Energy can not dissappear or be created, only change form, right? Earth is blasted by the sun 24/7, where does the excess energy go, because I guess it doesn't stay here or we'd cook

Submitted by mr_greenmash t3_11six1y in askscience

Edit to add: I guess a lot is reflected, but some warms land/air/oceans, some is used to generate electric energy, some is used for plant growth... But the energy also need to go somewhere. We can't just receive solar energy, and not let any go?

Does hest just slowly radiate into space? And how would that work? Transferring heat to a vacuum seems impossible.

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viscence t1_jchxkmb wrote

The sun manages to transfer heat through a vacuum just fine -- radiatively, by emitting photons of light. That is also how the earth loses heat. Like the sun, the earth has a temperature and therefore glows, radiating away heat. The earth is a lot colder than the sun, so it radiates much less, and invisibly in the infrared.

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BloodshotPizzaBox t1_jci5svo wrote

Just to add: the thing you want to google to learn more about this is "black body radiation" or "thermal radiation."

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dangil t1_jchydwx wrote

99.99??% of this energy is reflected or reemited by earth

The problem is that this tiny fraction can eventually increase the total energy inside earth. Depends on how well earth can radiate energy.

But ideally we let it all go except for a tiny fraction that builds biomass. Basically every form of energy on earth available to humanity or not comes from the sun’s energy.

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the_fungible_man t1_jci0mls wrote

>Basically every form of energy on earth available to humanity or not comes from the sun’s energy.

Two significant exceptions come to mind:

  • Nuclear energy does not come from the Sun.

  • Geothermal energy is not powered by the Sun.

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viscence t1_jci1l90 wrote

Oddly enough you can somewhat argue about both of these, as billions of years ago the gravitational effect of what would become the sun had a significant impact in getting that energy into what would become the earth... or that nuclear energy comes from isotopes formed from previous stars. It just becomes a matter of definitions at some point though.

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dangil t1_jci19cf wrote

Heavy nucleus were forged in a Star. Not ours though

Geothermal energy is basically gravitational energy from the formation of the solar system. Also related to the sun.

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Grindipo t1_jcld3tw wrote

Is it you, Lord Kelvin ?

The heat inside Earth comes from the radioactive decay of, well, radioactive elements inside.

It is true that the accretion of a planet releases a lot af heat, but without the radioactivity, the Earth would have cooled in less than a billion year.

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Ridley_Himself t1_jci18bb wrote

Heat can be transferred in four basic ways: conduction, convection, advection, and radiation. While the first three require a medium, radiation can travel through a vacuum.

All objects will emit thermal radiation at an intensity and range of wavelengths dependent on their temperature. Earth’s thermal radiation is infrared.

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fromagionado t1_jcmszjn wrote

In addition to reflected energy, most of the energy that gets soaked up on the light side of the planet continues to get radiated away during the night. That sort of balances it out. Then, depending on how well the atmosphere is capable of insulating Earth (increasingly well due to build up of aptly named greenhouse gases), the planet settles into an equilibrium state and that's the temperature we experience on average.

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