Since the Earth rotates, what would happen if...

[raphaelh42]

Hello

Since the Earth rotates, what would happen if you take an helicopter, and stay above the surface for 12 hours ? Would you arrive at the opposite of the Earth ?

Hmm I guess the wind would bring you with it, so let's say you do circles with a supersonic aircraft, what would happen ?

If you don't arrive to the opposite of Earth, because of which phenomenon ? I'm not sure to understand why things above the surface would rotate too, except maybe the wind bringing you with it...

[Genady]

8 minutes ago, raphaelh42 said:

If you don't arrive to the opposite of Earth, because of which phenomenon ?

In one word, inertia. Bodies continue moving at a constant speed and in the constant direction unless something disturbs that movement.

For example, if you throw something up while moving inside a car, the thing will go up and down into your hand despite the car's moving forward. 

[studiot]

1 hour ago, raphaelh42 said:

Hello

Since the Earth rotates, what would happen if you take an helicopter, and stay above the surface for 12 hours ? Would you arrive at the opposite of the Earth ?

Hmm I guess the wind would bring you with it, so let's say you do circles with a supersonic aircraft, what would happen ?

If you don't arrive to the opposite of Earth, because of which phenomenon ? I'm not sure to understand why things above the surface would rotate too, except maybe the wind bringing you with it...

This is a strange question, let's look into it further.

 

If you take a helicopter and and hover above the surface    -  what do you mean ?

If you take a helicopter and hover above the helipad for 12 seconds, 12 minutes, 12 hours or 12 days you will still be abov the helipad and not above the other side of the world.

If you fly the helicopter so you have some forward or backwards speed we distinguish two speeds

Ground speed

And air speed

The ground speed is of course zero when you are hovering over the helipad.

But the airspeed is only zero in 'still air'. Still air means the air is actually turning with the Earth at the same rate as the ground.

Otherwise it needs to be enough to counteract the tendency of your craft to move along with the wind and then needs to be some more if you actually want to go anywhere.

 

However the Earth's rotation does play a part since the flying time London to New York is 8 hours, Whilst the flying time New York to London is only 7 hours.

Is this actually the phenomenon you are actually thinking of ?

 

[TheVat]

2 hours ago, raphaelh42 said:

I'm not sure to understand why things above the surface would rotate too, except maybe the wind bringing you with it...

The chopper shares the Earth's momentum.  As does everything on the planet.  If you jump high on a trampoline at the equator, the trampoline and yard doesn't shoot away from you at 1000 mph (460 m/s) and drop you a few blocks to the west.

 

 

Galileo's boat is a helpful google search.

Edited March 12, 2023 by TheVat
minor repair

[raphaelh42]

4 hours ago, studiot said:

If you take a helicopter and and hover above the surface    -  what do you mean ?

I mean you stay in the air but don't move

4 hours ago, studiot said:

However the Earth's rotation does play a part since the flying time London to New York is 8 hours, Whilst the flying time New York to London is only 7 hours.

Is this actually the phenomenon you are actually thinking of ?

I didn't know, I'm very surprised

I was thinking about why the not moving things in the air would rotate the same as the Earth does, and not just arrive to the opposite location after 12 hours, or just arrive farther

 

If I understand correctly, since Earth's rotation influences the travel duration of aircraft, there is a positive speed value that would never allow you to reach B point?

One that would make you just stay at the same location? (And one that would make you go backwards? (but with this one you would reach B...))

Imagining the aircraft doesn't have a minimal speed value to respect for not falling

 

Sorry if Galileo's ship experiments answers to these new questions, I tried to fully read the Wikipedia article, but it isn't translated into my main language and I'm so tired right now, If I read it fully and get the answers to these new questions, I will tell

Edited March 12, 2023 by raphaelh42

[exchemist]

8 minutes ago, raphaelh42 said:

I mean you stay in the air but don't move

I didn't know, I'm very surprised

I was thinking about why the not moving things in the air would rotate the same as the Earth does, and not just arrive to the opposite location after 12 hours, or just arrive elsewhere

 

If I understand correctly, since Earth's rotation influences the travel duration of aircraft, there is a positive speed value that would never allow you to reach B point?

One that would make you just stay at the same location? And one that would make you go backwards? (but with this one you would reach B)

Imagining the aircraft doesn't have a minimal speed value to respect for not falling

The atmosphere, broadly speaking, rotates with the Earth so to a first approximation the rotation does not make anything suspended in the air move, relative to a point on the ground. If this were not so, you would feel a constant wind, always from the same direction, due to the difference in rotational speed between you, on the ground, and the air. 

When it comes to second order effects, the rotation of the earth plays a role in determining various patterns of air flow in the atmosphere, e.g the jet stream, the trade winds, etc.

But do not imagine these are simply due to a difference in rotation rate between the surface and the air above. The jet stream, for instance, flows from west to east, the same direction as the rotation of the earth, but faster, thereby creating a west-east wind, relative to the surface. This and many other air flows arise from a combination of heating and cooling in different parts of the globe with the effects of rotation, via Coriolis effects and so on.