5 ms·
>Zhong explained that the planet's mantle, which lies above >the core, generates vast amounts of heat. To cool the globe >down, hotter rocks rise up through t
by Infernal 8y ago
>Zhong explained that the planet's mantle, which lies above
>the core, generates vast amounts of heat. To cool the globe
>down, hotter rocks rise up through the mantle and colder rocks
>sink.
Unless I misunderstand something about the geology of the earth, there are no energy inputs to the core - it is simply hot, and always cooling, right? Maybe some heat is generated from the friction between counter-rotating layers of core, mantle etc., but bottom line is (as I understand it) there are no energy inputs to the core, it's a closed system that is always running down.
I'd love for someone who knows more about geology to confirm/deny/expand on this point.
- hammock 8y agoIt's poorly worded, he means the heat from the core/mantle generates convection currents. However, your understanding of the Earth's core is incorrect as well. Half of the internal heat is Generated from radioactive decay: https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget
- njarboe 8y agoHowever, in geology the phrase "Earth's core" means the metallic part of the earth that is made up of liquid and solid Ni/Fe at the center of the Earth. So most geologists think there is little to no radioactive elements present in the core (although some think potassium might be). In that case, the Earth's core does not generate heat, but the mantle does.
- kryogen1c 8y agoI don't know anything about geology or the Earth's core, but I do know that radioactive heating is still a one-way process. Entropy exists, and even if the short-term result is heat positive, the end result is always heat death.
- Infernal 8y agoYes, this was the question I was trying to get at. The linked wikipedia article above answers it though - energy from the sun only penetrates 10's of meters into the earth's crust, so for all intents and purposes the interior of the earth, considered as a closed system, has no energy inputs.
- hammock 8y agoNo inputs, but it is not "simply hot and always cooling." Even as a closed system, it is generating new heat
- kryogen1c 8y agoI'm not sure what your point is, so you might consider this splitting hairs. Heat is not being generated, it's being converted. That conversion requires a source that will run out. It will continue to be warm for any meaningful timeline to a human, but it is not infinite and will end in heat death.
- Infernal 8y agoOf course that is a wikipedia article! Thanks :)
- seppel 8y agoThe earth core is still heated heavily by radioactive decay.