Briefing Chat: Why scientists made papyrus scrolls, then burnt them

Reading ancient volcanic scrolls

0:00Hi, everyone. Benjamin here. Welcome to the Friday edition of the podcast, the briefing show where we talk about some of the stories that have been featured in the Nature Briefing, which is, of course, Nature's daily email roundup of the latest science news. Joining me this week is Sharmini Bundel. Sharmini, thank you for being here. Hello. I've got a question for you today, Ben. Okay. And that is, how do you read an ancient scroll that's been turned into basically an unopenable

0:31lump by a literal volcano? Do you know what? Strong question. Yeah, this is a big problem, particularly if you're a historian who is studying life around the time of the eruption of Mount Vesuvius, and you have a whole load of nearly 2,000-year-old scrolls that you tantalizingly can't get into. You can't actually read them because you can't open them. But some researchers have been making their own scrolls, making and baking their own scrolls, to try and help this problem.

1:02Really? Right. Because, of course, we talk a lot about antiquity then, and there's potentially absolute treasure, contemporaneous treasure, I suppose, hidden in these charred scrolls. But you can't just try and unwrap them, right? Because they will shatter into a million pieces. People tried. Really? Yeah. When they were discovered, there definitely are ones that people did try and open, and they're just shattered. And I think there are still historians trying to piece those ones together as well. Right. But there are loads left, and loads that haven't been touched, including the ones that were the worst burnt, if that's a phrase. But it's tantalizing. It's there. It's probably

1:38the only complete library from that period, if it is indeed even all the library that exists. It was basically this fancy villa in Herculaneum, near Vesuvius. And they've got hundreds of scrolls from it that are around the world in different museums that they can't get into. But loads of people are, as we speak, working on, how do we get into them? How do we look into them? And this is a new paper that I read about in Nature from a Plus One article. And it's using

2:09a slightly different technique to the ones that have been focused on so far. Okay. So if just brute force is clearly out then, you're saying that some researchers are trying to recreate the situation to then work out how to undo it. Exactly. So this is a new technique that they're trying, which is basically about trying to look for lead that is in the ink that would have been used to write on the scrolls. And so what they did was they've basically tried to recreate the technique. They've got some papyrus.

2:41They've got Egyptian reed pens. They've got traditional lamp black ink from Japan, trying to get as sort of authentic as possible to make their own scrolls, which they then rolled up and put in a furnace to basically recreate volcano conditions and see if they could then detect the lead in the ink, which they did using x-rays, basically. The x-rays can distinguish between the papyrus material and the lead in the letters that's written on it.

3:13So they can write, what, hello world on their fake scroll, roll it up, put it in the furnace, come back, put it in their equipment and bingo, there it is, hello world. Yeah, they've got... So this is, in fact, written in English and not ancient Greek or Latin. But yeah, they've got pictures of the text kind of like glowing in... There's a fluorescent scanner. There's different things that they've used. So traditionally, all these scrolls are being studied by CT scanning, so x-ray computed tomography. So people are taking these scrolls

3:43basically to like big synchrotron facilities to try and get into them, get all the details, all the sort of possible subtle differences between the inks and the papyrus. But usually, up until now, when people have been looking for this, they've been looking for really subtle differences because the CT scans focus on the carbon and then there's carbon in both the ink and the papyrus. So people have been using machine learning algorithms to try and parse out these subtle differences. So that's actually been going quite well, right? There's been results this year

4:18and last year where people have quite successfully been able to read the actual original, like some bits of texts from these scrolls. And I think earlier this year, the first complete scroll was analysed using this CT scan method. But this different method, which they haven't tried on an actual scroll, they've just sort of tested it out, as I said, on their own scrolls. They did do it in a big CT scanner, but they also did it in their own little x-ray setup, like a much smaller machine,

4:48because it's just much easier to do because the lead actually stands out. So this might also be interesting because you don't need to do the big scans and you can use a handheld x-ray fluorescence device and hopefully, yeah, see the glowing letters just like they have on theirs. Okay, because they want to make sure that this method works well, because these real scrolls are so precious. But is there a timeline for when they might give it a go on the real thing? I don't know if this team planned to. There are a lot of people, as I mentioned, already working. It's called the Vesuvius

5:22Challenge, basically, to try and decipher these scrolls. And there are a lot of teams working on that. And I think some of them are already looking for lead, looking at lead as a lead, a lead lead. So this paper will definitely be of interest to them. And it's also interesting because a researcher who wasn't involved in this work noted that because this team has made and baked their own scrolls, they obviously do know what it says. They know what the original text was. And as I mentioned,

5:53there's a lot of using algorithms to try and work it out. So you've got algorithms that can detect the subtle distinction between ink and paper, and then also able to sort of work out what those words likely are in a way that would be really difficult just looking at some blobs. So this is actually a controlled method of potentially training an algorithm on what to actually look for and test and refine the results. Because in this case, they actually know what it does say.

6:23Well, I love any story to do with antiquity. And I'm so keen to know what's on those scrolls, because who knows, right? It could be a shopping list. It could be... Quite a lot of philosophy, apparently, so far. More useful than a shopping list? I think it's context dependent. I think that's fair to say.

Developing edible medical batteries

6:38Right. Well, let's move on to our second story this week. And it's a story that I've been reading about in Nature, based on a paper in Nature Chemical Engineering. And it's about a battery, but a very particular kind of battery. Specifically, it's an edible battery. As a parent to a toddler, there is one thing I know, you do not eat the batteries. I'm pretty sure that's a basic rule of small children and also batteries. Why do we want the battery to be edible? Well, because it could be used to power medical devices, potentially. But you're absolutely right.

7:09Yeah, I was actually buying some coin batteries for my bike lights this week. And there's all sorts of warnings on them, right? There's bitter coating on them as well to try and make you want to spit it out, right? Particularly children, as you say, who are at greater risk of eating these things. And of course, eating batteries can be incredibly dangerous. As you say, they can give chemical burns, they can release toxic compounds, they can have plastic casings on them that can do you an injury inside. So it's a hard one to do. But as I say, if you could make a battery that could exist safely in the body, it could power medical devices. And that's what a team have been working towards.

7:44And they've created a battery with a substance resembling rice paper in some senses that can ultimately be absorbed by the body. Now, so far, it's only been tested on pigs, but it is showing some promise. So it's not just that it's not going to burn your insides, it actually would dissolve away safely and leave you with nothing? Yeah. So the team behind this work are, of course, very restricted in what they could make their battery out, right? Lithium-ion and alkaline batteries often contain toxic metals,

8:15for example. So what the team have done in this case is they've used magnesium and molybdenum trioxide as the electrodes in their battery. Now, these Chalmini, as I'm sure you know, are metallic micronutrients that the body needs. I did not know that. Okay. And when paired together in a battery, they provide a voltage high enough to power electronics. Now, there is also cellulose in this battery too. So it is a paper composite and this cellulose degrades over time. And there's other things there as well. They need an electrolyte. They've

8:47used a biodegradable ionic liquid. And the whole lot, as I understand, was dipped in beeswax to slow down the effect of stomach acid. Oh, because you need it to be sitting in there powering your internal devices for a while before it dissolves. Yeah, that's right. And what the team did, they simulated gastric fluid and tested the batteries and found that they began to come apart within a couple of weeks before dissolving completely after several months. So it showed that it could work, but I think they wanted to test

9:20it in a more realistic setting. So they packaged these batteries with fully biodegradable, non-toxic electronics inside these gel capsules. And there's a picture of it in the article, which we will link to in the show notes. And they tested these capsules in pigs. And you said medical devices, but what kind of things are we talking about? So in one example, then they used the battery to power this RFID tracking device inside the capsule. And this obviously gives out a signal that can be picked up outside the pig. Now, this could be used in humans, for example, to detect whether someone's taken their medication,

9:53right? You could fill this capsule with a drug and detect from outside the body, like, has it been taken? But they did another test as well. And they used the battery to power this device that electrically stimulated pig's stomachs. And this stimulation caused an increase in levels of the hunger hormone ghrelin. Now, things like these are being explored more broadly as a way to regulate the brain-gut connection, which we've talked about a lot on the podcast. And these would potentially be a less invasive thing than, say, a bariatric surgery or implants

10:25that regulate the activity of the digestive system. Yeah, the fact that it's dissolvable sounds extremely convenient for all sorts of possible medical uses there. Right. And it has to be said, this isn't the only team who are trying to crack this nut, right? There are a few groups who are working on these dissolvable batteries and are at a variety of stages through testing and what have you. But it seems like this battery from this work is comparable to other types of biodegradable battery. And from what I understand, the team are hoping to take this forward and get it tested in people in the not too distant

10:57future.

Summary and closing remarks

10:58Well, that's fascinating. I think we've got to come back to, don't eat the batteries, everyone. 100%. Don't eat them. Just in case no one didn't get that message from the beginning. Right. Don't eat the batteries, especially if only small children are listening to this, unless they're special edible batteries, which is very cool. Well, thanks, Ben. So as usual, I think we'll have a link to both of those stories in the show notes. Absolutely. And a link on where you can sign up to the Nature Briefing to get even more stories like it delivered directly to your inbox. But yeah, that's it for this week. And all that's left to be said is I've been Benjamin Thompson, Sharmony Bundell. Thank you so much for being here.

11:30See you next time.