Counteracting the inertia of Earth's rotation

[Bandersnatch]

Inertia is the resistance to acceleration. What you have been conceptualising as countering here - the spin of the Earth - is velocity. In common parlance the distinction can be blurry.

When viewed from a non-rotating reference frame - here it means the point of view of the Sun and the background stars - a point at the surface of the Earth at the equator has some linear velocity. If you want the drone to hover above that point as seen from the non-rotating reference frame, it has to have equal but opposite velocity, in addition to its hovering action.
Once you impart that velocity through the use of some force (like the drone's engines), and in the absence of other forces (like drag from the atmosphere), it'll hover at that spot forever. This is Newton's first law of motion.
Inertia only comes into play here when the drone is accelerating to that velocity, as it determines how much force is required. This is Newton's second law. Inertia is the mass in F=ma.

So if what you need to hover w/r to the Sun at the equator is equal and opposite surface velocity, there's no point in ever going 2000mph. You just get to 1000mph and either cut the engines (if there's no drag) or keep firing them to maintain that velocity.
You'd only need more/less speed if you wanted to change where exactly you want to hover. Maybe you wanted the Sun to be directly overhead or something.

The case with an atmosphere is no different than swimming against the current in a river. You want to stay at rest w/r to the river banks, you swim as fast as the current does, only in the opposite direction. Any other speed will move you w/r to the banks. And if you stop swimming = applying force against drag of the medium you're in, the current will quickly carry you away.

 

[hmmm27]

What am I (or you guys) not getting?

Well, what I don't seem to be getting is relevant context when you use the words "hover" or "speed". Or, the relevance of anything to do with "inertia".

There's a difference between waiting for information and being confused.

Much the same as if I were standing on a conveyor belt I would move with it , but if I ran against it at the same speed I would be running on the spot while the belt moves under me.

Now, that's not confusing at all.

 

[Baluncore]

Now, that's not confusing at all.

Think about a long conveyer belt , there is a mid point marker.

That does not clearly specify, if the marker is on the moving belt material, or on the fixed frame, next to the moving belt. You must be more precise when there are multiple possible interpretations. You know what you mean, but we cannot read your mind.

 

[Vic43]

That does not clearly specify, if the marker is on the moving belt material, or on the fixed frame, next to the moving belt. You must be more precise when there are multiple possible interpretations. You know what you mean, but we cannot read your mind.

Apologies. Yep on a fixed frame next to the belt

 

[Vic43]

Inertia is the resistance to acceleration. What you have been conceptualising as countering here - the spin of the Earth - is velocity. In common parlance the distinction can be blurry.

When viewed from a non-rotating reference frame - here it means the point of view of the Sun and the background stars - a point at the surface of the Earth at the equator has some linear velocity. If you want the drone to hover above that point as seen from the non-rotating reference frame, it has to have equal but opposite velocity, in addition to its hovering action.
Once you impart that velocity through the use of some force (like the drone's engines), and in the absence of other forces (like drag from the atmosphere), it'll hover at that spot forever. This is Newton's first law of motion.
Inertia only comes into play here when the drone is accelerating to that velocity, as it determines how much force is required. This is Newton's second law. Inertia is the mass in F=ma.

So if what you need to hover w/r to the Sun at the equator is equal and opposite surface velocity, there's no point in ever going 2000mph. You just get to 1000mph and either cut the engines (if there's no drag) or keep firing them to maintain that velocity.
You'd only need more/less speed if you wanted to change where exactly you want to hover. Maybe you wanted the Sun to be directly overhead or something.

The case with an atmosphere is no different than swimming against the current in a river. You want to stay at rest w/r to the river banks, you swim as fast as the current does, only in the opposite direction. Any other speed will move you w/r to the banks. And if you stop swimming = applying force against drag of the medium you're in, the current will quickly carry you away.

I guess I have been using confusing language which made it hard for you guys to understand what I was talking about. I'm glad you got the concept anyway . Thanks for your detailed response

 

[DaveC426913]

It would greatly simplify your grasp of all these scenarios if you (correctly) consider that everything - from the Earth's core up to the top of its atmosphere - is on average moving along with the rotation of the Earth (including all the air).

 

[Vic43]

You'd need to translate that into English / Physics if you want a meaningful response.

You would be describing the very hard task of keeping a flying machine flying West fast enough to keep the Sun overhead? (on the Equator, of course). Or maybe using a powerful fan to achieve the same thing.

From your posts above, I get the impression that you have argued yourself into a corner in an attempt not to be wrong. PF is not the one who's out of step here.

Seems I've been using wrong terms and confusing language. Sorry, I'm not trying not to be wrong. I guess it came across like that as my language wasn't precise and that made it hard for people to get what I meant. All good now , I think I've got my answers - I was right with the outcome of the concept , just didn't articulate the concept well enough.

 

[Vic43]

Do any of you guys know of an experiment that has been done regarding this scenario?

 

[Drakkith]

Do any of you guys know of an experiment that has been done regarding this scenario?

Yes, aircraft fly in the sky all the time. I imagine that at some time some airliner has been traveling west at just the right latitude and speed to cancel out Earth's rotation completely. In fact, at 56.5 degrees north or south the Earth's rotational velocity is about 575 mph, which is about the average cruising speed of a typical airliner. Anyone flying west into parts of Denmark, Sweden, or Latvia (or huge areas of Russia) is roughly canceling out Earth's rotational motion.

 

[Baluncore]

Do any of you guys know of an experiment that has been done regarding this scenario?

What scenario?
We live in the real world and understand the physics of the Earth. What experiment could disprove our understanding.

 

[Vic43]

Yes, aircraft fly in the sky all the time. I imagine that at some time some airliner has been traveling west at just the right latitude and speed to cancel out Earth's rotation completely. In fact, at 56.5 degrees north or south the Earth's rotational velocity is about 575 mph, which is about the average cruising speed of a typical airliner. Anyone flying west into parts of Denmark, Sweden, or Latvia (or huge areas of Russia) is roughly canceling out Earth's rotational motion.

What would be observed looking down at the ground from the aircraft? And I suppose it would have occurred flying east aswell, wht would be observed in this case?

 

[Baluncore]

What would be observed looking down at the ground from the aircraft? And I suppose it would have occurred flying east aswell, wht would be observed in this case?

It seems that you have lived your whole life, secluded in an apartment, without experience of transport in the real world. Do you ever go outside, to catch a train for example?

 

[Vanadium 50]

Do any of you guys know of an experiment that has been done regarding this scenario?

You mean like getting rid of the Earth's atmosphere and using a rocket-powered drone?
No.
And I would not be in favor of it.

 

[Vic43]

It seems that you have lived your whole life, secluded in an apartment, without experience of transport in the real world. Do you ever go outside, to catch a train for example?

Why are you being disrespectful chap? Ofcourse I've experienced transport. I just never seen the earth spin under a stationary craft (relative to a position outside our atmosphere like a star or whatever). If there was a wide train with a clear bottom that had a marker on the track underneath, that was travelling, and you had a drone travelling on the train , you let the drone travel a distance with the train so it was going at the same velocity , then you hovered the drone , it would be still going the same speed as the train , but if you then flew the drone in the opposite direction of travel until you got to the marker on the track and came to a hover over that point, I would assume that the train would then move under the drone?

 

[berkeman]

Thread is paused for a bit for Moderation...

 

[Drakkith]

What would be observed looking down at the ground from the aircraft? And I suppose it would have occurred flying east aswell, wht would be observed in this case?

Nothing special. It would look like you're flying normally no matter what direction you're flying in.

Edit: Sorry Berk, didn't see the thread was locked.

 

[berkeman]

No worries Drak.

@Vic43 -- I don't think folks are being disrespectful, some are just getting a bit frustrated that you are only understanding some parts of the explanations.

In summary, the speed of the aircraft (it needs to be a plane, not a drone) with respect to a stationary reference frame is the aircraft's speed relative to the ground, plus the speed of the ground (and air) with respect to a stationary reference frame. So if you want the aircraft's speed to be zero in a stationary reference frame (call it the star background reference frame), the aircraft has to fly west at 1000mph at the equator with respect to the Earth's surface and the associated atmosphere. As Drak points out, you can fly slower at latitudes away from the equator and still remain stationary in the stationary reference frame.

Thread is reopened in case that is not clear enough.

Edit/Add -- and if you stand at the North or South Pole, all you have to do is spin slowly (in the correct direction) to remain stationary against the star background...

 

[russ_watters]

just never seen the earth spin under a stationary craft

Why do you need it to, to understand the math? The math is very simple. An airplane flying flying east to west at the equator at 1,000 mph would see the sun remain stationary in the sky. A plane flying at 500 mph would see the sun move a (1000-500)/1000 = 50% of normal speed. What's the problem?

The world has supersonic aircraft. They've flown east and they've flown west. Has one ever flown west at exactly 1,000 mph at the equator? Why does it matter, to understand what they would see?

Note, you can approximate this at higher latitudes and slower speeds. I recently "saw" the sun travel backwards on a plane ride from the US to Asia. (in quotes because I had the shades closed, but I'm sure the pilots literally saw it.)

 

[gmax137]

I recently flew from the east coast of the US to the west. My plane took off at 6PM (eastern time) and arrived at 8PM (pacific time, three time zones west of my departure). I watched the sun get low in the sky and then set for nearly 5 hours.

 

[Vic43]

Thanks for the extra answers everyone, appreciated. I just want to make something clear, I am not trying to prove anything or anyone wrong , I just find the topic interesting.

 

[Vic43]

Don't you think it'd be a crazy sight to see though? Even from a vantage point standing on the earth. Looking up at a plane flying stationary in relation to the sun/star. The plane would be in the sky from sun up to sun down (if it could keep the speed of 1000mph for that whole time)

 

[Halc]

Even from a vantage point standing on the earth. Looking up at a plane flying stationary in relation to the sun/star. The plane would be in the sky from sun up to sun down (if it could keep the speed of 1000mph for that whole time

It wouldn't though. It would cross from horizon to horizon in 10-20 minutes perhaps, faster than would a normal airliner that doesn't fly at mach 1.4. If it crossed in front of the sun, it would be there only for a few moments.

Remember, from a vantage point standing on the earth, the observer is moving at 1000 mph relative to that aircraft.

I've been on such a plane, flying pretty much in pace with the sun, so it stayed more or less 'noon' the whole time. I just wasn't on the equator at the time, but more like over Greenland.

 

[berkeman]

Don't you think it'd be a crazy sight to see though? Even from a vantage point standing on the earth. Looking up at a plane flying stationary in relation to the sun/star. The plane would be in the sky from sun up to sun down (if it could keep the speed of 1000mph for that whole time)

As @Halc says, the plane would not appear stationary to you, it would zoom by at high speed and a few seconds later you would hear a sonic boom (if you are at low lattitude where the speed is supersonic).

Reminds me of a fun story from when I was a little kid living in Pasadena in Southern California. We were in a crowd waiting for the Rose Parade to start, and I was looking up a light pole and noticed the high clouds above moving with respect to the top of the light pole. I said, "Hey dad, I can see the Earth turning under those clouds!" My dad smiled, and said, "No son, even though you don't feel any wind down here right now, there is wind up there where those clouds are, and it's just the wind pushing the clouds along above us."

Learn something new every day...

 

[DaveC426913]

Don't you think it'd be a crazy sight to see though? Even from a vantage point standing on the earth. Looking up at a plane flying stationary in relation to the sun/star. The plane would be in the sky from sun up to sun down (if it could keep the speed of 1000mph for that whole time)

As others have pointed out, it would only be in your sky for a few minutes. Your portion of the sky,from east horizon to west horizon is only a few hundred km. The plane will cross that in minutes.

You will not see the plane stationary in relation to the sun.

 

[PeroK]

Don't you think it'd be a crazy sight to see though? Even from a vantage point standing on the earth. Looking up at a plane flying stationary in relation to the sun/star.

It wouldn't. You need to draw a diagram. The plane would not be stationary relative to the Sun to a ground observer.

The plane would be in the sky from sun up to sun down (if it could keep the speed of 1000mph for that whole time)

You're not going to see the plane for all that time. It would have travelled half way round the Earth in that time. You can only see the Sun for 12 hours because it's so far away.

 

[Vic43]

True my bad , I stand corrected on that one