Learn about why housecats are deadlier for local wildlife than wild predators; why soft drinks taste better from a can than they do from a plastic bottle; and how astronomers just found 100 new minor planets beyond Neptune.
Learn about why housecats are deadlier for local wildlife than wild predators; why soft drinks taste better from a can than they do from a plastic bottle (especially when it comes to Cody and his Mountain Dew habits); and how astronomers just found 100 new minor planets beyond Neptune.
Housecats have up to 10x larger effect on local wildlife than wild predators by Grant Currin
Why do soft drinks taste better from a can than they do from a bottle? by Grant Currin
Astronomers discover 100 new minor planets beyond Neptune by Grant Currin
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/why-soft-drinks-taste-different-out-of-cans-why-housecats-are-dangerous-for-wildlife-and-100-minor-planets-discovered-beyond-neptune
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 housecats are deadlier for local wildlife than wild predators; why soft drinks taste better from a can than they do from a plastic bottle; and how astronomers just found 100 new minor planets beyond Neptune.
CODY: Let’s satisfy some curiosity.
This might come as a shock, but that cute and cuddly kitty that lazes around your house all day? It’s actually a menacing predator. In a recent study, researchers and cat owners worked together to figure out just how much of an impact housecats have on native prey. If you’re a cat owner, you may want to sit down for this.
Ready? Domestic cats in North America kill between ten and thirty billion native animals per year. That’s a big environmental impact! Researchers at North Carolina State University and the North Carolina Museum of Natural Sciences wanted to learn more about how all that hunting affects ecosystems, so they recruited hundreds of cat owners in six countries to monitor where their cats go and keep track of how many, uh, gifts their cats brought them.
After analyzing data from 925 pet cats, the researchers found some distinct patterns. Cats rarely venture more than 300 feet from home, or about 100 meters. That means all their hunting is typically concentrated in a few backyards.
The cats killed between 14 and 39 animals per 100 acres, or one hectare, per year. It might not sound like a lot, but that’s a huge number of mice, birds, salamanders, lizards, and other fauna. When considered in terms of kills per area, domestic cats kill more prey than native predators their size! The cats killed less prey per day, but they had an outsized impact on their small home ranges — a two- to ten-time larger impact on wildlife than wild predators, to be exact.
Cats hunt where they are, mostly in neighborhoods and housing developments. That means they aren’t wreaking ecological havoc in places where nature is relatively undisturbed, like deep in national parks. That’s good news for those places, but it’s bad news for the kind of biodiversity that’s most accessible for people to enjoy.
After all, we’re constantly reaping the benefits of wildlife, even when we aren’t thinking about it. Singing birds brighten the morning commute, and lizards help suburban gardeners by eating pests. According to the researchers, letting cats outside is especially harmful to nature in the kinds of places that have relatively little biodiversity but where people enjoy it the most.
If that’s not enough of a reason to keep your cat indoors, consider the fact that indoor cats live about 10 years longer on average than outdoor cats, thanks to their lower risk of disease and injury. The consensus among veterinarians and environmentalists is clear: keep cats indoors. It’ll help save the lives of billions of animals — including your own.
Why does pop taste different from a can than it does from a bottle? And yes, I’m from the Midwest, so I call it pop. Ashley’s from California, so she calls it soda. I wouldn’t say we’re fighting about it, but...we’re fighting about it. [plenty of space for Cody to talk about his weird Mountain Dew habits]
The Coca Cola company claims that Coke tastes the same regardless of its packaging, but from personal experience? That doesn’t seem completely true. And it turns out that there are a few ways the container can affect the taste of pop, even if most of them are extremely subtle.
The biggest variable is carbon dioxide, the gas that provides that distinct, tingling mouthfeel of carbonation. Manufacturers put the same amount of CO2 in bottles and cans, but over time, it escapes — and that happens at different rates depending on the container. Glass bottles and aluminum cans are rigid with tight molecular structures, so it’s very difficult for carbonation to escape. But most plastic bottles are made of polyethylene terephthalate [TARE-uh-PFTHAAL-ate] (or PET), which is more permeable. Coke stored in a plastic bottle can lose up to 15 percent of its carbon dioxide in 12 weeks. That’s partly because it’s flexible and doesn’t keep the liquid under as much pressure as other materials, and partly because the PET literally absorbs some of the CO2.
Temperature also has an effect on carbonation. Liquids can hold onto more CO2 when they’re cold than when they’re warm, so more carbonation escapes in that first hiss when you open a beverage at room temperature than it does when it’s ice cold.
But the packaging can slightly affect a soda’s taste, partially through chemical interactions between the container and its contents. The FDA and food companies extensively test the materials used in food packaging, so there’s a lot of evidence that they’re safe, but some people can still detect extremely subtle differences between different materials.
Like, plastic bottles might slightly affect taste by leeching a chemical called acetaldehyde [ASS-uh-TAAL-duh-hide]. And aluminum cans are lined with a polymer that might sometimes absorb a small amount of flavor from the soft drink. But beyond those tiny differences, the main effect might just be in the taste of the container itself. After all, your tongue touches the bottle or can when you drink it. People who are especially sensitive to the taste of metal might pick up on that in the brief moment when the drink is passing out of the can and on their tongue.
So in the end — if you taste a difference, it’s not in your head. And if you’d rather drink your Mountain Dew from a can than a plastic bottle, more power to you.
Pluto isn’t the only minor planet circling the sun. A team of astronomers just found more than 100 new objects in the outer reaches of the solar system — some more than twice as far from the sun as Pluto.
Astronomers call any body in our solar system with an orbit beyond Neptune a trans-Neptunian object. That classification includes all the icy bodies in the Kuiper [KYE-per] belt, the comet factory known as the Oort [ORT] cloud, and heftier minor planets like Eris [EHR-iss], Haumea [how-MAY-ah], and Makemake [MAH-kay-MAH-kay]. There are a lot of trans-Neptunian objects we knew about already, and these new observations bring the full tally up to more than 3,000.
How do astronomers locate such small objects that are so far away? These new finds come courtesy of the Dark Energy Survey, or DES. As the name implies, DES was designed to study dark energy by taking high-quality images of galaxies and supernovae in the southern skies, but it just so happened that these strengths made DES data perfect for spotting faint, faraway objects in our own solar system, too.
The researchers started with four years of DES data and used software to identify seven billion “dots” — that’s what they called all the objects their instruments identified. Graduate student Pedro Bernardinelli was in charge of figuring out which of those seven billion dots were minor planets.
He whittled the list down to 22 million objects by removing anything that stayed in the same place on consecutive nights, like stars, galaxies, and supernovae. Those faraway objects are moving, but they’re so far away that they appear stationary when observed from Earth.
Bernardinelli described the next step as a massive game of connect-the-dots. He looked for sets of two or three observations that were close to each other over consecutive nights, and that would mean that they were really time-lapse images of the same object in orbit. That left him with a list of 400 candidates. After a lot more cross-checking and triangulation with other data, Bernardinelli and his collaborators found 316 trans-Neptunian objects. 139 of them are new to science.
Now that they’ve finished this first pass, the Dark Energy Survey team is going to use the same methods on their entire dataset using lower thresholds for the first big filtering stage. They think they’ll find up to five hundred more minor planets that no one had ever seen before.
ASHLEY: Let’s recap the main things we learned today
[ad lib optional]
CODY: Today’s stories were written by Grant Currin 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: Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!