Re: Colonizing the Galaxy in Eight Easy Steps

From: quibbler (quibbler247_at_yahoo.com)
Date: 06/13/04 

Date: Sun, 13 Jun 2004 12:36:18 -0600

In article <40cbd04b_1@news.iprimus.com.au>, copsR@yourdoor.com says...
> : "Albert" mailto:alwagner@tcac.net says:
> >
> > Quibbler is correct. And you are wrong. It is the difference in
> > pressure between the input and exhaust that allows work to be done. The
> > greater the difference the more work. Condensing the waste steam at the
> > exhaust increases the pressure differential and hence increases the
> > efficiency.
>
> Yes Albert, it *is* the difference in pressure between
> the input and exhaust that does the work.
>
> So we have now reduced the input to 0.5 STP to
> make it easier to boil.

Yes and that was the whole point. Because OTEC is constrained by low
temperature differentials in the hot and cool source, it is imperative
that it be made as easy as possible to produce steam. That requires a
reduction in pressure to facilitate the boiling. However, I am not
saying that I'm defending everything Savage was proposing. I'm just
pointing out standard features of open cycle OTEC design.

> So lets say the condensation
> reduces the pressure at exhaust to, say, 0.25 STP.
>
> How have we gained anything over your common or
> garden variety turbines where the energy input into
> the chamber increases pressure to above STP
> with the exhaust operating at STP?

Yep. We've gained the ability to more easily produce the steam to begin
with as you've already conceded.

>
> Or to simplify the question to a point where even a
> fan of Savage may understand it

Here's the problem. Your constant ad hominem distracts you from hearing
what anyone is saying. This link indicates that the some of the Savage
fans you dismiss include Arthur C. Clarke, Larry Niven and others.
http://www3.sympatico.ca/n.rieck/docs/millennial_project.html

In any event, I pointed out a number of flaws with Savage's proposals
myself. I didn't claim to be a fan of his work, though I have seen
it. What you can't seem to grasp is that even if Savage was wrong about
specific details of the efficiency of a particular OTEC system, that
doesn't mean that OTEC couldn't be used to efficiently and cheaply
produce electricity. The figures that I've seen suggest that large
scale expensive infrastructure would be necessary to realize cheap OTEC
power. But there is nothing preventing it, in principle, and Open cycle
OTEC is a comparatively efficient process.

> - what makes
> (0.50 - 0.25) bigger than (1.25 - 1.0)?
> Its the energy coming into the system that produces
> the pressure gradient to do the work. Not the starting
> pressure of the input chamber.

By your same argument, things like multistage flash distillers would
have no need to reduce the pressure in the vessels because they still
ultimately have to use the same amount of thermodynamic input. In
actual fact one wants to promote boiling as easily as possible and it
does result in greater efficiency to drop the pressure to start with.
Savage did not invent any of this and neither did I. Try doing some
research. Pretty much every open cycle OTEC system relies upon very low
pressure to permit boiling. Perhaps you should explain your views to
the designers and operators of existing OTEC plants and blow the lid off
their little scam with your massive knowledge of physics.

> And what is feeding energy into the input chamber
> in the first place? If we are feeding STP 80 degree
> seawater in, what is keeping the input pressure down.

Presumable a pressure pump maintains low pressure.

> You can't condense it all away to zero

Nor do you need to. Perhaps you don't realize this, but arguments
similar to your own were used to *prove* that it was impossible for man
to create a vacuum. Even folks like Gottfried Leibniz were taken in by
such arguments.

> Maybe its
> a conspiracy by those of us who have actually bothered
> to learn something about physics (e.g. the mechanical
> and structural consulting engineer who reviewed Savage
> at http://tinyurl.com/36hwy ) to hide our slow wittedness.

Yeah, I've seen these reviews, probably before you even heard of the
book. One suspects that you merely picked up some of the canned
criticisms, since people have complained about the turbine for some
time. There are many flaws with Savages plans in general, but issues of
ultimate turbine efficiency are not a show stopper. Perhaps if you
showed some evidence that you had actually thought about the criticism
and

>
> However I note that a 14 year old (who presumably
> has not begun to learn basic physics yet) found the
> book "well written enough for me to understand completely".

You expect anyone to be impressed with your cheap shots and straw men.
I don't give a *** if a 14-year-old likes it or not. Hopefully you
have a better argument than, "If a 14-year-old likes it then it must be
wrong".

 
> Am I talking to anyone older than 14 here?

I'd ask you the same question. 

-- 
      Quibbler (quibbler247atyahoo.com)
"It is fashionable to wax apocalyptic about the 
threat to humanity posed by the AIDS virus, 'mad cow'
disease, and many others, but I think a case can be 
made that faith is one of the world's great evils, 
comparable to the smallpox virus but harder to 
eradicate."  -- Richard Dawkins
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