3 ms·
Maybe this is obvious, but I always enjoy thinking of it: except for a comparatively little bit of radioactively decaying material inside the earth, and some ti
by hoorayimhelping 7y ago
Maybe this is obvious, but I always enjoy thinking of it: except for a comparatively little bit of radioactively decaying material inside the earth, and some tidal forces, all energy on this planet, every single joule of energy ever expended is just stored sunlight.
Sunlight hits photosynthesizing bacteria which create biological fuel molecules called sugars. Plants store these sugars and convert the energy in them into leaves and roots and organic material. Animals eat the plants and convert the stored energy into useful work. Plants and animals die, and the stored energy in their bodies is consumed by other life which turns them into work. Sometimes it gets captured by the earth before it can decompose and over very long timespans, it gets compressed and turned into super energy dense organic material called coal or petroleum.
All the gasoline we're expending, all the coal and natural gas we're burning is just stored sunlight in very efficient organic batteries. Even the wind energy we're capturing is created by the external energy of the sun injecting heat into our earth system and creating work.
- ta1234567890 7y agoSuper interesting. Would this mean Earth has been "growing" over time?
- jolmg 7y ago> except for a comparatively little bit of radioactively decaying material inside the earth, and some tidal forces There's also geothermal energy. EDIT: I erased what I said about tidal forces. I thought it referred to all currents in the ocean, but it specifically refers to the periodic pull the moon has on the Earth, to greater effect, on its water.
- trenchgun 7y agoGeothermal comes from radioactively decaying material. Geothermal is powered by naturally occuring fission. https://blogs.scientificamerican.com/observations/nuclear-fission-confirmed-as-source-of-more-than-half-of-earths-heat/ https://blogs.scientificamerican.com/observations/nuclear-fi...
- jolmg 7y agoI didn't know that most geothermal energy was from fission, but as the article says, not all geothermal energy comes from fission. There's also the release of heat as the outer core solidifies into the inner core. That's what I previously thought that most geothermal energy was.
- beerandt 7y agoOnly about half. The rest is likely residual from gravitational and tidal friction/compression and possibly other unknown sources.
- dredmorbius 7y agoPretty much just this. Tidal is another exception, and geothermal is both radioactive heat and latent heat of gravitational formation (about half each). But fossil fuels? That's burning buried sunshine. At a rate of about 5 million times faster than it formed. 23 tonnes of ancient biomass per litre of petrol -- nearly 100 tonnes per gallon. See Jeffrey S. Dukes (2003): https://dge.carnegiescience.edu/DGE/Dukes/Dukes_ClimChange1.pdf https://dge.carnegiescience.edu/DGE/Dukes/Dukes_ClimChange1....