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  • This episode was brought to  you by Music for Scientists,

  • now available wherever you stream music.

  • [♩INTRO]

  • When most people think of archaeology,

  • they imagine Indiana Jones-type digging in holes,

  • looking for objects made by ancient communities.

  • And that's partly true.

  • But there's another field where the archaeologists

  • are the ones making the objects.

  • It's called experimental archaeology.

  • Experimental archaeologists make  hypotheses about how people in the past

  • crafted various artifacts or  performed incredible feats.

  • Then, researchers test those hypotheses  by attempting to recreate the methods.

  • This can involve anything from  reconstructing Polynesian boats to brewing

  • the beer Egyptian pharaohs drank.

  • And by replicating these processes,

  • researchers gain an understanding  of how advanced ancient people were.

  • They can actually feel what it  was like to live in the past.

  • And they can even learn how  to improve our lives today

  • by resurrecting long-forgotten technologies.

  • Some of the most common things  experimental archaeologists

  • recreate are stone tools.

  • And surprisingly, replicating these objects  doesn't just reveal things about our

  • ancestors' handiwork, but also tells  us about their cognition and language.

  • In 2010, experimental archaeologist Lyn Wadley

  • explored ancient people's cognition  by replicating hafted spears.

  • Hafted weapons are made by attaching a stone blade

  • to a wooden shaft using a sticky substance.

  • And they seem pretty simpleuntil you make them from scratch.

  • Wadley performed chemical analyses  to determine the exact materials

  • people in Africa used to craft hafted  weapons around 70,000 years ago.

  • Then, she had a go at it herself  and published the results

  • in the journal Current Anthropology.

  • After collecting the materials, she used  a rock to carve other rocks into blades.

  • This is called flint-knapping, or just knapping.

  • And yes, using a stone to chip a rough  rock into a tool as sharp as a scalpel

  • is exactly as hard as it sounds.

  • In her test, Wadley used one of the  blades to whittle a stick into a shaft.

  • Next, she crushed rocks to make ochrewhich is a pigment made from rocks

  • rich in iron oxide, the same compound  that makes rust, rust-colored.

  • Then, she mixed the ochre with  beeswax and sap from an acacia tree

  • and cooked it in a fire to make glue.

  • By the time she finished crafting the spears,

  • Wadley concluded that humans  from that time were capable

  • of complex cognition, which involves  mental flexibility, abstract thinking,

  • planning abilities, and more.

  • Specifically, she proposed that people  had to engage in abstract thinking

  • to imagine how to inventmulti-ingredient adhesive.

  • They also needed to be mentally  flexible, because each batch of glue

  • has to be prepared differently depending on,

  • like, the stickiness of the  sap that particular day.

  • And people were using planning  because they needed to wait

  • up to six days for the glue to set.

  • Plus, they must have developed advanced language

  • to teach each other the skills.

  • And she isn't the only  researcher who's proposed this.

  • In fact, many scientists suspect language  showed up in the first place because

  • our ancestors needed to school each  other in the art of stone toolmaking.

  • But it's difficult to prove that because  talking, you know, doesn't fossilize.

  • So, in 2017, experimental archaeologists  taught stone-knapping to newbies

  • to determine how much communication  was necessary to learn the craft.

  • They chose a type of knapping that was  invented around two million years ago.

  • One group of newbies tried to learn  by observing expert flint-knappers

  • and imitating them, with no language involved.

  • And the results... were kind of terrible.

  • Another group of beginners  was taught with gestures.

  • And they did pretty well.

  • But a third group was taught  with spoken communication.

  • At first, they did as well as the gestural group.

  • But in the second phase of the  experiment, only the speech group

  • was able to remember the method  and perform it on their own.

  • This suggests that this kind communication  is the best way to help people

  • retain the information they've learned.

  • And while the researchers didn't look at  this specifically, that's likely true of

  • signed languages as well, since they  convey the same amount of information.

  • Either way, the researchers concluded  that language may well have emerged

  • to teach people to skillfully bang rocks together.

  • Now, stone tools were some of the first things

  • experimental archaeologists  recreated, starting in the 1800s.

  • But experimental archaeology didn't really  come into its own until the mid-1900s.

  • And one of the things that launched it was a boat.

  • In 1947, a Norwegian  anthropologist named Thor Heyerdahl

  • set out to prove a controversial hypothesis.

  • He proposed that the Polynesian  Islands in the South Pacific

  • were settled by South Americans  who drifted some 8000 kilometers

  • across the ocean in wooden rafts.

  • And to prove this was totally possiblehe and five other people went to Peru

  • and built the Kon-Tiki, a  13-meter-long balsa wood raft

  • based on explorers' records of  ancient South American boats.

  • Then they set off, and 101 days later,

  • successfully crashed into a reef on  the Tuamotu Islands in Polynesia.

  • Exceptit turned out  Heyerdahl's hypothesis was wrong.

  • In 2003, scientists used DNA  studies to show that South Americans

  • didn't actually settle Polynesia.

  • But the Kon-Tiki was still hugely significantin that it helped scientists reimagine

  • what was possible to study  with experimental archaeology.

  • And it paved the way formore successful experiment:

  • the 1976 voyage of the Hōkūleʻa,  a replicated Polynesian canoe.

  • This time, it wasn't just a boat being recreated:

  • It was a nearly forgotten navigation technique.

  • At the time, the scientific community  was debating how people settled

  • the Polynesian Triangle starting around 800 BCE.

  • The Polynesian Triangle comprises more  than 1000 islands sprinkled around

  • 25 million square kilometers of  ocean between Hawai'i, New Zealand,

  • and Rapa Nui, or Easter Island.

  • Many scientists argued that  Polynesians accidentally

  • found the various islands  by drifting with the wind.

  • Others gave the Polynesians more  credit and believed they deliberately

  • discovered islands using  finely-tuned navigation techniques.

  • To settle the issuearchaeologists, anthropologists,

  • and historians designedPolynesian voyaging canoe.

  • They based it on canoe drawings from the 1700s

  • and their best guess about what  earlier canoes looked like.

  • Next, they found a master navigator  from Micronesia named Mau Piailug

  • one of the few people left in  the world who was well-versed

  • in ancient Polynesian wayfinding.

  • Piailug and crew set off  from Hawai'i in the canoe,

  • navigating by the sun, the stars, the clouds;

  • the flight patterns of land-based birds;

  • and the feel of the ocean  swells, which change direction

  • as they bounce off distant  lands and blow with the winds.

  • After 34 days, they arrived  in Tahiti just as planned

  • a journey of more than 4000 kilometers.

  • And by succeeding, they demonstrated  that ancient Polynesians did have the

  • sophisticated skills required to explore  and populate thousands of islands.

  • And that's one of the things  about experimental archaeology:

  • It inspires a lot of respect for our  ancestors' knowledge and expertise.

  • That's certainly the case when it comes to  historic people's culinary talents, too.

  • Because yes, experimental  archaeologists also bake bread,

  • brew beer, and cook medieval meals.

  • Recreating long-forgotten food and drink  allows researchers to experience the

  • same tastes, smells, and other sensations  that ancient people experienced.

  • It can tell researchers  about ancient people's diet,

  • health, culture, and  knowledge of culinary science.

  • Plus, it's tasty.

  • Like, in 2019, an archaeologist, a physicist,

  • and a microbiologist resurrected  4000-year-old Egyptian yeast.

  • And they're using it to bake bread and brew beer

  • the way it was done in the time of the pharaohs.

  • Which is incredible for so many reasons.

  • First: Yes, yeast can survive inhibernation-like state for thousands of years.

  • And if you feed it the kind of grain  that it ate thousands of years ago,

  • in this case, emmer wheatit will wake up and be like,

  • Hey, let's make some bread.”

  • Knowing this, the scientists got access  to Egyptian artifacts in a museum.

  • Then, they took a specially-designed  syringe and suctioned up yeast

  • from beer vessels, bread pots, and  a bread loaf that had been buried

  • under a pharaoh's tomb.

  • Next, they began a series of experiments.

  • They brewed one beer using  yeast from a beer vessel,

  • and another beer using yeast from the bread,

  • because one question they're  trying to answer is how much

  • ancient Egyptians knew about the science of yeast.

  • If the bread yeast and the beer  yeast are the same species of fungi,

  • it might mean the Egyptians  were scraping the frothy yeast

  • off of their beer and  kneading it into their dough.

  • And that would suggest they knew  that the same mysterious something

  • was making their bread rise  and their beer ferment.

  • Which doesn't sound like a big deal  to us now, but would have been huge.

  • Our current understanding of history  is that scientists didn't know exactly

  • what yeast was and what it did for  beer and alcohol until the mid-1800s.

  • At the time we're filming in 2021,

  • it looks like the Egyptians actually  didn't know that, because the two beers

  • tasted very different.

  • But the upcoming DNA tests will tell us for sure.

  • In the meantime, these scientists  are trying to fill in the gaps

  • of the archaeological recordbecause inconveniently,

  • ancient Egyptians didn't leave behind recipes.

  • So the scientists are studying  chemical analyses of baked goods,

  • plus drawings of bakers on a tomb wall.

  • And they're conducting baking experiments  to figure out how ancient Egyptians

  • nurtured their sourdough and  baked it in clay pots buried

  • underground with a bunch of coals.

  • Besides just being a good time, this  is also important to learn because

  • bread and beer were central  to ancient Egyptian culture.

  • In fact, the people who built the  pyramids were paid in bread and beer.

  • So, baking and tasting  4000-year-old bread gives us a feel

  • for what it was like to be a pyramid  builderwithout all the heavy lifting.

  • Now as you've probably noticed,

  • experimental archaeology can  be an immersive experience!

  • And some experiences are  more immersive than others.

  • Like, when you build a Neolithic  farm and start living on it.

  • A lot of experimental archaeology  takes place at archaeological museums,

  • or open-air museums.

  • These are places that have  replicated farms, houses, forts,

  • or other structures from the past.

  • And the public can visit to learn  about life in various time periods.

  • But these museums can also be  sites for scientific research,

  • like at Lejre Historical-Archaeological  Experimental Center in Denmark.

  • This place is famous for an extreme experiment.

  • Around the world, there are archaeological  sites where houses or villages have

  • burnt down, maybe because of a cooking  accident or pyromaniac marauders.

  • And these sites can be difficult to analyze.

  • So in 1967, archaeologists at Lejre  filled a replica Iron Age long-house

  • with pottery and other objects.

  • And then they set it on fire.

  • 25 years later, other  archaeologists excavated the site.

  • Crucially, they were not told what the  original house looked like or what was in it.

  • The researchers then compared their  analysis of the charred remains

  • to the original house to help archaeologists  better interpret scorched sites.

  • Overall, the researchers were really accurate.

  • But they were shocked that  the 25-year-old burned house

  • had deteriorated so much it  resembled a legit Iron Age house

  • from more than 2000 years ago.

  • They concluded that some  other archaeological sites

  • might actually be burned dwellings  that have decayed beyond recognition!

  • In other experiments, archaeologists  are trying to replicate super-strong

  • Roman concrete and Bronze Age  insulation to learn how modern people

  • can build more sustainable structures.

  • Construction contractors  from Austria are even looking

  • at archaeological experiments  to improve building materials.

  • Because really, experimental archaeology  is part science, part adventure,

  • and part exploration, but  it's not just about the past.

  • It can also help us understand some  great skills and ideas from years gone by

  • that might help us live better lives today.

  • And it's efforts like these that are  celebrated in the album Music for Scientists,

  • a tribute to science and the  people who make it happen.

  • It was inspired by the beauty of science

  • and of making our worldand our past, more knowable.

  • The album is also an homage  to the people of science.

  • If you think you'd enjoy  listening to Music for Scientists,

  • check out the link in the  description to get started.

  • [♩OUTRO]

This episode was brought to  you by Music for Scientists,

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