Why can’t we feel the Earth moving?

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Why can’t we feel the Earth moving? – Dave H., age 12, Atlanta

Right now, you’re zooming through space at incredible speeds. As just one of all the living creatures on Earth, you’re along for the ride as our planet constantly moves in two major ways.

First, consider that the Earth spins around like a top. It’s rotating around the imaginary line that runs from the North Pole to the South Pole through the center of our planet. Earth completes one full rotation every 24 hours, with a speed of about 1,000 miles per hour at the equator (1,670 km/h).

While Earth is spinning on its axis, it’s also traveling around the Sun. It takes a year to finish the journey – that is, to make one full revolution and wind up back where we started. Earth hurtles along its path with a whopping average speed of 67,000 miles per hour (107,000 kmh).

These speeds are way faster than any vehicle you’ve ever traveled in. So why aren’t you dizzy or flying off into space? Why don’t you even feel the Earth moving?

It’s this kind of question that lit a desire in me as a child to understand the universe and our place in it. Now I have a Ph.D. in astronomy and teach college students some of the same physics principles that explain why you can’t feel Earth’s motion as it zips through space.

No jerks or bumps

Think about a time when you do feel motion, such as on a carousel ride at an amusement park. When it speeds up, slows down or turns quickly, your body notices because the motion isn’t smooth.

In contrast, the Earth’s motion is remarkably steady. It has been spinning on its axis and orbiting the Sun at nearly the same speeds for billions of years, with no sudden jolts or stops. As Earth travels its slightly oval-shaped path around the Sun, its speed does change to be a bit faster when it’s closer to the Sun and a bit slower when it’s farther away. But the changes happen so gradually and smoothly that you don’t feel them at all.

Imagine you’re flying on an airplane that has reached cruising altitude. The engines are humming, you’re soaring through the sky at hundreds of miles per hour – but everything inside feels calm and still. You can walk around, relax and forget you’re traveling at all. That’s because the plane, you and everything else inside it are moving at the same speed, in the same direction.

Just as passengers don’t feel the plane’s speed while smoothly cruising, we don’t feel Earth’s movement because we’re traveling at the same speed as our planet. You, your chair, the trees, buildings, oceans – everything is moving together with the Earth.

There’s no difference in motion for your body to detect unless Earth were to suddenly speed up, slow down or change direction – and, thankfully, that doesn’t happen.

Very small ants on a very big ball

Imagine holding a huge beach ball in your hands. Picture a tiny ant crawling on the surface of that ball.

Now, think about us on Earth. We are like that ant, but the ball we’re crawling on is almost 8,000 miles (almost 13,000 kilometers) wide at the equator. That’s about the distance you’d travel driving from New York to Los Angeles and back to New York.

Because the Earth is so humongous, any movement feels very slow and gentle to our comparatively minuscule bodies as we stand on its surface.

Another reason you don’t notice Earth’s motion is that there are no nearby “landmarks” in space to act as reference points. When you’re in a car on the highway, you see trees, signs or telephone poles rushing by. Those fixed points help your brain register motion. But in space, the stars are so far away that they appear completely still, even though we’re moving relative to them at thousands of miles per hour.

Luckily, these high speeds don’t fling us off into space thanks to gravity. Gravity is an invisible force of attraction. It pulls everything on the surface of the planet toward the Earth’s center. It’s like the Earth is giving us a giant, constant hug, keeping us safely grounded.

How do we know the Earth is actually moving?

Even though we don’t feel the Earth moving, people long ago figured out that it really is by watching the sky carefully.

Start with day and night. The Sun appears to rise and set because Earth makes one full rotation on its axis every 24 hours. If Earth weren’t spinning, one side would always face the Sun, and the other would be in darkness.

Then there are the seasons. Earth is tilted on the axis it spins around. Over the course of its orbit of the Sun, Earth’s tilt causes different parts of the planet to get more or less sunlight. That’s why we have summer, winter and everything in between.

At night, stars and constellations seem to move across the sky as Earth rotates. And their positions in the sky change with the seasons. Our view of the stars changes as we move along our yearly path around the Sun. If everything stayed still, the night sky would never change.

By seeing Earth spinning and orbiting, satellites and space telescopes have confirmed what astronomers have long deduced. We may not feel it, and we can’t see any obvious landmarks rushing by, but the clues are everywhere. Earth is on the move.

And it’s not just Earth – the Sun itself rotates and moves around the center of our Milky Way galaxy at hundreds of thousands of miles per hour. Nothing in the universe is truly standing still. Everything is in motion, from planets and stars to galaxies themselves.

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This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Nilakshi Veerabathina, University of Texas at Arlington

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Nilakshi Veerabathina does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.