Text 19215, 77 rader
Skriven 2014-11-10 00:38:00 av Michiel van der Vlist (2:280/5555)
     Kommentar till en text av Lee Lofaso (2:203/2)
Ärende: Life Under the Democr
=============================
Hello Lee,

On Sunday November 09 2014 17:44, you wrote to me:

 LL>>> In other words, the core of the earth is getting hotter.

 MvdV>> No, it is not.

 LL> Either the earth is getting hotter, or the earth is not getting
 LL> hotter. You can't have it both ways.

Yes one can. The core is cooling down, the surface is warming up.

 MvdV>> The heat flwo comes from two sources:

 MvdV>> 1) Fossile heat. Whe3n the earth was formed some five miljard
 MvdV>> years ago, it was very hot. It slowly cooled off and now only
 MvdV>> the core is stll molten. But the ccoling off in not finished.
 MvdV>> It is still cooling down.

 LL> How old is the earth?

About 5.000.000.000 years.

 LL> How old is man in comparison?

1/100.000

 LL> The earth has cooled down only a small fraction from what it was when
 LL> man first walked this earth.  Not even enough to notice.

Or so you think.

 MvdV>> 2) Radio-active decay. There is still some residual
 MvdV>> radio-activity from when the heavy elements were formed in the
 MvdV>> explosion of the parent stars that provided all the matter that
 MvdV>> our solar system is made off. The decay produces heat.

 LL> That may be.  But who cares about what happened to the stars eons ago?
 LL> I wasn't there.  You weren't either.

You and I would not be here if eons ago there had been no stars who's life
ended in an explosion.

The matter in the early universe consisted mostly of hydrogen and a ery little
bit of Helium. No carbon, no oxygen, no iron, and certainly no heavy elements.
The early stars that were almost pure hydrogen that was burned to Helium. Still
no heavy elements during their lifetime. The elements that are needed for
complex chemical processed needed to support life were formed when those stars
died in a supernova explosion. We are literaly made of star dust.

 LL>   And I do not expect either of us
 LL> to be there when the stars finally go out, as we will both have left
 LL> the place long before then.

 MvdV>> Both processes show tghe typical curve of exponential decay.

 LL> From a scientific and analytical point of view, that is nice to know.
 LL> But even then it does not really shed new light on what might be.
 LL> Some people believe global warming is caused by the earth's core
 LL> heating up.  Nobody really knows what the heck is going on at the
 LL> earth's core,

We have a fair idea. For one, we know that it is almost pure iron. Liquid iron.

 LL> as nobody has the means to measure what is going on that far below the
 LL> surface.

A lot can be gleaned. We know that seismic waves are reflected at bounderies.
We know that liquids only propagate longitudional waves whereas solids
propagate both transversal and longitudional waves.


Cheers, Michiel

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