Learn the “Dog Days of Summer”; why scientists did magic tricks for birds; and the smallest conceivable length of time. What are the "Dog Days of Summer"? by Steffie Drucker Farmers' Almanac Staff. (2015, June 29). What Are the Dog Days of Summer? Farmers’ Almanac. https://www.farmersalmanac.com/why-are-they-called-dog-days-of-summer-21705 Little, B. (2015, July 10). Why Do We Call Them the “Dog Days” of Summer? Animals; National Geographic. https://www.nationalgeographic.com/animals/article/150710-dog-days-summer-sirius-star-astronomy-weather-language?loggedin=true AstroPages | Precession. (2021). wwu.edu. https://www.wwu.edu/astro101/a101_precession.shtml Scientists did magic tricks for birds to see how they perceive the world by Steffie Drucker Garcia-Pelegrin, E. (2021, June 2). We performed magic tricks on birds to see how they perceive the world. The Conversation. https://theconversation.com/we-performed-magic-tricks-on-birds-to-see-how-they-perceive-the-world-161772 Garcia-Pelegrin, E., Schnell, A. K., Wilkins, C., & Clayton, N. S. (2021). Exploring the perceptual inabilities of Eurasian jays (Garrulus glandarius) using magic effects. Proceedings of the National Academy of Sciences, 118(24), e2026106118. https://doi.org/10.1073/pnas.2026106118 Magic Tricks May Fool You, but These Birds Can See Through Them. (2021). The New York Times. https://www.nytimes.com/2021/06/01/science/birds-magic-tricks.html Timmer, J. (2021, June 4). Researchers perform magic tricks for birds, who are not amused. Ars Technica; Ars Technica. https://arstechnica.com/science/2021/06/researchers-perform-magic-tricks-for-birds-who-are-not-amused/ Olkowicz, S., Kocourek, M., Lučan, R. K., Porteš, M., Fitch, W. T., Herculano-Houzel, S., & Němec, P. (2016). Birds have primate-like numbers of neurons in the forebrain. Proceedings of the National Academy of Sciences, 113(26), 7255–7260. https://doi.org/10.1073/pnas.1517131113 Starr, M. (2018). Crows Can Build Compound Tools Out of Multiple Parts, And Are You Even Surprised. ScienceAlert. https://www.sciencealert.com/crows-are-so-smart-they-can-make-compound-tools-out-of-multiple-parts Planck Time Is How Long It Takes Light To Travel One Planck Length by Joanie Faletto The Planck scale: relativity meets quantum mechanics meets gravity. (from Einstein Light). (2021). Unsw.edu.au. https://newt.phys.unsw.edu.au/einsteinlight/jw/module6_Planck.htm Williams, M. (2010, November 19). What is Planck Time? - Universe Today. Universe Today. https://www.universetoday.com/79418/planck-time/#ixzz2OhJ0gDig 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 the “Dog Days of Summer”; why scientists did magic tricks for birds; and the smallest conceivable length of time.
What are the "Dog Days of Summer"? by Steffie Drucker
Scientists did magic tricks for birds to see how they perceive the world by Steffie Drucker
Planck Time Is How Long It Takes Light To Travel One Planck Length by Joanie Faletto
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/dog-days-of-summer-magic-tricks-for-birds-planck-time
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 where the term “Dog Days of Summer” comes from; why scientists performed magic tricks for birds; and the smallest conceivable length of time.
CODY: Let’s satisfy some curiosity.
Here in the Northern Hemisphere, it’s the "Dog Days of Summer," which last from roughly July 3rd to August 11 each year. I think we’d all agree it’s summer — but what does that have to do with dogs? Despite what you may have heard, it’s not about what the weather does to our canine companions, or that it makes us all laze around like dogs. Instead, it all centers on a certain divine dog from long, long ago.
In the night sky, the constellation Orion the Hunter is trailed by two trusty dogs, Canis Major and Canis Minor. Sirius, the brightest star in the sky, is sometimes called the "Dog Star" because of its prominent position in Canis Major. It's the dog’s nose or collar tag, depending on how you think its head tilts.
The ancient Greeks and Romans coined the term "Dog Days of Summer" for the period when they'd see Sirius rising with the sun. Those days do often happen to be the hottest of the year, but not for the reason the Greeks thought. They believed it was because the sun got extra power from Sirius, but it's actually because of Earth's tilt. When the North Pole tilts toward the sun from June through August, the Northern Hemisphere gets the sun’s most direct rays.
The "Dog Days" are also associated with war, chaos, and disaster, probably because of how the intense heat affected people and the natural world. People and plants alike tended to weaken and wilt over the long, hot days. Tempers tend to flare in hot temperatures, too. In Egypt, the Nile River would rise around the same time that Sirius did, which could both nourish crops and flood villages.
When the phrase was translated to English 500 years ago, it became the victim of a game of telephone: English speakers didn't understand the true origin of the phrase, but its partial meaning lived on. Here's the thing though: the constellations aren’t at the same place in the sky every year. The Earth wobbles like an unbalanced top, and that shifts our orientation to the stars. So in thousands of years, the Dog Days will actually happen in the middle of winter! Maybe by then, the phrase will represent days so cold that they make dogs cozy up by the fire.
Magic tricks work because our minds function in predictable ways, and magicians use that to their advantage. Which begs the question: would a magic trick work on another animal? A team of scientists recently set out to answer that question, and the answer taught us something important about bird brains.
Corvids are a family of big-brained birds that includes ravens, crows, and jays. Their brain-to-body mass ratio is similar to apes and whales and just slightly lower than ours. They’ve demonstrated the ability to make tools and recognize themselves in mirrors, which we thought only humans and some advanced mammals could do. And they regularly use sleight of hand — er, beak — to protect their food. Like squirrels and chipmunks, these birds store food to eat later. This is where the magic happens: They pretend to drop their food in several spots along the way to their secret stash so onlookers can’t find and steal it.
Scientists at the University of Cambridge put these natural magicians to the test: They performed three classic sleight of hand tricks for six Eurasian jays and 80 people to compare who kept better track of the bait (in this case, the jays’ favorite worms). The first two maneuvers, called “palming” and the “French drop,” use different techniques to make it look like the worm moves from one hand to the other while it actually stays in the original hand. The third trick was a “fast pass,” where the worm is quickly tossed into the opposite hand.
Humans were consistently stumped by all three tricks, picking the wrong hand between 70 and 90 percent of the time. But the birds weren’t fooled by the first two tricks, which rely on spectators’ understanding of how objects move between hands. Scientists say that’s because birds don’t have expectations for how hands work — they just picked the hand where they saw the worm last.
But the jays were fooled by the fast pass. Their downfall was that they focused too closely on the starting hand and likely lost track of the worm when it got tossed outside their field of vision. That suggests that jays have mental blind spots similar to those we humans do.
Still, any magicians planning to play an aviary might want to rework their repertoire. Or perform for a pack of dogs instead: That trick where you pretend to throw the ball but don’t gets them every time!
What’s the tiniest length of time you can think of? A millisecond? A picosecond? Nope, the smallest conceivable length of time is one you’ve probably never heard of. It’s called Planck Time, and it’s got some special powers that your garden-variety picosecond could only dream of.
To understand Planck Time, you first need to understand the Planck scale. This was originally proposed in 1899 by German physicist Max Planck. He came up with units of measurement based on physical constants of the universe, rather than random objects like other measurements do. That’s why physicists sometimes call them “God’s units.” The first unit in the Planck scale is the Planck length, which combines Planck’s constant — that’s a number that has to do with quantum physics — with the constant of gravitation and the speed of light. It might be a little confusing, but the important thing to know is that it’s absolute, because it’s based on measurements of physical reality itself, and it’s really, really tiny: if you counted one Planck length every second, measuring the diameter of an atom would take you 100,000 times the age of the universe.
To get Planck Time? Just divide that number (which, again, is tiny) by the speed of light (which is huge), and you’ve got a unit of time. How long is that unit of time? Well, there are more units of Planck time in one second than all the seconds since the Big Bang.
Here’s what’s so special about these units of measurement. According to special relativity, time moves more slowly the closer you get to the speed of light. If you were speeding around the galaxy in a spaceship and I was here on Earth, time would move more slowly for you than it would for me and you’d return looking younger than I did. And if you measure length by how long it takes light to cover that distance, that means that lengths are longer for me than they are for you. But because the Planck scale is based on values from the physical laws of the universe itself, you and I should still see those units as the same. And that might pose a problem for special relativity.
But no need to fret: these units are way, way too small for us to measure them — at least not yet. We also barely understand how the physical constants these units are based on actually interact. So maybe it’s enough to know that if you want to count a second in Planck Time, you’re going to need to have a few billion years on your hands.
Let’s recap what we learned today to wrap up. Starting with
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ASHLEY: Today’s writers were Steffie Drucker and Joanie Faletto.
CODY: Our managing editor is Ashley Hamer.
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: Join us again in about 1.603 times ten to the 48th planck units to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!