Something I've been wondering. Does the earth's core have negative heat capacity?[1]<p>I've read that it is usually modeled as a self-gravitating system[2], and that such systems can end up in states with negative heat capacity [3].<p>[1] > "If the system loses energy, for example by radiating energy away into space, the average kinetic energy actually increases." <a href="https://en.wikipedia.org/wiki/Heat_capacity#Negative_heat_capacity_.28stars.29" rel="nofollow">https://en.wikipedia.org/wiki/Heat_capacity#Negative_heat_ca...</a><p>[2] > "The Earth’s outer core is a rotating ellipsoidal shell of compressible, stratified and self-gravitating fluid." <a href="https://www.uleth.ca/dspace/handle/10133/3672" rel="nofollow">https://www.uleth.ca/dspace/handle/10133/3672</a><p>[3] > "Negative heat capacities can only occur in isolated or nearly isolated systems. They are
impossible in truly extensive systems in canonical ensembles or for that matter in grand
canonical ensembles. However, far from being a strange phenomenon only found in the
thermodynamics of black holes they occur widely on a macroscopic scale in astrophysics and
with less precision on a microscopic scale throughout physics and chemistry. They are the
origin of the large fluctuations that occur at phase transitions and we speculate that they
cause those transitions." <a href="http://adsabs.harvard.edu/full/1977MNRAS.181..405L" rel="nofollow">http://adsabs.harvard.edu/full/1977MNRAS.181..405L</a><p>Edit:
Also, the link to the paper leads to a 404 page...
Stabilization of body-centred cubic iron under inner core conditions, Nature Geosciences, nature.com/articles/doi:10.1038/ngeo2892
This headline seems a bit overzealous, as if this new theory is the final answer.<p>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 and coming to an entirely different conclusion?<p>Doesn't it seem more appropriate and useful for the scientific community and publishers of these studies to be careful not to state their findings as conclusive and act as if their most recent study does much more than to estimate what might be happening?
Funniest ad placement seen in a while:<p>"Spinning within Earth’s molten core is a crystal ball"<p>... with the Canadian Foreverspin.com ad just above this. I want one, and please, keep on spinning.