Learn about the world’s first vending machine that was invented nearly 2,000 years ago; why scratching an itch can make it spread; and, why you probably don’t realize it when your beliefs change. In this podcast, Cody Gough and Ashley Hamer discuss the following stories to help you get smarter and learn something new in just a few minutes: The World's First Vending Machine is 2,000 Years Old — https://curiosity.im/2HCKIgk When Your Beliefs Change, You Probably Don't Realize It — https://curiosity.im/2HCKCFu If you love our show and you're interested in hearing full-length interviews, then please consider supporting us on Patreon. You'll get exclusive episodes and access to our archives as soon as you become a Patron! https://www.patreon.com/curiositydotcom Download the FREE 5-star Curiosity app for Android and iOS at https://curiosity.im/podcast-app. And Amazon smart speaker users: you can listen to our podcast as part of your Amazon Alexa Flash Briefing — just click “enable” here: https://curiosity.im/podcast-flash-briefing.
Learn about the world’s first vending machine that was invented nearly 2,000 years ago; why scratching an itch can make it spread; and, why you probably don’t realize it when your beliefs change.
In this podcast, Cody Gough and Ashley Hamer discuss the following stories to help you get smarter and learn something new in just a few minutes:
If you love our show and you're interested in hearing full-length interviews, then please consider supporting us on Patreon. You'll get exclusive episodes and access to our archives as soon as you become a Patron! https://www.patreon.com/curiositydotcom
Download the FREE 5-star Curiosity app for Android and iOS at https://curiosity.im/podcast-app. And Amazon smart speaker users: you can listen to our podcast as part of your Amazon Alexa Flash Briefing — just click “enable” here: https://curiosity.im/podcast-flash-briefing.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/why-itches-spread-ancient-vending-machine-and-not-realizing-when-your-beliefs-change
CODY: Hi! We’re here from curiosity-dot-com to help you get smarter in just a few minutes. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about the world’s first vending machine that was invented nearly 2-thousand years ago; and, why you probably don’t realize it when your beliefs change. We’ll also answer a listener question about why scratching an itch can make it spread.
CODY: Let’s satisfy some curiosity.
The World's First Vending Machine is 2,000 Years Old — https://curiosity.im/2HCKIgk (Cody)
The world’s first vending machine is two-thousand years old. Care to guess what country it came from? [ad lib]
CODY: The geographic answer to the vending machine’s point of origin is Egypt during the first century C.E., but it was controlled by Rome at the time, and was designed by Heron [Hair-in] of Alexandria. Heron created something that looked like any old pitcher at first glance, but it could dispense a set amount of holy water whenever a coin was dropped in the slot at the top. The strange device solved a major problem that the churches of his town were struggling with. See, before you could enter certain temples in Egypt at the time, you had to cleanse yourself with sanctified water. But it was too much trouble to the priests to have to hand out the water at the door, blessing each handful as they did. And when the priests just left a large pool of pre-blessed water for worshippers to help themselves, they inevitably helped themselves to far more water than they needed. The vending machine changed all that. The priests could just bless the water in the vending machine, then leave it at the door to mete out a reasonable amount (and do a little fundraising to boot). When a heavy enough coin was dropped in the slot at the top, it would pull out a stopper and let the water flow freely until a counterweight sealed it closed again. The next major advance in vending machine technology came about 1,800 years later, when the invention of instant coffee made coffee dispensers a reality. But as for the mechanics of the machine itself, they were pretty much the same thing as Heron's device. Maybe it's not surprising that his design would survive the millennia — he was a Renaissance man who predated the Renaissance. Luckily for modern snack companies, he wasn't too protective of his intellectual property. [ad lib]
Listener Question - Scratching an Itch (Ashley)
ASHLEY: We got a listener question from Julian, who asks, “Is there any biological reason for why once you scratch an itch on your back it spreads to other parts? I know once I ask my girlfriend to scratch my back, I immediately ask her to go higher or lower after the initial itch.” Great question, Julian!
Yes, there is a biological reason for this, and scientists actually know the answer! So, for a long time, we thought that itching was just a mild form of pain. While we now know that pain and itch each have their own sets of pathways and chemical signals, pain is still the number-one way to cure an itch — I mean, scratching, slapping, even intense heat or cold can make an itch go away. And in a study published in the journal Neuron in 2014, scientists dug deeper into why. When you scratch, it sends pain signals to the brain, which scientists think interfere with those original itch signals to calm your itch. But it also does something else: it makes your brain respond to those pain signals by producing the neurotransmitter serotonin to control the pain. The problem with that is that serotonin also activates nerve cells in the spinal cord that are responsible for relaying itch signals from your brain to your skin. So what happens? Those itch-specific nerve cells get all excited and start sending more itch signals to your brain, which tells your mouth to tell the person scratching your back “Oooh! Higher! No, now lower! A little to the left!” That might sound like a malfunction of your nervous system, but it’s not all bad news. Identifying the interaction between serotonin and those nerve cells has the potential to help scientists develop drugs that can calm itchiness in people with chronic skin conditions. Thanks for your question, Julian! If you have a question, send it into podcast at curiosity dot com.
[ARM AND HAMMER]
CODY: Today’s episode is sponsored by Arm & Hammer, and their new Cloud Control Cat Litter.
ASHLEY: Which is why Arm & Hammer created new Cloud Control litter. There's no cloud of nasties when I scoop ... it is 100% dust-free, free of heavy perfumes, and helps reduce airborne dander from scooping.
CODY: So what happens in the litter box STAYS in the litter box.
ASHLEY: Right! If you’re a cat owner, then you definitely want to check this out. New Cloud Control Cat Litter by Arm & Hammer. More Power to You.
When Your Beliefs Change, You Probably Don't Realize It — https://curiosity.im/2HCKCFu (Cody)
CODY: We all may believe we're rational thinkers with open minds, ready to be swayed by convincing evidence. But in reality, research suggests that when your beliefs change, you probably don’t realize it. Because your brain fights attempts to be open-minded and hates being wrong so much that it actually adjusts your memories to make you right in retrospect. Now this is some science that might make you reevaluate your mind’s shortcomings, and be careful about being persuaded in the future.
A study from researchers at Grand Valley State University were looking to find whether people were even aware that a persuasive article had changed their minds. They recruited more than 200 undergraduate volunteers and asked them to share their beliefs about whether spanking children was an effective form of discipline. The researchers picked this topic because previous research had shown that people are more likely to change their mind on topics they don’t know much about and they don’t feel very strongly about.
The students first filled out a pre-screening survey rating their beliefs. Two months later, after enough time had passed to forget the survey, the students were given articles to read that presented arguments either in favor for or against the effectiveness of spanking. After they answered questions about the article's content, they again rated their beliefs and were also asked to recall their beliefs at the beginning of the study.
As could be expected for an issue they didn't know much about, reading articles for or against spanking was enough to change the students' minds. But when they were asked to recall what they believed at the beginning of the study, the students remembered their previous beliefs aligning more closely with their new beliefs than they actually did.
The researchers blame poor metacognitive awareness and propose that people do not monitor changes in beliefs but rather use the information they have on hand, in the moment, to reconstruct their previous beliefs.
Of course, this study only looked at an issue that the students didn't feel strongly about and didn't have much knowledge in. It's probable that people who believe something more strongly or who are experts on an issue would be less affected. Confirming those ideas will take more research, but in the meantime, be aware of your mind's shortcomings. You might be more easily persuaded than you think.
CODY: Before we wrap up, we want to give a special shout-out to Muhammad Shifaz and Dr. Mary Yancy, who are executive producers for today’s episode thanks to their generous support on Patreon. Thank you SO. MUCH.
ASHLEY: If you’re listening and you want to support Curiosity Daily, then visit patreon-dot-com-slash-curiosity-dot-com, all spelled out.
CODY: Join us again tomorrow for the award-winning Curiosity Daily and learn something new in just a few minutes. I’m [NAME] and I’m [NAME]. Stay curious!