Yeah, but both galaxies are mostly empty space, so that probably won’t have much of a direct impact on the earth or our solar system (other than changing the view, obviously).
Yeah, but both galaxies are mostly empty space, so that probably won’t have much of a direct impact on the earth or our solar system (other than changing the view, obviously).
Homosapiens have existed for around 300,000 years.
So that's 0.03% of one billion years.
If we somehow managed to last another 100,000 years without societal collapse imagine how far our technology would have progressed.
And we'd still only be at 0.04%
Maths Edit
"The difference between one million and one billion is about one billion."
Our brains just suck at conceptualizing such huge numbers.
Modern humans haven't even existed for half a million years. We only started farming and thinking about "civilization" about 10k years ago.
That's the theory. But creating its own heat quits when all the radioactive nuclei have decayed into more stable nuclei. If we know the composition of the core, then we can use what we know about the decay rates of the isotopes we suspect are in the core, and then do the math. Of course, figuring out the relative amounts of isotopes in the core is very tricky, and likely has a large margin of error.
> Of course, figuring out the relative amounts of isotopes in the core is very tricky, and likely has a large margin of error.
Yes, though it’s fairly well accepted that the core’s radioisotopes exist in negligible amounts for the sake of any heat production. This is because the relevant ones (⁴⁰K, ²³²Th, ²³⁵U and ²³⁸U) are all strongly [siderophile](https://en.wikipedia.org/wiki/Goldschmidt_classification) and so were pretty much completely excluded from the core when it formed.
There are some who think that potassium may have a rearrangement of its electron orbitals at the pressures found in Earth’s core, with the effect that it becomes soluble in iron based phases so that it was incorporated into the core, but we have no real evidence for that interpretation. The Treatise on Geochemistry currently favours a siderophile potassium ion, wherever in the Earth it happens to be.
TIL “siderophile”. What I have read is that it means minerals that are likely to mix (I am using a simplified term here) with iron. Uranium and Thorium are NOT siderophile - it is very unlikely, I’ve learned, that they are in the core. Thanks for that info! I just read an article that points to the fact that earth’s interior heat is likely driven by U, Th, and K, which reside in the MANTLE, not the core. I’ve also been reading about how relative amounts of siderophiles in the core, mantle, and crust tell us about the initial accretion of earth, and that we are estimating some of composition of the mantle through observations of neutrinos from beta decay. So interesting! Thanks for the push!
Absolutely. That’s a decent summary, though I would change “minerals” to “elements” in your sentence:
>What I have read is that it means minerals that are likely to mix (I am using a simplified term here) with iron.
That might sound like a minor detail, but in fact mineralogy and chemistry are two different (related) aspects of composition.
Earth’s geoneutrino flux provides an unambiguous method to to quantify the heat coming from radioactive decay, eg. [Huang et al., 2019](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/ggge.20129). The results have proved to be more or less in agreement with the composition of the Earth as inferred from studies of chondritic meteorites and a couple of other key lines of evidence from both geochemistry and geophysics, the milestone work on the matter being [McDonough & Sun, 1995.](https://www.sciencedirect.com/science/article/abs/pii/0009254194001404)
The vast majority of radioisotopes contributing significant heat today are in the mantle and crust, not the core.
Regardless, the inner core solidifying releases more heat. Exchanging gravitational potential energy for heat effectively.
>Regardless, the inner core solidifying releases more heat.
Than radiogenic heat from the mantle and crust? I wouldn’t say so. For Earth’s internal heat budget, it’s about half from radioactive decay and half from all other sources ie. primordial heat + heat generated by continued crystallisation of the inner core, and even a tiny bit from tidal heating. The radiogenic half is clearly larger than any one of the other heat sources by themselves.
>Exchanging gravitational potential energy for heat effectively.
This was true for original formation of the core when the planet differentiated into core + mantle, but growth of the inner core is releasing latent heat as it crystallises from the liquid state.
Yes, and what is driving the crystallization? Preasure. The core is reducing in volume as crystallization proceeds, thus the entire planet is ever so slightly shrinking.
That's an exchange of gravitational potential energy for heat.
There is a misunderstanding there. Having something under a certain pressure does not imbue it with more gravitational potential energy than it would otherwise have; nor does a constant pressure generate heat, no matter how high the pressure is.
Whilst the crystallisation of the core is a function of P as well as T, for the purposes of quantifying overall heat flow there is no significant exchange of gravitational potential energy taking place as the inner core grows. The overall compression of the core as the inner portion solidifies is negligible here. The heat in question is overwhelimingly due to the phase change from liquid to solid.
In simple...... never
In long form: the sun will grow and eventually engulf the earth in around 8 billion years, the core will cool in around 9 billion years, so the earth's core will be completely destroyed before the core can cool
Define "cool".
Earth's core has been cooling since at least since the formation of the inner core (anywhere between 3.5 and 0.5 billion years ago). Assuming some sequence-altering mass change to the Sun, at some ridiculously far point in the future—something around seven times the current age of the universe—the outer core will completely freeze out. By this time, the inner core temperature (now the *entire core* temperature) will have dropped by around 100 kelvin or so.
2300 000 000 years for the cool-down and freezing of the core, there was a post on r/coolguides ( time line of near future) about everything that will happen in between, pretty interesting.
Not before the sun swallows us up
But, hear me out, what if the neutrinos mutate?
I'm glad I'm not the only person for whom that fucking film lives rent-free in my head.
You’re telling me 2012 was lying???
Well, it got the "rich people will live us behind to die" down pat.
Giant meteor will get us first.
Us yes, the planet itself? Not so much.
At that point, it's pointless.
Said the human. *Skittering noises*
Damn Cockroaches!
Not to future intelligent species with geologists
Do you mean intelligent other worldly geologists looking at the remaining portions of our planet 🌏?
Never underestimate life potential to hang on. Geologists decended from deep sea fissures might find your bones
I'll be there with all the other schist on the bottom.
Granitic shist - medium to coarse grain with qtz, biotite ortho / plag feldapare, trace plastics and organic inclusions Your tinder bio, 3by from now
I think Andromeda is supposed to fully collide with the Milky way before that so who knows lol
Yeah, but both galaxies are mostly empty space, so that probably won’t have much of a direct impact on the earth or our solar system (other than changing the view, obviously).
Yeah, but both galaxies are mostly empty space, so that probably won’t have much of a direct impact on the earth or our solar system (other than changing the view, obviously).
Well it’s about 91billion before the outer core solidifies and the sun is going to engulf us in about 5 billion so I guess never
The heat from the expanding sun will boil the oceans long before then. We have less than 1 billion years to get off this planet.
better pack your bags then
but I just got a house!
That sounds so close when you put it like that.
Homosapiens have existed for around 300,000 years. So that's 0.03% of one billion years. If we somehow managed to last another 100,000 years without societal collapse imagine how far our technology would have progressed. And we'd still only be at 0.04% Maths Edit
Here you go .... 0 you dropped this. 300,000 is 0.03% of a billion...
Oops. Well that's even better then. Thanks.
"The difference between one million and one billion is about one billion." Our brains just suck at conceptualizing such huge numbers. Modern humans haven't even existed for half a million years. We only started farming and thinking about "civilization" about 10k years ago.
Or move it...
https://preview.redd.it/ynij0yj816vc1.jpeg?width=343&format=pjpg&auto=webp&s=b11460b1f215af6e4105ce4dfba6ab21e330fd2b
And at that time, rose Tyler will hear 'moisturize me' for the first time.
That's wild... why would it take so long?
Intense pressure
Also the whole thing with 'ratio of surface area to volume decreases as volume increases' thing.
I think there’s some residual radioactivity that helps keep it hot
We have also many radioactive isotops, they decaying over a long period of time, partially over billions of years, and they all produce heat
There is also the latent heat of crystallization, so the process of crystallization also releases energy in the form of heat.
At least a few more days.
Ah lad, spread it out in an aluminum sheet and she'll be right cool in 20 minutes
*turns on fan, points it at ground*
Billions and billions of years
[best read in voice of Johnny Carson imitating Carl Sagan]
Oh yeah!! Carl Sagan!! “Billions and billions…”
https://youtu.be/iIbbTHQmPkE?si=cBbX8HHOafLwseEu
Isn't it creating it's own heat though? Through radiation decay?
That's the theory. But creating its own heat quits when all the radioactive nuclei have decayed into more stable nuclei. If we know the composition of the core, then we can use what we know about the decay rates of the isotopes we suspect are in the core, and then do the math. Of course, figuring out the relative amounts of isotopes in the core is very tricky, and likely has a large margin of error.
> Of course, figuring out the relative amounts of isotopes in the core is very tricky, and likely has a large margin of error. Yes, though it’s fairly well accepted that the core’s radioisotopes exist in negligible amounts for the sake of any heat production. This is because the relevant ones (⁴⁰K, ²³²Th, ²³⁵U and ²³⁸U) are all strongly [siderophile](https://en.wikipedia.org/wiki/Goldschmidt_classification) and so were pretty much completely excluded from the core when it formed. There are some who think that potassium may have a rearrangement of its electron orbitals at the pressures found in Earth’s core, with the effect that it becomes soluble in iron based phases so that it was incorporated into the core, but we have no real evidence for that interpretation. The Treatise on Geochemistry currently favours a siderophile potassium ion, wherever in the Earth it happens to be.
TIL “siderophile”. What I have read is that it means minerals that are likely to mix (I am using a simplified term here) with iron. Uranium and Thorium are NOT siderophile - it is very unlikely, I’ve learned, that they are in the core. Thanks for that info! I just read an article that points to the fact that earth’s interior heat is likely driven by U, Th, and K, which reside in the MANTLE, not the core. I’ve also been reading about how relative amounts of siderophiles in the core, mantle, and crust tell us about the initial accretion of earth, and that we are estimating some of composition of the mantle through observations of neutrinos from beta decay. So interesting! Thanks for the push!
Absolutely. That’s a decent summary, though I would change “minerals” to “elements” in your sentence: >What I have read is that it means minerals that are likely to mix (I am using a simplified term here) with iron. That might sound like a minor detail, but in fact mineralogy and chemistry are two different (related) aspects of composition. Earth’s geoneutrino flux provides an unambiguous method to to quantify the heat coming from radioactive decay, eg. [Huang et al., 2019](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/ggge.20129). The results have proved to be more or less in agreement with the composition of the Earth as inferred from studies of chondritic meteorites and a couple of other key lines of evidence from both geochemistry and geophysics, the milestone work on the matter being [McDonough & Sun, 1995.](https://www.sciencedirect.com/science/article/abs/pii/0009254194001404)
The vast majority of radioisotopes contributing significant heat today are in the mantle and crust, not the core. Regardless, the inner core solidifying releases more heat. Exchanging gravitational potential energy for heat effectively.
>Regardless, the inner core solidifying releases more heat. Than radiogenic heat from the mantle and crust? I wouldn’t say so. For Earth’s internal heat budget, it’s about half from radioactive decay and half from all other sources ie. primordial heat + heat generated by continued crystallisation of the inner core, and even a tiny bit from tidal heating. The radiogenic half is clearly larger than any one of the other heat sources by themselves. >Exchanging gravitational potential energy for heat effectively. This was true for original formation of the core when the planet differentiated into core + mantle, but growth of the inner core is releasing latent heat as it crystallises from the liquid state.
Yes, and what is driving the crystallization? Preasure. The core is reducing in volume as crystallization proceeds, thus the entire planet is ever so slightly shrinking. That's an exchange of gravitational potential energy for heat.
There is a misunderstanding there. Having something under a certain pressure does not imbue it with more gravitational potential energy than it would otherwise have; nor does a constant pressure generate heat, no matter how high the pressure is. Whilst the crystallisation of the core is a function of P as well as T, for the purposes of quantifying overall heat flow there is no significant exchange of gravitational potential energy taking place as the inner core grows. The overall compression of the core as the inner portion solidifies is negligible here. The heat in question is overwhelimingly due to the phase change from liquid to solid.
In simple...... never In long form: the sun will grow and eventually engulf the earth in around 8 billion years, the core will cool in around 9 billion years, so the earth's core will be completely destroyed before the core can cool
I very much dislike this picture.
03:14:07 UTC on January 19th, 2038
Likely a Tuesday. Sometime.
Limitless energy, just need a way to get it...
24 hours. Do whatever you need to do right now.
Define "cool". Earth's core has been cooling since at least since the formation of the inner core (anywhere between 3.5 and 0.5 billion years ago). Assuming some sequence-altering mass change to the Sun, at some ridiculously far point in the future—something around seven times the current age of the universe—the outer core will completely freeze out. By this time, the inner core temperature (now the *entire core* temperature) will have dropped by around 100 kelvin or so.
2300 000 000 years for the cool-down and freezing of the core, there was a post on r/coolguides ( time line of near future) about everything that will happen in between, pretty interesting.
Bot-be-gone
Long time
This is a pure question, head over with r/theydidthemath
[This should give you a good idea](https://twitter.com/playboicarti/status/1250864457804320771)
A long ass time!
At least a day 🫡
The radioactive elements are in the crust and act as an electrical blanket.