Can Earth's rotation generate power? Physicists divided over controversial claim

https://www.nature.com/articles/d41586-025-00847-0

by qnleigh • 1 year ago

106 216 1 year ago

nature.com

threeseed• 1 year ago

Current = 25.4 ± 1.5 nA, Voltage = 17.3 ± 1.5 µV.

Making total power for the 30cm shell = 0.44 picowatts.

cedws• 1 year ago

Still more net energy than fusion reactors have ever produced.

number6• 1 year ago

That's untrue

Retric3• 1 year ago

No, it took far more electricity to make than it produces over any conceivable lifetime.

ChrisNorstrom• 1 year ago

My Stupid Question, please don't laugh:

If you did this on a massive enough scale, to generate serious amounts of power, would that accidentally slow the Earth's rotation down over time?

6510• 1 year ago

I'm not saying that is why we left Mars.

aeve890• 1 year ago

Yeah, after making an oopsie with a runaway greenhouse effect in Venus. All this has happened before and it will happen again.

fallingknife5• 1 year ago

It's definitely not why we left Mars because Mars still rotates every 24:30. We left Mars because of the hostile Martians, of course.

foxglacier• 1 year ago

No because of conservation of angular momentum. Maybe it would cool the Earth's interior faster than otherwise though. It's heat flow from the inside to the outside that drives the fluid flows in the mantle and generates the magnetic field.

FilosofumRex• 1 year ago

Earth's rotation has been slowing down despite principle of conservation of angular momentum, at about 2 mille-sec/century. Dinos had an hour shorter days than we do now.

I'm not an EE, but isn't this related to Tesla's last invention which bankrupted him - I believe he was working on electricity generation from thin air.

ChuckMcM• 1 year ago

It isn't a stupid question, it is a good one. The answer would depend on how the field is generated in the first place.

Given a field generated by asymmetric rotation of the molten core at the center of the Earth, 'shorting it' (apply a load) would presumably affect the core's rotation. In terms of relative energy however, the poor coupling at the surface would suggest that this would be a very challenging way to divert any meaningful amount of power from the core itself. It would however have to deal with points in time where the core reverses its magnetic field. The papers on core reversals are fun to read.

I think more usefully, the presence of the voltage, might be an interesting way to localize one's location and orientation.

I remember brainstorming "off the wall" power generation ideas and one that has yet to be realized would be to inject dust ahead of a wind turbine with a collector in the back. Then using the Van DeGraf effect to generate power instead of lightning as it currently does.

fpoling2• 1 year ago

If one needs location, then the magnetic field can be measured directly. It is already considered as a potential alternative for GPS, https://www.electronicdesign.com/markets/automation/article/...

The main problem is that locally measured Earth magnetic field varies on a daily basis and is strongly influenced by solar storms.

A better alternative is to use variations in Earth gravity to improve inertial navigation. That vastly more stable.

marshray• 1 year ago

The term "generate power from Earth's rotation" is basically saying "convert kinetic energy from Earth's angular momentum". If you extract energy, by conservation of energy that energy has to come from somewhere. So yes, we would normally expect Earth's rotation to slow.

But I think if you do the math, it would be absolutely miniscule.

whatshisface• 1 year ago

They are one step ahead of you. :-)

"We previously showed that even in an extreme scenario where our civilization somehow would obtain all its electrical energy from the effect described here, Earth’s rotation would slow by <1 ms per decade [2]."

modeless• 1 year ago

Alternatively, we could speed up the Earth! Let's get rid of those pesky leap seconds!

ngruhn• 1 year ago

fast forward a hundert years and there is a massive culture war between the "rotation slowdown deniers" and people religiously buying "rotation friendly" products.

nopelynopington• 1 year ago

I've often wondered about a similar issue with wind power. Would enough wind turbines dampen the force of wind?

nprateem• 1 year ago

If a politician talks in front of a wind turbine, does it make a sound?

padjo• 1 year ago

On a local level they absolutely do, in a wind farm one turbine can shadow another and reduce its output significantly. It makes wind farm layout a tricky optimisation problem. On larger scales the impact is pretty minimal though, there’s so much energy spread over such a large area that significantly reducing it a global scale is not a concern.

bee_rider• 1 year ago

Fundamentally, yes, right? For some definition of “enough.”

Actually, after some quick googling (so, maybe someone actually knows better) it seems like this is an issue where there’s an active discussion? Maybe somebody actually involved in the field knows more.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2004JD00...

https://esd.copernicus.org/articles/3/79/2012/esd-3-79-2012....

But that came out in 2012. I bet you could find some other article citing it, as rebuttals.

It seems a bit implausible to think we could somehow pull enough energy from the wind to really matter, but then again carbon based climate change also seemed a bit implausible so, I guess, who knows?

j453• 1 year ago

Not stupid at all, especially if only one part of physics exists and not quantum physics.

chrisjj• 1 year ago

would that accidentally slow the Earth's rotation

No. Incidentally :)

Kerbonut• 1 year ago

I had an idea somewhat related to this where we use the solar winds as a sort of road and the earth's magnetic field as a sort of rotor to convert kinetic energy from the sun into electricity.

evan_• 1 year ago

Sounds like solar power with extra steps

BurningFrog2• 1 year ago

This kinda sorta how auroras/northern lights work.

vessenes2• 1 year ago

This is really cool. Question for EEs / Material Scientists reading the paper - they mention you could shrink the cylinders and get the same voltage provided a "suitable material" could be found. Any back of the envelope or explanation of materials needed to make these cylinders say 1/1000th their current size? That'd be an extremely useful amount of energy when put into say a 1000x parallel array.

It seems hard to imagine that this kind of shrink-down could go on forever, but on the other hand, the earth is just sort of hurtling us around with great energy while it rotates.

ninetyninenine• 1 year ago

Wouldn't this slowly slow the earths rotation down? Let's say everyone tried to build power plants using this.

ziofill4• 1 year ago

Ah didn't see this comment and I asked the same. Yes, right? The energy has to come from somewhere...

mmooss4• 1 year ago

https://news.ycombinator.com/item?id=43522519

ziofill4• 1 year ago

Wouldn't this eventually slow down Earth's rotation? The rotational kinetic energy of our planet is 1/5 M * R^2 * w^2 with (approximately) M = 6e34 kg, R = 6.3e6m, w = 7.4e-5 rad/s, which gives approximately 5e36 joules. Yearly we need roughly 3e16 Wh. Yeah ok there's plenty. Woah! (also, I may be off by some orders of magnitude)

Retric3• 1 year ago

0.44 picowatts = 4.4e-13 watts so not in a detectable fashion before the sun consumes the earth billions of years from now.

ziofill4• 1 year ago

Well, the watts that come out of the rotational energy must match the ones we need, for energy conservation.

frozencooler2• 1 year ago

Doesn’t driving west to east on a highway slow down the Earth’s rotation, via the power transferred into the ground?

BurningFrog2• 1 year ago

Only while you're driving.

amarant2• 1 year ago

Yes, but that energy is returned when you break

logifail2• 1 year ago

Reminds me of a glorious question from undergraduate physics:

Calculate the change in the length of the Earth's day if the UK were to switch to vehicles driving on the right-hand side of the road rather than the left..

rocqua• 1 year ago

It's actually driving north south that changes the rotation speed. Because your 'real' speed gets higher as you get closer to the equator, you 'steal' momentum from the earth as you get closer to the equator.

Its effectively the same principle as a figure skater pulling in their arms when spinning, to spin faster.

thayne4• 1 year ago

Then when you stop the angular momentum of your car is transferred back to the earth.

MathMonkeyMan2• 1 year ago

This is addressed in the last paragraph of the article:

Even if it works, the method will not generate energy from thin air. It would tap Earth’s kinetic energy and, in doing so, cause the planet’s spinning to slow over time — although only slightly. If the technique provided all of Earth’s electricity needs, which was around 11 trillion watts in 2022, this would slow the planet’s spin by 7 milliseconds over the next century, the authors calculate. This is similar to the change in speed caused by natural phenomena such as the Moon’s pull and changing dynamics inside the planet’s core.

api3• 1 year ago

which was around 11 trillion watts in 2022, this would slow the planet’s spin by 7 milliseconds over the next century, the authors calculate.

Really puts how small we are on a cosmic scale into perspective.

If we did it for a million years at current energy use scale it would shorten our day by about 1.1 seconds.

aeternum3• 1 year ago

Isn't friction from the atmosphere already slowing the planet's spin? Many weather effects like hurricanes ultimately derive their energy from a combination of the earth's rotation and thermal/uneven heating effects so I don't see why this is contentions.

Like most things, nature is already doing it and has been for millions of years.

mmooss4• 1 year ago

How much velocity loss would be needed for an impact on the environment, or on some humans someplace?

ForHackernews• 1 year ago

It's kind of insane how much energy is involved in big masses of rock flying around in space.

thayne4• 1 year ago

Where does the angular momentum go?

foota• 1 year ago

The IERS will never stand for this!

DriverDaily2• 1 year ago

Can we put energy in to speed it up?

That way a day can be 24 hours exactly instead of 23 hours, 56 minutes, 4 seconds, etc...

incognito124• 1 year ago

I mean, solar day is 24h, it's the sidereal day that's 23.9344696h

Detrytus• 1 year ago

Don’t follow your logic: if the day is currently shorter than 24 hours we need to slow the Earth rotation down, not speed it up.

golol• 1 year ago

Where does the angular momentum go?

fsckboy2• 1 year ago

it's the angular momentum that gets transferred to the earth's spin, and all the other numbers, energy, power, are simply how the books are balanced. GP should have asked the question in terms of momentum in the first place.

with energy, you need to consider friction, losses, thermodynamics 3rd law, but with momentum it's pure.

teamonkey• 1 year ago

Torque is applied, the paper mentions a magnetic braking effect.

throwaway48476• 1 year ago

Would this reduce the magnetic field stength allowing more cosmic rays to reach the surface.

xattt• 1 year ago

I, for one, look forward to ground-level auroras.

dang• 1 year ago

The paper is here: https://arxiv.org/abs/2503.15790

(via https://news.ycombinator.com/item?id=43520716, but we merged that thread hither)

Panda_• 1 year ago

https://archive.is/5GHWF

nyc1112• 1 year ago

Why does the earth have a magnetic field?

frozencooler2• 1 year ago

The earths rotation creates it. Or was this rhetorical.

nyc1112• 1 year ago

No, it was a serious question. Does anything that rotates create a magnetic field even if it is not an electrical material?

qnleigh7• 1 year ago

This is a great question, and it's not as simple many comments here make it seem to be. This Veritasium video has a great explanation (and an enormous ball of molten sodium).

EncomLab• 1 year ago

It's incredible the lengths humanity is willing to go to avoid adopting nuclear energy - despite the US navy driving mobile reactors millions of miles over the last 70 years.

deepfriedchokes• 1 year ago

The Navy isn’t constrained by economics. Nuclear doesn’t make sense economically compared to things like solar and batteries.

SecretDreams5• 1 year ago

things like solar and batteries.

Magnets too - let's just go magnets everywhere.

Reality is solar isn't viable everywhere. And it's not optimal to put it in places where you use the sun to grow food.

We should follow a holistic approach.

* Wind where it's windy.

* Solar where it's sunny - ideally on buildings/away from farms.

* Hydro where possible.

* Nuclear where it makes sense, i.e. stable geography, low occurence of natural disasters, lots of land.

* Some natty gas plants for overflow - not saying commission new ones or prioritize natty, but it's sensible to utilize existing peaked plants.

I'm not a big fan of large scale battery storage solutions, but they can work sometimes. I think they're more sensible for residential/commercial use and, when paired with solar, can really help add robustness to the grid. But, for mega energy storage, I think hydro based solutions are more sensible.

Nifty39292• 1 year ago

I haven't seen any data that backs that up based on general principals. Most of the cost is in artificially-imposed operational requirements - however well founded.

Also, remember that nuclear, unlike solar, has a lot of room for improvement still, both in how it's done, and how it's regulated. Solar has already been tremendously optimized, while nuclear has not.

The cost argument seems to be advances by the same people who impose or support the additional operational requirements, and who also just have a philosophical aversion to nuclear power.

There are hundreds of nuclear power plants already in operation, many decades old. There have been only a very small number of minor accidents (3 come to mind: Chernobyl, Three mile island and Fukushima), in which only a few dozen people were killed. Nuclear, even using old technology, has proven to be far safer and better for the environment than any scalable alternative, including solar. New designs are even safer.

kjkjadksj2• 1 year ago

Why do we have to be constrained by economics unlike the navy? The state within the state has access to nuclear powered ships so it is just a question of widening that capability to the members of the state living outside the walls of the keep. Not a matter of establishing precedent or anything. That part is done and long proven. The federal government even has experience managing water and power for entire geographical regions today.

timewizard3• 1 year ago

The Navy isn’t constrained by economics.

In what way is it not? It has a budget and a mission. Economics are a huge part of their existence. Far more is spent on health care every year over the Navy.

Rury• 1 year ago

The Navy isn’t constrained by economics

And solar less so than nuclear. Nuclear receives only ~1-3% of energy subsidies in the US [1].

[1] https://en.wikipedia.org/wiki/Energy_subsidies_in_the_United...

pmontra3• 1 year ago

Many countries would have to buy nuclear fuel from other countries much like they do for gas and oil. On the other side very few countries can build their own solar panels so it seems the same sort of problem. However if you accept to depend from potential hostile countries at least solar panels don't do much harm when they fail and it takes very little effort to install the equivalent amount of power of a nuclear power plant. If we only could all get along and have a global power grid with always 12 hours of sunshine on it.

devmor• 1 year ago

Until we solve the storage problem, the manufacture of batteries required to store solar power at night and during other low generation times is actively doing harm even without failing.

I don’t think this invalidates your point but I do think it is incredibly important to recognize that environmental harm done slowly over time is no less impactful than that done by a disaster.

fallingknife5• 1 year ago

Unfortunately the arrangement of the continents would require undersea transmission lines for this. Would be an interesting future where the Bering Strait is the most valuable real estate on Earth for the American-Euraisian grid connection. But more likely we would build fusion reactors or get over our nuclear phobia before building something like that.

abdullahkhalids• 1 year ago

Most country that can invest a few hundred million can build their own solar panels that will be significantly cheaper than existing and future fossil fuel prices. It's just those panels will be 2x+ the price of those produced in China. So can't compete in the free market.

bmacho2• 1 year ago

You can do solar energy with mirrors (the ancient Greeks were able to produce that) and steam turbine/stirling generator.

grepfru_it5• 1 year ago

Solve the waste problem and you solve nuclear. Waste is still the giant elephant in the room and a lot of people have a fifth grade solution to the problem (we will bury it under ground! We will fly it to the sun! We will resuse it until it is no longer radioactive!)

I used to have a neighbor who worked for the DOE, all of the viable solutions are blocked by people who don’t want it in their backyard. Can’t really move forward until that is solved..

fallingknife5• 1 year ago

Burying the waste is an excellent solution. We are currently dealing with the much more dangerous problem of hydrocarbon combustion waste by releasing it into the atmosphere.

Ylpertnodi• 1 year ago

Waste is still the giant elephant in the room and a lot of people have a fifth grade solution to the problem (we will bury it under ground! We will fly it to the sun! We will resuse it until it is no longer radioactive!)

Could the waste be 'sent' into space? Bonus points for sending a certain human with it. Serious question, though.

cyberax2• 1 year ago

Waste is still the giant elephant in the room and a lot of people have a fifth grade solution to the problem (we will bury it under ground! We will fly it to the sun! We will resuse it until it is no longer radioactive!)

The correct solution: put it into dry casks and do nothing right now. Store it simple underground storage facilities or on the grounds of active nuclear power plants.

The casks are fine for the next 300 years, and during that time we can either:

1. Perfect the nuclear fusion, it will provide plenty of neutrons to transmute the waste.

2. Perfect fast fission reactors. See above.

3. Use some of the excess of too-cheap-to-meter green energy for accelerator-driven subcritical fission reactors.

4. Yep, use rockets to slowly launch the waste into space. We can already design a storage capsule that can survive re-entry.

In any case, we have literally hundreds of years to come up with a solution and there are many viable paths.

kjkjadksj2• 1 year ago

What problem with the waste? Reactors are working and generating power today for many thousands of americans. Whatever is being done with waste today seems to work well enough to continue reactor operations without any major headlines. Just seems to be a bit of cognitive dissonance here between what is claimed online and what we see today out in the field generating power.

walleeee• 1 year ago

Some MSRs can consume spent nuclear fuel, that's a 7th grade solution at least

AtlasBarfed3• 1 year ago

Lftr! Breeds burns almost all the fuel.i think the waste products it does make are shorter term.

npodbielski• 1 year ago

I wonder how many wats of power we would be able to generate before earth slows down for i.e. 1 second longer day.

IshKebab• 1 year ago

That's easy to work out but I can tell you not it's going to be more than we will ever use.

barbazoo• 1 year ago

Typical human response

Beijinger• 1 year ago

You have no idea, what amount of energy we will be able to use the long run.

janpot• 1 year ago

"640K ought to be enough for anybody"

tiagod• 1 year ago

We have potentially millions or billions of years of history in front of us. If we find a way and a motive to have self-sustaining communities outside this planet, and considering our own history, it looks at least plausible that we will continue spreading, after dominating an entire planet against the brutal odds of natural selection, which we basically hacked with our consciousness to reach this state.

Keep in mind that energy is not electricity. When a rocket is burning huge amounts of fuel to reach orbit, that's energy we're using, a lot of it.

af78• 1 year ago

I'm taking figures from https://en.wikipedia.org/wiki/Rotational_energy

Moment of inertia of the Earth: I=8.04e37

Angular velocity, with sidereal rotation period of 23.93 hours: ω0=2π/(23.93 × 3600)

Angular velocity, with sidereal rotation period of 23.93 hours plus one second: ω1=2π/(23.93 × 3600 + 1)

Rotational energy difference: .5 × I × ω0 ** 2 - .5 × I × ω1 ** 2 ≈ 4.96e+24 J

For comparison, according to https://ourworldindata.org/energy-production-consumption the total amount of energy consumed on Earth in 2023 was 180E3 TWh i.e. 6.48e+20 J

Slowing down the Earth by one second would be equivalent to 7661 times this amount.

adalacelove• 1 year ago

According to Wikipedia [1] we consume 9717 Mtoe or equivalently 408 TJ (per year, although it is not explictely stated, which I find annoying).

The earth moment of inertia is about I=8e37 kg m2 [2]

The energy extracted by a slowdown of angular speed from wa to wb would be 1/2 I(wa2-wb2).

Approx wa=2pi/86400 and wb=2pi/86401. Energy extracted: 4.9e24J=4.9e12TJ.

We would have energy for about 12 billion years.

If I double check with Kagi's assistant with Claude 3.7 (I'm in my phone and I could easily have made an error) it starts with my exact reasoning and figures but messes up final numbers (so close!!!) to give a total of 40 billion years, which nevertheless is the correct order of magnitude.

[1] https://en.m.wikipedia.org/wiki/World_energy_supply_and_cons...

[2] https://scienceworld.wolfram.com/physics/MomentofInertiaEart...

mmooss4• 1 year ago

https://news.ycombinator.com/item?id=43526555

j453• 1 year ago

The topic is very interesting. The spin of science, is not.

Side story: What's to argue over?

There's no shortage of scientists with breakthroughs who are pretty much abused by their profession and colleagues, sometimes for decades, simply for exploring possibilities and capabilities that are more than safe and conservative and incremental.

Either it's true, or it's not, and it can be explored, or not.

Division breeds who is right and wrong, not what is right or wrong.

Maybe it can be proven, maybe not. Maybe it's true and we don't understand it yet. The naysayers might just not be wanting someone else to succeed.

j453• 1 year ago

Happy to be downvoted over silent disagreement.

Even happier to get input and maybe learn.

vessenes2• 1 year ago

I didn't downvote, but since you asked for feedback, I'd venture a guess that most who did think your post doesn't add anything to the discussion. It's vague, not topical to the paper and isn't falsifiable.

A related topic, the emDrive, which had plenty of controversy, is something readers of this thread want to talk about; the specifics are a better fit for this crowd than the meta questions, esp. when vaguely introduced.

1970-01-01• 1 year ago

A bad question, as it has been doing that literally (rotationally) since before life started. This power is busy generating the magnetosphere. We would not be enjoying our nice oxygen atmosphere and would be as dead as Mars if Earth's rotation wasn't also powering a dynamo.

mr_mitm5• 1 year ago

It doesn't take any energy to maintain a static magnetic field though.

jagger27• 1 year ago

Earth's magnetic field isn't static, though.

pfdietz• 1 year ago

The currents that produce the magnetic field are flowing in liquid metal with nonzero resistivity.

fallingknife5• 1 year ago

Earth's rotation is also generating the power that is moving the Moon's orbit slowly away from Earth. There will be no more total solar eclipses in 600 million years because of this.

deadbabe• 1 year ago

Suggest a hard sci-fi story where humans abuse this so much the Earth basically stops rotating.

Rygian• 1 year ago

I've already read one where some weird alien ants hollow out the earth to make it spin faster, and take advantage of the increase in speed to generate power somehow (maybe by building a geostationary conductive belt around the planet, that acts as the "stator"?)

Hyperboreanal• 1 year ago

Saying what book you're talking about is kind of a spoiler now for anyone that happens to be reading its series. Are there spoiler tags on HN? <SPOILER> The Long Utopia, book 4/5 of the Long Earth series by Pratchett and Baxter. </SPOILER> The series has very meh characters/dialogue, excellent ideas and sense of nearly possibility-unlimited discovery that's executed very well, highly recommend if that's your cup of tea. Ended up skipping all the flashback chapters near the end of the series though, that felt like a load of filler

MaxikCZ• 1 year ago

Wouldnt hollowing the earth not change its rotation speed? And if the hollowed material would be deposited on surface, wouldnt the speed actually decrease?

hammock• 1 year ago

Eric Nylund’s Jack Potter series. See an earlier comment

owenpalmer• 1 year ago

Imagine trying to speed up the Earth's rotation!

bigmadshoe• 1 year ago

Reminiscent of 'The Gods Themselves' by Isaac Asimov

bmacho2• 1 year ago

Imagine a massive planet spinning in empty vacuum. Can the inhabitants slow down their planet, and generate electricity?

I suspect that they can generate electricity with angular momentum with it, that can be only used to do work with the equivalent angular momentum.

randomNumber7• 1 year ago

Maybe if we use the moon (and ideally get 2 more) we can build a giant generator.

drewolbrich• 1 year ago

The Moon's tidal forces are already slowing down the rotation period of the Earth, which was apparently only 5 hours long about 4.5 billion years ago.

qnleigh7• 1 year ago

Yes, but when you consider the combined system of the earth and everything that affects its orbit, angular momentum is conserved.

themaninthedark• 1 year ago

There was a decent science fiction serris based on this premise:

https://www.goodreads.com/book/show/700919.Signal_to_Noise

https://www.goodreads.com/book/show/737628.A_Signal_Shattere...

jaggederest• 1 year ago

Eric Nylund's books are uniformly excellent, even (perhaps surprisingly) the Halo tie-ins

genewitch4• 1 year ago

Never heard of him

genewitch4• 1 year ago

"Decent"

yhager• 1 year ago

By quoting the word "Decent" you mean it is actually excellent, or is it actually poor?

pavel_lishin2• 1 year ago

I thoroughly enjoyed them! I think I have both in paperback, though as a teenager, I managed to read them out of order.

watersb• 1 year ago

Ideally enjoyed these. Can't find them as ebooks.

The first one was where I first encountered the idea of the "One Electron Universe":

https://en.m.wikipedia.org/wiki/One-electron_universe

A major plot point of these books is an alien technology that enables teleportation by somehow tapping into the Earth's angular momentum.

LegionMammal978• 1 year ago

It would be interesting if this works. Last time people were hyping up a tiny effect with big ramifications that can only exist due to a subtle 'loophole', it was the EmDrive stuff that turned out to be driven by measurement errors. But I'm no expert in electrostatics.

api3• 1 year ago

I was about 99.99999% sure that one was bogus because it was violating bedrock conservation laws. I'm not sure that this does. AFAIK there is no conservation law that says a spinning mass can't extract power from that.

Still... it would have been hilarious of the EmDrive had worked.

"Well, they've progressed! Last time we checked in on the third planet in this star system its inhabitants were still using warp drives to heat food. They appear to have realized this."

Certhas7• 1 year ago

For the EmDrive it also was that the claimed theoretical mechanism was mathematically impossible, because it was based on equations that (like all known equations and everything ever observed) satisfy the conservation laws.

That's a good question actually. Supposedly this is extracting energy from the rotational kinetic energy of the earth. I haven't looked at the paper but you'd need to worry about conservation of angular momentum here.

Given that the cited physicists didn't dismiss this out of hand I assume this is accounted for somewhere...

qnleigh7• 1 year ago

Well conservation of energy says you can't extract energy out of nowhere. In the paper they claim that the extracted energy comes at the price of slowing down Earth's rotation. But then this seems to violate conservation of angular momentum... Maybe it depletes Earth's magnetic field instead?

sroussey• 1 year ago

The Earths rotation already generates power for us: wind. It’s why the jet stream only goes one direction.

cma• 1 year ago

Foucault's pendulum also orbits in one way, but is that generating more power than put into it by starting it off?

kurthr• 1 year ago

And don't forget the tides, both solar and lunar.

I'm sure a large enough mirror and photocell could get power out of the aurora borealis.

An argument that the magnetic field in a location remains completely constant as the earth rotates seems bizarre, but so does the idea that it's large enough to economically extract power.

kadoban2• 1 year ago

Are the tides caused by Earth's rotation? My understanding is they're not.

I know they're a bit of an inter-related system, but I thought if anything tides mess with rotation (eventually causing tidal lock), not so much the other way around.

How big are the solar tides? Never really considered that tbh. Looked it up, they're about half the size of the Lunar ones? Wild.

babyent• 1 year ago

Is it possible to speed up the wind?

righthand• 1 year ago

Sure, cause constant heating and cooling and loop it.

_dain_• 1 year ago

Yes, run power to wind turbines to use them as giant fans

jcgrillo• 1 year ago

Yes that's how airplanes work

peterashford• 1 year ago

Wind power is mostly due to solar energy. Earth's rotation contributes a very small amount and even that smaller effect is more located in the upper atmosphere where we don't collect wind power versus solar caused pressure gradients

rokkamokka• 1 year ago

While true, if the earth stopped rotating the sun would also stop being "evenly" distributed around the globe, which would affect wind patterns a lot

IncreasePosts• 1 year ago

Isn't that more of the sun+rotation?

fsckboy2• 1 year ago

a substantial amount of wind is also caused by (differential) solar heating: that's why wind doesn't only go in one direction

if you've ever spent time at the seashore, the wind comes in off the sea during the day (because of rising thermals on the land side) and blows back offshore at night (because the land cools and the sea is now warmer) that time in between the air is dead-still, and that's when the swarms of gnats can find you.

veqq• 1 year ago

But the earth's rotation makes the solar heating _differential_

timewizard3• 1 year ago

It’s why the jet stream only goes one direction

Yet local winds blow in almost every direction. So to access that energy you'd need a structure 5 miles tall.

thayne4• 1 year ago

Or a balloon or kite five miles up.

bhk2• 1 year ago

None of the power comes from the Earth's rotation. Angular momentum is conserved in a closed system.

thayne4• 1 year ago

But it isn't a closed system. Tides transfer angular momentum from earth's rotation to the moon's orbit.

aurizon2• 1 year ago

We could use this, by adding power, to fine tune the day to eliminate leap years...;)

ada19812• 1 year ago

Interesting. Yes could we put power into a similar system and accelerate the rotation?

aurizon2• 1 year ago

turn fast enough = we can all fly... while we wear armor like a turtle...

mentalgear• 1 year ago

how practical is this, eg how big would a device have to be to produce any meaningful energy?

miller_joe• 1 year ago

Strong flashbacks of Southland Tales (2006). Underrated movie with this as a core premise

shadowgovt• 1 year ago

I have no idea on the claims here, but there is one method for extracting work from the magnetic field that I very much enjoy.

A magnetorquer is an attitude control system on a satellite that runs on electricity. Run the electricity through an electromagnet. The magnet couples to Earth's magnetic field and turns the satellite, like a compass needle.

signa11• 1 year ago

but _why_ does the earth rotate ?

exabrial• 1 year ago

They made a really terrible movie about this.

Spoiler: they nuked a bunch of stuff.

asdefghyk• 1 year ago

I ask, ..... Would Extracting power would have the side effect of slowing down the earths rotation ?

dabbz• 1 year ago

Futurama already did this episode though? It caused the Earth to stop spinning.

K0balt• 1 year ago

I mean… yes, the earth’s rotation can easily generate power. All you need is a gyroscope spinning in a vacuum on frictionless supports to make that work. Of course it’s only 1 revolution per day, but still, if it’s big enough…

It’s hard to beat solar though.there are very few technologies that stack up better financially than “just buy more panels” in most of the populated world. Batteries are really the key.

Can Earth's rotation generate power? Physicists divided over controversial claim

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