cross-posted from: https://lemmynsfw.com/post/21136052
I heard something new that realy makes you wander. If the earth is rotating as they say than how airplanes can go in straight line? If earth is moving under them they should land way off the desired destinacion… 😮 They are not connected to the earth so rotacion shouldnt apply to them, it applyes only to cars and runing animals but not on airplains and bierds… Also when you jump from baloon that is wery high up, you shouldnt fall straight down, if the earth is rotating it should move under you and you could newer fall on the same spot that you jumped over… 🫢
I cant beleave this newer came to my mind for entire life… 😵
Think of it this way: imagine a slowly moving stream. Anything in the stream will move along with the current and from its perspective will be “stationary” in the current, right?
But then think about the surface of the stream: the air above it isn’t moving, so the stream surface is rubbing along the air interface, creating drag. This means that the air is going to end up moving a little bit in the direction of the stream, and the stream surface is going to be moving a bit slower than the main body of water.
Wrap that in a circle, and that’s what the layers of the earth’s atmosphere are like. So a skydiver is “diving” in an atmosphere that is relatively (but not completely) stationary above a certain spot on the earth.
For an experiment you can try yourself, fill a bucket with water, and then spin around in a circle holding the bucket. All the water stays in the bucket instead of sloshing out one side due to the bucket moving through space. This is a combination of inertia and force acting on the contents of the bucket.
The earth is big enough to have a gravitational force strong enough to resist shear) the rubbing at the interface), and there’s nothing really out there in space for it to rub against. So the air is more impacted by the gravity of the moon and the heat of the sun than it is by friction against space or inertia overcoming gravity to send things flying off the earth at an angle.
Ok so when you talk abou inersia, does that mean that if you drive airplain in the same direction as earth rotacion you will gain more speed and inertia will get stronger than gravity and you will slowly start to levitate? And if that is trye than going in oposite direction will make you go slower than just standing on the ground and gravity should have bigger efect on you and start pushing you to the flor of airplain?
Let me ask you the same thing about swimming in moving water… relative to the water, do you slowly start to levitate?
No; if the referent is the water, to you it is stationary and the ground is moving past it; other than the slight movements at the interfaces, you’ll have the same interaction with the water no matter which way you move.
Likewise, the earth is both spinning AND rotating around the sun with an axial tilt. So if you fly in the direction of the earth’s rotation, you’ll be going faster relative to some fixed point in space, but relative to the earth’s surface, there isn’t a noticeable difference in forces going one way or the other. If there were, you’d already have flown off the surface just by standing up. Refer back to my bucket example for how that works.
Ok so since inertia happends when object change its state, it is when we change our speed or when we change our trajectory.
For example when i sit in car and it quckly accelerates i feel inertia, or when it run 100km/h for 5min i dont feel anything but if it accelerates quickly to 150km/h i feel inertia again. Or if he starts turning while keeping its speed to 100km/h i will feel inertia if that turn is curved enough, if its to soft i may not feel it.
On earth while just standing we dont change our speed, its constant so there is no inertia because of that. But we change our trajectory constantly because we dont go straight, we are constantly turning since its rotating. So inertia should apply to us right? But gravity is stronger and thats why we dont fly of the ground?
That’s a wonderful ELI5 explanation! I absolutely love it. If I had to critique it, I would challenge you to explain the jet streams at >30,000 ft. Stupid fluid dynamics making air move weird. You did a great job presenting the facts in a relatable way that I think most people can grasp and understand