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Can Earth's rotation generate power? Physicists divided over controversial claim (nature.com) 11 points by qnleigh 13 minutes ago

https://archive.is/5GHWF by Panda_ 8 minutes 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) by dang 9 minutes 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. by vessenes 11 hours ago

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

Making total power for the 30cm shell = 0.44 picowatts. by threeseed 14 hours ago

[flagged] by MichaelRo 13 hours ago

I don't see a problem with the LLM answer. The field near an FM station can reach 100mV or more. The maximum safe exposure levels for general public at 100MHz is 30V/m according to standards. by serm56 11 hours ago

The part about FM sounds like BS, but much more than 1V at the antenna is definitely possible if you're close to an AM station, enough to cause unintentional receivers to emit sounds. by userbinator 10 hours ago

Well, I'm expecting an average case, not "playing AM radio with grass", because in the vast majority of the cases, antennas won't be situated within a few meters of the radio tower:

https://www.youtube.com/watch?v=b9UO9tn4MpI by MichaelRo 9 hours ago

Still more net energy than fusion reactors have ever produced. by cedws 13 hours ago

No, it took far more electricity to make than it produces over any conceivable lifetime. by Retric 10 hours ago

That's untrue by number6 11 hours 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) by ziofill 10 hours 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. by Retric 10 hours ago

Well, the watts that come out of the rotational energy must match the ones we need, for energy conservation. by ziofill 9 hours ago

Sure, but there’s no “eventually” it happens instantly.

The only way you’ll care about what happens eventually is if you’re concerned about some detectable result. Meanwhile individual rocket launches to Mars extract like 10^18+ times as much energy as this will over it’s lifespan and those still aren’t detectable. by Retric 9 hours 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. by Kerbonut 12 hours ago

Sounds like solar power with extra steps by evan_ 2 minutes ago

by 9 hours ago

Would this reduce the magnetic field stength allowing more cosmic rays to reach the surface. by throwaway48476 9 hours ago

I, for one, look forward to ground-level auroras. by xattt 9 hours 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? by ChrisNorstrom 13 hours 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. by ChuckMcM 13 hours 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. by fpoling 9 hours 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]." by whatshisface 12 hours 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. by ngruhn 11 hours 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. by marshray 13 hours ago

I've often wondered about a similar issue with wind power. Would enough wind turbines dampen the force of wind? by nopelynopington 10 hours 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. by padjo 9 hours ago

If a politician talks in front of a wind turbine, does it make a sound? by nprateem 10 hours ago

I'm not saying that is why we left Mars. by 6510 13 hours ago

Yeah, after making an oopsie with a runaway greenhouse effect in Venus. All this has happened before and it will happen again. by aeve890 11 hours ago

Alternatively, we could speed up the Earth! Let's get rid of those pesky leap seconds! by modeless 11 hours 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. by foxglacier 13 hours 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. by FilosofumRex 13 hours ago

It's slowing down mostly because of drag induced by tides, which involve the sun and the moon. The total system including the earth, moon, sun and everything else does conserve angular momentum.

But this paper seems to imply that Earth, isolated from evening else in the solar system, could be made to slow down. This does seem like a violation of conservation of angular momentum... by qnleigh 11 hours ago

This is poorly discussed in the article and AFAICS it reaches wrong conclusion.

I think the energy comes from weakening of the magnetic field and the energy stored within it, not from slowing down earth rotation. Earth as the result may rotate faster as the moment stored in the field will be transferred back to Earth as in the example with a sphere from the article. by fpoling 8 hours ago

I once read a book (Signalz, by F. Paul Wilson), where someone got transmitted power working, and it was part of ushering in eldritch dimension-dwellers. In that book, Tesla was part of some kind of dark wizard cabal.

Don’t remember, exactly. It was a while ago. by ChrisMarshallNY 9 hours ago

by 12 hours ago

Wouldn't this slowly slow the earths rotation down? Let's say everyone tried to build power plants using this. by ninetyninenine 11 hours ago

Ah didn't see this comment and I asked the same. Yes, right? The energy has to come from somewhere... by ziofill 10 hours ago