Do Wind Farms Slow the Earth?

If they did, then maybe every Jet that sits on a runway with brakes applied at full throttle would speed it back up.

LOL!!!

Déjà vu

Thank you. I have now read the previous post and believe my question to be the next logical step not taken in the earlier thread.

If we extrapolate the number and the time in service would there be a measurable difference?

-A-

Maybe I am thinking backwards, but wouldn't the wind be pushing rather than braking?

Wind derives it's energy from variations in atmospheric pressure that has nothing to do with the earth's rotation.

Wind direction at the surface of the earth is random compared to rotational direction.

Look at a weather map.

See post 3.

WOW!

Excellent discourse!

Very well put.

Ditto, GA!

The heat load difference is a good point. However, I think Lyn is right in saying there would be negligible net effect caused by the turbine action.

I do, however, think Lyn and others are wrong in saying the rotation of the Earth does not affect the wind. There is an inertial lag between the rocks and the air causing a general inclination at the equator.

That being said, Lyn is more correct in pointing out the Sun as having a much larger effect on the convection currents and that especially, wind currents at the surface vary too much for the turbines effect to rise above the background noise.

All in all, carrying this argument to it's logical conclusion doesn't seem to amount to much more than an air-biscuit in a wind storm.

-A-

Well, it's time for a beer, then.

Just one?

After this one, perhaps <hic>.

We're on vacation so I went to the pub and had a glass of stout for you.

Drinking his beer and taking his credit....what a vacation...

It wasn't sour grapes, it was Guinness.

You give me too much credit.

"All in all, carrying this argument to it's logical conclusion doesn't seem to amount to much more than an air-biscuit in a wind storm".

The most astute observation so far in this intellectual tai chi.

Been a nice read though...got my juices flowing for the day....thanks to all!

So nice of you to condescend to read our pitiful effort. Next time, don't waste your time.

The comment doesn't strike me as condescending or even particularly offensive.

You might be reading too much into it.

...or perhaps I'm reading too little from it.

Cantankerous ol' cuss, ain't ya?

Best keep a tight rein on that dumbphone of yours, as it sends conflicting opinions on comments that it doesn't take a moment to process.

Refer my #51 relative to your #89, turncoat....you actually agree with me...

Touche'.

Were you once an international dispute mediator? Basically you did not answer the question, but posed more, yet it seems to be a very satisfying answer. Makes one buy the fact that we don't really know the overall effects of our input to the environment, so the question can't really be answered. Brilliant - absolutely brilliant.

GA. Only if the materials to build it came from a place closer to the centre of Earth's mass than where they were erected, though...

It isn't the distance from the center of the Earth's mass that matters. It is the distance from the axis of rotation.

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So if you build a skyscraper in New York or London from materials taken from sea level near the equator, the effect would not be to slow the rotational speed, but to increase it.

Good point.

Great analysis.

However, I still have some nagging doubts. I agree that IF there is NO NET movement of wind in one direction, then all the turbines have no effect on the Earth's rotation. But the jet streams in both North and South hemispheres all travel East. If the jet streams all stopped, the Earth would speed up a bit, because angular momentum is conserved. Turbines don't reach up into the jet streams, but what I wonder is whether there is some other movement of air to the West that counterbalances the jet streams, just as the Westerlies counterbalance the Easterlies? If so is it close to the Earth's surface where turbines can affect it?

Ok, then if one country built several High Rise Sky Scraper buildings and the country on the opposite side of the planet only built low buildings, spaceship earth could get a bit of a speed wobble and throw us out of our current orbit of the sun?

Cheers

The centre of Earth's mass would shift a tiny amount, not enough to cause any significant change in the Earth/Sun orbit. After all, this sort of thing has been going on for centuries now and is tiny in comparison with continental drift, which has been going on for millenia.

If the height slows the Earth by conservation of centrifugal motion, then you have an other problem arising as a result of the Earth slowing relative to the wind. The wind would speed up! If the Earth were to stop spinning right now, we would have 900MPH winds until the air slowed down to match. BUT if we have enough turbines to slow the wind, then we put rotational speed back into the Earth.

Ofcourse no effect.

That is same as two people fighting inside a moving train - train not affected.

You can ask your question in different way:

Do High Rise Buildings slow the Earth ? Ofcourse No.

Maybe the whole concept is a myth.

We think that we perceive the wind but yet we can not it itself and can only see what we assume to be effects caused by it. Therefore it must be a myth.

People who speak in only absolute terms will only be absolutely wrong, as you are.

Well , I was expecting to receive a "Good Answer" instead of a criticize.

See post #11.

Read it carefully.

Actually historically about 3,000 years ago there was very long sunny day ( earth stoped rotation ) - Recorded in the old testament for a long war day and confirmed in the chinese history records.

You are delusional.

Yes friend , it is mentioned in the old testament and also recorded in the old Chinese history - Search for that your self.

We don't need to search records of old Chinese history, nor even the old testament, to see the truth in Lyn's appraisal.

And seeing that you are in agreement:

'...Yes friend,...'

there doesn't even seem to be any debate.

We seem to have found common ground in our agreement; you are delusional.

It seems like it the Earth had stopped, the area where to which the old testament relates and the area to which ancient Chinese records relate would not have both experienced a 'very long sunny day'.

Those places are far enough away in the east-west direction that if it were bright and sunny in China it would be just morning on the Mediterranean Sea....assuming somewhere near Shanghai or Beijing.

If it were bright and sunny on the Mediterranean it would be near twilight around Beijing or Shanghai.

Unfortunately I only had 2 good answers left to give out today, and they went to Usbport and PWSlack, I hope to get a shipment in by Friday, maybe I can give you one then or maybe you can say something that is on topic and makes intelligent sense and earn one.

GA points are hard earned on this forum, even excellent contributions rate only almost GA's in many instances.

However criticism is essential in any intellectual discussion else it becomes mired in self congratulation( or is that flagellation?)...

Note; I have off topic'ed myself which grants me a -5 GA points, I would need 7 people to GA this response to gain a GA point.

Absolutely true Lyn.

Wrong!

Any time you take material from a spinning entity and place it further from the center, you increase the radius of gyration and slow it down. Think of the figure skaters performing spins, arms moved in from the extended position speeds the rotation and vice versa.

The net effect should be zero....The winds of the Earth move in all different directions but are powered by heat, so what we have is heat being converted to electricity and then back to heat as the electricity is used, energy is conserved...

The map you posted doesn't suggest that the wind blows generally from all different directions.

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The map you posted suggests that the winds over most of the earth have a easterly component. Only between 30 to 60 degrees north or south latitude does it show the winds having a westerly component.

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If the winds in the areas with westerly components are not stronger than than the winds in the far larger areas with easterly components, perhaps there is a net effect. Perhaps windmills would increase the rate of rotation (or cause the decrease to occur more slowly).

Oops. Scratch that last bit about the possibility of increasing the rate of rotation.... completely the wrong way. The effect would be slowing, if any effect exists.

Several smart folks keep saying that there is no effect of the Earth's rotation on the wind, but there is.

SolarEagle's picture shows it. The North-South convection currents are obviously heat related but the clockwise rotation at the equator is promoted by the inertial lag of the air above the spinning surface.

Building a large wall that stood in the way of the equatorial trade winds would slow them down and entrain more air mass along with the spinning earth, thus slowing it down. Even the fluid friction of the wind interacting with mountains and trees is subtracted from the rotational energy of the Earth. Understanding of course, this net effect is near zero does not mean that it does not exist.

I understand that these numbers a NEGLIGABLE. point of fact, these forces are likely to be orders of magnitude less than the effect of the moon on the Earth's rotation. I believe the moon is causing the Earth's rotation to slow, and therefore lengthen the Earth day, by something like 1.7ms per hundred years.

-A-

SE's globe represents the average wind currents over many years. There is far too much random wind current activity .

It does not take into account the location of wind farms.

Surface winds are random, globally.

deleted.

Most all wind energy captured by a wind farm is solar energy.

It is also doubtful that the deployment of a water wave (or tidal) electrical generator network would cause a decay in the orbit of the moon.

When you get fight down to it, it's all solar energy. isn't it?

Most of it is, but not all of it.

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Some wind is attributable to differences in temperature of the Earth's surface, not attributable to solar radiation. The difference in temperature that exist between volcanoes and the cool ocean water is an example.

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Also some wind is attributable to temperature difference between heat given off by nuclear reactors and cooler areas nearby.

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An argument might even be made (though it is not as simple as the first two arguments) that lunar tidal effects and the Coriolis effect convert some rotational energy to wind.

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I'm on a stupid phone, so I can't show thermal image of earth which shows many different hot spots that can contribute to the winds, too.

Mostly I think it's solar that drives surface winds.

I think you are mostly right.

Most of it. The term "renewable" causes abrasion in these parts, though. From where on Earth (pun intended) would one get a new star when its force is spent?

Are you kidding? Have you stepped outside your back door on a dark night and looked up at the sky? There're billions of them!

there isn't enough wind to "power the Earths needs" one of the fundamental shortcomings of wind power is the relationship between wind prone areas and population centers that utilize electricity. no matter what type of non Superconducting transmission lines you might use will experience losses in voltages through plain old resistance and distance, the further it travels the more you lose as far as its affect on planetary rotation.......that's levity, right?

Let's start with a more basic question. Does having an atmosphere affect the speed of earth's rotation?

If not, then I think Solar Eagle is right on track. Follow the energy balance.

I would say that having an atmosphere does affect the speed of the Earth's rotation, though not very much.

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Having oceans affects the speed of the Earth's rotation. Tides tend to slow the Earth's rotation and transfer energy to the moon. Atmosphere is likely to have a similar (though much smaller) effect.

I thought the transfer of energy between the earth and the moon due to tidal movement was a two way street.

As I understand it, the energy is mainly transferred to the moon. The earth is spinning faster than the moon is orbiting.

The main effects are lengthening of the Earth's day and the widening of the Moon's orbit.

That is counter-intuitive...but I defer.

Counter intuitive?

I bet it becomes obvious with simplified review.

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The Earth is spinning (once per ~24 hours) faster than the Moon orbits the Earth(once per ~ 30 days).

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The water on the Earth is drawn my the Moon's gravity toward the areas closer to the Moon. This causes a bulge or water with a significant mass closer to the Moon and depressions on the sides of the Earth where the average surface is close to parallel to the direction of the Moon.

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The friction and impediments to flow experienced by the water causes the bulge to be offset in the direction of the Earth's spin (to the East). The works to decrease the rate of the Earth's spin, lengthening the day.

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The offset of this significant mass of water has a corresponding amount of gravity which is attracting the Moon, not exactly perpendicular to its path, but slightly ahead. This means the gravitational attraction has a small component in the direction of travel and is therefor working to increase the speed of the Moon.

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This increase in the speed of the moon widens the orbit making the gravitational potential energy between the Earth and Moon less negative.

the potential energy is less negative, eh?

Yes. Exactly.

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Far away from each other, two masses have nearly zero potential gravitational energy (just consider the two masses, not other masses that might or might not be near).

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Assuming the two masses were at rest initially; as the two masses are drawn closer together, there will be an increase in velocity/kinetic energy. This is a transfer of gravitational potential energy (from near zero to more negative) to kinetic energy.

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Similarly when trying to escape the gravitation of a planet, one must overcome the negative gravitational potential energy.

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The convention for placement of the zero (and making gravitational potential energy negative) arises from the difficulty of assigning any other universal level for zero.

show me two planetary masses at rest, or even one.

Who said planetary?

By the way, your 'even one' part is easy. I get to choose the point of reference, right?

If you are going to include things like thermal motion as a disqualification for being at rest then the question becomes without value for anything macroscopic as 'at rest' will have lost meaning for anything macroscopic.

I believe the OP, and all the discussion that has followed, has been hypothesizing about the impact of wind on the rotational speed of the earth (a planetary body). I will also hazard a guess that an atmospheric bulge (relative to space) also appears in a constant path from the terrestrial water bulge to the moon. I'm trying to hang with you truth, but I'm a bit dazed. Nothing we have talked about is at rest.

This line of the discussion stems from my response to your seeming incredulity toward my mention of negative gravitational potential energy, in which I attempted to clarify my explanation with an example of the interaction of two hypothetical masses effectively alone in space.

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It was my hope that this explanation would be understood in its generality and that making all the connections back to the planetary system being discussed would be unnecessary.

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At any rate the hypothetical masses in the example only started at rest. If you prefer, simply don't consider that first instant. But really, the idea that something at rest is used to explain the use of a particular convention shouldn't destroy the premise when talking about things that you don't consider at rest.

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'At rest' is after all just common nomenclature for the condition of being stationary with respect to a chosen (typically inertial) frame of reference.

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It is probably possible to render 'at rest' meaningless in the macroscopic world via some reductio ad absurdum argument, but I don't see any benefit to that.

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What exactly is your objection/misunderstanding? Is it still related to negative gravitational energy? If so, how does an example that begins with hypothetical masses at rest hinder your understanding of a more complex system?

Calm down my friend; I did use the word defer.

When a body (maybe the moon) causes a (tidal) bulge in the water on another body (maybe the earth), I feel like it may have released some energy to do so.

It is otherwise counterintuitive to me....obviously not to you.

I wasn't upset. I was just trying to explain something that seems pretty clear to me, but that you say seems counter-intuitive to you. I didn't intend for my comment to come off abrasively.

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I can understand your feeling that the tidal bulge should represent some transfer of energy from the other object to the object bulging. Hopefully you will tolerate my attempt to correct that view.

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A similar interaction might be useful to consider:

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-A truck with a tarp over the cargo is driving through air that is moving the same direction as the truck but 30 times slower. The air (Moon) interacts with the tarp (oceans) and causes luffing (tides/bulge). The air did not have to slow down to cause the tarp to luff, right?

_{Er, actually, widening the orbit coincides with slowing down. Sorry about that - it's back to that skater "doing an axle" with arms clenched or outstretched again. Pluto takes longer to orbit the Sun than Mercury, and evermore shall do so - another example.}

'..._{Er, actually, widening the orbit coincides with slowing down. Sorry about that - it's back to that skater "doing an axle" with arms clenched or outstretched again. Pluto takes longer to orbit the Sun than Mercury, and evermore shall do so - another example}._...'

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Er, actually, despite your feeling that your comment disagrees with what was written, it doesn't.

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Just think about it for a moment. If a satellite is in orbit and a rocket is used to increase the speed of the satellite, what happens to the orbit? It isn't going to get smaller. It is going to get larger and as it gets larger the satellite will slow down.

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Nothing mentioned in the post you responded to conflicts with the ice skater analogy you are so fond of.

The friction might have an effect on the rotation, but I suspect the loss of friction of all the trees we've cut down more than make up for it.

In order for this to happen the atmosphere would have to be "anchored" in space. There would be 1000 mph winds at the equator. and the drag from the mountains would have slowed the planet to a near stand still eons ago.

No, the air mass rotates with the planet.

The atmosphere is "anchored" loosely in the same way the oceans are "anchored" loosely by gravitational interaction with the sun and moon.

The "anchor" isn't enough to lock the atmosphere into place (and I think the winds would be closer to 2000 mph if the atmosphere were at a stand still compared to the Earth's rotation, but we both agree is not the case), but it probably does drag some around, much like tides in the oceans.

The peripheral speed is, obviously, greatest at the equator. Roughly, given that a day is 24 hours, the earth rotates through 360 degrees or 21,600 minutes of arc per day or 900 knots. That's 1035.72 statute miles per hour.

You are correct. My mistake (I knew the circumference was a little over 24,000 miles, but I only had 12 hours in my day for some reason....silly).

1000mph exceeds Mach 1...

Sun flare activity has far more impact than any wind farm landscape humans could construct in the next 1000 years. Neither of them slow the earths rotation. Both of them slow the earths rotation. How can that be? The earth may slow, but it may not be for the reason you think. The earth may not slow, but it may not be for the reasons you think. Not only is the atmosphere not anchored in space, the earth is not anchored in space.

There may be a point here, but it escapes me.

Yes; no; maybe; I don't know?

sometimes it speeds it up, sometimes it slows it down, all the while there are thousands of other influences.

OOh,

That makes sense, for sure.

Fact is we may never know.

I just don't buy into the" earth stopped for a day" to satisfy some mortal. As advocated by Marzoky

It is unfortunate that we do not permit the writers of the bible the opportunity to use the same license to exaggerate, distort, modify, or deceive that other humans throughout history are free to use for their literary purposes. In this case however, it is obvious that the earth appearing to stop rotating is really caused by a buildup of temporal quanta emitted from sunspots that speeds up the passage of time, thus making it only SEEM to have stopped the earth's rotation when it is clearly indicated that it is the sun's motion, not the rotation of the earth, that is being stopped. This question can clearly be settled bu a simple experiment. For only a relatively short time we can temporarily (conveniently it could be the next time we have a buildup of temporal quanta) we can reroute the electrical grid power to the wind power generators, reversing them and turning them into fans, then we MEASURE the change in the rotation of the earth! That would settle this issue. Then any further disagreement could be ended, and we could all live happily ever after. After all, this is an engineering website, not a scientific site, so what really matters is the truth, not speculative theory and hypotheses.

AAs far as know the bible may be speculative theory and hypothesis.

"buildup of temporal quanta emitted from sunspots that speeds up the passage of time"

Apart from this seeming to explain how Noah reportedly lived for so long (ie extended buildup of temporal quanta) I don't buy it....

Who proved such temporal quanta resulting from sunspots speed up time? What empirical evidence do we have...? How can you even speculate the use of wind turbines to counter the effect of a coronal mass ? Even so, are we not protected from such effects by the magnetosphere ?

"what really matters is the truth" Who's truth ?

We have established that the atmosphere rotates at the same speed as the earth, while not physically connected.

So, let's take a huge leap and say that, by some MIRACLE the earth stops.

What you have then is a1,000 MPH wind blowing across the surface of the earth.

That's gonna require a SUPER MIRACLE to keep from destroying everything on the surface of the planet.

How are you rating your miracles? It seems to me that if stopping the Earth is rated only as a "MIRACLE", then stopping the atmosphere at the same time doesn't rate as a "SUPER MIRACLE". I would rate it as more like an "AFTERTHOUGHT MIRACLE." Or maybe "It's a miracle that I didn't forget to stop the atmosphere too," kind of miracle.

Maybe we need a more objective rating scale for miracles, like the Richter Scale for earthquakes. In fact, I wonder how stopping the Earth's rotation (atmosphere included to avoid high winds) would rate on the Richter Scale. The scale would have to include Supernovas, just in case the reason there was a long day was that there was a supernova that day. And just to be complete, the Big Bang would probably be at the upper end of the Scale. But it has to get tiny, too. How big a miracle would it take to cause the mutations that led the human race to become smart enough to invent beer? Oh yeah, and for life to develop from the primordial soup into the organisms that humans use to make beer?

Agreed. Super Miracles are often conglomerates of sub-miracles. As an added mystery, it seems that some sub-miracles are more often referenced than others. Google would then move them to a higher or lower category, maybe pseudo or integral class miracles. It begs the question. Does observing a miracle (say, a glass of stout) actually have the ability to impact it's classification.