Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: hamdani yusuf on 25/07/2020 23:45:56

Title: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 25/07/2020 23:45:56
If all windmills on earth are designed to catch only eastward wind,  while westward wind can blow freely,  will it accelerate earth rotation?
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 26/07/2020 00:13:45
If all windmills on earth are designed to catch only eastward wind,  while westward wind can blow freely,  will it accelerate earth rotation?
By conservation of angular momentum, all you need is one windmill with a vertical axis at the north pole, rotating against Earth's spin.  Yes, any torque applied to Earth's crust is going to alter its rotation, transferring its angular momentum to something else.  So my farting in your general direction is enough.  One windmill, even a toy one, is enough.  Of course it will resume its original spin as soon as the windmill stops, so it's temporary. All effects are still temporary, and vanish once the thing to which the angular momentum was transferred gives that momentum back. It's more difficult to permanently change it.

That said, there's no way all the windmills applying eastward torque on Earth is going to actually out-torque the westward forces acting on Earth such as the tides.  The Earth's spin will not actually increase *, but will rather slow its spin at a slightly lower pace. It would spin faster only relative to what it would have without the windmills, not faster than it was moving an hour ago.

* The Earth's spin doesn't decrease steadily in the short term. There are fairly short intervals when it increases, so if the windmill thingy was done during one of those intervals, it would temporarily increase the spin above the natural increase.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 27/07/2020 03:17:59
That said, there's no way all the windmills applying eastward torque on Earth is going to actually out-torque the westward forces acting on Earth such as the tides. 
That depends on how many windmills/how much power is generated.
The atmosphere can have different angular speed than Earth's crust. So it's possible to increase earth crust's angular momentum eastward while decreasing atmosphere's total angular momentum. Besides, earth is not a completely isolated system. It interacts with its surrounding, such as solar wind.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 27/07/2020 09:45:07
climbing the stairs increases your distance from the rotation axis, so it increases the moment of inertia and this reduces teh rotational speed, but not much.
will it accelerate earth rotation?
No
To do that you have to have something outside the Earth to push against.
The atmosphere is part of the Earth
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 28/07/2020 10:19:56
climbing the stairs increases your distance from the rotation axis, so it increases the moment of inertia and this reduces teh rotational speed, but not much.
will it accelerate earth rotation?
No
To do that you have to have something outside the Earth to push against.
The atmosphere is part of the Earth
afaik,  molecules in upper atmosphere collide with solar wind.   they also occasionally collide with meteors.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 28/07/2020 10:35:54
climbing the stairs increases your distance from the rotation axis, so it increases the moment of inertia and this reduces teh rotational speed, but not much.
will it accelerate earth rotation?
No
To do that you have to have something outside the Earth to push against.
The atmosphere is part of the Earth
afaik,  molecules in upper atmosphere collide with solar wind.   they also occasionally collide with meteors.
Let me know when someone builds a wind turbine that tall.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 01/08/2020 08:42:15
Let me know when someone builds a wind turbine that tall.
The wind turbines don't have to catch the solar wind directly. They are built in lower atmosphere as usual. If they only catch eastward wind, then there would be overall net westward wind in the atmosphere, relative to the earth crust. Assuming that solar wind and meteors don't have preference on particular earth rotational direction, they are expected to oppose the net westward wind produced by the wind turbines.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 01/08/2020 11:14:40
the net westward wind produced by the wind turbines.
https://xkcd.com/1378/
Title: Re: Can windmills affect Earth's rotation?
Post by: CPT ArkAngel on 03/08/2020 22:04:35
In my opinion, you can only transfer some momentum if the solar win has a net effect on the net wind direction of rotation and it will depend where you put your windmill. Tides also.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 03/08/2020 22:14:21
I guess you could pretend that the world is one of these
https://en.wikipedia.org/wiki/Crookes_radiometer
But fundamentally the winds are driven by the Sun.
Title: Re: Can windmills affect Earth's rotation?
Post by: CPT ArkAngel on 03/08/2020 22:23:18
In a meteorological course, I remember to have predicted a counter wind at very high altitude to compensate for the wind we are usually seeing for the weather and airplane flights. I told myself the wind directions are due to the coriolis force, evaporation, convection, pressure, temperature and terrain friction. I told myself the solar wind should be negligible. Everybody was skeptic. One day we saw the wind of the upper atmosphere in realtime on a meteorological site and there it was, a uniform thin layer going all in the opposite direction of the general direction of the lower atmosphere.

The solar wind has not a big effect on the net rotation of the earth's wind.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 04/08/2020 06:38:11
the net westward wind produced by the wind turbines.
https://xkcd.com/1378/
(https://imgs.xkcd.com/comics/turbine.png)
That's funny, but it doesn't represent the idea proposed in this thread.
Consider this spinning globe.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fcraziestgadgets.com%2Fwp-content%2Fuploads%2F2014%2F05%2Fspinning-jupiter-globe.gif&hash=d775916d934604f6732fce1979db2c11)
The spherical glass prevents external forces from directly affect rotation of inner ball, which is floating in a fluid.
If I add a small impeller on the equator, anchored to the inner ball, directed westward and turn it on, the fluid will rotate westward. Due to conservation of angular momentum, the inner ball will rotate eastward faster.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 04/08/2020 08:38:15
but it doesn't represent the idea proposed in this thread.
Did you read what you actually said?
" wind produced by the wind turbines."
Wind turbines do not produce wind.
They are not fans.
The cartoon depicts exactly the mistake you have made.
And also
Due to conservation of angular momentum, the inner ball will rotate eastward faster. system as a whole will not rotate.
Fixed it for you.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 04/08/2020 17:51:08
the net westward wind produced by the wind turbines.
https://xkcd.com/1378/
(https://imgs.xkcd.com/comics/turbine.png)
That's funny, but it doesn't represent the idea proposed in this thread.
Consider this spinning globe.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fcraziestgadgets.com%2Fwp-content%2Fuploads%2F2014%2F05%2Fspinning-jupiter-globe.gif&hash=d775916d934604f6732fce1979db2c11)
The spherical glass prevents external forces from directly affect rotation of inner ball, which is floating in a fluid.
If I add a small impeller on the equator, anchored to the inner ball, directed westward and turn it on, the fluid will rotate westward. Due to conservation of angular momentum, the inner ball will rotate eastward faster.

Your theory is suggesting that the wind blows without impedance if windmills are not present, it also suggests (although I stand to be corrected, if you would clarify please)they do not originate from temperature differences but in the earths rotation.

Subtract wind from the waves and trees and hills and etc and add the energy to the windmill base, both at the same direction of action you have an equal vector ! You seem to wish to know where the energy is coming from for the electric ?
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 05/08/2020 06:23:40
Your theory is suggesting that the wind blows without impedance if windmills are not present, it also suggests (although I stand to be corrected, if you would clarify please)they do not originate from temperature differences but in the earths rotation.
No. I assumed that without windmill, the overall restrictions on the wind are balanced between westward and eastward direction, thus they don't have net effect on earth rotation. The homogenously directed windmills create the imbalance which makes the crust of the earth rotates faster eastward.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 05/08/2020 08:32:07
Your theory is suggesting that the wind blows without impedance if windmills are not present, it also suggests (although I stand to be corrected, if you would clarify please)they do not originate from temperature differences but in the earths rotation.
No. I assumed that without windmill, the overall restrictions on the wind are balanced between westward and eastward direction, thus they don't have net effect on earth rotation. The homogenously directed windmills create the imbalance which makes the crust of the earth rotates faster eastward.
A windmill adds a nearly balanced pair of forces
The air pushes on it, but, by slowing that air down, it ensues that the air pushes less hard on the Earth.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 05/08/2020 18:56:47
Your theory is suggesting that the wind blows without impedance if windmills are not present, it also suggests (although I stand to be corrected, if you would clarify please)they do not originate from temperature differences but in the earths rotation.
No. I assumed that without windmill, the overall restrictions on the wind are balanced between westward and eastward direction, thus they don't have net effect on earth rotation. The homogenously directed windmills create the imbalance which makes the crust of the earth rotates faster eastward.
If the wind energy inpacts the earth it has an effect, both wind directions with a residual exess in one direction. If it counteracts other opposite airflow  its dissipated in one way or another, with the same residual exess. The net force is the same. The energy that is extracted to generate the electric is the atmospheric energy of freeflowing winds, water vapour(quite a major ammount) pressure atmospheric expantion.

If you collected all of the energy from the sun a la permanent eclipse across the whole planet and did not release it to the planet the atmosphere would shrink, the water would drop from the air, so windmills will sort of do a similar thing, but  only if the energy is not released into the atmosphere, such as endothermic industrial processes.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 05/08/2020 19:07:09
Are  there any large scale industrial endothermic processes driven by windmills?
Your theory is suggesting that the wind blows without impedance if windmills are not present, it also suggests (although I stand to be corrected, if you would clarify please)they do not originate from temperature differences but in the earths rotation.
No. I assumed that without windmill, the overall restrictions on the wind are balanced between westward and eastward direction, thus they don't have net effect on earth rotation. The homogenously directed windmills create the imbalance which makes the crust of the earth rotates faster eastward.
If the wind energy inpacts the earth it has an effect, both wind directions with a residual exess in one direction. If it counteracts other opposite airflow  its dissipated in one way or another, with the same residual exess. The net force is the same. The energy that is extracted to generate the electric is the atmospheric energy of freeflowing winds, water vapour(quite a major ammount) pressure atmospheric expantion.

If you collected all of the energy from the sun a la permanent eclipse across the whole planet and did not release it to the planet the atmosphere would shrink, the water would drop from the air, so windmills will sort of do a similar thing, but  only if the energy is not released into the atmosphere, such as endothermic industrial processes.
Are  there any large scale industrial endothermic processes driven by windmills?
Title: Re: Can windmills affect Earth's rotation?
Post by: David Cooper on 11/08/2020 19:01:47
If you have a satellite that's rotating slightly, you can presumably stop that using the gyroscopes, but only at the cost of having to run them continually. To stop the rotation so that you don't have to run motors all the time, you'd need to use gas jets, and that gas has to be lost to space in order for it to become external torque.

With the Earth and its atmosphere, there may be some gas escaping (hydrogen and helium in particular), and that escaping gas may have a component of movement passed to it by a movement of the atmosphere acting more eastward than westward or the reverse, so that could translate to external torque, but it would be an infinitesimal amount. More of this may happen near the poles where I'm guessing the solar wind is stronger (on the basis that that's where aurorae happen), so the prevailing direction of the wind in those regions could have some relevance to this. But there will be so little of this happening as to be irrelevant to any measurable change in rotation speed of the Earth. Some of the variation may be due to movement of material in the core which we know moves around as the magnetic poles wander about. Some of the variation will be due to ice melting on land: as sea level rises, you have more mass away from the poles and that will slow the Earth's rotation just like the ice skater moving his/her arms further out from the axis of rotation. The pressure distribution of the air around the planet due to temperature differences will also cause variation in the same way by varying how much weight of gas is at different distances out from the axis of rotation, and the same kind of variation applies to the distribution of water in the atmosphere.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 11/08/2020 23:26:54
If you have a satellite that's rotating slightly, you can presumably stop that using the gyroscopes, but only at the cost of having to run them continually. To stop the rotation so that you don't have to run motors all the time, you'd need to use gas jets, and that gas has to be lost to space in order for it to become external torque.

David, as I discovered along time ago that in the long term the only way to affect the earths ;

position in space
Orbital speed
Moon
Tides
Etc


Is you

have to exeed the maximum surface escape velocity of the earth moon system

Otherwise it is like the tides, it flows one way then the other. The maximum escape velocity from the surface is 11kms at surface level (very thick atmosphere) . I am not sure but i believe even h bombs did not long term affect us, 11kms 11,000m/s  is faster than anything exept rail guns, which are not very big at all, and mass wise tiny.
Title: Re: Can windmills affect Earth's rotation?
Post by: David Cooper on 13/08/2020 22:18:09
If the bearings are good (and they are) you don't need to run  motor to keep the gyro spinning.

Good point - the gyro could have components that aren't connected up at all physically but just float in space while being kept in place and made to rotate by magnetic means. No wear and no friction.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 13/08/2020 23:17:22
If the bearings are good (and they are) you don't need to run  motor to keep the gyro spinning.

Good point - the gyro could have components that aren't connected up at all physically but just float in space while being kept in place and made to rotate by magnetic means. No wear and no friction.
It seems they come in two flavours; I hadn't realised how complicated it is.
https://en.wikipedia.org/wiki/Control_moment_gyroscope
https://en.wikipedia.org/wiki/Reaction_wheel
But presumably, Alan doesn't believe in them because they rely on the conservation of angular momentum.
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 11/10/2020 14:08:05
A major split of this thread has been made.  New topic is "Can heat affect Earth's rotation?"

https://www.thenakedscientists.com/forum/index.php?topic=80717.0

Please confine posts concerning angular momentum changes without external torque to that topic.
Title: Re: Can windmills affect Earth's rotation?
Post by: mikahawkins on 11/10/2020 16:37:05
No, it won't. The Earth spins because it formed in the accretion disk of a cloud of hydrogen that collapsed down from mutual gravity and needed to conserve its angular momentum. It continues to spin because of inertia.
Basically the Earth and all the windmills on Earth will constitute a single system.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 13/10/2020 05:39:51
Conserving angular momentum doesn't necessarily mean conserving angular velocity.
How A Massive Dam in China Slowed the Earth's Rotation

Most of us agree that the answer to the title question is no, as long as the earth can be treated as an isolated system. Otherwise, the answer could be yes.
Here are some phenomena violating earth's isolation :
- Meteor shower, mostly burn in the atmosphere.
- Solar wind, besides the influence through direct impact, is also stripping light gases from upper atmosphere.
- Launching of satellites and other spacecraft, which are mostly eastward, hence tends to slow down earth rotation.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 13/10/2020 08:51:51
It's always been accepted that there are small effects.
But the origins of the other thread lie in Alan's claim that the weather is powered by the Earth's rotation- which is plainly wrong, and the idea that you can interconvert  energy, angular momentum and linear momentum which is also obviously wrong.

Essentially a windmill will affect the Earth's rotation.
But it will have largely the same effect if it is jammed and can't rotate, or replaced by a tree.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 13/10/2020 09:25:22
Essentially a windmill will affect the Earth's rotation.
But it will have largely the same effect if it is jammed and can't rotate, or replaced by a tree.
How would it affect the Earth's rotation? Would it accelerate, or rather, decelerate earth rotation?
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 13/10/2020 13:13:53
Essentially a windmill will affect the Earth's rotation.
But it will have largely the same effect if it is jammed and can't rotate, or replaced by a tree.
How would it affect the Earth's rotation? Would it accelerate, or rather, decelerate earth rotation?
Most of this has already been answered in the first reply to this topic.
The erection of a windmill (or the growing of tree) typically involves the movement of mass from here to there, which alters the moment of the system, and thus changes the rotation speed.  Which way depends on where the material is move to and from, so a windmill laying on the ground and then flipped upright will slow the Earth's spin since that is an increase of moment. This change in moment is the reason behind the China dam video you posted. The dam is apparently far enough south that it increases the moment, and thus decreases the spin rate, but even that isn't indefinite since the weight of the project will sink the crust that buoys it up, and thus restores the moment close to where it was without the project. Your bathtub does this, just on a smaller scale.

Secondly, the atmosphere is always more or less in equilibrium with the crust.  If the wind on the surface prevails in one direction, friction slows the one and speeds the other, tending always towards equilibrium.  So imagine I toss a ball to the west. That speeds Earth's spin momentarily and shortens the day, but in moments the ball hits the ground and comes to rest, and the spin is restored. Putting up a windmill (or tree) is like that: Each might put a force on the ground, but that just takes away the same force that would have had the same friction elsewhere, so the net effect is temporary and negligible.

The atmosphere does change momentum due to the weather, and as has been pointed out somewhere, the daily variation (microseconds was it?) of length of day is quite measurable. The energy from the sun does mess with the equilibrium.

Third: A windmill has angular momentum of its own that a tree doesn't.  So a north facing windmill (or Ferris wheel for that matter) will increase the length of day if it spins clockwise, and decrease it if it spins counterclockwise. This has nothing to do with wind, friction, or force. It is just a thing having more than its share of the angular momentum of the system, just like your satellite put into orbit.

Most of us agree that the answer to the title question is no, as long as the earth can be treated as an isolated system.
Of course not. There's tides, which put an immense torque on Earth. That effect is many orders of magnitude greater than any other external effect. Angular momentum is never lost, but it is transferred from spin momentum to orbital momentum. The day used to be a single digit of hours long and the year was shorter. Trees and windmills are not responsible for the current 24 hour day.

Quote
Here are some phenomena violating earth's isolation :
- Meteor shower, mostly burn in the atmosphere.
Negligible since there is no particular asymmetry to it. There are about as many adding to our momentum as those decreasing it.  A big one is an exception. The biggest was Theia, and that one is responsible for the ~6 hour spin rate way back in the early days. There's no telling what the spin (or tilt, or even orbital distance/length of year) of Earth was before that impact.

Quote
- Solar wind, besides the influence through direct impact, is also stripping light gases from upper atmosphere.
Solar wind is symmetrical and applies no torque. Similarly, stripping gas changes the mass and moment and has no effect on rotation rate.

Quote
Launching of satellites and other spacecraft, which are mostly eastward, hence tends to slow down earth rotation.
It doesn't change the momentum of the system, but yes, for the reasons mentioned above.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 13/10/2020 14:02:30
The day used to be a single digit of hours long and the year was shorter.
When the day was shorter, there should be more days in a year.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 13/10/2020 14:10:53
Negligible since there is no particular asymmetry to it.
I've also mentioned this in my previous post. If the windmills are massive enough to create significant net movement between the atmosphere and earth crust, then small meteors would tend to slow the atmosphere more then earth crust, since they would be burnt down, hence produce net torque to the earth system. Ditto for solar wind.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 13/10/2020 14:14:22
If the windmills are massive enough to create significant net movement between the atmosphere and earth crust,
What do you mean?
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 13/10/2020 14:21:58
The day used to be a single digit of hours long and the year was shorter.
When the day was shorter, there should be more more days in a year.
More days doesn't necessarily make the year longer if it's because the days are shorter.

The length of the year is increasing. There are four factors, two positive and two negative.  In what I think is the correct order of decreasing significance.  The higher the effect, the greater its influence, but the list seems to be in order of reverse permanence. The bottom one will win in the end, despite it being the smallest effect.

1) Tides are always pushing the Earth to a higher orbit, just like they're pushing the moon to a higher orbit. This effect will end if the Earth would ever become tidal locked, but it cannot while we have a moon.  The day will eventually be very short again if Earth lives long enough for the moon to come back and impact it.  Only then will the day length grow again until it matches the year length at the time.

2) The sun is losing mass by burning it, and the decrease of gravitational pull drives Earth to a higher orbit. It is possible that it will lose enough mass that when the sun grows to a red giant, we'll be outside its radius. It will definitely grow to Earth's current orbit, but the jury is out whether our orbit will be high enough at that time to escape death by:

3) Friction, with dust, or maybe the sun if it grows enough to touch us.

4) Orbital energy and momentum is continuously radiated away at the rate of 200 watts in the form of gravitational waves. Yes, a closed system is not entirely closed, per general relativity.

If the windmills are massive enough to create significant net movement between the atmosphere and earth crust
Windmills don't create any net movement, massive or not. See the example of my throwing a ball. They are effectively trees, and slow the local wind here rather than it being slowed equally somewhere else, just like a dam generates energy from water going downhill, water that would have gone downhill at the same rate even with the dam not there.

Quote
then small meteors would tend to slow the atmosphere more then earth crust, since they would be burnt down, hence produce net torque to the earth system.
There's no torque to meteors since they fall equally on one side and the other. The fact that they heat up on the way in makes zero difference. That's like solar energy adding heat but not momentum.
You're apparently ignoring the replies being posted, and just repeating the same things. Reply to the replies to your comments rather than just repeating the original comment with slightly different wording.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 05:01:10
If the windmills are massive enough to create significant net movement between the atmosphere and earth crust,
What do you mean?

I mean that when the windmills collectively reduce windspeed in one direction while not significantly reduce windspeed in the opposite direction. So if windspeed in all points on earth surface are measured and vectorially summarized, the result is non-zero.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 05:13:40
Secondly, the atmosphere is always more or less in equilibrium with the crust.  If the wind on the surface prevails in one direction, friction slows the one and speeds the other, tending always towards equilibrium.  So imagine I toss a ball to the west. That speeds Earth's spin momentarily and shortens the day, but in moments the ball hits the ground and comes to rest, and the spin is restored. Putting up a windmill (or tree) is like that: Each might put a force on the ground, but that just takes away the same force that would have had the same friction elsewhere, so the net effect is temporary and negligible.
That's true if you only throw the ball once and then stop throwing, also assuming the ball doesn't reach orbital velocity. 
If you continuously throwing many balls, and the balls just fallen are immediately thrown again by other ball throwers, then you will have a stream layers of balls rotating in one direction, and the earth crust rotating in the opposite direction (relative to without ball throwings).
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 05:22:03
There's no torque to meteors since they fall equally on one side and the other. The fact that they heat up on the way in makes zero difference. That's like solar energy adding heat but not momentum.
Let's have a still water in a pool. A rotating basket ball is dropped and float on it. Water molecules hit the ball equally on one side and the other, but nonetheless the ball's rotation slows down, and finally stop.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 14/10/2020 08:44:01
If the windmills are massive enough to create significant net movement between the atmosphere and earth crust,
What do you mean?

I mean that when the windmills collectively reduce windspeed in one direction while not significantly reduce windspeed in the opposite direction. So if windspeed in all points on earth surface are measured and vectorially summarized, the result is non-zero.
If the wind doesn't push the windmill, the wind pushes the earth.
If the wind does push the windmill, the windmill pushes the earth.

The effects cancel and there's no net effect.

on one side and the other, but nonetheless the ball's rotation slows down, and finally stop.
And the water is set spinning.
Eventually, it pushes on the earth and alters the spin of the earth (very slightly).

But when you set the ball spinning you also pushed on the earth and altered it's spin slightly.

When all these process have finished they cancel out and the earth spins like it did before.

This was all pointed out earlier.
Have you actually read the thread?
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 09:40:32
And the water is set spinning.
Eventually, it pushes on the earth and alters the spin of the earth (very slightly).


Analogously, the gas stripped by solar wind leaving the earth taking away some of the angular momentum.

Quote
But when you set the ball spinning you also pushed on the earth and altered it's spin slightly.

When all these process have finished they cancel out and the earth spins like it did before.
Let's start with the ball not spinning before dropped from a drone above the pool. The drone spin the ball clockwise, consequently the drone spin counterclockwise, hence maintaining zero angular momentum. The ball is then dropped while still spinning clockwise, and the drone keeps spinning counterclockwise until the end of the experiment.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 14/10/2020 11:02:11
The drone spin the ball clockwise,
In doing so the ball spins the drone the other way.
The drone pushes the air.
The air pushes the earth and everything cancels out.
Analogously, the gas stripped by solar wind leaving the earth taking away some of the angular momentum.
It's not an analogy because, in this case, something actually leaves the earth.
Launching the Voyager probe will have made a difference too.
This is one of the real, but tiny, effects.

But nothing that happens entirely "on Earth" can affect the angular momentum of the Earth.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 14/10/2020 12:48:15
, just like a dam generates energy from water going downhill, water that would have gone downhill at the same rate even with the dam not there.
Technically not true, take the hoover, lower transportation of sediment due to the removal of energy from the fast flowing colorado has led to life expectancy of the dam to be only 100 years before it is sedimented to the cusp of the dam wall, same at other dams. The lake upstream, lake Powell will act more as a sediment block rather than a acompanying dam. Also now lower excavation rates and flow in the lower colorado.




I mean that when the windmills collectively reduce windspeed in one direction while not significantly reduce windspeed in the opposite direction. So if windspeed in all points on earth surface are measured and vectorially summarized, the result is non-zero.
All that has happened is windmills are taking the place of  trees,  mountains oceans in the particular direction but the wind in the opposite direction will still hit the above listed features, thus cancelling out. Wind energy makes waves waves make sound and heat, wind bends trees, trees make sound heat etc.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 17:06:29
It's not an analogy because, in this case, something actually leaves the earth.
In my analogy above,  the ball represents the earth,  while the pool water represents solar wind.
The water molecules that once touch the ball will move away from it, taking away some of the momentum.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 17:09:22
All that has happened is windmills are taking the place of  trees,  mountains oceans in the particular direction but the wind in the opposite direction will still hit the above listed features, thus cancelling out. Wind energy makes waves waves make sound and heat, wind bends trees, trees make sound heat etc.
Do you think that if windspeed in all points on earth surface are measured and vectorially summarized, the result is always zero?
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 14/10/2020 17:22:48
It's not an analogy because, in this case, something actually leaves the earth.
In my analogy above,  the ball represents the earth,  while the pool water represents solar wind.
The water molecules that once touch the ball will move away from it, taking away some of the momentum.
Do you know that, by normal standards, the "solar wind" is a very good vacuum?

"Ultra-high vacuum (UHV) is the vacuum regime characterised by pressures lower than about 100 nanopascal (10−7 pascal, 10−9 mbar, ~10−9 torr)"
from
https://en.wikipedia.org/wiki/Ultra-high_vacuum


"The wind exerts a pressure at 1 AU typically in the range of 1–6 nPa ((1–6)×10−9 N/m2), although it can readily vary outside that range."
From
https://en.wikipedia.org/wiki/Solar_wind#Pressure
Any effect is going to be tiny.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 14/10/2020 17:24:08
Do you think that if windspeed in all points on earth surface are measured and vectorially summarized, the result is always zero?
Averaged over any reasonable time frame and measured WRT the Earth, yes.
If it wasn't then the atmosphere would all have left the Earth.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 14/10/2020 20:47:02
All that has happened is windmills are taking the place of  trees,  mountains oceans in the particular direction but the wind in the opposite direction will still hit the above listed features, thus cancelling out. Wind energy makes waves waves make sound and heat, wind bends trees, trees make sound heat etc.
Do you think that if windspeed in all points on earth surface are measured and vectorially summarized, the result is always zero?
No the net wind is in all directions is actually in the direction that the earth rotates but faster. The atmosphere rotates faster than the solid body of the planet. Could not tell you of the core.

As for vectors of wind, the net direction energy of the wind with wind mills is the same as without windmills, just the same as a dam removes energy from water by water exerting force on it rather than the water in the river bed. 

As for gravity, it's all about barycentre, so as the water in whatever moves one way the planet moves the other.
Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 14/10/2020 22:57:20
No the net wind is in all directions is actually in the direction that the earth rotates but faster. The atmosphere rotates faster than the solid body of the planet. Could not tell you of the core.
Do you have the source? Or at least a reasoning for that? Is it because the atmosphere is further than the crust, from the earth center?
Since the crust is continuously slowed down by the tide, the earth core should rotate faster.
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 15/10/2020 03:32:52
I've not had much time to keep up, but some comments:

I mean that when the windmills collectively reduce windspeed in one direction while not significantly reduce windspeed in the opposite direction. So if windspeed in all points on earth surface are measured and vectorially summarized, the result is non-zero.
The sum is rarely zero, yes, and that is the primary factor in small variations from one day to the next, which they do measure.  If you plant trees in areas of prevailing easterly winds and put up car parks in areas of prevailing westerly winds, the spin rate of the planet would be measurably different.  I think that's what you're trying to convey. Trees are no different than windmills. The generation of electricity from it makes no difference.

That's true if you only throw the ball once and then stop throwing, also assuming the ball doesn't reach orbital velocity. 
If you continuously throwing many balls, and the balls just fallen are immediately thrown again by other ball throwers, then you will have a stream layers of balls rotating in one direction, and the earth crust rotating in the opposite direction (relative to without ball throwings).
Remember that a windmill isn't a fan. It doesn't throw balls, it catches them, and that just moves the catching of the ball a short time sooner. The ball is going to stop even if nobody is catching them, even if there is a continuous stream. But the time delay does introduce a temporary momentum to the ball when comparing the two scenarios.

Let's have a still water in a pool. A rotating basket ball is dropped and float on it. Water molecules hit the ball equally on one side and the other, but nonetheless the ball's rotation slows down, and finally stop.
That transfers angular momentum to the water, so a poor analogy for dust in space which does not get angular momentum transferred to it by losing some dust to Earth.  Also, that dust probably already has more angular momentum before than after hitting Earth.  It is spinning the same way for the same reason all the planets orbit in the same direction, and it well might increase the spin.  Still, it constitutes friction of a form, and that is an external force. I cannot assert that it doesn't exert at least some torque.

Do you think that if windspeed in all points on earth surface are measured and vectorially summarized, the result is always zero?
Probably never. Due to variations of levels of friction between here and there, the equilibrium state will average a state of equal force between surface and atmosphere, and that might result in a rotation rate (of both the air at the surface and the entire atmosphere) that is different than the rotation rate of Earth (23:56 hours).

No the net wind is in all directions is actually in the direction that the earth rotates but faster. The atmosphere rotates faster than the solid body of the planet.
Reference please.  It well might, but I've not heard this. It certainly is eastbound where I live, but not everywhere.
Looking at today's map, it's looks pretty dang westbound.
https://earth.nullschool.net/#current/wind/surface/level/orthographic=-23.18,15.62,495/loc=-34.263,51.134
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 15/10/2020 21:43:55
]
Reference please.  It well might, but I've not heard this. It certainly is eastbound where I live, but not everywhere.
Looking at today's map, it's looks pretty dang westbound.
https://earth.nullschool.net/#current/wind/surface/level/orthographic=-23.18,15.62,495/loc=-34.263,51.134
I believe it is East bound, just like the earth, sun rises in the east sets in the west.

www.sciencefocus.com/planet-earth/how-does-the-atmosphere-rotate-with-the-earth
No the net wind is in all directions is actually in the direction that the earth rotates but faster. The atmosphere rotates faster than the solid body of the planet. Could not tell you of the core.
Do you have the source? Or at least a reasoning for that? Is it because the atmosphere is further than the crust, from the earth center?
Since the crust is continuously slowed down by the tide, the earth core should rotate faster.
Super rotation in venus
www.space.com/amp/venus-atmosphere-super-rotation-mystery-solved.html
Title: Re: Can windmills affect Earth's rotation?
Post by: Colin2B on 15/10/2020 23:13:56
No the net wind is in all directions is actually in the direction that the earth rotates but faster. The atmosphere rotates faster than the solid body of the planet.
This is incorrect. I think you are confusing with the Coriolis effect.
The actual wind movement is N-S, S-N, but this gets deflect by the Coriolis effect. So, for Polar areas (latitude 60°-90°) the prevailing winds are Easterlies (from the East), between 30° and 60° they are Westerlies, 0° to 30° N Easterlies.
These are only the prevailing directions, at any time and place the local wind depends on the weather system passing overhead and the local terrain.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 15/10/2020 23:33:33
No the net wind is in all directions is actually in the direction that the earth rotates but faster. The atmosphere rotates faster than the solid body of the planet.
This is incorrect. I think you are confusing with the Coriolis effect.
The actual wind movement is N-S, S-N, but this gets deflect by the Coriolis effect. So, for Polar areas (latitude 60°-90°) the prevailing winds are Easterlies (from the East), between 30° and 60° they are Westerlies, 0° to 30° N Easterlies.
These are only the prevailing directions, at any time and place the local wind depends on the weather system passing overhead and the local terrain.

Yes Colin, that is the meterological. If the earth is rotating and we are discussing the slowing of the rotation, North South does not factor, they are judged to have rotated inline with the planet ?

BUUUUUUUTTTT,  The ns balances out because of pressures that create wind jet streams etc. N S in the northern hemisphere are at a low altitude  level, S N in the northern hemisphere is high altitude, hot If rises and descends as low after super chilling in the upper atmosphere to cryogenic temperatures that descend on the pole, if this where not the case the poles should be quite balmy, as is seen when hot air pushes in to the actic circle.
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 16/10/2020 00:00:35
I believe it is East bound, just like the earth, sun rises in the east sets in the west.

www.sciencefocus.com/planet-earth/how-does-the-atmosphere-rotate-with-the-earth
The entire content of that page (besides ads and links to unrelated pages with probably equally terse content):
Quote from: scienceFocus
Bound to the Earth by gravity, most of the atmosphere spins along with it as a result of friction with the ground and the viscosity or ‘stickiness’ of the different layers of air above it.

Above 200km, however, the incredibly thin atmosphere actually spins faster than the Earth. The cause of this bizarre ‘super-rotation’ effect remains unclear, but has also been detected on Venus.

Not saying it's wrong, but that's just a headline, not an article.

FYI, the link I gave shows current (live) surface air speeds, not momentum of the atmosphere.  So it is what the Earth 'feels', and I would think that would have to have no net speed east or west over time, else momentum would be transferred from one to the other until equilibrium is reached.  By all means, the net speed of the atmosphere doesn't need to be similar to the speed at the surface, but I'd have personally guessed that it would rotate slower, due to the same reasons the mantle rotates slower than the core below it, and for the same reasons.
OK, so my guess might be wrong, but that article didn't even begin to discuss it, only saying the reason is 'unclear'.

Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 16/10/2020 00:12:40
Hi all
Halc just a bit of housekeeping

Quote
   The atmosphere does change momentum due to the weather, and as has been pointed out somewhere, the daily variation (microseconds was it?) of length of day is quite measurable.

The values of change to length of day tend to be in the millisecond range, you could quote them in microseconds but the values are 10^-3 millisec and 10^-6 microsec so quoting microsec a little misleading as to the range of daily change occurring to the rotational kinetic energy and angular momentum to the solid earth.

However given your above statement it seems you may be shifting your opinion slightly ?

Are you now agreeing that the motions of the atmosphere generated by buoyancy/acceleration due to change in density in a gravitational field due to solar energy input to the system generating heat, cause changes to the momentum of the atmosphere

If so you may like to look a little closer at the other link petrochemicals provided;

www.space.com/amp/venus-atmosphere-super-rotation-mystery-solved.html

Quote
The scientists discovered the Venusian atmosphere received angular momentum though thermal tides, which are variations in atmospheric pressure driven by solar heating near the planet's equator.
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 16/10/2020 01:17:11
as to the range of daily change occurring to the rotational kinetic energy and angular momentum to the solid earth.
Just like to point out that Earth isn't solid, and doesn't rotate at one rate. Its kinetic energy isn't a simple function of its moment and spin rate.

Quote
However given your above statement it seems you may be shifting your opinion slightly ?
...
Are you now agreeing that the motions of the atmosphere generated by buoyancy/acceleration due to change in density in a gravitational field due to solar energy input to the system generating heat, cause changes to the momentum of the atmosphere.
What I said is completely in line with my initial reply to this topic. There's nothing in that post that says that the windmill has no immediate effect.

It is all the nonsense about angular momentum of a system changing without external torque that defies physics, as does 'energy to momentum', asserted by both Alan and you in your respective first posts in what is now the split topic.
If you disagree, keep the discussion in the other topic, not this one.
Title: Re: Can windmills affect Earth's rotation?
Post by: Colin2B on 16/10/2020 03:49:04
North South does not factor, they are judged to have rotated inline with the planet ?
They are not really true N/S, Coriolis affects both high and low level air movements.

N S in the northern hemisphere are at a low altitude  level, S N in the northern hemisphere is high altitude, hot If rises and descends as low after super chilling in the upper atmosphere to cryogenic temperatures that descend on the pole
This is too simplistic a model.
There is more than one cell of rising/descending air. For example in the northern hemisphere at around Latitude 30° - the Horse Latitudes - high level air is flowing towards this latitude (from both NE & SW - Coriolis effect) and cold air is descending to flow NE and SW near ground level. At ground level, friction causes the winds to flow more directly high to low pressure rather than along the isobars.
The jet streams are just that, streams. As @Halc says, there is no mass movement of air eastwards.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 16/10/2020 12:46:17
I believe it is East bound, just like the earth, sun rises in the east sets in the west.

www.sciencefocus.com/planet-earth/how-does-the-atmosphere-rotate-with-the-earth
The entire content of that page (besides ads and links to unrelated pages with probably equally terse content):
Quote from: scienceFocus
Bound to the Earth by gravity, most of the atmosphere spins along with it as a result of friction with the ground and the viscosity or ‘stickiness’ of the different layers of air above it.

Above 200km, however, the incredibly thin atmosphere actually spins faster than the Earth. The cause of this bizarre ‘super-rotation’ effect remains unclear, but has also been detected on Venus.

Not saying it's wrong, but that's just a headline, not an article.

FYI, the link I gave shows current (live) surface air speeds, not momentum of the atmosphere.  So it is what the Earth 'feels', and I would think that would have to have no net speed east or west over time, else momentum would be transferred from one to the other until equilibrium is reached.  By all means, the net speed of the atmosphere doesn't need to be similar to the speed at the surface, but I'd have personally guessed that it would rotate slower, due to the same reasons the mantle rotates slower than the core below it, and for the same reasons.
OK, so my guess might be wrong, but that article didn't even begin to discuss it, only saying the reason is 'unclear'.


Have I gone mad? You asked for evidence of earth's rotation of atmosphere being faster than the crust, you have it.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 16/10/2020 13:02:45
Have I gone mad?
I'm not qualified to answer that.
ou asked for evidence of earth's rotation of atmosphere being faster than the crust, you have it.
No
That's some evidence that a tiny fraction of the Earth's atmosphere spins faster than the Earth.
On the other hand, we know that, in the log run, the Earth's rotation is synchronised to the atmosphere as a whole, because, if it wasn't there would be a net torque which would accelerate the air until it caught up with the Earth or until the earth caught up with it.

The alternative is that there's some net torque from space acting to accelerate the spin of the Earth in which case...
It's not windmills, and it should be in the other thread. (where I will ask for the millionth time where the torque comes from and the people who don't do science won't be able to answer)
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 16/10/2020 13:08:49
North South does not factor, they are judged to have rotated inline with the planet ?
They are not really true N/S, Coriolis affects both high and low level air movements.

N S in the northern hemisphere are at a low altitude  level, S N in the northern hemisphere is high altitude, hot If rises and descends as low after super chilling in the upper atmosphere to cryogenic temperatures that descend on the pole
This is too simplistic a model.

Yes simplistic and true, easy to understand indesputable and insurmountable. The fact is that hot air does rise.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 16/10/2020 13:28:53
The fact is that hot air does rise.
What happens next?
Title: Re: Can windmills affect Earth's rotation?
Post by: Colin2B on 16/10/2020 15:48:42
N S in the northern hemisphere are at a low altitude  level, S N in the northern hemisphere is high altitude, hot If rises and descends as low after super chilling in the upper atmosphere to cryogenic temperatures that descend on the pole
Quote
This is too simplistic a model.
Yes simplistic and true, easy to understand indesputable and insurmountable. The fact is that hot air does rise.
No, simplistic and false, disputable, surmountable. Above all, wrong as it assumes a non rotating earth.

The fact is that hot air does rise.
So what? That neither makes a nett movement relative to earth surface (see @Halc quote), nor does it create a change of angular momentum.
As @Bored chemist  says, what happens next?
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 16/10/2020 19:14:27
N S in the northern hemisphere are at a low altitude  level, S N in the northern hemisphere is high altitude, hot If rises and descends as low after super chilling in the upper atmosphere to cryogenic temperatures that descend on the pole
Quote
This is too simplistic a model.
Yes simplistic and true, easy to understand indesputable and insurmountable. The fact is that hot air does rise.
No, simplistic and false, disputable, surmountable. Above all, wrong as it assumes a non rotating earth.

The fact is that hot air does rise.
So what? That neither makes a nett movement relative to earth surface (see @Halc quote), nor does it create a change of angular momentum.
As @Bored chemist  says, what happens next?

ThTs a contradiction in 2 statements. I've give you links of atmospheric rotation on earth and venus, yet all I'm getting in return is nonsensical statements.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 16/10/2020 19:18:40
I've give you links of atmospheric rotation on earth and venus,
No you have not.
hat's some evidence that a tiny fraction of the Earth's atmosphere spins faster than the Earth.
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 17/10/2020 00:57:05
Hi all
So petrochemicals, No your not going mad
you provided the information requested, only problem is it disagrees with a few of the previous posts;

like this from BC
Quote
Averaged over any reasonable time frame and measured WRT the Earth, yes.
If it wasn't then the atmosphere would all have left the Earth.

So petrochemicals has shown evidence of a layer of earth and venus atmosphere that maintains a phenomenon of atmospheric super-rotation  How is it the atmosphere has not departed ?

Also Halc you specifically requested this information from petrochemicals so it may be pertinent you address the diagram explanation, as to how this angular momentum is generated in the link that was provided, because Colin and BC seem to be struggling to understand it.

Quote
"The fact is that hot air does rise."

So what? That neither makes a nett movement relative to earth surface (see @Halc quote), nor does it create a change of angular momentum.
As @Bored chemist  says, what happens next?

I think that was already answered
http://www.space.com/amp/venus-atmosphere-super-rotation-mystery-solved.html


Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 17/10/2020 01:18:02

I think that was already answered
As has so often been the case, you are wrong.

What happens after the hot air rises is that it cools and falls.
Did you not know that?

Do you know that the comparable effect on Earth exists above 200Km
Do you know that the conventional  definition of the start of  "space" is 100 Km?
So, what you are talking about is, at best, a tiny effect- so small that it's fair to say it's not even part of the atmosphere.
So petrochemicals has shown evidence of a layer of earth and venus atmosphere that maintains a phenomenon of atmospheric super-rotation  How is it the atmosphere has not departed ?
You forgot to read what I said.
You quoted it
"Averaged over any reasonable time frame"
But you forgot to understand it.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 17/10/2020 02:48:12
Hi all
So petrochemicals, No your not going mad
you provided the information requested, only problem is it disagrees with a few of the previous posts;

like this from BC
Quote
Averaged over any reasonable time frame and measured WRT the Earth, yes.
If it wasn't then the atmosphere would all have left the Earth.

So petrochemicals has shown evidence of a layer of earth and venus atmosphere that maintains a phenomenon of atmospheric super-rotation  How is it the atmosphere has not departed ?

Also Halc you specifically requested this information from petrochemicals so it may be pertinent you address the diagram explanation, as to how this angular momentum is generated in the link that was provided, because Colin and BC seem to be struggling to understand it.

Quote
"The fact is that hot air does rise."

So what? That neither makes a nett movement relative to earth surface (see @Halc quote), nor does it create a change of angular momentum.
As @Bored chemist  says, what happens next?

I think that was already answered
http://www.space.com/amp/venus-atmosphere-super-rotation-mystery-solved.html


Thank goodness for that. Perhaps a better way of understanding it would be ,"why is the crust not keeping up with the core and atmosphere" to which I would suggest it's because of heat making wind that causes friction on the crust, which after all is on a liquid  core, if you blow on a boat it does tend to drift, but it's only a hypothesis. Perhaps we should start a thread on weather the whether can affect the rotation of the earth ??? The drift is something to be reckoned with.
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 18/10/2020 00:42:13
HI all
so BC to this;

Quote
"The fact is that hot air does rise."

So what? That neither makes a nett movement relative to earth surface (see @Halc quote), nor does it create a change of angular momentum.
As @Bored chemist  says, what happens next?

I think that was already answered
http://www.space.com/amp/venus-atmosphere-super-rotation-mystery-solved.html


BC States;
Quote
As has so often been the case, you are wrong.

So as to hot air rising and "what happens next" is postulated in the link, so not me your disagreeing with I"m afraid, I would suggest you study it and review where it contradicts a lot of what you have posted on this thread. (including the posts moved to new theories )

BC You also state:
Quote
What happens after the hot air rises is that it cools and falls.
Did you not know that?

So this maybe is where your struggling to grasp the reality of the position of your argument, this occurs because the atmosphere of the earth and similarly the atmosphere of venus are not in inertial reference frames.

Which means the conditions of the laws of conservation of momentum are not met, you previously dismissed this fact as lies we tell children,

So to help you, consider what would be the physical reality of one of these tealight mobiles lit in an inertial reference frame like the international space station ?
 



Title: Re: Can windmills affect Earth's rotation?
Post by: Colin2B on 18/10/2020 10:32:58
So petrochemicals has shown evidence of a layer of earth and venus atmosphere that maintains a phenomenon of atmospheric super-rotation ..........
........ how this angular momentum is generated in the link that was provided, because Colin and BC seem to be struggling to understand it.
No we are not struggling to understand either of these phenomena nor how they are generated, what we are struggling to understand is this:
....Perhaps a better way of understanding it would be ,"why is the crust not keeping up with the core and atmosphere"
Our contention is that the Earth’s crust is keeping up with the atmosphere, the atmosphere is not getting ahead.

If @Petrochemicals had said “a thin layer of rarified gas, some 100km above the atmosphere, is rotating ahead of the surface”
Or if he had said “venus atmosphere maintains a phenomenon of atmospheric super-rotation”
Then we would have agreed with both of those.
However, neither of these indicate that on Earth “the crust is not keeping up with the atmosphere”.
Evidence please, as @Halc has already requested.

Petro is trying to directly relate what happens on Venus to what happens on Earth and as I have tried to explain, and what you are both struggling to understand, is that the 2 are very different.

Venus has a single circulation cell (Hadley cell) in each hemisphere and Petro is trying to suggest this is what happens on Earth. It does not.
Venus, to quote the article “Compared to Earth, Venus twirls at a leisurely pace on its axis, with its surface taking 243 Earth days to complete one rotation.”. The significance of this is that on Venus there is negligible Coriolis effect, whereas on Earth this is significant and results in the circulation being broken into 3 separate cells which prevents the super rotation effect seen on Venus and along with geography results in much more chaotic winds than seen on the more stable Venus. The model Petro is quoting relates to a nonrotating Earth, so is not relevant to explaining Earth’s atmosphere.

Petro also quotes this thin band of rotation at 200km. In explanation he states that “N S in the northern hemisphere are at a low altitude  level, S N in the northern hemisphere is high altitude, hot If rises and descends as low after super chilling in the upper atmosphere to cryogenic temperatures that descend on the pole”
Leaving aside the ‘cryogenic temperatures’, this relies on the lapse rate. This is the reduction of temperature with height and generally follows the pattern of a temperature fall of 6.49°C/km from sea level to 11 km. From 11 km up to 20 km the constant temperature is −56.5 °C. The 11km is significant as being the top of the troposphere, where the majority of our weather is formed and which contains the majority of atmospheric mass.
At about 85km the lapse rate reverses dramatically with temperature increasing rapidly with height, so by 200km the mechanism postulated by Petro is not viable.

Just so we are very, very clear. I am not questioning what happens on Venus, nor at 200km on Earth, I am questioning the effect on Earth as explained by petro.

How is it the atmosphere has not departed ?
It’s called gravity. Some of the extremely light gasses do escape, but many are retained even at this high altitude.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 18/10/2020 10:49:26
what would be the physical reality of one of these tealight mobiles lit in an inertial reference frame like the international space station ?
The flame would be blue.

Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 19/10/2020 01:10:48
Hi all,
Colin thanks for your detailed response. just a couple of points in regards to the value of comparisons of earth and venus, my input on that would be, yes take onboard your comments and my only response in that regard is I"m tending to focus on the laws of physics, and what the different conditions may highlight.
Also in regards to this statement by BC

Quote
Averaged over any reasonable time frame and measured WRT the Earth, yes.
If it wasn't then the atmosphere would all have left the Earth.

And my subsequent response when highlighting the super-rotation in the link provided by petro earlier
Quote
  How is it the atmosphere has not departed ?

was a little tongue in cheek comment as to value of that prediction also

Now BC you ask in regards to the tea light mobile analogy ;
Quote
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?

I am responding as if that's not a loaded question,  :)
 
I gave the ISS as a reference to the conditions it can portray in experiments for the requirements set out in the conservation of momentum.

below is a direct quotes from the links;

https://en.wikipedia.org/wiki/Momentum   

"but in any inertial frame it is a conserved quantity"

https://en.wikipedia.org/wiki/Buoyancy
"This can occur only in a non-inertial reference frame, which either has a gravitational field or is accelerating due to a force other than gravity defining a "downward" direction"

Title: Re: Can windmills affect Earth's rotation?
Post by: hamdani yusuf on 19/10/2020 04:04:42
I gave the ISS as a reference to the conditions it can portray in experiments for the requirements set out in the conservation of momentum.
ISS is not an inertial frame of reference. It rotates once every 90 minutes. So it's possible to throw a ball from a point on a side wall of an ISS room through the center of the room and then end up at the same point where it was started. It would take 45 minutes. This sequence of events is not possible in an inertial frame of reference.
https://www.quora.com/Does-the-orientation-of-the-ISS-change-with-respect-to-the-Earth
Quote
Robert Frost, works at NASA
Answered October 2, 2017
Nominally, the ISS flies in an LVLH (Local Vertical Local Horizontal) attitude. That means that the vehicle pitches at four-degrees-per-minute in order to keep its belly pointed towards the Earth. So, nominally, the orientation of the ISS appears rather consistent with respect to the Earth.

This is desired because the vehicle was designed to be in an attitude in which the comm antennae pointed up at the TDRSS, the GPS antennae point up at the GPS satellites, the thickest shielding is in the direction of greatest debris damage risk, the windows point towards Earth for Earth observation science, and other external payloads can point at their desired topic, consistently.

However, we fly at a slight bias from LVLH 0,0,0 in order to be at an attitude in which the external gravity torques and external drag torques cancel each other out over a ninety-minute orbit. This is called a TEA (Torque Equilibrium Attitude). These TEAs change over time and with changes in vehicle center of mass and cross-sectional area.

We also alter the attitude of the ISS to support docking and undockings, captures and releases, and reboosts.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 19/10/2020 08:38:37
I am responding as if that's not a loaded question, 
Could you try answering it as if it is a physics question?
The answer is yes or no.
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 20/10/2020 00:59:32
Ok Colin go and argue the toss here,
they are amatuer metreologists.

https://www.theweatherclub.org.uk/sites/default/files/circulation%20-%20no%20coriolis.png(https://www.theweatherclub.org.uk/sites/default/files/circulation%20-%20no%20coriolis.png)

From

https://www.theweatherclub.org.uk/index.php/node/373
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 20/10/2020 01:13:54
Ok Colin go and argue the toss here,
they are amatuer metreologists.
This 'amatuer metreologist' can immediately see that the picture you've chosen to post seems to assume a non-rotating planet heated equally on all sides by a ring of orbiting suns.
Interesting that the image is named "coriolis.png" when it shows no Coriolis effect.

The site does indeed tag this picture with the words "If we were on a planet which didn’t rotate".  So the site is not wrong in posting such a simplified dynamic. My question is why you chose to post that image instead of the one below it that shows a more accurate depiction of the average movements.
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 20/10/2020 02:03:31
Hi all,
So hamdani yusuf,
 
yes take your point, however in regards to the conditions of the laboratory that is the ISS, it allows the possibilities to demonstrate certain conditions which we could only imagine previously,

For example the fact of buoyancy and therefore natural convection  ceases to occur on ISS

https://en.wikipedia.org/wiki/Buoyancy
"This can occur only in a non-inertial reference frame, which either has a gravitational field or is accelerating due to a force other than gravity defining a "downward" direction"

https://en.wikipedia.org/wiki/Natural_convection
below is an extract from the above link;

Quote
The driving force for natural convection is gravity. For example if there is a layer of cold dense air on top of hotter less dense air, gravity pulls more strongly on the denser layer on top, so it falls while the hotter less dense air rises to take its place. This creates circulating flow: convection. As it relies on gravity, there is no convection in free-fall (inertial) environments, such as that of the orbiting International Space Station

which I believe the above should make clear as to the conditions this highlights as to when considering the merits of applying the laws of conservation of momentum to the earth's atmosphere.

As what is asserted by BC stating atmospheres momentum is conserved and then here stating;


Quote
What happens after the hot air rises is that it cools and falls.
which seems to be contrary to;

Quote
https://en.wikipedia.org/wiki/Momentum   

"but in any inertial frame it is a conserved quantity"

So how's the tea light mobiles doing, would they make a good present for the occupants of the ISS ?

Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 20/10/2020 08:39:43
I am responding as if that's not a loaded question,
Could you try answering it as if it is a physics question?
The answer is yes or no.
Title: Re: Can windmills affect Earth's rotation?
Post by: Colin2B on 20/10/2020 09:27:30
Ok Colin go and argue the toss here,
they are amatuer metreologists.
I don’t need to because as @Halc points out there is no toss to argue; they clearly understand the differences I was describing.
By the way, some of them are professionals  ;)

Colin thanks for your detailed response. just a couple of points in regards to the value of comparisons of earth and venus, my input on that would be, yes take onboard your comments and my only response in that regard is I"m tending to focus on the laws of physics, and what the different conditions may highlight.
That is precisely what I was doing.
The physics is in the detail and you have to look at these as systems; what the different conditions are, the different inputs and starting conditions etc. If you don’t consider these as a whole system your ‘laws of physics’ will give you the wrong output ie conclusions.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 20/10/2020 12:35:24
I"m tending to focus on the laws of physics,
Good.
The laws of physics answer the original question very simply and very clearly.
"Can windmills affect Earth's rotation?"
No more so than a tree.

So, since the laws of physics- on which you are concentrating, have answered the question you can stop posting about it but, in teh mean time...

Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 20/10/2020 21:17:24
Hi all,
So Colin regarding the laws of physics, I take it you agree the laws of physics apply on earth the same as venus ?

Now In the link provided by petro;
http://www.space.com/amp/venus-atmosphere-super-rotation-mystery-solved.html

It states;

Quote
The scientists discovered the Venusian atmosphere received angular momentum though thermal tides, which are variations in atmospheric pressure driven by solar heating near the planet's equator. They also found planetary-scale waves in the atmosphere as well as large-scale atmospheric turbulence worked against this effect from thermal tides


And this from the abstract;

https://science.sciencemag.org/content/368/6489/405

Quote
The solid surface of Venus rotates very slowly, once every 243 days, but its thick atmosphere circles the planet in just 4 days. This phenomenon, known as super-rotation, requires a continuous input of angular momentum, from an unknown source, to overcome friction with the surface. Horinouchi et al. mapped the planet's winds using ultraviolet observations of Venus' clouds from the orbiting Akatsuki spacecraft (see the Perspective by Lebonnois). They incorporated these data into a global model of angular momentum transport in the atmosphere, finding that the super-rotation is maintained through thermal tides driven by solar heating


Now given the numerous posts on this thread including the ones prior to the split to new theories
https://www.thenakedscientists.com/forum/index.php?topic=80717.0

How does this papers findings fit with the numerous posts from Colin Halc and BC as to the requirement of an external torque force and the man on the back of the truck analogy ?.

I would invite anyone to revisit these or read for the first time if new to this discussion.

Do you think the lead author Takeshi Horinouchi has met with similar derogatory comments and has covered that, with what looks like British understatement;

"There was a suggestion that thermal tides might be contributing to the acceleration behind super-rotation, but I think the mainstream assumption was different, so this was a surprise," Horinouchi said.[/quote]

it would appear the findings are more in agreement with this post I made earlier.


Quote
However it is possible to increase/change momentum of the atmosphere due to the conditions/dynamics occurring ie solar input to a fluid changing density in a gravity field creating buoyancy force and subsequent acceleration. 


Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 20/10/2020 21:39:41
You do know that UV light won't actually penetrate the clouds on Venus to any great extent, don't you?
So this bit
mapped the planet's winds using ultraviolet observations of Venus' clouds
Only really supports The same thing that we know about the Earth. As that web page says
"Above 200km, however, the incredibly thin atmosphere actually spins faster than the Earth. "

Now, when you remember that "space" by convention starts at 100 km, it's fair to say that, at best a vanishingly small part of the atmosphere rotates faster than the Earth, isn't it?





How does this papers findings fit with the numerous posts from Colin Halc and BC as to the requirement of an external torque force and the man on the back of the truck analogy ?.
It fits just fine.
If you gave the man a long stick so he could brace against the Moon, then he could push the truck.
Nobody has ever said that tides don't have an effect.
And that's what the paper refers to "The scientists discovered the Venusian atmosphere received angular momentum though thermal tides"

Now, perhaps you could stop posting bull an answer this

Quote from: Bored chemist on 18/10/2020 10:49:26
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?
Title: Re: Can windmills affect Earth's rotation?
Post by: Petrochemicals on 20/10/2020 23:00:17
Ok Colin go and argue the toss here,
they are amatuer metreologists.
This 'amatuer metreologist' can immediately see that the picture you've chosen to post seems to assume a non-rotating planet heated equally on all sides by a ring of orbiting suns.
Interesting that the image is named "coriolis.png" when it shows no Coriolis effect.

The site does indeed tag this picture with the words "If we were on a planet which didn’t rotate".  So the site is not wrong in posting such a simplified dynamic. My question is why you chose to post that image instead of the one below it that shows a more accurate depiction of the average movements.
Ok Colin go and argue the toss here,
they are amatuer metreologists.
I don’t need to because as @Halc points out there is no toss to argue; they clearly understand the differences I was describing.
By the way, some of them are professionals  ;)
So hot air does not rise from the equator and cir ulate to the poles? Very very simplistic I know, but it's what happens. The different weather bands are just weather bands, dry air from the poles, moist air from the tropics.This is an intricacy of the circulation, just like the hypothesised butterfly effect.

Are you suggesting that the polar air remains in situe and the equator likewise with no effect between?
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 20/10/2020 23:17:51
So hot air does not rise from the equator and cir ulate to the poles?
No, it doesn't.
https://en.wikipedia.org/wiki/Atmospheric_circulation

Did you really not understand that, or are you trolling?
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 21/10/2020 00:10:56
HI all;
So  to this "How does this papers findings fit with the numerous posts from Colin Halc and BC as to the requirement of an external torque force and the man on the back of the truck analogy ?".

BC states;
Quote
  It fits just fine.
If you gave the man a long stick so he could brace against the Moon, then he could push the truck.
Nobody has ever said that tides don't have an effect.
And that's what the paper refers to "The scientists discovered the Venusian atmosphere received angular momentum though thermal tides"

So you really need to consider what has been highlighted by that paper, you obviously haven't read it or don't understand the implications.

what moon of venus is the stick pushing against exactly ?  ha ha ha you are funny
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 21/10/2020 02:58:14
HI all;
So  to this "How does this papers findings fit with the numerous posts from Colin Halc and BC as to the requirement of an external torque force and the man on the back of the truck analogy ?".
The motion of the atmosphere of Venus is in equilibrium, not accelerating in its angular momentum, so it has no need of eternal torque in the form of a long stick pushing on its nonexistent moon.
Yes, the gravitational tides do exert a torque on Venus, as they do on all planets, including Pluto, which is the only 'planet' to become tide locked with something.  OK, Mercury as well, but in a weird way that doesn't keep one face point at something.

The air currents in this narrow band at the equator are driven mostly by thermal tides, which are also significant air movers on Earth and Mars, accounting for a larger tidal bulge than the gravitational tides, despite the fact that thermal tides effectively do not exert any external torque. The torque from the tides is all internal, and thus is balanced by equal and opposite torques (friction, turbulence, etc) to the point where there is no net torque by the atmosphere on the planet below it.

So you really need to consider what has been highlighted by that paper, you obviously haven't read it or don't understand the implications.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 21/10/2020 08:36:57
what moon of venus is the stick pushing against exactly ?  ha ha ha you are funny
The thing that is in orbit around venus is the Sun (well, they are both in orbit round their centre of mass, but it's the same thing in the end- there's something to push against.

Why is that funny?

It's as if you didn't realise that the man on the truck is not on Venus, but surely you wouldn't be that silly?

This is funny.
There are two types of people; one group can extrapolate from the available information.


So you really need to consider what has been highlighted by that paper, you obviously haven't read it or don't understand the implications.
I considered the relevant implications.
If that paper implied that the conservation laws were broken then either it would be wrong, or it would line the authors up for a Nobel prize.

It seems much more likely that you have misunderstood it, and it does not suggest that the conservation laws have been broken.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 21/10/2020 08:37:38
Now, perhaps you could stop posting bull an answer this

Quote from: Bored chemist on Yesterday at 12:35:24
Quote from: Bored chemist on 18/10/2020 10:49:26
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 22/10/2020 00:48:53
Hi all

So BC to this
"How does this papers findings fit with the numerous posts from Colin Halc and BC as to the requirement of an external torque force and the man on the back of the truck analogy ?."

you state;
Quote
It fits just fine.
If you gave the man a long stick so he could brace against the Moon, then he could push the truck.
Nobody has ever said that tides don't have an effect.
And that's what the paper refers to "The scientists discovered the Venusian atmosphere received angular momentum though thermal tides"

So when it's pointed out to you there is no moon you change your position to:

Quote
The thing that is in orbit around venus is the Sun (well, they are both in orbit round their centre of mass, but it's the same thing in the end- there's something to push against.

Now what exactly has that statement got to do with thermal tides ?

which from my understanding are caused by a variation in atmospheric pressure and therefore density due to the differential heating of the atmosphere by the sun, so called in analogy to the conventional gravitational tide.

So In keeping with my previous  statement;

Quote
However it is possible to increase/change momentum of the atmosphere due to the conditions/dynamics occurring ie solar input to a fluid changing density in a gravity field creating buoyancy force and subsequent acceleration.

Which has been disputed previously.

So Halc I ask again how does this papers findings, of continually generating fresh angular momentum to an atmosphere  by input of solar radiation possibly fit with your previous statements.

Maybe some of that angular momentum to sound momentum transferred by frictional coupling you didn't account for earlier will be included in your explanation.



Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 22/10/2020 01:31:23
[thermal tides] which from my understanding are caused by a variation in atmospheric pressure and therefore density due to the differential heating of the atmosphere by the sun, so called in analogy to the conventional gravitational tide.
Thermal and gravitational tides are not analogous since only the latter exerts an external torque on the system, and thus can change the system momentum.

Quote
However it is possible to increase/change momentum of the atmosphere due to the conditions/dynamics occurring ie solar input to a fluid changing density in a gravity field creating buoyancy force and subsequent acceleration.
OK, but then you're not considering a closed system. There is external force/torque in the system you're describing in this statement. It doesn't come from solar input, which is only contributing energy, not force.
We (the rest of us) are talking about the entire atmosphere, not a piece of it, in which case your statement does not hold up. The Venus atmosphere has essentially the same momentum from day to day. No increase as you're claiming.

Quote
So Halc I ask again how does this papers findings, of continually generating fresh angular momentum to an atmosphere  by input of solar radiation ...
I don't recall any such 'findings' in the paper. Nowhere does it say that the momentum changes. It is in equilibrium, with minor fluctuations (small momentum exchanges with the ground) over time just like on any rocky planet (less fluctuation with the gas giants) that averages to zero change over time. Yes, there's heat from the sun, and that creates wind (ooh, they discovered wind on Venus, surprise!), and wind is air moving, but that cannot change the momentum of the system since there is no eternal torque exerted at any point.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 22/10/2020 08:48:15
So when it's pointed out to you there is no moon you change your position to:
That's not a change in position.
I said you need something to push against.
To be fair, I'm not the first person to say this. It's generally attributed to Newton.
Are you saying it is wrong?
If so; good luck.

Either they are really tides and are a result of gravity (OK, it's a pull rather than a push).
Or they are not, in which case they must be due to the (damned near vacuum) "air" at the top of the atmosphere pushing against the layers lower down.

And if it's the latter case, on average they must push each other equally hard, and the two pushes must cancel out.
You are correct in saying that I didn't look into it very carefully.
That's because I didn't need to- not since Newton's day.


Now, perhaps you could stop posting bull an answer this

Quote from: Bored chemist on Yesterday at 12:35:24
Quote from: Bored chemist on 18/10/2020 10:49:26
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?

Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 22/10/2020 10:21:24
Hi all

So Halc in regards to Venus atmosphere having approx the same angular momentum is true however it is not a closed/isolated system,
Also the paper does state that thermal tides are generating angular momentum, not transferring it from say the momentum of the solid planet.

If you factor in atmospheres are uncoupled from the Solid planet and generates this net motion within the atmosphere ( action reaction pairing within the atmosphere by displacement)

Therefore angular momentum created,
Which brings angular momentum transfers to other forms of momentum such as sound waves and thermal motion in inelastic collisions.

Therefore this in effect is a continuing flux of the amount of momentum of a System. ( and factors in momentum such as the transfers like sound)

Consider does earth’s atmosphere transfer more momentum back out to space than it directly receives from the sun ?

It can do this because it’s not a closed system!
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 22/10/2020 12:16:18
the paper does state that thermal tides are generating angular momentum
Then it is wrong.
You can't.
It's a conserved quantity.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 22/10/2020 12:16:39

Quote from: Bored chemist on Yesterday at 08:37:38
Quote from: Bored chemist on 20/10/2020 21:39:41
Now, perhaps you could stop posting bull an answer this

Quote from: Bored chemist on Yesterday at 12:35:24
Quote from: Bored chemist on 18/10/2020 10:49:26
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 23/10/2020 17:48:25
So Halc in regards to Venus atmosphere having approx the same angular momentum is true however it is not a closed/isolated system
It is until you've identified an eternal torque being applied to it. None are mentioned in the article, so if we're going by that, it is a closed system.

Quote
Also the paper does state that thermal tides are generating angular momentum, not transferring it from say the momentum of the solid planet.
That is an internal torque from the atmosphere, not an external one, so there's no external momentum transfer identified. I also notice you choose to ignore the equal and opposite momentum transfer applied by the same atmosphere that cancel it out, all identified in the same paragraph.

Quote
Therefore angular momentum created
This qualifies your post to be in the new theories section. Please desist in posting your own ideas born of ignorance in the actual science sections of the forum.

Quote
Which brings angular momentum transfers to other forms of momentum such as sound waves and thermal motion in inelastic collisions.
None of this belongs in this section either. Post these irrelevant assertions in a new topic in New Theories.

Quote
Consider does earth’s atmosphere transfer more momentum back out to space than it directly receives from the sun ?
Momentum cannot be transferred to or from space.

It can do this because it’s not a closed system!
[/quote]
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 23/10/2020 23:08:51
This qualifies your post to be in the new theories section.

Not while we have a "That CAN'T be true!" section.

Would one of the Mods please oblige...
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 24/10/2020 02:14:55
Hi all,

So where do I begin after that kicking, maybe BC first.

Quote
Not while we have a "That CAN'T be true!" section.

Would one of the Mods please oblige

Then maybe Halc


Quote
Momentum cannot be transferred to or from space.

So I think Halcs statement should be put straight in to that section.

Now given you didn't know sound waves carried/transfer momentum may be forgiven but there are some pretty famous equations for electromagnetic radiation.

So as stated previously energy is the currency of the physical world hence ;
 
There is a relationship between photon momentum p and photon energy E that is given by total energy of a particle as E^2 = (pc)^2 + (mc)^2. We know m is zero for a photon, but p is not, so that E^2 = (pc)^2 + (mc)^2 becomes E = p/c, or rearranged gives

       p =E/c        and is equivalent to Compton’s result         p=h/λ.


So light matter interaction
https://en.wikipedia.org/wiki/Compton_scattering

and the continuous reverse effect of Thermal radiation being electromagnetic radiation generated by the thermal motion of particles in matter.

https://en.wikipedia.org/wiki/Thermal_radiation


I'm afraid this is not a new theory and is/should be included in any calculations of conservation,  I can knock out a few approx numbers earth and its atmosphere if it helps put some values to it, seeing how its so new and all

There are no values for the total momentum of sound waves per sec on earth, that you seem to be ignoring, but there is pretty good data for the energy of light waves.

Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 24/10/2020 14:11:16
I see  that you didn't mention the obvious one
https://en.wikipedia.org/wiki/Radiation_pressure
but I guess that's because you don't really know what you are talking about.
Your problem is that Halc's still correct.

At best he's guilty of sloppy language. He said "Momentum cannot be transferred to or from space."
rather than "Momentum cannot be transferred to or from space unless some bunch of aliens are pointing a light source specifically at one side of the planet."

The Sun, for example, shines pretty much evenly across the face of the Earth.
So it produces no torque.
And all the other radiation sources are the same (as well as being too far away to matter).

So, are you blaming little green men (and a beam that we somehow don't notice...)
or do you accept that he's practically speaking correct?
Given what reaches us from space,
Momentum cannot be transferred to or from space.





Quote from: Bored chemist on Yesterday at 08:37:38
Quote from: Bored chemist on 20/10/2020 21:39:41
Now, perhaps you could stop posting bull an answer this

Quote from: Bored chemist on Yesterday at 12:35:24
Quote from: Bored chemist on 18/10/2020 10:49:26
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?

Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 24/10/2020 14:15:59
There are no values for the total momentum of sound waves per sec on earth,
Yes there is- since we are talking about effects that come in from outside the Earth.
We have a pretty much exact value for the momentum carried to us via sound.
It's zero.
It's exactly zero- because sound does not carry through space.

Interesting to see you bang on about something irrelevant. Are you trying to distract attention from the fact that you don't have a valid argument?
Well, it's not working.
In space, nobody can hear you scream.





but there is pretty good data for the energy of light waves.
There's even evidence for the momentum they carry.
But they are not (on average) carrying angular momentum.
So they don't change the spin of the Earth.

It's as if you still have not got to grips with the fact that momentum and energy are different.
You can't convert one into the other.
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 25/10/2020 01:15:50
HI all
So I believe a little reminder is required for clarity for the reader as to the reference to sound waves generated by frictional coupling of earth's atmosphere in the part of this thread before it was split, and the relevance to my referring to it in my the last post, and to address the misleading aspect of anyone suggesting sound waves traveling through space

Below is the posts of earlier in this discussion

https://www.thenakedscientists.com/forum/index.php?topic=80717.300

Quote


So what Halc stated is clearly wrong as he believes sound waves don't  transfer momentum, and what BC states is disingenuous and incorrect given the dynamics under discussion are the frictional coupling of the atmosphere and the surface of the earth which are not perfectly elastic coupling therefore sound waves do exist and are transferring momentum out symmetrically, which as stated previously under the laws of conservation, a percentage of said momentum came from the angular momentum of the solid earth/atmosphere total.

So as I stated before, for you position to be credible you need to address this continuous transfer away from the angular momentum budget.

So Bc nobody is suggesting sound is traveling through space.

What is the focus is the momentum carried away from the frictional coupling of earth's surface with the atmosphere, and needs an explanation given sound waves can generate heat. In fact, sound waves almost always generate a little bit of heat as they travel and almost always end up as heat when they are absorbed.
 
which gives 
Frictional coupling is known to alter the rotational velocity of earth.
 
Sound carries momentum away from said frictional collisions.

which by  turn  converts to thermal motion.
   
Then leads to a continuous effect of Thermal radiation (being electromagnetic radiation generated by the thermal motion of particles in matter) allowed to transfer some of this momentum out to space.

https://en.wikipedia.org/wiki/Thermal_radiation
Title: Re: Can windmills affect Earth's rotation?
Post by: Halc on 25/10/2020 01:17:55
I
Your problem is that Halc's still correct.

At best he's guilty of sloppy language. He said "Momentum cannot be transferred to or from space."
rather than "Momentum cannot be transferred to or from space unless some bunch of aliens are pointing a light source specifically at one side of the planet."
That's not momentum being transferred to or from space. It is coming from photons in this case, which, if external to the system, constitutes external force.  Similarly a meteor coming in is momentum being applied by the meteor, not from space, despite the fact that the meteor happens to occupy space.

I stand by my original statement.

Yes, gem has identified a conceivable source of torque if you work out the effect to something like 40 digits. Somehow I don't think the super-rotation of a segment (around 1/1000th) of the atmosphere of Venus is caused by the net angular momentum of random incoming photons.

Quote
Momentum cannot be transferred to or from space.
Indeed.  If it can, then one could answer a question like what's the momentum of the 1000 km diameter sphere of space 1-light hour directly north of Earth?  Not the momentum of the contents of that volume, but the momentum of the space itself.

gem's post about momentum being converted to heat is straight up nonsense. He again confuses energy with momentum.
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 25/10/2020 10:49:14
So Bc nobody is suggesting sound is traveling through space.
Then nobody is talking about it affecting the spin of the Earth
What is the focus is the momentum carried away
Momentum is a conserved quantity.
You can not "carry it away" unless there is somewhere to carry it to.
And  there's no plausible way to carry it away from the Earth.
So the rotation of the Earth stays constant.

Why are you trying to argue about this?
Sound carries momentum away from said frictional collisions.
In which direction, and where to?
On average the  sound spreads out symmetrically- so there is no net change in momentum.
There is nowhere for it to spread to except the Earth which is where it came from.

If you really want to look ai impractically tiny effects, they do exist.
But none of them involves turning heat into momentum- because that's impossible.
https://en.wikipedia.org/wiki/Yarkovsky_effect
https://en.wikipedia.org/wiki/Yarkovsky%E2%80%93O%27Keefe%E2%80%93Radzievskii%E2%80%93Paddack_effect
https://en.wikipedia.org/wiki/Poynting%E2%80%93Robertson_effect

Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 26/10/2020 00:06:25
Hi all,

So BC thank you for the links for radiation pressure, just to confirm I am not suggesting this is a source of torque.

I am questioning the validity of the atmosphere's/earths suitability to conserve momentum.

Therefore to that end  I am labouring the point of momentum carried by sound waves due to frictional coupling and you quite rightly state;
Quote
On average the  sound spreads out symmetrically

So I would ask firstly, where did the momentum that is known to be carried/transferred by sound waves transfer from, because of the frictional coupling between surface and atmosphere ?

(Momentum of sound = energy/phase velocity)

secondly, given that sound waves ultimately converts to heat (thermal motion of matter)
https://en.wikipedia.org/wiki/Thermal_radiation   "part in brackets below direct quote from link provided"

and it is known Thermal radiation (being electromagnetic radiation generated by the thermal motion of particles in matter)
transfer momentum in wave form, therefore  where did the momentum carried by thermal radiation transfer from also ?

        p =E/c =h/λ. 

So Halc/BC Not confusing heat and momentum, and how do you account for thermal radiation then leaving the earth's atmosphere/surface out to space ?




Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 26/10/2020 09:05:00
I am questioning the validity of the atmosphere's/earths suitability to conserve momentum.
Fine.
Show the error in Emmy's working
https://en.wikipedia.org/wiki/Noether%27s_theorem
So I would ask firstly, where did the momentum that is known to be carried/transferred by sound waves transfer from, because of the frictional coupling between surface and atmosphere ?
There isn't any momentum in the set of sound waves produced by an event.
The initial momentum is zero, and no momentum is provided, so the total final momentum of the sound waves is still zero.

There is some to the left and some to the right, but their sum is exactly zero.

That's because it's a conserved quantity.
Why are you not understanding this?
Title: Re: Can windmills affect Earth's rotation?
Post by: gem on 27/10/2020 00:45:20
Hi all,

So BC you refer to Noether's theorem to counter my position of questioning the validity of the atmosphere's/earths suitability to conserve momentum.
https://en.wikipedia.org/wiki/Noether%27s_theorem

We have covered this previously, but just to restate the earth's atmosphere does not fulfil the requirements for conservation laws of momentum as required by Noether's theorem.

As is demonstrated by it having a pressure gradient, also it not being an inertial reference frame, (Lorentz invariance) and therefore the subsequent buoyancy effect due to solar input (anisotropic) is known to change momentum, so therefore momentum is not conserved in the atmosphere.

Given the inelastic collisions that produce sound waves are known to affect the momentum total of the solid earth by way of change in LOD, and lets say its a transfer of momentum from earth to atmosphere, we know sound waves are produced and as you say;

Quote
There is some to the left and some to the right, but their sum is exactly zero.

Yes sound waves carry momentum away in all directions so each part if added up from the scene of the collision sum to zero but they carry momentum away as is detected by anyone listening, so how is that momentum recovered to be transferred back to the solid earth and maintain its length of day ?
Title: Re: Can windmills affect Earth's rotation?
Post by: Bored chemist on 27/10/2020 08:59:27

Quote from: Bored chemist on 22/10/2020 12:16:39
Quote from: Bored chemist on 22/10/2020 08:48:15

Quote from: Bored chemist on Yesterday at 08:37:38
Quote from: Bored chemist on 20/10/2020 21:39:41
Now, perhaps you could stop posting bull an answer this

Quote from: Bored chemist on Yesterday at 12:35:24
Quote from: Bored chemist on 18/10/2020 10:49:26
Just checking on something.
You chose the ISS. I presume that's a reference to the fact that it is in free fall because it is in orbit.
Is that correct?
When you stop being stupid/ lazy and answer that, then we can move on to this
We have covered this previously, but just to restate the earth's atmosphere does not fulfil the requirements for conservation laws of momentum as required by Noether's theorem.