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New theory explains how Earth’s inner core remains solid despite extreme heat

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Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#21

Post by jessriedel »

beevai142 wrote: post #11
technologyvault wrote: post #8

This headline seems a bit overzealous, as if this new theory is the final answer. This new theory, noted as contradicting one from 2014 and 30 years of previous conventional scientific wisdom, came after researchers "looked into larger computational samples of iron than studied previously". What will be the headline and tone in several more years, when someone comes along and studies an even higher number of samples…

I expect the article itself is more carefully worded than the press release. I don't think people in the scientific community in general really care much about the press releases. The publicity is more something that the funding organizations and universities have started to require in recent years --- you may even get some quantified "career points" of some sort from them depending on the grant. The press releases a…

There are many researchers who are eager to have their work publicized, both for reasons of pride and grant-writing. They often are far from diligent in working with the journalist to make sure the article is written with sufficient modesty. Yes, universities and funders have began directly soliciting hype journalism, but the researchers themselves still benefit, and follow incentives.

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#22

Post by sandworm101 »

jcoffland wrote: post #14

> The ultimate goal of Earth Sciences is to understand the past, present and future... That is the ultimate goal of all science.

But what of the scientists working to improve lives? You dont have to do blue sky research in a shiny tower. Some scientists are in the trenches looking not to discover but to apply discoveries in the real world.

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#23

Post by [deleted] »

nonbel wrote: post #17
pdonis wrote: post #12

Earlier quoted context omitted.

If you look at the Wikipedia article in more detail, you will see that the negative heat capacity of a self-gravitating, isolated system arises from the virial theorem. Heuristically, as a self-gravitating system radiates energy away into space, it becomes more tightly bound; that means it contracts. But as it contracts, the "orbital speeds" of its constituents increase (because decreasing orbital radius means increa…

Interesting, thanks. I still am not sure what the technical meaning of "isolated" is here. But wouldn't such an object continue heating up "infinitely" (maybe stopping at some phase-transition temperature) without constant input of energy?

[deleted]

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#24

Post by pdonis »

nonbel wrote: post #17
pdonis wrote: post #12

Earlier quoted context omitted.

If you look at the Wikipedia article in more detail, you will see that the negative heat capacity of a self-gravitating, isolated system arises from the virial theorem. Heuristically, as a self-gravitating system radiates energy away into space, it becomes more tightly bound; that means it contracts. But as it contracts, the "orbital speeds" of its constituents increase (because decreasing orbital radius means increa…

Interesting, thanks. I still am not sure what the technical meaning of "isolated" is here. But wouldn't such an object continue heating up "infinitely" (maybe stopping at some phase-transition temperature) without constant input of energy?

> I still am not sure what the technical meaning of "isolated" is here.

Technically, it means an object of finite spatial extent surrounded by vacuum, and nothing else in the entire universe. Obviously that's an idealization. :-) But it makes the mathematical model tractable.

> wouldn't such an object continue heating up "infinitely"

Not necessarily; it might reach a stable state where it can't radiate any more energy. Cold white dwarfs, cold neutron stars, and cold planets are possible examples of such states. ("Cold" here basically means "at absolute zero", i.e., in the ground state for its configuration of particles.)

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#25

Post by jcoffland »

sandworm101 wrote: post #22
jcoffland wrote: post #14

> The ultimate goal of Earth Sciences is to understand the past, present and future... That is the ultimate goal of all science.

But what of the scientists working to improve lives? You dont have to do blue sky research in a shiny tower. Some scientists are in the trenches looking not to discover but to apply discoveries in the real world.

Right but all of these discoveries aim to predict the future through modeling. In other words, they seek a model which says that if this and this occur than we can expect this result with some probability.

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#26

Post by Sir_Substance »

sundvor wrote: post #15

Funniest ad placement seen in a while: "Spinning within Earth’s molten core is a crystal ball" ... with the Canadian Foreverspin.com ad just above this. I want one, and please, keep on spinning.

>I want one, and please, keep on spinning.

Really? When they first came out I figured they were tailgating on inception, but it's been a few years and they're still around. What's the attraction?

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#27

Post by sundvor »

Sir_Substance wrote: post #26
sundvor wrote: post #15

Funniest ad placement seen in a while: "Spinning within Earth’s molten core is a crystal ball" ... with the Canadian Foreverspin.com ad just above this. I want one, and please, keep on spinning.

>I want one, and please, keep on spinning. Really? When they first came out I figured they were tailgating on inception, but it's been a few years and they're still around. What's the attraction?

Just haven't seen them before (i.e. a high quality machined spinners), and I reckon my 6y son would love it too.

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#28

Post by evanb »

pdonis wrote: post #24
nonbel wrote: post #17

Earlier quoted context omitted.

Interesting, thanks. I still am not sure what the technical meaning of "isolated" is here. But wouldn't such an object continue heating up "infinitely" (maybe stopping at some phase-transition temperature) without constant input of energy?

> I still am not sure what the technical meaning of "isolated" is here. Technically, it means an object of finite spatial extent surrounded by vacuum, and nothing else in the entire universe. Obviously that's an idealization. :-) But it makes the mathematical model tractable. > wouldn't such an object continue heating up "infinitely" Not necessarily; it might reach a stable state where it can't radiate any more energ…

"Cold" in astrophysical settings tends to mean T << µ (the chemical potential) which usually justifies a low temperature expansion in T/µ, although thermal effects can be qualitatively important.

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#29

Post by pdonis »

evanb wrote: post #28
pdonis wrote: post #24

Earlier quoted context omitted.

> I still am not sure what the technical meaning of "isolated" is here. Technically, it means an object of finite spatial extent surrounded by vacuum, and nothing else in the entire universe. Obviously that's an idealization. :-) But it makes the mathematical model tractable. > wouldn't such an object continue heating up "infinitely" Not necessarily; it might reach a stable state where it can't radiate any more energ…

"Cold" in astrophysical settings tends to mean T << µ (the chemical potential) which usually justifies a low temperature expansion in T/µ, although thermal effects can be qualitatively important.

> "Cold" in astrophysical settings tends to mean T

Yes, I know, but this in itself does not preclude energy being emitted by radiation. To preclude that, the object needs to be in a genuine ground state--no internal transitions possible that can reduce its total energy. That's a considerably stronger condition than T << µ.

Re: New theory explains how Earth’s inner core remains solid despite extreme heat

#30

Post by DrScump »

technologyvault wrote: post #8

This headline seems a bit overzealous, as if this new theory is the final answer. This new theory, noted as contradicting one from 2014 and 30 years of previous conventional scientific wisdom, came after researchers "looked into larger computational samples of iron than studied previously". What will be the headline and tone in several more years, when someone comes along and studies an even higher number of samples…

Like other content on this site, it's just ripped from the original publisher and author, with the author credit cut out. The title is the same on the original:

https://www.kth.se/en/forskning/artiklar/new-theory-explains...

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