Learn about how quickly certain people adjust to time changes; how you can help slow jungle loss; and why ice cubes grow spikes. Early birds adjust to time changes faster than night owls by Grant Currin “Springing forward” affects early birds less than night owls, study finds. (2021, July 20). EurekAlert! https://www.eurekalert.org/news-releases/472466 Nield, D. (2021). Your Genes Could Affect How Well Your Body Adjusts to Daylight Saving Changes. ScienceAlert. https://www.sciencealert.com/how-well-we-adjust-to-daylight-saving-time-can-depend-on-our-genetics Tyler, J., Fang, Y., Goldstein, C., Forger, D., Sen, S., & Burmeister, M. (2021). Genomic heterogeneity affects the response to Daylight Saving Time. Scientific Reports, 11(1). https://doi.org/10.1038/s41598-021-94459-z More from archaeologist Patrick Roberts: Pick up "Jungle: How Tropical Forests Shaped the World — and Us": https://www.basicbooks.com/titles/patrick-roberts/jungle/9781541600096/ Website: https://www.patrickjroberts.com/ Follow @palaeotropics on Twitter: https://twitter.com/palaeotropics Cheyenne Mountain Zoo Sustainable Palm Oil Shopping Guide app: https://www.cmzoo.org/conservation/orangutans-palm-oil/sustainable-palm-oil-shopping-app/ WWF Palm Oil Buyers Scorecard: http://palmoilscorecard.panda.org/ Spiky ice cubes by Ashley Hamer (Listener question from Monica in Los Angeles) Occasionally the ice cubes in my freezer’s ice trays will develop a stalagmitelike shape without any obvious, unusual interference. Can you please explain what causes this? (2007, April 30). Scientific American. https://www.scientificamerican.com/article/experts-ice-spikes/ Spikes on Ice Cubes. (2011). Utoronto.ca. https://www.physics.utoronto.ca/~smorris/edl/icespikes/icespikes.html Monica’s ice spike picture: https://drive.google.com/file/d/1oHVKZkDqGF5ktgNxnIU7QceAKa9u6-e0/view?usp=sharing Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Learn about how quickly certain people adjust to time changes; how you can help slow jungle loss; and why ice cubes grow spikes.
Early birds adjust to time changes faster than night owls by Grant Currin
More from archaeologist Patrick Roberts:
Spiky ice cubes by Ashley Hamer (Listener question from Monica in Los Angeles)
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/adjusting-to-time-changes-saving-jungles-spiky-ice-cubes
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 how early birds adjust to time changes faster than night owls; and what you can do to slow the loss of jungles, with archaeologist Patrick Roberts. We’ll also answer a listener question about why ice cubes grow spikes.
CODY: Let’s satisfy some curiosity.
This Sunday, everyone in the United States gets an extra hour of sleep as Daylight Saving Time comes to an end. But that’s only because we all lost an hour of sleep when it began back in March. That’s never easy, but new research shows that some people take it a lot harder than others. I’m looking at you, night owls. Cody. [CODY: Hey, that’s me!]
Researchers have been ragging on Daylight Saving Time for years. It apparently causes rates of heart attacks, traffic accidents, and workplace injuries to spike. But it turns out the shift affects people differently depending on what researchers call their chronotype.
Scientists have found connections between a person’s sleep patterns and certain details of their DNA. That means scientists can look at a person’s genome and make a pretty good guess as to whether they’re an early bird or a night owl. That’s exactly what researchers did back in the spring of 2019 with a group of newly minted doctors who were starting their first year of residency. The researchers selected two groups for the experiment — the 130 residents whose DNA most strongly suggested they were early birds and another 130 whose DNA suggested they were night owls.
Once the participants were chosen, they got wearable sleep trackers that let the researchers monitor their sleep patterns for the first week of Daylight Saving Time.
For the early birds, it took just one day — Monday — to adjust their sleep schedules and get to bed on time. By the time Tuesday night rolled around, doctors with an early chronotype were falling asleep at the same time as they had been the previous week.
Things weren’t so easy for the night owls. Most of them were still struggling to get back into their bedtime rhythm by the following Saturday. That’s a whole week!
These findings are important for a couple of reasons. First, they show that Daylight Saving Time doesn’t affect us equally. That’s important to know because whether or not we spring forward and fall back is a choice. In the words of one researcher behind this study, Daylight Saving Time, quote, “makes everything worse for no good reason,” end quote.
The study also showed that medical residents across all chronotypes are chronically sleep deprived. That’s hardly news, but it’s important for them and the patients they serve.
The researchers did the same experiment at the end of Daylight Saving Time, on the first Sunday in November. The results come as no surprise: everyone — night owls and early birds alike — appreciated the extra hour of sleep.
Yesterday, Patrick Roberts told us why the world's jungles are being destroyed and what's at stake for our planet. Today, he's going to tell us how we can help. Patrick Roberts is an archaeologist and author of the new book, "Jungle: How Tropical Forests Shaped the World — and Us." And Cody asked him if there’s anything we can do on an individual level to help save jungles.
[CLIP 3:35]
So take a global perspective, support the local indigenous communities who know how these jungles work, and try to buy products that contain sustainably sourced palm oil. In the US, one app you can download is the Cheyenne Mountain Zoo Sustainable Palm Oil Shopping Guide — it's a little buggy, but it has a good list of products that are color-coded according to sustainability. To check out which companies are doing it right, you can visit the WWF's Palm Oil Buyers Scorecard at palm oil score card dot panda dot org. And of course, pick up the new book from Patrick Roberts: "Jungle: How Tropical Forests Shaped the World — and Us." We'll have links to all of that in the show notes.
We got a listener question from Monica in Los Angeles, who writes, “Attached are a couple of photos of some ice cube trays I use at work. After filling them with bottled water and leaving them alone in the freezer, within a few hours, some of the cubes have what I can only relate to creatures from "The Abyss" but in frozen form! But HOWWWW does this happen??? Hopefully this will be one you can address on your show, and maybe include the photos in the show notes.”
Great question Monica, and we have indeed included a link to the picture in the show notes: it basically looks like the ice cube is reaching an arm up toward the heavens! From what you tell me, I’m betting two things about the conditions here: your work freezer is really cold, and that bottled water is impressively pure. Here’s why I think that.
If the freezer is cold enough, it’ll form sheets of ice on the surface of the ice cube tray before the water at the bottom has a chance to freeze. That’s no good, since water expands as it freezes and that liquid water now has nowhere to go. But! If that top ice sheet has even the tiniest hole in it, that liquid water has an opening to expand through. So that water begins to freeze, and as it freezes, it expands, and as it expands, it forces itself up through the hole and freezes around the hole’s edge. That forms a hollow spike filled with liquid water. Water keeps being pushed up that spike until all of the water is frozen. The result is a frozen-solid spike sticking straight out of your otherwise uniform ice cube. This happens most predictably when the ambient air is around 20 degrees Fahrenheit or negative 7 degrees Celsius — when the water is pure, and when the container has vertical sides, like an ice cube tray does.
This doesn’t just happen in freezers, though. If the weather turns freezing fast enough, it can happen outside, too. It doesn’t usually happen in natural bodies of water like lakes and streams, since they take too long to freeze. But spikes have been known to form in manmade containers like bird baths and pet bowls. If you want to see some pictures of this weird phenomenon in action, you can check out Monica’s photo or click on the University of Toronto link in the show notes — that page has a wealth of ice spike images and videos. Thanks for your question, Monica! If you have a question, send it in to curiosity at discovery dot com or 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 about why the largest living organism on Earth is NOT a blue whale;
A dark-matter hunting experiment that may have just found dark energy;
4 magic words that could double your chances of getting what you want;
A heroic experiment that’s shed light on the centuries-old mystery of why asthma gets worse at night;
And more! Okay, so now, let’s recap what we learned today.
[ad lib optional]
ASHLEY: The writer for today’s early bird story was Grant Currin.
CODY: Our managing editor is Ashley Hamer, who was also a writer and audio editor on today’s episode.
ASHLEY: Our producer and lead audio editor is Cody Gough.
CODY: Have a great weekend! [AD LIB SOMETHING FUNNY] Then, join us again Monday to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!