Eli5: If the earth is spinning at 1000mph how come when we jump up in a straight line we don’t end up in a different place on the ground?

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Eli5: If the earth is spinning at 1000mph how come when we jump up in a straight line we don’t end up in a different place on the ground?

In: Earth Science

Because you’re also moving along with the Earth at 1000 mph at the moment you leave the ground, so you are still moving with the Earth even when you’re in mid-air. Then, when you land, you land at about the same place you jumped; you and the Earth have both moved around the same distance over the time it took for you to jump and land.

Because we have momentum and the atmosphere is also moving along with the rotation at the same speed. It’s just like how if you’re in a car going 60 on a highway and you toss a ball up and down it doesn’t suddenly fly backward at 60.

Atmoshphere kinda puts us in a quasi snowglobe, kind of like when your on a airplane your not all thrusted to the back of the airplane. Tho if you stopped the earth or the atmosphere we would have serious issues.

Consider a record spinning at 45rpm. That’s 45 revolutions per minute. Now slow it down to 1 RPM. Thats a whole lot slower at the edge, right? Now slow it down to 1 revolution per day. To give you an idea, normal clocks hour hands spin at 2 rpd. The earth spins at about 1rpd. This is why it doesn’t feel like anything, and why we don’t change location when we jump, along with all the other explanations of inertial conservation.

Imagine you’re on an airplane and decide to jump in the aisle. You will appear to land in the same position you jumped from because you are moving the same speed as the plane. In the same way, even tho Earth itself is moving fast, when you jump, you land in the same place because you are moving the same speed.

However, if you want to be extremely technical, technically you *dont* land in the same place you left from.

Let’s say you are a world class athlete who can stay in the air for an entire second every time you jump. Although relative to your airplane you will appear to land in the same spot, relative to the Earth, you will actually have moved 880 feet. (assuming you were flying at 600 mph)

Likewise, when you stand on the ground and jump, you land in the same position relative to earth. However, relative to a stationary point in space, given the earth is rotating at 1000mph, orbiting the sun at 67,000 mph, and our solar system is flying through the galaxy at 490000 mph…. That’s… Uhh….. Combined….. A max of like 818400 feet per second. So if you can jump for one second, you’ll technically end up in a completely new place…..

And actually, you are in a completely new place every second whether you jump or not. And nobody has ever been where you are right now.

Pretty cool, right?

Think about throwing a ball. If you run when you throw the ball, the speed of you running is added to the speed of the throw. If you toss the ball up a few feet and catch it, it moved vertically. But if you walk and throw it up and catch it, it moved diagonally, but still, to your frame of reference, only moved vertically, yet the ball moved forward with your speed as it moved through the air out of and back into your hand.

Think about a car crash. You’re going 60. If your car went sudden stop, you’d still be going about 60 (through the windshield). Your body was moving 60 and yet, if you were to jump inside of the car, you wouldn’t feel it.

So as the earth spins, you spin at the same rate. When you jump, you’ve still got that speed.

The same reason you can jump on a moving train or airplane. You are already moving with the Earth as it spins.

You do! Except the Earth is so big that it isn’t noticeable unless you jumped really, really high.

It’s not a perfect analogy but imagine standing on a carousel or merry-go-round and jumping up. If it is moving fast you might stagger a bit as you land and end up in a different place to where you jumped.

But now imagine one that is only rotating around once per day. That motion is going to be so slow (even if it was a really big carousel) that in the brief time you are in the air you won’t have had much chance to move away from where you started.