What makes earth round

And they need to use as little paint as possible. What shape will require the least amount of paint to cover it? If they need a hint, you can point out that if, for example, they were to flatten their Play-Doh into an extremely thin, broad sheet, this shape would have a lot of surface to paint see Figure 1.

As students try to reduce the surface area, what you should observe is that—in an attempt to make the surface as small as possible—they squeeze their Play-Doh into a shape like a ball or sphere , which is the correct answer. Of all possible shapes—hot dogs, rings, cubes, irregular lumps—a sphere has the smallest amount of outside area. You can also think of it as the most compact shape, with all parts of the Play-Doh as close to each other as they can get. Reflect on how students made the Play-Doh into a ball.

They squeezed it from all directions see Figure 2. So whenever a shape is squeezed together from all directions, it forms a sphere. To see an example of this, students can blow some soap bubbles. No cubical bubbles, no pyramids, no pancake-shaped bubbles—just spheres! Remembering what happened with the Play-Doh, students can try to think of something similar that might be happening with the soap bubbles.

Now, the eraser will be spinning clockwise. Slowly rotate it back, while continuing its spin, will bring the tip to the top, rotating counter-clockwise. Share your thoughts about this story. To comment, you'll need to login into your Facebook account. Your comment will post immediately.

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Campus Maps. News Center. Social Media. UNLV Mail. Behind the Curve, a new documentary now streaming on Netflix, follows the lives of several people who believe that the Earth is flat, as depicted here.

To commemorate the anniversary, the college has several events planned including five public lectures. Nora Caberoy will present the next lecture on March 28 at p. Do you want to prove that the Earth is round? As such, he was able to help us break down reasons why the Flat Earth Theory falls flat. OK, so how do we know — scientifically — that the Earth is a sphere? Why did people once think that the Earth was flat?

So the small mass - and weak gravity - of the whole mountain is unable to overcome the hard shape of the rock and ice lumps to become round. Read more: Curious Kids: Why do stars twinkle? Fluffy mountains like these got swept together billions of years ago to make the planets we recognise today. But some of them are still minor objects in the Solar system. These bits of leftover planet-building material, called asteroids and comets, have very lumpy shapes.

Some are shaped like potatoes and others like eggs. The largest of these minor bodies, such as Ceres and Pluto, have enough gravity to look round like a planet. They are called dwarf planets.

Some, like Haumea, spin very fast, giving them an stretched shape, like this:. Hello, curious kids! Ask an adult to send your question to us. You can:. The amount of mass throughout Earth, however, is huge and really adds up.

Scientists theorize that about 4. As gravity pulled the matter in on itself, it began to spin and clump up, forming the sun, planets , moons , and other space objects. Earth's rocky core was the first part of our planet to form, with dense matter sinking to the center and binding together. Then lighter pieces gathered and formed Earth's crust. As Earth's mass added up from all this matter and gravitational forces increased, the matter attempted to take the most efficient shape possible: a sphere.

If Earth was a cube , its corners would be farther away from its center than other points. Because gravity acts equally on everything, the corners would need to be pulled closer to the center.

The result of evening out the uneven places is that you end up with a shape in which every point on the surface is the same distance from the center. The only shape that fits that definition is the sphere. So, gravity is the answer to why Earth is round! If you've seen pictures of asteroids that exist in outer space, you may have noticed that some of them are irregular, rocky shapes. That's because they're not big enough to pull themselves into a sphere.

If they continue to grow and gain mass , eventually they, too, will form themselves into a sphere. Astronomers have made that ability — the ability to form into a sphere — as one of the requirements to be considered a planet! If you've seen pictures of Earth from space, Earth does indeed look like a perfectly- round ball. Its true shape is closer to that of an ellipsoid. Earth's constant rotation creates centrifugal forces that make Earth wider at the equator than the poles. How much wider?

About 70, feet wider! You've probably also noticed that Earth's surface isn't flat. High mountain ranges and deep ocean trenches also contribute to Earth's slightly-irregular shape. Earth's shape is also not static. It's always changing. Sometimes these changes are regular, such as daily tides that affect the oceans and Earth's crust. Other changes are irregular and extremely slow, such as the movement of Earth's tectonic plates. Sometimes natural disasters can result in sudden changes, such as is the case with earthquakes , volcanic eruptions , and meteor strikes.

There's actually a field of science dedicated to measuring and monitoring Earth's size and shape. It's called geodesy , and scientists with the National Geodetic Survey keep an eye on Earth's ever-changing shape and size. Can you believe that people once thought Earth was flat? We're excited for you to read it, BillyBobJoe! Let us know what you think! There are a lot of layers to Earth.

And, it depends on what you'd call 'inside'. We technically live on the Earth's crust--which is the outermost layer. But, there's also the atmosphere surrounding our planet. So, if you count the atmosphere, we kind of live inside Earth--but the best answer would be we live ON the planet.

Many people used to think so hundreds of years ago! However, now we know that the Earth is round. We hope that you read through this Wonder to learn more about why the Earth is round! This was what people believed hundreds of years ago! Thanks for sharing, Part. For internet safety, we had to remove the link from your comment.

Hi, kha!! Earth is round, but it not actually a perfect sphere!! Hundreds of years ago, people thought the Earth was flat, but science since then has proved that the Earth is round. Great question, Austin!! We encourage you to take a Wonder Journey to find out!! Let us know what you find! Thanks, Crystal! Way to go, Super Smart Wonder Friend! Interesting question, Wonder Friend!

We encourage you to keep learning about the Earth by researching online and at your library! Hi, Wonder Friend! Thanks for stopping by Wonderopolis! We're glad you enjoyed this Wonder of the Day, Bannanaminer! Thanks for hanging out with us in Wonderopolis! Perhaps someday, Quan! Do you know the criteria scientists use to determine if something is considered a planet? Check out Wonder of the Day 73 to find out! Great job, C. Gravity gives our planet its round shape!