Curious Kids US

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. Why does the Earth spin? Sara H., age 5, New Paltz, New York A globe was the first thing I ever bought with my own money. I was maybe 5 years old, and I was really excited to take it home. As I quickly discovered, you can spin it in the direction that the earth actually spins. There’s an imaginary line between the North Pole and the South Pole. We call it the rotation axis. For the Earth, the rotation axis points toward a bright star, Polaris, which is visible on clear nights in the Northern Hemisphere. Satellite images over one day show Earth rotating on its axis. NASA/EPIC, edit by Tdadamemd If you want to know which way to spin your globe, make the...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. What makes someone Indigenous? – Artie, age 9, Astoria, New York “In 1492, Columbus sailed the ocean blue.” You may have heard that in school. The rhyme makes it easier to remember that 1492 was the year when an Italian explorer named Christopher Columbus set sail from Spain and landed in a chain of islands near modern-day Florida called the “West Indies.” Europeans called the enormous land mass that we now know as North and South America the “New World” because, before the very late 15th century, nobody on the east side of the Atlantic Ocean even knew it existed. A few Viking explorers had reached the Americas hundreds of years earlier, but little is known about their visits. From Europeans&...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. How many Amazon packages get delivered each year? – Aya K., age 9, Illinois It’s incredibly convenient to buy something online, right from your computer or phone. Whether it’s a high-end telescope or a resupply of toothpaste, the goods appear right at your doorstep. This kind of shopping is called “e-commerce” and it’s becoming more popular each year. In the U.S., it has grown from a mere 7% of retail purchases in 2012 to 19.6% of retail and US$791.7 billion in sales in 2020. Amazon’s growing reach For Amazon, the biggest player in e-commerce, this means delivering lots of packages. In 2021 the company shipped an estimated 7.7 billion packages globally, based on its nearly $470 billion in sal...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. Is a zombie apocalypse caused by fungi, like the Cordyceps from “The Last of Us,” something that could realistically happen? – Jupiter, age 15, Ithaca, New York Zombies strike fear into our hearts – and if they’re persistent, eventually they get inside our heads. Animals taken over by zombies no longer control their own bodies or behaviors. Instead, they serve the interests of a master, whether it’s a virus, fungus or some other harmful agent. The term “zombi” comes from Vodou, a religion that evolved in the Caribbean nation of Haiti. But the idea of armies of undead, brain-eating human zombies comes from movies, such as “Night of the Living Dead,” television shows like ̶...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. Why do we use gasoline for small vehicles and diesel fuel for big vehicles? – Methdini, age 15, Sri Lanka Gasoline fuels most light-duty vehicles, such as passenger cars and pickup trucks. Heavy-duty vehicles, like buses, delivery trucks and long-haul tractor-trailers, typically run on diesel. Both fuel types are needed because gasoline and diesel engines have different strengths. As my automotive engineering students learn, this makes them suitable for different uses. Let’s start with what they have in common. Gas and diesel engines both work through a process called internal combustion. First, they mix fuel with air because the fuel needs oxygen from the air to burn. Next, they compress the fuel-air mixture, which ma...