Learn about why the marijuana classifications of indica and sativa aren’t based in science; how clean your washing machine really gets your clothes; and why researchers staged sword fights to learn about the Bronze Age.
Learn about why the marijuana classifications of indica and sativa aren’t based in science; how clean your washing machine really gets your clothes; and why researchers staged sword fights to learn about the Bronze Age.
Indica and sativa marijuana classifications aren't based in science by Andrea Michelson
How clean are clothes from the washing machine? by Ashley Hamer (Listener question from Kathleen)
Researchers staged sword fights to learn how fighters used their Bronze Age swords by Kelsey Donk
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/marijuana-categories-arent-based-in-science-scientists-staged-bronze-age-swordfights-and-how-clean-are-your-clothes-really
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about why the marijuana classifications of indica and sativa marijuana aren’t based in science. Then, we’ll answer a listener question about how clean your washing machine really gets your clothes. You’ll also learn about why researchers staged sword fights to learn about the Bronze Age.
CODY: Let’s satisfy some curiosity.
As marijuana goes mainstream, more and more people are flocking to dispensaries. Sometimes, they’ll find a mind-boggling array of strains with names like “Gorilla Glue,” “Blue Dream,” Death Star, Nice Guy, Pineapple Express, Jack Herer, Sour Diesel [Cody keeps listing strains, Ashley cuts him off]
Anyway, you go into one of these dispensaries, and the strains are labeled with the type of cannabis they contain and a list of their supposed effects. But it turns out that the classification system this relies on is centuries old — and it’s not holding up under modern scientific techniques.
Cannabis growers, sellers, and consumers typically categorize strains as indica, Sativa or hybrid. They say indica puts you “in da couch” — supposedly those strains give you a relaxing quote-unquote “body high.” On the other end of the spectrum, sativa strains are said to provide a more energizing “head high” that can manifest as creative euphoria or, in some cases, anxiety. Anything labeled as hybrid is supposed to put you somewhere in the middle.
Or so we thought. It turns out that this classification is not actually based in science. The false dichotomy goes all the way back to the late 18th century, when French biologist Jean-Baptiste Lamark identified a new species of cannabis that had been sent to him from India. [ASHLEY: If that name sounds familiar, it’s because he’s the guy who said the stupid thing about evolution!] CODY: Lamark noticed that the wild-grown plant from India was smaller and had firmer stems compared to cultivated European cannabis. The thick stems made the crop unsuitable for producing hemp fiber, but Lamark did find that consuming it led to, quote, “a sort of drunkenness that makes one forget one’s sorrow, and produces a strong gaiety” end quote. India became indica, and cultivated hemp’s wild sister was born.
Today, most scientists recognize just one species of cannabis, Cannabis sativa L. Others might break that down into three subspecies: Cannabis sativa, indica, and ruderalis [ROO-derr-AAL-iss]. But when it comes down to it, there’s really no difference between indica and sativa plants on a molecular level. The real explanation for cannabis’s varied appearance and effects is in its terroir [tare-WAH], or where and how it’s grown. Everything from soil to sunlight to altitude can affect the final product, so when you plant a seed to grow OG Kush in California, it’ll will turn out differently from the same strain grown in Colorado. That’s similar to what happens to wine grapes. But unlike the wine industry, which is heavily regulated, the cannabis world doesn’t have a governing body to standardize how growers name their strains.
For now, the indica/sativa classification remains as a tool for explaining the varied effects of cannabis to consumers. But when strains don’t behave according to this oversimplified system, users may end up a bit more dazed and confused than they bargained for.
We got a listener question from Kathleen, who writes, “My fiancé and I have an ongoing debate about our machines. How clean does our washing machine really get our cloth items?” Great question, Kathleen!
It all depends on how you’re doing your laundry. Let’s start with how your washer gets your clothes clean. You put your laundry in the washer with a cupful of detergent, close the lid, and start the wash cycle. The first thing that happens is that the detergent mixes in with the water to help it penetrate into stains. Detergent is a surfactant, which means it can help oil and water mix — super important for getting out day-old pizza grease. The problem is that detergent can only penetrate so far: soapy water can get between the threads in a T-shirt, but it's less effective at burrowing between the tiny fibers that make up each thread to remove the particles trapped within. Luckily, the rinse cycle saves the day. When fresh water replaces the soapy water, the difference in detergent concentration actually creates an electric field that draws those dirt particles out. The charged surfactant molecules that surround each dirt particle carry it away through the electric field like a microscopic Maglev train. Cool, right? It looks simple, but your washing machine has some complex physics going on that gets your clothes surprisingly clean.
But while detergent and water might be enough to get dirt out, it’s different for microbes like bacteria and viruses like — yes — COVID-19. You may have to use some extra weapons to rid your clothes of those bugs. One of them is heat. The CDC recommends washing your clothes on the warmest appropriate water setting and drying them completely. A recent study found that viruses similar to COVID-19 thrive in cold, humid environments, so sticking clothes in the dry heat of an electric dryer will be the best protection against infection. Another weapon you can use is bleach, if it’s appropriate for the load.
But there’s one harbinger of microbes that many of us don’t think about: the machine itself, which can carry bacteria that could transfer to future loads. The lesson here: even your washer needs washing. Experts recommend sanitizing your machine every so often by running an empty load with very hot water and bleach. Afterward, wipe down any rubber seals to remove lingering moisture.
But in general? Your washer and dryer are perfectly good at cleaning your clothes. The combination of heat, detergent, and agitation is enough to rid garments of pretty much everything you need it to. Thanks for your question, Kathleen! If you have a question, email it to podcast at curiosity dot com or leave us a voicemail at 312-596-5208.
Here’s something fun: researchers staged real sword fights to learn how Bronze Age fighters used bronze swords.
When you think about what makes a good sword, strength is probably high on the list. The Valyrian steel swords from Game of Thrones never went dull. Sokka’s Sword from Avatar: The Last Airbender was forged from a meteorite. The Sword of Grayskull from He-Man was indestructible. But weapons from the sword-loving Bronze Age were made of, obviously, bronze. And bronze is pretty soft — it’s actually much easier to bend and destroy than iron. How could that be? Is it possible that the thousands of bronze swords archaeologists have found in graves and rivers were just status symbols?
To find out, a team of archaeologists had seven bronze swords forged by a traditional bronzesmith. Then, they recruited specialists in Historical European Martial Arts, or HEMA [HEE-muh], to reenact the moves from a real medieval fencing manual. At the conclusion of each fight, the researchers recorded the marks left on the weapons. Their goal was to measure the microscopic dings and dents and figure out if bronze could really be used for sword fighting.
When they were done with their fighting, the archaeologists compared the marks on their replicas with marks on actual Bronze Age swords. The marks matched up! Which demonstrated that the real historical weapons weren’t just for decoration.
Finally, they examined 110 swords from Bronze Age Italy and Great Britain for the same types of marks from specific moves. Certain marks were associated with certain eras and locations, suggesting that specific moves had evolved and spread from region to region over long stretches of time. These fighters weren’t fooling around. After all, if you use a bronze sword in a ‘clumsy way,’ you’ll destroy it, one researcher said. It takes training to make the most of such a soft metal.
It’s funny to imagine archaeologists reenacting sword fights, but the research is also pretty groundbreaking. It introduces a whole new way to study civilizations and the objects that were central to their culture.
Leave us a voicemail at 312-596-5208!
CODY: Before we recap what we learned today, here’s a sneak peek at what you’ll hear next week on Curiosity Daily.
ASHLEY: Next week, you’ll learn why rubbing dirt on your wounds might actually be good advice;
An easy trick for telling stars and planets apart when you’re looking up at the night sky;
Why it’s so easy for elephants to get drunk;
That time you were able to puy life insurance policies from vending machines;
And more! Okay, so now, let’s recap what we learned today.
[ad lib optional]
CODY: Today’s stories were written by Andrea Michelson, Ashley Hamer, and Kelsey Donk, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Today’s episode was produced and edited by Cody Gough.
CODY: Have a great weekend, and join us again Monday to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!