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Posted by Ken S. Tucker on May 29, 2008, 2:30 pm
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On May 28, 7:59 pm, david.willi...@bayman.org (David Williams) wrote:
> -> > -> Dave, it's taken since May 21st, (1 week) just for you to
> -> > -> discover Venus has NO PLATE TECTONICS!!!
> -> > -> It will take months for you to figure out WHY NOT!!!
>
> -> Explain that.
> -> Ken
> -> PS: You Old Fart.
>
> A little older than I was before May 21, which was my birthday.
Ok, I think I'll toast your mom for passing a big
head like you had as a baby....cheers!
> But you wrote the above. You explain it.
>
> There are good reasons why Venus *may not* have plate tectonics. Its
> never lost most of its crustal material in a big collision, as Earth
> did, so the crust is presumably a lot thicker and stronger than
> Earth's, and less likely to be broken into plates. But that doesn't
> explain the small number of craters.
IMO, I think that explanation is too complicated.
I'll use the Standard Solar System Evolution Theory.
Compared to Earth, Venus had more meteor bomb-
bardment, (~1/r^2) and more energetic (1/r), and
had more radial surface heating, all compared to
Earth. So when the Venusian crust finally hardened
500,000,000 years ago was in accord with SSSET.
> Either we have to accept the meltdown hypothesis, or we must
> hypothesize some other way in which the planet's surface is rapidly
> renewed. (That's "rapidly" in cosmological terms, maybe taking hundreds
> of millions of years, but not billions.) It seems plausible to me that
> there *is* some kind of tectonic activity, but rather different from
> that on Earth. If Venus's plates are small, maybe only a few hundred
> kilometres in size, each bit of ground would spend only a short time on
> the surface before being subducted and replaced by new ground appearing
> at a spreading margin.
Maybe, but there is no evidence of that conjecture.
> And each plate would have few, if any, craters,
> so there would be no obvious gradient of crater density from the oldest
> part of the plate to the newest.
Ok possible, but for all intents and purposes, Venus lacks
anthing like *CONTINENTAL TECTONICS* and Earth has.
> Magellan, Venus Express, etc., have managed to peer through the haze
> and let us map the surface, but our knowledge of Venus is still very
> sketchy. Maybe someday a probe will land there that is able to
> withstand the temperature and pressure for a long time, so it can
> observe any seismic activity, and so on. I hope I'm not too old to be
> around then!
> dow
Yeah, I'm off beer and on to Tang, it's the least sugared
juice I can find!
Ken
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