Like fossil fuels come from organic matter that grew because of the sun. Is there any form of energy on that cannot be traced back to the sun in some way?
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Almost.
- Nuclear energy comes from natural materials of the earth that arrived in their current form (it is basically recycled supernova energy from long long ago)
- Geothermal comes ultimately from the gravitational energy of the earth itself compressing and heating it
Literally every other energy source (edit: aside from tidal and some others that people pointed out) is some form of modified and stored sunlight, in some way or another.
Although geothermal could be because of the rotation of the earth compared to its core along with tidal forces.
Although I’m not sure how much of that is from the sun or just in general.
Not sunlight though. Just the sun’s gravitational affect on the earth as well. But nuclear is definitely extrasolar
It could be, but it’s not. A big part is nuclear decay, strangely enough. Some is from primordial heat, and some is from the motion of the core, but mostly from regions rising and falling, not rotation.
There is also kinetic energy when objects in space crash into the earth. RIP 🦖🦕
Hypothetically those would average to O as they strike randomly though right?
This guy doesn’t have numbers on their keyboard.
Well it’s still incoming energy, and it’s a scalar quantity. One could argue that average velocity/momentum incoming from the strikes might be zero, but I don’t think that’s the case either
Yeah, AFAIK the big meteor showers all come from the “oncoming” direction as Earth orbits the sun. That actually might average out to zero linear momentum, depending on how they’re spaced, but it definitely is reducing the Earth’s angular momentum around the sun.
Oh yeah that’s what I was thinking of, so it would still add heat to our system ok
Geothermal comes ultimately from the gravitational energy of the earth itself compressing and heating it
One thing that’s at least 97-percent certain is that radioactive decay supplies only about half the Earth’s heat. Other sources – primordial heat left over from the planet’s formation, and possibly others as well – must account for the rest.
https://newscenter.lbl.gov/2011/07/17/kamland-geoneutrinos/
A surprising amount of geothermal energy comes from radioactive decay. Gravitational binding energy is indeed very large, but much of that heat has already radiated away before a solid crust formed.
But it sounds like, based on other comments, those things are from stars too, right? Like the sun caused the formation of our planet. It also contributes to tidal forces. And radioactive materials also came from other stars if not our own star. Right?
If main sequence stars were candles, supernova would be a nuclear bomb. Elements heavier than iron are only produced in events that are so energetic, the luminosity can exceed that of the entire galaxy they are in. What was a star becomes a neutron star or black hole afrer the supernova. Main sequence stars do not produce heavy elements until they die.
So if you want to say that radionucleotides come from stars, I won’t play semantics police, but that is reductive to the point of missing out on how incredibly unique supernovae are as a stellar phenomenon.
That’s so rad actually. Thank you for enlightening me. Isn’t that amazing that the elements on our planet came from those events
To add to this most of the suns energy leaves the planet. Very little is retained. What the sun provides is a source of low entropy.
Geothermal, which at this point in geological history mostly comes from decaying radioactive elements. It’s of minor industrial importance, but it fuels undersea vent ecosystems, and does see some use in traditional cultures.
Speaking of radioactive elements, our nuclear generators all run on energy trapped from ancient cosmic catastrophes. Probably colliding neutron stars, for the most part. Hydrogen fusion has been made to happen for research and in atomic bombs - although interestingly we can’t use the same kind as the sun does.
Tidal energy is used for some power generation, and it comes from the kinetic energy left in the Moon, and to a lesser degree the Earth itself, from the formation of the solar system.
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Do you have any source for the radioactive decay part? I always thought the Earth was hot inside simply because it hasn’t finished cooking down from when it formed as a ball of molten stuff. Like a hot potato.
Uh, I’ll find one, and edit. It confused the shit out of Victorian scientists, because they had a good guess how old the Earth is from biology, and had thermodynamics, but it was telling them volcanism shouldn’t still be happening.
Edit:
Wikipedia mentions it in the geothermal article, but the source is a textbook, and who has time and/or money for that? There’s also the article on the age of the Earth. Ah, here we go, in the article on Earth’s internal heat budget. Somebody also linked a paper on it elsewhere in this thread.
These give slightly different numbers from each other, but the gist is that radioisotopes (Uranium, Thorium and Potassium being the primordial ones) account for at least half.
Oh interesting. It turns out it’s more like a demonically possesed hot potato, that is still cooling down but also gets warmer from demonic activity under the earth.
More like a hot banana, going by the potassium.
I actually had no idea radioactive potassium was primordial until I read this. That’s neat.
kinetic energy left in the moon
Does that mean that one day the moon will stop revolving and we will be tidal locked? If so, does that theoretically happen before the sun consumes us?
It gets both slower and further away (to stay in orbit) every year, by like 2 cm IIRC.
If you could go back a couple billion years it would be huge in the sky. There was even a period, called the Jatulian, where you might not have asphyxiated in the early atmosphere. There wouldn’t be much else to look at, though, and just your skin germs would be futuristic enough to completely change the course of life on Earth, once they get into the environment.
So it will eventually escape it’s orbit?
Uhh, I actually don’t know the answer to that. Orbital mechanics is hard; see me being bamboozled elsewhere in the thread. At some point I’m guessing tidal forces from the sun would start having a major impact, since in reality they’re both in it’s gravitational well at the same time as they orbit each other. Usually that doesn’t make orbits more stable.
Also, the sun will go red giant in 4 or 5 billion years, and will eat Venus for sure. The Earth and Moon may well suffer the same fate, we’re kind of right on the projected edge.
Nuclear (fission) energy did not originate in our sun, it originated in some other sun a long time ago, or potentially a neutron star merger.
Tidal energy originates from gravitational collapse and the conservation of angular momentum when our planet and moon formed, and does not rely on our sun, but similarly originated in the dust clouds that formed our solar system which were put there by some other sun.
Geothermal is a hybrid of these two, with some combination of nuclear decay heating and gravity-driven heating.
Hydrocarbon, wind and hydroelectric all heavily involve our sun somewhere in the process though.
Tides are from the pull of the moon’s gravity. And the moon formed from another body colliding with the Earth. It’s not just due to angular momentum and the moon forming out of cosmic dust like the Earth did.
Without angular momentum it would have fallen back down to the Earth instead of going into orbit. It’s the orbit specifically that powers the tides, not just it being there.
But yeah, you’re right. Beyond providing the materials dust was not involved.
Tides don’t rely on the sun but are affected by the sun.
They said “tidal forces,” not “tides.” Tidal forces refer to the differential of gravitation between two points on an object. It applies in any situation where gravity is a factor, although typically only very large massive objects experience noticeable effects. That said, the concept of spaghettification (objects being stretched out as they approach a black hole’s event horizon) is based on the fact that tidal forces near a black hole would be so enormous they would be observable for even small objects like people.
Hm. Touche.
Everyone is giving you some great answers, but there are since more subtle ones worth mentioning too.
When you take a picture of space, the light from those other stars hits the camera sensor and induces a tiny electrical charge, which is captured, amplified, and analyzed to create the image. Your eyes actually work that way too.
It’s not an energy source as you typically think of it; it never powers anything, but technically it is* energy that exists on Earth that didn’t come from our sun.
That’s awesome. Now that you mention it I remember reading that supermassive black holes are a source of cosmic radiation too.
If it doesn’t have to be energy that’s used as such, there’s more answers.
Neutrinos stream through us each moment at a flux pretty similar to sunlight. Day and night; they sail right through the Earth for the most part. Most of it is from the sun’s core (directly), but some of it is from distant cosmic monsters like supernovae and jets whipping around black holes, and some of it escapes from nuclear reactions on Earth, in particle accelerators and nuclear generators or from decays in nature.
Gravitational waves from distant black hole mergers have been detected on Earth, and they do carry energy.
Meteors hit the Earth, and sometimes they carry enough energy with them to cause damage, like in Chelyabinsk.
You mentioned cosmic rays. The most energetic ones far exceed the energy of anything our accelerators produce, and it’s still a mystery where those unusually powerful ones come from.
Stars give out a lot of electromagnetic energy in the form of radio, microwave, infrared, ultraviolet and x-rays as well as visible light, and probably gamma rays too, although I haven’t heard anything about that one. Many frequencies of light are heavily or even fully absorbed by the upper atmosphere of Earth, which is part of what makes space telescopes necessary.
Lighting strikes on Jupiter are very noticeable as noise on some radio bands. I’m not actually sure how much of the wind that powers that is the Jupiter equivalent of geothermal, and how much is ultimately from sunlight. I’m guessing it skews to the latter, though.
Tidal.
Gravitational interaction between the Moon and Earth orbiting each other and the Sun …
Moon/Earth were formed within the influence of the Sun and the solar system.
Unless a giant comet ( attracted by Sun’s larger gravity well?? ) introduced something extra-solar , almost everything is under the influence of the Sun.
Geothermal comes from the heat in the core, produced by gravity crushing the particles together during the Earth’s formation.
Nuclear energy comes from the fission and fusion of particles here on earth.
Tidal energy comes from the gravitational pull of the moon.
Hydro comes from the movement of water (though you could trace this back to the sun causing the water cycle).
Earth wouldn’t coalesce without the sun. Thus no geothermal.
Nuclear materials were formed in supernovas. Can’t have that without a star.
Moons tides wouldn’t exist if Earth didn’t have an orbit of its own. Again, sun needed.
Hydro you already figured out.
I guess it depends on how far back you want to go. The sun wouldn’t exist without gravity.
Well, seeing as how the question is directly asking “is there any energy you can’t eventually trace back to the sun”, you shouldn’t ever stop going back unless you can reach a definitively non sun answer
(Gravity arguably works - probably the nuclear attraction force as well, electromagnetic I believe)
Yeah, although I’m not sure if I’d consider the four fundamental forces as “energy”, exactly.
When most people ask the question, they mean in the context of the current environment, where the Earth, moon, etc. are already formed.
Where did the Sun’s energy come from?
The gravitational collapse of a cloud of mostly hydrogen in the vacuum of space.
And anything falling together under gravity was given that kinetic energy from somewhere* and ultimately it can all be traced back to the Big Bang.
As for where that energy came from, it’s possible we’ll never know. Most organised religions (and no doubt a few disorganised ones) have their theories, of course. You may subscribe to one of these.
* This is the principle most commonly simplified as “what goes up, must come down”
What’s really interesting is that “what goes up, must come down” doesn’t hold at the scale of the universe. A naive thinker might imagine big bangs happen in cycles, but in fact this doesn’t appear to be the case, because space itself is expanding faster than galaxies are falling back together. And it’s not just faster now, but it’s accelerating! At some point, space will be expanding faster than the speed of light, and because of that, the entire universe will disappear from our view.
Despite that, the Milky Way galaxy is still close enough to the Andromeda galaxy that they’ll collide in about 5 billion years, so don’t worry, there’s still interesting things to come! If you want to see it, though, you’ll need to be somewhere other than Earth, because by that time the Sun will have advanced in its life cycle enough to render Earth completely uninhabitable by all known forms of life.
Just to add onto this comment, it’s thought that the Sun is slowly getting hotter and more energetic as it gets older and in approximately 1 billion years, the Sun will be hot enough to render the Earth uninhabitable for life as we know it.
In approximately 5 billion years, the Sun will reach the end of its life and expand into a red giant, swallowing up Mercury, Venus and potentially Earth in the process. Interestingly, once the Sun reaches this phase of its life, it could potentially warm up some of the outer moons enough for them to have liquid water, if they can hold onto an atmosphere of course.
Someone please correct me if I said anything wrong, I’m just a casual space nerd and not a professional astronomer.
Ran we starlift the Sun to make it last longer?
What does “lift” mean in this context? A web search turns up a Doris Day musical from 1951 which is kind of funny to think about but I’m guessing is not what you mean.
As for the general case of modifying the Sun - or any star - in some way, it’s all but certain to need a huge number of resources (or amount of energy, or both), and considering the Sun is on the order of a million times larger than Earth, far more than can be obtained from Earth alone.
I mean, I’d like to be proven wrong and there’s some exotic-physics way of causing the helium in the Sun to spontaneously turn back into hydrogen, but if that was easy, you’d expect that we’d see stars do that by themselves occasionally. We don’t, which implies there would still need to be some kind of energy input required to get it started.
Without exotic physics, we’d pretty much need on the order of the energy that the star had output from birth up to that point, and if we had that, we’d be better off using that energy in other ways.
We could get all Earth life off Earth and into a self-sustaining, space-faring habitat with a minuscule fraction of the resources. We might be better off aiming for something like that.
https://en.wikipedia.org/wiki/Star_lifting
any of several hypothetical processes by which a sufficiently advanced civilization could remove a substantial portion of a star’s matter which can then be re-purposed, while possibly optimizing the star’s energy output and lifespan at the same time
Brane cosmology suggests the collision of two branes can result in a big bang event, but yes, that is beyond an event horizon.
No, geothermal energy comes from the earth core for example.
It’d be interesting to think of novel ways of getting power from sources other than the Sun.
Theoretically, one could, say, build a space-elevator-like device and use the centrifugal force pushing it away from Earth to run a generator. Of course, for that to work, the weight would have to continually receed from Earth, and may require continually replacing the weight. Ultimately that would rob the Earth of angular momentum.
That feels like a perpetual motion machine, because the Earth coming together in the first place released energy. I’m guessing it would take more energy to get the weight to geostationary orbit than you could get back.
Maybe it would work if you lowered an asteroid down, instead. And then you could mine it on arrival.
Edit: Nope, it maths. I think it’s down to angular momentum being kind of separate from the gravity well.
So, first off, I’m definitely not arguing this would be a feasible way to get energy in a practical sense in the real world.
But, it wouldn’t be a perpetual motion machine. It’d produce less and less energy as the Earth ran out of angular momentum, ultimately approaching zero.
I don’t think I’ll do the monster math on this, but my gut tells me one could technically and theoretically (not so much in practice) get more energy out of that than it took to get the weight up there. (It might be that the Moon would limit how much energy could be got out of this scheme as well, but I think even with the Moon involved, I think it could still be a net energy gain.) That said, without running the numbers, you might well be right!
Ah shoot, it looks like you posted a minute after my edit, and probably didn’t see it.
Orbital mechanics is big-boy stuff, and gets really subtle the moment you’re doing anything non-trivial. This is just two-body, so in theory it should be doable, but the tether pulling out energy as it goes along makes it more complicated. It’s a bit much tonight, but maybe I’ll give it a shot later. One thing that’s clear just from the equation for orbit energies is that there’s no limit to how much energy can end up inside the weight itself, as it gets faster in proportion with increased height.
For the calculations, I was thinking maybe one could cheese it a bit and get a relatively decent vague idea of the answer if not a more rigorous idea.
My vague idea was that gravity follows an inverse square law while the centrifigul force equasion is linear relative to the length of the tether. We know that gravity pulls toward Earth and the centrifigul force pulls away. So the net force on the weight at any one time is the centrifigul force equasion (a linear equasion) minus the gravity equasion (an inverse square equasion). We also know that the point at which that sum reaches zero is exactly the altitude of a geostationary orbit.
Work equals force times distance. So suppose we just took the area under the curve of that net force equasion from r equals the radius of the Earth to r equals roughly the furthest we vaguely guess we could send the weight before it starts to get sucked into the Moon’s gravity well. And then we divide that by the area under the curve from r equals the Earth’s radius to r equals the altitude of a geostationary orbit. That should at least give us a figure like “the amount of energy we could get back in theory would be roughly x times what it takes to get the weight past the geostationary orbit altitude threshold.”
The mass of the weight would be a term in that net force equasion, but if we just decided the mass was “one unit”, that’d make things a bit simpler. If we only care about the ratio of the energy we get back to the energy we put in, the weight should cancel out anyway.
This approach would certainly ignore a lot of things, but if the answer was “A Large Number™”, I think it would still be reasonable to handwave the details. (If the result was like 1.1 or something, probably “no, that doesn’t even work in theory” is the much safer bet. Let alone if it was less than 1.)
I guess if we wanted to get even more sophisticated, we could take into account things like the weight and tensile strength of carbon nanotubes and see if it would be infeasible to build a tether sufficiently strong without adding a huge amount of weight during the ascent. But I’d be willing to pretend in this thought experiment that we have some material with infinite tensile strength and zero weight at our disposal.
Anyway! Still not trivial math, quite, and definitely not terribly precise or rigorous, but not quite so “big-boy stuff” as modeling the rotational frames and such.
Yeah, that’s probably a better approach than using the energy of the orbits.
Okay, so if we set the weight to 1kg, force is rRe2 - GMe/r2, where Me is the mass of the Earth and Re is it’s rate of rotation, which is a low number in radians per second. The antiderivative along r is then -1/2r2Re2 - GMe/r, but you actually don’t need that because you just take the derivative again to find extreme points. rRe2 - GMe/r2 can be restated as (r3Re2 - GMe)/r2, and that numerator is a diverging, increasing function as you move away from 0, which means yes, the energy is unlimited.
Welp, I was wrong. I think the trick here must be that the rotation of the Earth didn’t actually come from the gravitational collapse itself, but from the pre-existing inhomogeneities of velocity distributions in the early solar system. Even if you could slingshot the mass around the sun, back into the Earth, and collect it again, you would somehow transfer enough of Earth’s angular momentum back to the sun to offset the energy gained.
Wouldn’t that technically be from the sun, too, though? Since the earth orbits the sun due to its mass/gravitational pull?
What I posted would take energy from the angular momentum of the Earth rotating on its own axis, not the (angular?) momentum of the Earth revolving around the Sun.
Honestly, I’m not 100% sure the right way to talk about where the Earth’s angular momentum about its own axis came from. I want to say gravity while the Earth coalesced from dust/gas, but I’m not sure that’s quite true because I think the gravity would only kindof “concentrate” the angular momentum that was already present in the gas/dust that was already present in the cloud. (Like, when an ice skater pulls their arms toward their body and speed up, that doesn’t add energy or momentum to the system that is the ice skater.)
So, maybe it’s more accurate to say it’s kinetic energy from the Big Bang and/or supernova(s?) that produced the gas/dust that eventually formed the Earth?
But I’m pretty sure this scheme would get energy from a source that wasn’t ultimately from the Sun.
https://youtu.be/N1pIYI5JQLE?si=uciOf3JzwF8S6qDy
Y’all need to pay attention to the actual question being asked. Geothermal, nuclear, tidal are all originating with the formation of the galaxy and the formation of stars.
Ask yourself: WHERE did the earth get X,Y,Z? Where does nuclear materials come from: supernovas. How do planets form? A gas cloud coalesces, the star forms, and the remaining gasses coalesce in that gravity well formed by the star. Without a star forming in the middle, you get no solar system. You get cold blob of gas or a cold dead rock. Where does tidal come from: same gravitational interactions that require a sun sized object - tides aren’t 100% earth & moon.
Stars are like the seed needed to form crystals. Without them, nothing else forms. Just a bunch of basic chemicals floating around.
OP said the sun, indicating they meant our sun. Other commenters have clarified that fissile material (and a shit-ton of the other stuff further down the periodic table) didn’t come from our sun, but other suns.
I mean ya okay I see that. But still very neat that all energy in every form we have can be traced back to a star if not our own star. That’s so interesting! Let’s get started on the Dyson sphere.
That video was above my pay grade I think. But ya I like what you’re saying here. Sounds like all of our energy does come from a star if not our own star
The heat in the Earth’s mantle and core comes from the gravitational potential energy of the original stellar dust clouds the Earth originally accreted from. So, geothermal energy mostly isn’t. And there’s also evidence that a few natural uranium deposits have undergone natural nuclear fission chain reactions. That one’s a pretty negligible amount, though. Other than that, no, it all traces back to the sun.
Earth wouldn’t have coalesced without the sun in the middle. Otherwise we’d still be a gas blob.
Nuclear materials were formed in supernovas. They wouldn’t exist in the first place without a star.
Nuclear materials were formed in supernovas. They wouldn’t exist in the first place without a star.
Well, yeah, sure. But that star is not the Sun.
Earth wouldn’t have coalesced without the sun in the middle. Otherwise we’d still be a gas blob.
I mean, sure? It wouldn’t be a gas blob, but it would be a very different system. But that still has nothing to do with it – even if the gravity of the sun influences how the earth coalesces, it’s still not where the thermal energy of the core came from. That came from the potential of the dust itself.
Which wouldn’t have the potential if the larger sun didn’t form first to create the gravity to allow the rest to form.
Star != Sun is just pointlessly pedantic. You’re not trying to learn anything, just be a smartass.
Which wouldn’t have the potential if the larger sun didn’t form first to create the gravity to allow the rest to form.
This is simply incorrect. The gravitational potential of the body would be there regardless of what else is going on around it. And either way, the OP’s question was not about some hypothetical where the sun doesn’t exist, it’s about where energy came from in the real world.
Star != Sun is just pointlessly pedantic. You’re not trying to learn anything, just be a smartass.
? The OP’s question was literally “is there energy on earth that didn’t come from the sun.” I am not the one being pedantic here.
Would hydro and geothermal count? Wouldn’t count wind because wind is caused (mostly) by the sun heating things up.
I wouldn’t count either then. Hydro is ultimately powered by precipitation, which is caused by the sun evaporating water. Geothermal is ultimately caused by the gravity of the sun affecting the earth.
I agree with hydro, but you’re wrong about geothermal. Tidal forces caused by the Sun are minuscule compared to that of the Moon. Also, Earth still has a decent amount of latent heat caused by its formation.
Does it? I thought it was overwhelmingly radioactive decay driving it at this point.
Geothermal is ultimately caused by the gravity of the sun affecting the earth.
No, that’s how it works on the Jovian moons, but Earth’s interior is heated by some mix of radioactivity and retained primordial collision heat.
Well there is still nuclear, piezoelectric, and kinetic, at least.
What are you going to use to actuate your piezoelectric or pedal generator? If it’s alive, it’s probably eating sunlight somehow itself.
Rocks collide in space all the time. 🤷🏻♂️
I guess if you can catch a meteor, that is plenty of energy, haha.
Hydro is also the sun - rain is delivered by (solar) evaporation and wind.
Fishy-breath Mantis
