Learn about why too much sleep may be just as harmful as too little; what light echoes detected by NASA might be able to teach us about how black holes evolve over time; and why you can’t tickle yourself. In this podcast, Cody Gough and Ashley Hamer discuss the following stories from Curiosity.com to help you get smarter and learn something new in just a few minutes: Too Much Sleep May Be Just as Harmful as Too Little — https://curiosity.im/2DPVnDZ Light Echoes from a Black Hole Were Detected by an Instrument Aboard the ISS — https://curiosity.im/2MTuvWA Can't Tickle Yourself? That Means Your Brain Is Good Working Order — https://curiosity.im/2DRtITc 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 why too much sleep may be just as harmful as too little; what light echoes detected by NASA might be able to teach us about how black holes evolve over time; and why you can’t tickle yourself.
In this podcast, Cody Gough and Ashley Hamer discuss the following stories from Curiosity.com 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/too-much-sleep-can-be-harmful-why-you-cant-tickle-yourself-and-black-hole-light-echoes
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 why too much sleep may be just as harmful as too little; and what light echoes detected by NASA might be able to teach us about how black holes evolve over time. We’ll also answer a listener question about why you can’t tickle yourself.
CODY: Let’s satisfy some curiosity.
Too Much Sleep May Be Just as Harmful as Too Little — https://curiosity.im/2DPVnDZ (Ashley)
We talk a lot on this podcast about the benefits of sleep, but pump the brakes before you crash for 10 hours this Friday or Saturday night. Research suggests that too much sleep could be just as harmful as too little. [ad lib]
ASHLEY: In 2016, a study in the International Journal of Cardiology looked at the sleep habits of nearly 400-thousand Taiwanese adults over seven years. It found that when compared to people who slept six to eight hours per night, those who slept less than four hours per night increased their risk of dying from heart disease by 34 percent. But get this: those who slept more than eight hours per night? Nearly identical — their risk of dying from heart disease increased by 35 percent. Likewise, a 2015 study in the journal Neurology found that people who slept more than eight hours a night experienced a higher risk of stroke, and a 2009 study in Sleep Medicine found the same thing for risk of type II diabetes.
CODY: But hang on, those are just correlations. What if it's a person's lousy health that leads to oversleeping, and not the other way around?
ASHLEY: Good point, but a team of researchers looked into this in 2014. They studied the genetics behind these sleep-based health effects with nearly 900 pairs of twins for a study published in the journal Sleep. They used statistical models that examined genetic interactions, and that helped them figure out how much a health issue like depression was influenced by genetics. As in, how much it was inherited and how much it was due to a person’s environment. They also looked at whether sleep had an effect on that heritability. They found in people who got around 7 to 9 hours of sleep per night, depressive symptoms had a heritability of about 27 percent. For people who got less than seven or more than nine hours of sleep a night, the heritability nearly doubled to around 50 percent. That's right: under- and oversleeping actually messes with your DNA. So what can you do about this? Well, the amount of sleep you need depends on lots of factors, particularly your age. The National Sleep Foundation recommends adults get somewhere in the ballpark of seven to nine hours of sleep a night, although some can get away with as little as six or as much as 10. Generally, if you're waking up feeling well rested without nagging headaches or back pain or grogginess, you're probably fine. If you think you might not be sleeping the right amount, though, then try your best to get to bed on time — and get OUT of bed on time, too.
Light Echoes from a Black Hole Were Detected by an Instrument Aboard the ISS — https://curiosity.im/2MTuvWA (Cody)
Remember last week when we talked about NASA’s first neutron star mission? You know: they say it’s the world’s first demonstration of X-ray navigation in space, and for 18 months, a payload attached to the International Space Station will keep its eye on neutron stars for starquakes and other phenomena? I’m talking about NASA’s Neutron Star Interior Composition Explorer, or NICER. And in January, a detector aboard NICER spotted something strange coming from a black hole, which could help scientists figure out how black holes evolve over time. The instrument spotted the signature of a black hole, nicknamed J-1820. While J-1820 was feeding on a star, X-ray light from the black hole flowed across space and into the detector. Astronomers say the X-ray waves formed what they call light echoes, which bounced off the gas spinning near the black hole. These echoes are intriguing because they show how that region is changing in shape and size.
Here's how a light echo works: the light that travels directly from an object is the first light that reaches us, meaning it’s also the light that creates an image in our telescopes. The clouds of dust and debris around the object reflect some of that light, which means that light takes a longer path and shows up later — sometimes, months later. That creates a ring of light that expands from the object at a pace that seems faster than the speed of light. But this is only an illusion created by the position of the detector and the dust's parabolic shape.
This find is part of a larger question for scientists to understand how black holes work. Black holes form from the collapse of a super-massive star after it runs out of usable fuel and explodes into a supernova. Since black holes are — as the name suggests — pretty dark, the best way we can see them is when they start pulling in material nearby. This doomed star near J1820 is a perfect example. Scientists want to know how the swirling gas near the black hole changes while the black hole picks up material from the companion star. They hope that by watching the black hole morph over a few weeks, they can begin the difficult extrapolations to how black holes evolve over millions of years. One small blip for NICER; one infinitely powerful gravitational field for mankind to study!
LISTENER QUESTION - Can't Tickle Yourself? That Means Your Brain Is Good Working Order — https://curiosity.im/2DRtITc (Tyler in Arlington, Virginia, asks…) (Ashley)
ASHLEY: We got a question from a curious listener like you! Tyler in Virginia asks: why can’t you tickle yourself? This is an excellent question, Tyler. The answer gets into how your brain knows where you stop and everything else begins. Your brain is wired with mechanisms that helps it differentiate between you and the world around you. Every time you pet a cat or type on your keyboard, a flurry of messages are zipping from your brain to your hand and back. When your brain tells your hand to move, it makes two copies of that command: one is to move your hand, and the other is a reference to help it make predictions for what’ll happen next. Once that movement happens, your hand sends a signal back to your brain to let it know how things went, like how soft that cat was, or what you typed on the keyboard. Then, your brain compares to its reference copy. If everything goes smoothly, there won’t be any surprises: it predicted that the cat would be soft, and it was. End of story. You can see where this is going: your brain knows what to expect when you move your hand to tickle yourself. But there’s something else going on when you tickle yourself that makes it feel different than someone else doing it. In a study from the year 2000, neuroscientist Sarah-Jayne Blackmore scanned people's brains to see how they reacted when they were tickled by a robot versus their own hands. But there was an extra twist: a third condition had the participants control the robot, but with various amounts of electronic delay or movement discrepancies. Meaning, they might remote-control the robot hand to tickle themselves, but they'd actually feel it a few hundred milliseconds late or from a slightly different angle. Participants rated the unonctrolled robot tickle as most ticklish, but the controlled robot tickling was interesting. They reported a gradual increase in the ticklishness of the robot hand they controlled as the delay and movement changes increased. According to Blackmore and her team, that shows that it was the discrepancy between what the participants' brain expected and what actually happened that led to the ticklish feeling. And brain scans showed that the prediction was important because different parts of the brain activated when people tickled themselves than when someone else tickled them. So, long story short, When you try to tickle yourself, your brain puts a stop to the fun — and believe it or not, there’s even more science behind all this that you can read about on curiosity-dot-com and on our free curiosity app for android and ios. Just remember: the fact that you can’t tickle yourself is actually a good thing. It’s a sign that your brain knows which parts are you and which parts are the outside world. Thanks for your question, Tyler!
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