Talk:Planetary core

message: It would be great if as a part of this topic, someone could explain the methods scientists used to determine what the Earth's core consists of?
Under "Core heat source", the article says: "This value is calculated from a variety of factors: secular cooling, differentiation of light elements, Coriolis forces, radioactive decay, and latent heat of crystallization." Coriolis forces are not real or true forces, only apparent forces. They are what makes a ball thrown by someone on a turntable or merry-go-round seem to swerve. There is no swerve. It is a mere appearance. It is surprising that a non-force, which can move nothing, should be claimed to be a source of heat. This article needs revision by hard-headed and well-qualified people. ClarkoEye (talk) 07:28, 4 July 2020 (UTC)
thread_title: Comment

message: Well, I came here looking for this information, so I'll use the talk page as to suggest what should be put in. My primary question is what "powers" the core? Originally the compression of matter and gravity generated the heat, but now it is hundreds of millions of years later and it still hasn't cooled, and the magnetic strength of the Earth (caused by an ever rotating iron core) is still about 90% as it once was, which IMO, even jumps up in strength sometimes, ie. ice age, and isn't more of losing energy than preparing for a magnetic pole switch. 
Is it the Earth's orbit around the sun, transferring the momentum to the Earth's core? Or the sun's slow orbit around other stars, and with the galaxy et al powering all this? Or the sun's magnetic field? What then? -- Natalinasmpf 14:56, 11 Mar 2005 (UTC)
replies: text: The Earth is four and half billion years old, and the Sun warms its interior not at all.  In that time, without an internal power source (namely radioactive decay of potassium-40, uranium, thorium, etc.) it would be much cooler now than it actually is, and the crust and mantle much thicker than they are.  This was worked out by Lord Kelvin in the 19th century when he famously decided that the Earth was billions of years younger than geologists then knew it to be, because he knew his thermodynamics and rates of cooling, but wasn't taking radioactive decay into account. --arkuat (talk) 01:37, 13 July 2011 (UTC)

text: You are welcome to post claims to the contrary, with your citations, but the claim that I've made has been uncontroversial in refereed publications for decades.  --arkuat (talk) 06:49, 14 November 2008 (UTC)

text: The sources you're looking for are cited in Geothermal gradient. I'll cite them here when I restore the section on what powers the Earth's core.  It's about 20% residual mechanical heat and 80% heat of radioactive decay of uranium, thorium, and potassium-40 according to the sources cited in that article. --arkuat (talk) 01:32, 13 July 2011 (UTC)
thread_title:  What "powers" the core? 

message: I'm curious about the history of scientists discovering that planets have a core, and how they came about to that conclusion --geekyßroad. meow? 05:33, 22 October 2007 (UTC)
replies: text: This is a hard question to answer, but seismology might give you a start. Basically, sound travels at different speeds, earthquakes cause "sounds" that can be measured all over the planet, and the measurements can be used to deduce things about the core and other layers of the planet based on how fast the sounds traveled through the various layers.  If seismology doesn't address your specifically historical concerns, try Age of the Earth and Kelvin's bad guess about it. --arkuat (talk) 06:39, 8 November 2008 (UTC)
thread_title:  history 

message: Sadly the whole article is a real mess; full of contradictory figures and unexplained statements of fact, which are actually the result of someone's mathematical modelling. For example statements about the abundance of certain elements in the Earth's core when in reality it is speculative and unknowable.
It's a shame as it could be an interesting topic. Needs a complete rewrite. 109.144.211.95 (talk) 01:14, 3 May 2024 (UTC)
thread_title:  Incoherent mess