Science Friday - Zapping Nerves Into Regrowth | Celebrating the Maya Calendar In Guatemala’s Highlands

Episode Date: May 24, 2024

An early study found that electrical stimulation could improve hand and arm function in people with spinal cord injuries. Also, for thousands of years, Indigenous communities in Guatemala have used observations and mathematics to track astronomical events.Zapping Nerves Into RegrowthResults of an early trial published this week in the journal Nature Medicine found that people with cervical spinal cord damage showed some improvements both in strength and movement in arm and hand function after they received electrical stimulation near the site of their injury. The improved function persisted even after the stimulation stopped, indicating that the treatment may be inducing nerve cells to regrow in the damaged area.Sophie Bushwick, senior news editor at New Scientist, joins Ira to talk about the work and what it could mean for people with severe spinal cord injuries. They also talk about other stories from the week in science, including creating the most powerful X-ray pulse ever reported, investigations into the microbiome of the scalp, and some epic cosplay—testing out the practicality of some ancient Greek armor in combat scenarios.Celebrating the Maya Calendar In Guatemala’s HighlandsEvery 260 days, Indigenous communities in the highlands of Guatemala celebrate a new cycle of the Maya calendar. This ceremony has persisted for thousands of years, from pre-Columbian times to today. The latest of these ceremonies happened in early May.Joining Ira to talk about the importance of astronomical ceremony is Willy Barreno, a Maya calendar keeper based in Quetzaltenango, Guatemala, and Dr. Isabel Hawkins, astronomer and senior scientist at the Exploratorium in San Francisco, California.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

The Maya calendar recently entered another 260-day cycle. We have science within our practices that had been confused with, like, religions are sacred. And then that's why communities still believe in what we do and how we count time and how we advise the community to behave. It's Friday, May 24th, and yep, today is Science Friday. I'm SciFri producer Charles Bergquist. Coming up, Ira talks with a Maya calendar keeper about pre-Hispanic astronomy traditions in Guatemala. But first, let's check in on some of the week's

news and science. Some hopeful news for people with spinal cord injuries this week. Results of an early trial published this week in the journal Nature Medicine show some improvements in arm and hand function after people received electrical stimulation near the site of their spinal cord injury. Sophie Bushwick, senior news editor at New Scientist, is back to tell us more. Hi, Sophie. Hi, Ira. This is really exciting. Tell us more about this spinal cord research. Yeah, this is a really great intervention because these are external pads that are placed on the

skin near the site of the spinal cord injury. And the participants in this trial received electrical stimulation from the pads while they were doing physical therapy to improve hand and arm function. And more than two-thirds of those who tried it said they had a significant improvement in their ability to grasp things and to move their hands after they had this treatment. That's a lot of people, isn't it? Yes. And gains like that for someone who's maybe is suffering from paralysis or other problems from the spinal cord injury can really be life-changing. It suggests also that they might have nerves regrowing as a result of this therapy because

even after the pads were removed, they continued to have this improvement. So they didn't have to be actively receiving the electrical stimulation to benefit from it. That is really amazing. Is this something that could help all kinds of spinal injuries? Well, this only applies to certain kinds. So this isn't going to be suitable for everybody. There needs to be parts of the spinal cord remaining intact in order for this nerve regrowth to happen. But about two-thirds of people with spinal injuries have the kind of injury that could

benefit from this type of treatment. Usually, you know, when we talk about severe spinal cord injury, it's in the context of getting people to walk again. but here they're looking at hands. And that's important also, right? Right. That's a big quality of life issue. You know, for me, I'm someone who doesn't have a spinal cord injury. I don't know what it's like for someone in this, but participants in the trial have said that hands and arm function is really huge in terms of improving their quality of life while they're living with this type of injury. Yeah, I can imagine that. Okay, let's move on to a different kind of zap. And I'm talking about the X-ray laser at California's Slack National Lab has fired the most powerful X-ray pulse ever reported. Wow.

Yeah, you know, this pulse exists in only a few hundred billionths of a billionth of a second. And in that time, it has about a terawatt of power going. So that's a thousand times more than the average yearly output of a nuclear power plant. You know, it just seems amazing how you can pack thousands of power plants into one zap. It's super cool. And the reason they want to do it is, you know, this isn't going to be like a pew-pue laser situation. This is going to be so they can peer into these teeny little details of materials. You know, look at the behavior of electrons and molecules on this incredibly tiny scale. That's the kind of research that the super powerful x-ray pulse can enable. Right. Not to be confused with lasers used for fusion, right? This is not fusion research. That's right. This isn't

going to be powering our homes anytime soon, but it could be unraveling some, you know, fundamental mysteries of the universe. That's good too, right? I like it too, yeah. I do, yeah. Let's move on to some other tech news. Open AI got into some trouble this week for the voice used in one of its products and a conflict with actress Scarlett Johansson. But there's other chat Cheapety2 news as well, right? That's right. In one study researchers, we're looking at how chat GPT gives housing advice. So if you're a potential home buyer, where does it advise you to live? And they found racial bias in the suggestions from the chat bot.

People who were black were more likely to be recommended to live in poorer neighborhoods and people who were white were recommended to live in more wealthy ones. Now, is this just another typical case of these models reinforcing existing biases? That's exactly right. So the study, they looked at three U.S. cities, Chicago and New York City, which are relatively segregated, and then San Antonio, Texas, which is more integrated racially. And the chatbot that racial bias had exhibited was stronger in Chicago and New York City, as opposed to the more integrated city of San Antonio. Now, I'd like to know how the model knows if someone was black to guide them towards certain housing areas. Well, in this particular study, the researchers just entered profiles of people. So they had people tell the chat bot what race they are, what gender they are, what their wealth is, their socioeconomic status, and then ask for recommendations. But, you know, these bots are trained on all this past data. And our past data, our existing data, it encodes a lot of bias, you know, racial bias, bias based on gender, ageism. And it can come out in weird ways. So for, For instance, a previous study found that when asked to judge people who spoke either African-American vernacular English or standard American English, the bots showed bias against the people who

spoke AAVE. So it's almost like this constant battle to make sure that we're seeing all the potential harms of these bots and that companies are constantly working to try to remove them. Well, is anyone actually planning to use CHET, GBT, or other AI products for real estate? Is this a real problem as we speak? Oh, it definitely is. In 2023, two real estate platforms, Zillow and Redfin did offer these chat GPT plugins to have recommendations, and they had to remove them after a month because they flagged issues with the ability of these bots to meet fair housing standards.

Yeah. You know, I love a good microbiome story, and you have one this week about the scalp microbiome. Who knew, but I guess I would have suspected. That's right. The scalp has a microbiome just like the skin does. And then researchers use that information to find a potential treatment for dandruff. Often when people who have dandruff have a lot of this particular species of fungus, malacasia restricta, and that makes the cells on your skin of your scalp clump together and form those pretty telltale white flakes. And, you know, a lot of people who have this issue, they'll use chemicals that treat the fungus, but then the fungus just comes back.

So instead, the researchers had a bunch of volunteers wash their hair and then they tested their scalp microbiome and compared the scalps of people who had dandruff and people who didn't. And people who were not prone to dandruff had a lot of this bacteria called cutobacterium acnees, which, as you might guess from acne, when it's on the rest of your skin, it causes acne. It can cause real problems. But on the scalp, it seems to have this protective effect against the fungus that causes dandis. No kidding. That is amazing. So I'm picturing someday where we'll see ads on TV for acne bacteria in your shampoo. Well, what they did is instead of putting the bacteria itself in the shampoo, they developed this lotion that contains propionic acid. That's an acid produced by these acne bacteria. And volunteers who used it on their scalp said that it did help treat their dandruff.

So this could be actually an actual product. Oh, for sure. You might not be able to find it in the drugstore today, but maybe down the line will all be, you know, taking a leaf out of the acne bacteria book. I'm waiting. Next up, some pretty epic dress-up play involving Greek armor? What's this about? I love this study. So there's this famous suit of armor called the Dendra armor.

It's about 3,500 years old, and it's one of the oldest complete suits of metal armor from the Bronze Age, and this is from Bronze Age Greece. researchers were like, this is a really heavy, bulky suit. Could warriors actually wear it in sustained combat? Or is it more of like a ceremonial outfit that they would have worn for decoration? Yeah. So what did they find out? So what they found out is if you put replicas of this armor on modern Greek soldiers,

they had the Hellenic Marines volunteer to help test this. And then they had them do 11 hours of these activities inspired by descriptions of combat in Homer's Iliad. and they found that they held up pretty well. You know, the soldiers were tired at the end of the day after a long day of hitting a shield with a replica sword or a spear. They used bows and arrows and rocks. They even rode on chariots. And they had them do all these exercises for 11 hours.

They had them eat a menu of foods inspired by this era of history. And then afterwards, they were okay. Somewhere there's a video of this that we're all going to want to see. Oh, yes. If you've ever wanted to see someone riding a chariot that's on a treasurer. Mill, you definitely want to check out the video of these exercises. Yeah, so they had no meals ready to eat in this fight. They had real. No, actually, their meal sounded really good. They had a heavy breakfast and a heavy dinner

with snacks in between and the food included bread. They had red wine with both their big meals. They had goat cheese and onions. It sounded much better than an MRE. The idea of all these combat moves is coming out of Homer. Well, Homer is, he was actually putting these stories down hundreds of years after the events he's describing. So he's not exactly the most reliable source, but we just don't have a ton of firsthand information about that era. And we do think that that battle was sort of like today's high intensity interval exercises. You know, the soldiers would go to battle and they'd have maybe an intense fight and then they'd retreat back behind their battle lines to rest and to have a snack. So, um, Homer's not an ideal source, but he is a potential source. And by putting these soldiers through these paces, it is really a rigorous study for exercising a lot under these conditions and seeing how people hold up while they're wearing something really bulky like that armor.

So they did conclude then that this armor is actually useful. It just doesn't weigh them down. It actually could be useful in battle conditions. Yes, they were monitoring the volunteers throughout testing their bomb. body and skin temperature, taking blood samples, measuring how much energy each of these exercises was expending. And using computer models afterwards, they found that this could be sustainable for an 11-hour combat period. Unless the weather was extremely bad and extremely hot, your average elite Mycenaean warrior would definitely have been able to wear this. Yeah, I get that,

considering our summer coming up here. Yes. Finally, giving people Al vision, I mean a 360-degree view. How does that work? This is amazing. So basically, volunteers were wearing a VR headset, and on top of their head, they had a 360-degree camera. And the way that this software worked was when a volunteer turned their head slightly, the VR view would give them an even bigger turn than they actually did. So when they turned their head sort of 90 degrees to the side, their view in the VR headset was behind them, 180 degrees behind them. I would imagine it would take some time to adapt to this. Right? Definitely. It did take a little while, but then people, once they had adapted, were really comfortable with this owl's eye view. They were able to navigate and to pick

things up. And then when it was time to take the headset off, after that, they had a little bit of trouble readjusting back to normal human view. Yeah, I'd ask if I could take it home with me. You know, this is working so well. I'd like to have. I would love to use it if I'm trying to look behind me while I'm sitting in the car. Instead of using the rear-facing camera, you can just turn your head a little bit and see behind you. Hey, I think you've got a product here. Instead of your backup camera, why do I need it? Right? I've got it on my head. Yeah, you just need to drive around everywhere in a VR headset. What could go wrong? Exactly. Always great to have you, Sophie. Thanks for taking time to be with today and have a great holiday weekend.

You too. Thanks. Sophie Bushwick, senior news editor at New Scientist. Every 260 days, indigenous communities in the highlands of Guatemala celebrate a new cycle of the Mayan calendar. This ceremony has persisted for thousands of years, and the latest one of these celebrations happened earlier this month. The Maya have long been accomplished astronomers, and the tradition of using the sun to keep time persists to this day. Joining me to tell us about the significance of this astronomical ceremony are my guests.

Willie Moreno, Mayan calendar keeper based in Ketsiltenango, Guatemala, and Dr. Isabel Hawkins, astronomer and senior scientists at the Exploratorium in San Francisco, California. Welcome both of you to Science Friday. Thank you for having us here today. Thank you, Ira. You're welcome. Willie, tell me about the ceremony and what the significance of it is. Yes, thank you.

I think, first of all, we will have to think about monkeys first. Monkeys? Monkeys are very important for culture. They are known as the scribes and the ones who keep track of histories, but also they are the masters of art and pottery in the Popol book, which is one of the most important books for the Mayas. So there are two monkeys in the jungles of Guatemala. One is the sour monkey, and the other one is the spider monkey.

Both of them are like the ones who see everything on top of the trees, so what's going on down there. So both of them will have four extremities. So if you add four and four, you would get the number eight. So the celebration that it happened, you know, just a while ago here in Guatemala, it's called in English the A-Monkey ceremony for Waxhaki Bats. And that is the representation of the balance between the night and the day. I don't know if this answer is clear. I just want to make it very poetic because we come from a very poetic language and then very symbolic way to celebrate life.

The ceremony itself is it actually based on the cycles of the sun's movement? Not necessarily. This ceremony, I would say it in this way, it takes place every nine months average. The calendarical or the mathematical systems for the Mayans and Mesoamericans is number 20. If you multiply 20, 13 times, you get a period of time of 260 days. And that's the average time for a human to be in the mom's womb, average nine months. So this is the base of all the astronomical cycles. But then, The first one, it will be multiplied 20 times 13 and then you get 260 days. So every 260 days, we have a day called a monkey or wachshaki bats, and that's when we do this celebration. Isabel, you've been going to these ceremonies for years as an astronomer educated in the Western way. What is it like to observe these ceremonies?

Yeah, it's really amazing. I mean, when I started going to Guatemala, was in 2010, when the Smithsonian, you know, when the Smithsonian National Museum with the American Indian asked me to develop a website on Maya astronomy and the Maya calendar because in 2012, December 21st was when the big count or long count calendar, which spans cycles of 5,215 years, would turn over. That so-called 13 back tunes would turn over. And then people made up these stories that there would be the end of the world or some catastrophe would happen. And so I agreed to do this calendar website for the Smithsonian under the condition that I would go and interview the calendar keepers in Guatemala. But being there, it's an amazing entry.

You have to climb up. You start seeing some black smoke up on the hill. And this very triangular, pointy cave. where much of the offerings are given, really to connect with these cycles and to connect with the energy of the earth and the power of the sun and the moon and the sky. And then from there, the calendar keepers

will set up this beautiful altar, a circular altar, that is aligned with cardinal directions and with key points of the position of sunrise in the eastern horizon as seen from this cave. and it was using those precise observations that these count of the days has been going on for thousands of years. Willie, as a calendar keeper, is it true that the Mayan astronomers also predicted astronomical events like eclipses? I think it's a great question.

When you mean predicted, it's like, you know, like the forecast. You know, like today the weather channel forecast storms, you know, tornadoes and hurricanes. I think humans have always have that ability, you know, in the sense of observing what is going on on nature. You know, my grandmother would say, oh, there's going to be an earthquake by seeing, you know, the clouds. Oh, there is going to be a rain, you know, also because of seeing just the behavior of the trees. But obviously, 500 years ago when the Europeans arrived, they misunderstood the way that we were checking on time. And there was hard times when we were called witches because we were able to predict what was going on. But it's more about forecasting.

And this is what I just talk on behalf of my culture. Did we have science within our practices that had been confused with like religions or sacred? And then that's why community still believe in what we do and how we count time and how we advise the community to behave. And so how do you forecast an eclipse? By counting with our fingers. We have numbers like 148 and 177 to check on like moon eclipses, but like longer eclipses, you know, if we have the 260, if we multiply it by 46, we will have something like 11,000 days. And I don't have the anger number right now. And that was when a solar eclipse will occur. But then that's like the base of this is 2013 and then, you know, multiply 20 times 13 and then you

multiply your 46 and then that's how you get an eclipse. It's absolutely incredible how you can gain a tremendous amount of accuracy just through observation. I think that technology, you know, since the Industrial Revolution, has in a way enhance our capacity to do science that is perhaps more focus on, particular themes or topics and go deeper. And we use technology for the sake of measurement, precision, and speed. However, that same technology has, in a way, dulled or taken away our intrinsic capacity as human beings to use our bodies as the instrument of observation. And I think when you think about 500 years ago, when people were out in the world,

out in nature all the time. And the Maya had special people that were the Achkir means an expert on time or an expert in the sun and expert in the day because kih means day, sun, and time. So ah is a prefix that in the Mayan language implies expertise. So people studied, people were experts, people were scribes, people took count of the days. They observed the moon, the sun, and the planets was. great precision. And they were able to identify cycles of when the moon would come back and be in that alignment, the sisy, which is when the sun, Earth, and Moon are in alignment.

I'd like to thank my guest, Dr. Isabel Hawkins, astronomer, and senior scientists at the Exploratorium in San Francisco, California, and Willie Moreno, my end calendar keeper based in Quataltonango, Guatemala. Thank you, Ira. That's it for today. But if you like that, conversation, we have a special newsletter all about astronomy and space science from Latin America, available in both English and in Spanish. It's in collaboration with our friends at El Pais, America Futura, to sign up head to sciencefriiday.com slash astronomy. That's sciencefriady.com slash astronomy. On Monday's episode, go for a swim with an unusual sea creature called the Salp. Researchers now know how they corkscrew their way through the water. I'm SciFRI producer Charlesburg

Thanks for listening. Have a great holiday weekend and we'll see you soon.