Cosmologic philosophy: fine tuning of earth's core (Introduction)

by David Turell , Tuesday, October 30, 2018, 19:06 (2006 days ago) @ Balance_Maintained
edited by David Turell, Tuesday, October 30, 2018, 19:27

An inner part of the core rotates at a different rate than an outer part, creating the magnetic filed that protects us and our oceans:

https://www.americanthinker.com/blog/2018/09/calculating_life_on_mars.html

"Seismic data, taken over a period of several years (Zhang, et al., Science 2005), suggest that the (innermost, solid iron) core is rotating slightly faster than the rest of the Earth, at 0.3-0.5 degrees/yr. We don't know if this super-rotation is constant or varies over time. The analysts did not suggest a cause, hence relatively little attention has been devoted to the phenomenon.

"If I invert the question and ask, "Why is the Earth rotating slower than its core?," then the answer becomes clear to me, and I can even calculate and estimate its magnitude. The slowing down may be caused by tidal friction, produced by the Moon. This also means that the super-rotation has been going on for billions of years.

"We may assume that the differential rotation at the inner-core boundary with the (still liquid) outer core "winds up" the magnetic lines of force and thus produces and strengthens the geomagnetic field. I have calculated that the geomagnetic field has a decay time of only about 20,000 years, based on the likely conductivity of the iron core. Clearly, some kind of energy source is required to maintain the magnetic field. I suggest that the source is kinetic energy of rotation.

"This is the standard explanation for the existence of the magnetosphere, the outermost layer of the Earth's atmosphere, consisting mostly of ions of atomic hydrogen, protons, magnetically trapped and spiraling around the lines of force, produced as the Earth neutral exosphere is dissociated and ionized by solar UV radiation.

" The magnetosphere shields the Earth's lower atmosphere from the direct impact of the "solar wind," consisting mainly of high-speed protons and some heavier nuclei. The solar wind would help to ionize the atmosphere and also "sweep away" the outer portions – thus speeding up the "escape" of this outermost atmosphere, the exosphere, as it is labeled, where the density is so low that the mean free path between collisions becomes long enough that one can ignore collisions. The concept of temperature loses significance.

"We may assume that similar processes happened on Mars. I believe that its core was liquefied by tidal friction, but it has cooled and is no longer liquid. Mars no longer has a general magnetic field like the Earth. Its magnetosphere has now disappeared, but its shielding effect may have lasted long enough, I believe, to maintain an ocean on Mars's surface for some time.

"Lundin and others have measured the removal of the Martian upper atmosphere by the sweeping action of the solar wind. The crucial question is this: did the Mars atmosphere and surface ocean exist long enough to permit the creation of life forms – as it did on Earth?

"I can calculate a "survival time" for the ocean using available physical theory. However, this calculation is complicated by the greenhouse effect and possible freezing over of the ocean surface, which would stop its evaporation. In addition, covering up the ocean, or the remaining puddles of water, affects survival. But I don't know how long it takes for living forms to come into being; I assume that this interval is fairly short."

Comment: Although this article has as a main thrust the issue of life on Mars, it clearly shows how the design of the Earth has protected this planet and the life it supports by a special rotation of part of its core. Without the magnetic envelop around the Earth its oceans would have disappeared and any life would have been fried by the radiation that would have reached the surface. The Earth is strikingly special.