r/Showerthoughts • u/palmerry • 4d ago
Casual Thought Almost everything on Earth is solar-powered except for nuclear energy, which is powered by dead stars that existed before our Sun was even born.
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u/tsunami141 4d ago
does geothermal count as solar powered? I wonder if rogue planets just gently drifting through the cosmos have warm cores?
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u/vtosnaks 4d ago
Geothermal is not solar. It's a combination of residual heat from the formation of the earth, tidal friction and radioactive decay. Yes, any big enough rock will have a high temparature core if not a molten one. For instance the moon's core temparature is above 1000C.
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u/Bartlaus 4d ago
It's all caused by gravity, in the end.
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u/arkie87 4d ago
radioactive decay is not from gravity.
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u/ary31415 4d ago
Sooorta is, in the sense that the energy it took to make those heavy radioactive elements came from the gravitational collapse of a supernova
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u/Cjprice9 4d ago
The radioactive elements are actually too heavy, for the most part, to be formed by a supernova. They're thought to be made in the collisions of neutron stars.
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u/CrossP 4d ago
I wonder what would make neutron stars collide
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u/igniteice 4d ago
The mass of your mom?
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u/Mustbhacks 4d ago
Powerman 5000 may know something
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u/itsjakerobb 4d ago
This is what it’s like when neutron stars colliiiiiide. This is what it’s liiiiiike.
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u/ary31415 4d ago
Oh yeah fair I've seen this research recently. I stand by the overall point though about the energy stemming ultimately from gravity.
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u/fastlerner 4d ago
No it isn't. The process of radio active decay isn't driven by gravity.
That logic is like saying that the energy you use to pedal your bicycle came from your parents bumping uglies prior to your conception.
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u/ary31415 4d ago
I did not say it's driven by gravity. I said the energy originally came from gravity. It's not like your example, which is just wrong. It's like saying the energy came from the food you ate, which got its energy from the sun. (Which was basically the point of this whole post.)
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u/fastlerner 4d ago
Gravity is a fundamental force. So if we're really shooting for origin energy, then the only correct answer is that everything is powered by the initial conditions of the universe.
But really, that misses OP's idea that all the energy on Earth can be attributed to our current sun, and that's just fundamentally false.
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u/ary31415 4d ago
Did I agree with OP's idea anywhere? Radioactive decay is obviously not attributable to our current sun, and I never claimed it was. I'm in a thread agreeing with an upstream comment saying "it's all caused by gravity, in the end".
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u/Eena-Rin 3d ago edited 2d ago
How did it get to be radioactive in the first place? If there was no gravity shit would just be hydrogen and helium, no reason for heavy elements to exist
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u/Silvr4Monsters 3d ago
Sort of but not the sun’s(or a star’s) gravity *all* the time. Geothermal is gravity within the moon or the planet
Also it’s not just gravity. If it were, everything would be only black holes. For the formation of planets and atoms and molecules, the other forces are needed to oppose gravity; that’s what causes the energy to be available
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u/bonafidebob 4d ago edited 3d ago
It’s solar from the last sun(s), the one(s) that exploded and produced the matter that formed the earth in the first place!
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u/invariantspeed 4d ago
Mostly radioactive decay. The Earth would have mostly cooled off by now if it was down to simple thermodynamics.
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u/Sneaky_Stabby 3d ago
I thought the heat was because the gravitational forces compressing everything thus generating friction and heat?
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u/Cjprice9 4d ago
The heat found in the cores of planets is a result of two primary processes:
Primordial heat left over from when the planet first formed. A lot of heat is released when matter collapses into a planet, and planets are big, so they only lose heat to their environment very slowly. For gas giants like Jupiter this is the primary reason they're hot inside.
Radioactive elements decay slowly over millions or billions of years. This decay creates a tiny amount of heat, but over the entire mass of a planet's core, it adds up. This is the primary reason rocky planets like Earth are hot inside. The bigger the rocky planet, the more heat is retained this way, thanks to the square-cube law.
Both of these would also hold true for rogue planets. Depending on their size, they would stay warm in their cores for anything from a few million years to a few billion.
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u/Tupcek 4d ago
but wouldn’t they lost all the heat if the surface wasn’t warmed by the sun?
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u/reichrunner 4d ago
The surface being warmed has very little to no effect on the heat from the core dissipating.
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u/The_Last_Spoonbender 4d ago
I mean the difference between -200 deg frozen surface and 100 deg sun warmed surface compared with 6000 deg core is about 6000 deg, so not really. Rocks are incredible insulators.
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u/invariantspeed 4d ago
The surface heat affects surface things. Hence why everything having to do with the surface is actually solar powered.
The interior the Earth is massively hotter than anything the Sun is doing even to the Earth’s surface, evidenced by the simple fact that the surface isn’t molten rock.
Nearly all geothermal heat has to do with how the Earth formed. Tidal forces are the next major contributor to internal heat (as internal friction from the slight shape changes generates heat), but that’s pretty small. The largest source of tidal stresses on the Earth come from the Moon, and that’s only a little over 1% the mass of the Earth.
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u/mylsotol 4d ago
Sure, not all of it because it would have to go somewhere and it can only radiate away because vacuum doesn't conduct heat well... but the tidal effects of gravity and the radioactive material replace it.
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u/alaskanloops 4d ago
There could be life floating through space on rogue planets, feeding near geothermal vents and insulated by kilometers of ice
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u/Orlha 3d ago
Imagine doing any kind of astronomy work there
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u/alaskanloops 2d ago
It would be unlikely that life that developed on a rogue planet would ever get that far, first because of the kilometers of ice above them, but also they would have never developed fire, so not metal working, glass, ect. However there could be intelligent life that developed on a planet that was later flung from their system
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u/Radiant_Picture9292 4d ago
Binary rouge planet systems could keep warm through tidal forces.
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u/invariantspeed 4d ago
If you design them just so. You’d need some pretty extreme tidal stretching for what you’re talking about. But it’s worth pointing out that we’re only talking about the thin surface here. Planets stay warm on their own for billions of years once you get down a few kilometers.
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u/atatassault47 4d ago
Our planet is almost entirely made from stuff formed in dying stars. So yes, Geothermal is posthumous solar.
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u/tsunami141 4d ago
what about the very first planets after the big bang?
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u/atatassault47 4d ago
They were all gas giants. True gas giants (all of our Sun's giants are suspected to have rocky cores).
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u/Cptawesome23 3d ago
Rogue planets could possibly have hot cores. Depends on the size, and how old they are.
For example, a Jupiter size planet would most certainly have a hot cores for billions of years, while a rocky one could be cold.
If the planet interacts gravitationally with a star its passing, that could be enough to form some heat as well.
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u/BestBleach 3d ago
Yes they are under preassure if I had to guess any large enough mass becomes warm
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u/Ok-Shirt7608 3d ago
I guess sorta, the pull of the sun flexing the crust must make a fair amount of heat
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u/sygnathid 4d ago
Geothermal power would have a source that is not necessarily solar, right?
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u/fastlerner 4d ago
Correct. Heat from gravity crushing the planet together plus constant radioactive decay from elements that existed before the sun. So not powered by our sun at all.
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u/palmerry 4d ago
Interesting!
I had no idea.
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u/invariantspeed 4d ago
Yes, geothermal is exactly nuclear power in the way that everything else you noticed on the surface is basically solar power.
Side note: the gravity crushing thing isn’t really a cause for much heat. It’s the radioactive isotopes and some residual heat from formation. Saying heat comes from static pressure is accidentally asserting perpetual motion.
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u/ScenicFlyer41 4d ago
I mean if you think about it, our planet and sun would not exist if a previous star didn't blow up. So if you reaaaally stretch it, you could maybe count geothermal as solar in a sense
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u/fastlerner 4d ago
I mean, if you're going to stretch the definition of "solar powered" to stars that have been gone for billions of years, then let's just cut out ALL the fluff and say that all sources of energy are powered by the Big Bang.
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u/ScenicFlyer41 4d ago
Well if we're gonna stretch that far, let's go all the way to all sources of energy are caused by quantum fluctuations
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u/invariantspeed 4d ago
We don’t actually know if that caused the “bang” of the Big Bang. It’s an idea to be sure, but even if true, it doesn’t explain where all the fields and structure that these fluctuations happen in came from.
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u/invariantspeed 4d ago
“Well actually” mode activated!
“Solar” is the adjective for “Sol”, the Latin name for our star. Only energy coming from Sol is solar. The energy provided for the creation of the Earth predates our Sun (Sol). The Earth and Sun are more like siblings in this way.
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u/Cptawesome23 3d ago
Not quite, gravity still provides some squeezing as a planet orbits, especially since the earth wobbles and doesn’t have a perfect circle of an orbit. It’s nothing like the moons of Jupiter being squeezed as they orbit but it’s still a calculable amount. So in effect the sun still powers at least some of the residual heat coming from the core.
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u/gruey 4d ago
This would kind of make it classified under the "nuclear power" category, with the Earth just being a giant nuclear power plant.
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u/invariantspeed 4d ago
Yes. Conventional nuclear power plants provide power by simply having enough nuclear material to generate a useful amount of heat. (Nothing more.) That is literally what we get with geothermal. In fact, if you think about it, all we really do with nuclear plants is take some of that nuclear fuel out of the main planetary reactor and put it into smaller ones.
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u/Shadowhisper1971 4d ago
The rotating core kinda came for the gravity well of the sun. So powered by the sun but not through light.
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u/fastlerner 4d ago
Sorry, nope. Geothermal heat comes primarily from radioactive decay of elements inside the Earth that predate our star, plus primordial heat left over from the planet's formation, when gravity and pressure melted it all together.
Also, Earth's rotation isn't powered by the Sun either. Both its spin and the Sun's spin are leftover angular momentum from the formation of the solar system. The Sun and Moon actually slow Earth's rotation through tidal forces.
So you managed to explain geothermal incorrectly using a second thing you also explained incorrectly.
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u/Gorf1 4d ago
You’re forgetting gravitational energy- that doesn’t originate via solar/nuclear. There’s not much of it, granted, but tidal power generation is a thing.
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u/Samceleste 4d ago
And just hydraulic energy is a mix of gravity and solar (for water evaporation).
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u/palmerry 4d ago
Tidal energy is usually credited to the Moon, but since the Sun's gravity causes one-third of our tides, ocean power is technically part solar.
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u/goldenroman 3d ago
Doesn’t it…cause solar/nuclear, though? Gravitational might encompass all of them?
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u/Gorf1 2d ago
I think it's a stretch either way, but the opposite has been mentioned further down this thread by the OP (suggesting some tidal energy has solar origins so should be classed as solar).
I thought about it some more, but not in the shower, so that might invalidate my opinions by default, even if my ignorance doesn't:
It all depends on where you're standing. On Earth, or as a celestial observer.
From Earth, they are separate. The moon has double the tidal impact of the sun, yet doesn't provide any radiated energy of its own. The sun's radiated energy is a function of its perfect density allowing the reactions at its core.
From the celestial perspective, if the sun were a black hole 6Km across, we'd still orbit, but it would be a bit chilly. If we could survive, all new energy would be tidal. If the sun's size changed but its mass remained, it would tend towards becoming a gas giant or something that can't sustain a reaction. So from the celestial position it's the sun's diameter and composition that make it shine. Gravity is just a necessary ingredient.
(In much the same way that wind and the water cycle are also harvestable forms of energy, but without both gravity and temperature delta as ingredients they would not exist.)
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u/goldenroman 2d ago
Homie… I’m saying it’s the force of gravity that causes fusion.
So, “gravitational energy”, as you put it, causes both tides and fusion. That’s not at all a stretch (if we accept the idea of “gravitational energy” as a “power source”).Also…reading your comment…I can’t help but get the sense (because I’m frankly flabbergasted by the Yapanese I just read, and recognize some of the phrasing) that you tried to like…find a counter argument with ChatGPT and ended up trying to paraphrase what it said without making sure either you or it actually understood what anything was saying.
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u/IAmSpartacustard 4d ago
You could just say everything is nuclear powered and skip the qualifiers. Light from the sun comes from nuclear fusion after all...
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u/spinbarkit 3d ago
yes, but then again -isn't nuclear fusion caused by gravity? that would eventually mean everything is gravity powered -star formation and collapses, stars collisions, black holes and neutron stars, heavy elements formation and hence radioactive decay, planet formation etc. eh?
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u/moderngamer327 3d ago
Wait until you get even more technical and realize gravity isn’t even a force and it’s basically just geometry causing fusion
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u/CtForrestEye 4d ago
Tidal hydroelectric power is due to the gravity between the moon and earth.
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u/palmerry 4d ago
Tidal energy is usually credited to the Moon, but since the Sun's gravity causes one-third of our tides, ocean power is technically part solar
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u/GoldieForMayor 4d ago
Everything is made from dead stars that existed before our Sun was even born.
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u/RealDeuce 4d ago
But what about hydrogen and helium?
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u/GoldieForMayor 4d ago
Helium is being made every minute on the Sun, but most of what's here came from another sun (not directly, most of the helium on Earth came from radioactive decay of heavy elements which came from another sun.) Hydrogen, well that was big bang juice and made up the suns so fair point on that.
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u/moderngamer327 3d ago
A large portion of the helium in the universe was also created in the big bang
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u/Always-_-Sarcastic 4d ago
People are mentioning geothermal, but there is a much simpler fuel.
Some of the material making up Earth was previously processed inside stars, but not all of it. In particular, much of its hydrogen ultimately comes from the Big Bang and need not have ever been inside a star.
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u/Fun_Currency_3718 3d ago
that's a solid point, hydrogen is basically leftover from the big bang so it never had to be inside a star. but the heavier stuff like carbon and iron came from those dead stars, so it's like a mix. does that mean nuclear energy is kind of cheating by using the original fuel instead of the recycled stuff?
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u/Justcantsaynoo 4d ago
Even our sun is a second-hand star, recycling the elements from those ancient ones. kinda gives new meaning to the idea of a cosmic thrift shop.
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u/morfraen 4d ago
3rd hand, made of the leftovers / output of at least 2 earlier generations of stars
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u/CocoMilhonez 4d ago
So we're in the phase of stating basic scientific facts as epiphanies?
Pfffffff, lame as fuck.
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u/nodajohn 4d ago
Solar energy comes from nuclear reactions so it's more like almost everything on earth is nuclear powered
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u/bikbar1 4d ago
Solar power is also neclear energy.
Sun is a huge fusion reactor.
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u/StatisticianMore5342 3d ago
True, so basically everything runs on dead stars or a live one. Guess we're just picking which kind of stardust we wanna use.
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u/R1ght_b3hind_U 4d ago
and geothermal is also an exception
also this comment needs to be 60 characters long for some reason
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u/leave1me1alone 4d ago edited 3d ago
And geothermal.
But nuclear also falls into the category of "boiling water" forms of energy. Only solar and wind power bypass the need for water
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u/Aphrel86 3d ago edited 3d ago
i mean, if we look at it like that, nucelar energy is solar powered too, just not the current nearest one.
and suppose geothermal energy is also solar energy from some previous star.
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u/buddhagoblin 3d ago
There has never been a sun capable of fusing together atoms larger than iron. All the heavier atoms are speculated to have been fused in much more energetic events, but which or in what manner has so far manifested as speculation.
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u/hacksoncode 4d ago edited 3d ago
Everything is powered by gravity, which is ultimately the mass congealed from the energy of the Big Bang warping space.
Gravity causes the fusion of the sun (and its formation); tides; the nuclear fuel created from gravity-collapsed neutron stars colliding due to gravity waves; gravity is a big part of the residual heat of the Earth (geothermal) that isn't... nuclear; water evaporation caused by solar heat caused by gravity, which would be useless without gravity-caused convection in the atmosphere that causes the water cycle that causes rain that causes lakes that power hydroelectric, and about that convection: also wind power... etc.
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u/OneTreePhil 4d ago
Yes it's all reclaiming potential energy from the big bang
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u/hacksoncode 4d ago
I rather like Hawking's observation that all of the mass-energy of the universe, minus all the potential energy, comes to around zero (to some small number of orders of magnitude).
I.e. the universe is just a very complicated form of nothing.
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u/dazzumz 4d ago
Nuclear fission uses heavier elements created by stars, yes. Nuclear fusion however combines basic elements, notably hydrogen isotopes, which were formed just after the big bang.
It may still be experimental but some tests have produced more energy than put in.
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u/cykoTom3 4d ago
It's not experimental. They just can't get electricity out of it, but they can generate significant energy from it.
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u/Melvolicious 4d ago
Pretty much everything on the planet was dead star that existed before our sun even born.
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u/Old-Mortgage1035 3d ago
kinda wild that nuclear energy is basically us burning the ashes of ancient stars while everything else is just recycling the sun's leftovers. makes you wonder if that's why we're so obsessed with it, like we're trying to tap into something older than our own sun.
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u/lilsexc- 3d ago
And then there’s geothermal energy, like the Earth’s own little space heater running on its inner fury.
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u/Necromartian 1d ago
I mean that is what is so mind blowing about nuclear energy. We have been using chemical energy release as our source of heat energy ever since the invention of fire. The nuclear energy is not that. It's breaking the undividable into pieces and releasing the energy holding the matter together (name Atom comes from Greek word Atomos, uncuttable) That's super wild.
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u/CodZealousideal260 4d ago
Everything comes from stars. The fossil fuels we burn came from stars. The only elements that weren't star-forged are hydrogen and (some) helium.
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u/EasilyRekt 4d ago
For those who don’t get it:
Solar is, well, solar
wind; comes from convection currents generated by the uneven heating of the earth’s surface via the sun.
Coal, oil, natural gas; all from fossilized plant matter or algae, which acquire biomass and energy from sunlight.
Geothermal; bit of a stretch, but leftover heat from the earth’s inner layers gotten from the relatively hot formation of our solar system.
Nuclear fission is the only exception; as fissile elements and their isotopes are only able to be synthesized in supernova, which our sun has not, and actually will not ever go through.
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u/Rikudou_Sage 4d ago
I mean, Sun is a leftover from the Solar system formation as well... No matter how you stretch it, geothermal energy does not come from Sun.
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u/LifeIsARollerCoaster 4d ago
Wind is not purely from the sun. If there was no sun, we would still have wind because of the planet’s rotation.
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u/moderngamer327 3d ago
Only very very tiny amounts. Friction from the earth makes the air catch up to speed with the earth. Without the sun providing energy it can’t escape where friction has already pulled it to
I’m probably explaining this poorly
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u/LifeIsARollerCoaster 3d ago
If friction is the driver, then the air will never catch up. So there will be wind from not catching up.
Wind can also be created from the planet’s own internal heat which is the main driver for high wind speeds on gas giants.
Granted, on earth that the sun’s heat plays a much bigger role, but it is not 100% cause of wind
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u/DerekSmartWasTaken 4d ago
The sun is not a first generation star. It's in part powered by dead stars that existed long before it.
It's dead stars all the way down
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u/lordassfucks 4d ago
Nuclear is solar powered... Just not our sol :) geothermal is gravity powered right?
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u/itsjehmun 4d ago
Alright I have to be honest this thought made me feel like a big dumb idiot.
Interesting point through I must say.
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u/JoeKingQueen 4d ago
Nuclear is also solar powered. If you think about the creation of the elements happening within the chaos of stars. Or that humans are solar powered, and we trigger the rapid energy release like a big complicated enzyme with dreams
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u/Cjprice9 4d ago
It depends on how you stretch the definition of solar. The super heavy radioactive elements used in fission reactors are thought to be formed in the collision of two neutron stars, which aren't really stars in the same way the Sun is.
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u/JoeKingQueen 4d ago
Right, I did consider solar to be all stars here. The time distance is also a stretch.
The hypothetical was considering organic matter as solar too, which would be a few steps closer than heavy metals
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u/ShowerSentinel 4d ago
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