’s the bad news?
NATE: Well…despite the low number of attacks worldwide, a shark repellent would actually be a good thing. Surfers obviously don’t love having to worry about sharks chomping at them in the waves. Same with divers and anyone who gets in the ocean. But the bad news is that most shark repellents are just gimmicks.
CALLI: Ahh. Too good to be true?
NATE: In Australia, for example, there is simply no oversight or regulations regarding the claims made by companies that manufacture repellents.
CALLI: So they can basically claim whatever they want?
NATE: Sure. And there are some pretty wild claims made. That said, there is a bright side - some of the products actually show promise.
CALLI: Okay. I wanna hear more about that.
NATE: There are a few different categories of shark repellents that are being sold. The first is visual.
CALLI: Like…a sign that says “I’m not food, don’t eat me?”
NATE: I know you’re joking, but actually - you sorta, yeah that. One guy actually put the words “I’m broccoli” on his surfboard because, you know, sharks don’t eat broccoli.
CALLI: I’m guessing that’s one of the repellents that doesn’t work?
NATE: That’s an extreme - and totally not serious example. But the real idea is that any predator looks for visual cues to figure out what’s for dinner, right? So some people put a big eye-shaped dot on their surfboards because sharks have been known to back off once they realize they’re being watched.
CALLI: So if the surfboard looks like it’s staring back at the shark…it’ll flee in terror?
NATE: That’s the thinking. The bad news is…it probably doesn’t work. Some fish have that dot on their tail fins, which actually causes the shark to attack them back there, thinking it’s their heads.
CALLI: I think I get it - if the fish can get the shark to go after its tail, it can maybe get away without getting its head eaten?
NATE: Right - great for fish. But making your surfboard actually look MORE like food isn’t the best idea. Another idea that has fairly mixed reviews involves smell. Spilling out stuff that stinks to sharks might make them hit the road.
CALLI: What kind of stuff is stinky to sharks?
NATE: Dead sharks…
CALLI: Oh…gross.
NATE: But that doesn’t really work, either. Or - at least - they haven’t found a stink that really repels all sharks. But another method is showing some promise. Magnets.
CALLI: Magnets work better than stink?
NATE: Apparently so. A study found that magnets attached to fishing nets reduced the number of bycatch - including sharks - by about a third.
CALLI: That seems like a success.
NATE: Totally. Sharks can sense the magnetic field and shy away from it. But to really make it work, you have to have pretty powerful magnets. But that leads me to probably the best option - electric-field-generators.
CALLI: Right - sharks have that organ that can detect electric fields, right?
NATE: Yep. It’s called the ampullae of Lorenzini - they are these little tubes that can pick up electrical and magnetic fields - and get this. Researchers poured chum in the water to attract sharks, and then pushed a surfboard out into the water with a piece of tuna dangling off of it to kinda look like a surfer foot. Without the electric field generators, sharks went for the tuna surfer about 96% of the time. But when they flipped on the electric field - that was more than cut in half.
CALLI: So the electric fields actually worked?
NATE: It appears so. And they think it could work in the real world even better, because most surfers aren’t made of tuna and splashing chum around them when they surf.
CALLI: Good point. But speaking of surfers - who is this actually for? If there are so few shark attacks, why are companies spending so much money trying to sell these devices?
NATE: It actually has less to do with surfers and swimmers - and everything to do with fishing. A fishing net is like a buffet built for a shark. If fisheries can keep sharks away, that means bigger catches, less waste, and more profit.
CALLI: That makes sense.
NATE: That said, I don’t know why they didn’t just ask Batman what he used because, like back in 1966 he had a spray that just seemed to work great.
CALLI: Of course, of course it would be Batman.
[SFX: WHOOSH]
CALLI: A new study shows that humans have consumed so much groundwater that the North Pole has been shifting a little more than 4 centimeters per year!
NATE: Whoa. And here I feel like my six glasses per day is a lot!
CALLI: I know, right? It turns out that between 1993 and 2010 humans have removed some 2 thousand one hundred and fifty gigatons of groundwater. That’s about the same as 860 million Olympic sized swimming pools.
NATE: Okay…THAT’s a lot!
CALLI: I’ll say - We’ve used enough groundwater to raise the world’s sea level by a quarter inch. But until now, scientists weren’t exactly sure how moving all that water around would affect the Earth’s motion through space.
NATE: So how bad is it? And what’s gonna happen?
CALLI: Well…to answer that, let’s talk a minute about how the Earth spins. Our planet isn’t exactly shaped like a beach ball - some scientists have likened it more to a lumpy potato. It spins on an axis - that imaginary pole that goes straight through the middle from the North Pole to the South Pole - and it’s tilted about 23.5 degrees.
NATE: Right! And it’s that tilt which gives us our four seasons. For example, you and I are currently in summer, because the Northern Hemisphere is tilted toward the sun, and when we tilt a little further away, in the later months we’ll be in our winter.
CALLI: Exactly, but there’s a wobble.
NATE: A wobble?
CALLI: A wobble. Think about it - one scientist said the Earth is a little like a softball full of water. When you throw it the water swooshes around in there and…it wobbles.
NATE: How big is this swooshing wobble?
CALLI: It changes all the time - by about 10 meters a year. And all of our water and wind and weather are basically behind that wobble.
NATE: Got it. So it would make sense that if humans moved enough water, we’d have some kind of effect on it, too.
CALLI: Exactly. Except scientists didn’t know exactly how big the effect would be until Ki-Weon Seo, a geophysicist at Seoul National University and his colleagues used a computer model to simulate how different water movements affected the Earth’s tilt. They were shocked to learn that groundwater removal had such a huge impact - our tilt moved about 31 and a half inches eastward.
NATE: Here’s maybe a dumb question, but how can that have such a huge impact? I would guess that the groundwater, we’re removing gets used pretty close to the spot where it was removed from, right? Like…we’re not pumping it all into one spot.
CALLI: That’s a good point. So when you pump water from underground and spray it on crops, it eventually makes its way through rivers and eventually into the ocean.
NATE: Aha. That makes sense. So does this mean we should prepare for another ice age? Is this wobble gonna toss us all into outer space or what?
CALLI: Not quite. They don’t believe this will have much of an effect on our climate or weather patterns, but they are quick to point out that the impact human activity has on our planet is greater than we imagined, and definitely more complicated. If we can change the way the Earth spins, then we need to get serious about the ways we’re changing our climate.
[SFX: WHOOSH]
CALLI: Have you ever seen one of those hairy old moles some people have?
NATE: Have you ever met my uncle Vernon? He grows them for sport, bless his heart.
CALLI: Well…it turns out your Uncle Vernon’s hairy moles might just hold the key to solving certain types of hair loss.
NATE: That’s funny, because Uncle Vernon has hair everywhere except his head. Please don’t tell me scientists are going to start implanting hairy moles on people’s heads.
CALLI: Not quite. But a research group out of the University of California, Irvine has finally figured out what’s going on inside those moles that makes them so hairy. It turns out those thick hairs are triggered by aging pigment cells.
NATE: Aging pigment cells? I thought the whole idea behind hair loss was that the cells got older and started shedding hair.
CALLI: That’s why this finding was such a surprise for this team of researchers, and also what made them curious in the first place. These moles are also called nevi, and we’ve all seen them. They’re like big freckles.
NATE: Yeah…moles.
CALLI: They have a ton of aging pigment cells, and yet they are really good at growing hairs, even though aging cells - or what they call senescent cells - are usually thought to be kinda on their way out.
NATE: So what’s going on here?
CALLI: They actually found that these aging pigment cells produce a ton of this molecule called osteopontin, which signals sleepy hair follicles to activate their stem cells and…grow.
NATE: And not just grow, as anyone who’s seen my Uncle Vernon can attest. Those mole hairs are big and thick.
CALLI: Healthy, right? More research was done on mice that lacked the gene for coding osteopontin and guess what…
NATE: …no osteopontin? They didn’t grow hair?
CALLI: Their hair growth rate was pretty low, which supported the idea that osteopontin was a strong trigger for hair growth.
NATE: Okay. So what’s next? In the future will our heads look like a big, hair mole?
CALLI: Not if I can help it. But this finding along with more research can start to hone in on just exactly what triggers our hair follicles to grow, and that can lead to meaningful treatment for common hair loss.
NATE: Who would have thought hairy moles would actually be a good thing?
CALLI: Goes to show, it’s important to stay curious!
[SFX: WHOOSH]
NATE: Let’s recap what we learned today to wrap up. New self-proclaimed shark repellents are hitting the market with mixed reviews. Some - like visual repellents - might actually inadvertently attract sharks, while others, like electric field generators show real promise in keeping sharks at bay. Shark Week continues all week long on Discovery. For the latest, head to SharkWeek.com!
CALLI: A recent study found that humans have pumped over 2150 gigatons of water out of the ground between 1993 and 2010, causing the Earth’s tilt to change by over 30 inches.
NATE: Turns out, the hairy moles on your uncle’s back might teach us a thing or two about how to combat hair loss! Aging pigment cells in a mole produce something called osteopontin which triggers hair growth and scientists are hoping this can one day be used as a treatment.