January 8, 2019

**SIGH** Entropy must increase or stay constant WITHIN A CLOSED SYSTEM. (badly mistitled OP)

This is a FAR more important qualification than any requirement for equilibrium -- in fact the equilibrium argument is superfluous. Complex life evolved freely -- wantonly -- on Earth because Earth is anything BUT a closed system. The Sun constantly beams down a torrent of energy onto the Earth's surface. Virtually all of this radiation is eventually re-radiated back into space, where it expands virtually unimpeded into an effectively infinite volume, creating all the entropy that could ever be required, and allowing the local decrease in entropy that is absolutely characteristic of every living organism. In the process of being absorbed, flowing from one point to another, and eventually being lost again, that energy does useful work on the Earth's surface, including creating energetic molecules which plants and animals alike rely on for survival. That accumulation of 'negentropy' is perfectly allowed by the laws of thermodynamics in an open system. If we were to regard the Sun, the Earth, AND all the radiation emitted by the Sun as a closed system (it isn't perfectly, but close enough) then entropy is increasing massively overall, and the fact that a little turbulence in the flow of energy has produced all the complexity of life on earth is not even a jot in the entropy balance.

The suggestion that an impact is involved is also completely unnecessary. We have known since the days of the Miller-Urey experiment that radiation alone is sufficient. All the faddish theories about "life formed in outer space" will eventually be discarded as being as untenable as they are unnecessary. The attraction of these theories is romantic, not scientific -- there are no holes in any theories demanding an extraterrestial origin of life.

March 12, 2017

Use a two-part sail, which splits in two for the deceleration phase.

http://www.transorbital.net/Library/D001_AxA.html
http://www.lunarsail.com/LightSail/rit-1.pdf

scroll to Fig. 5 on p. 8. This paper describes laser-pushed sails, but microwave-pushed sails would use similar principles. Interestingly, both electric and magnetic sails can be used for propulsion.

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June 27, 2016

Quick answer to the question: Where does the radioactivity come from ? Basically, "radiobarite" ...

I.e., barite (BaSO4, the major barium mineral) containing small amounts of radium as RaSO4. Both have extremely low solubility in water (under normal conditions), so any radium salt that gets dissolved quickly precipitates back out, together with the more abundant barium, as soon as it encounters sufficient sulfate ions in solution. Here's a 2010 post on that:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x249200

Note that's per gram, not per kilogram.

July 31, 2015

Stewart's response to this was absolutely epic -- watch the video !

http://thedailyshow.cc.com/videos/vc61pl/when-barry-met-silly---

November 18, 2014

*Simple* carbon compounds are widespread, but have nothing to do with life.

This is rather like finding sand and calling it "the rudiments of semiconductor manufacture". It might be, but chances are overwhelmingly against it.

Carbon is not a particularly rare element. It is a reactive element, so it's usually found in combination with other elements, and **ALMOST ANY COMPOUND CONTAINING CARBON IS LABELED AN 'ORGANIC COMPOUND'*** by convention. "Organic" in colloquial usage means "associated with a living organism"; in scientific usage it means "contains carbon", with only very simple compounds like CO2, CO, and metal carbides being excluded. Simple organic compounds like methane, formaldehyde, hydrogen cyanide, even methanol, are not evidence of life or even the probability of life. It just means that carbon reacted with whatever was present, and that usually includes hydrogen (the most abundant element in the universe) and oxygen (which forms particularly strong bonds with carbon).

I've never understood the attraction of the hypothesis that life originated elsewhere. If such a thing had occurred, it would be fundamentally impossible to prove. And it only "begs the question" -- if you ask "where did life come from ?" and the answer is "somewhere else", then you have to ask, "well, how did it originate *there*?" and you can't answer that, because you can't investigate "there". Frankly, it seems like more of a hopelessly romantic -- even magical -- notion than a testable scientific hypothesis, but for some reason, it's become en vogue (again -- *sigh*) among so-called science journalists and won't go away, despite a paucity of evidence and a complete absence of even remotely unambiguous evidence. Frankly, it just seems to pander to a public appetite for romance over reason.