
A wrench in Earth's engine - dnetesn
https://phys.org/news/2018-10-wrench-earth.html
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Infernal
>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.

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hammock
It'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
However, 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.

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kryogen1c
I 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
Yes, 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
No inputs, but it is not "simply hot and always cooling." Even as a closed
system, it is generating new heat

~~~
kryogen1c
I'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.

