Significance of the solar wind

Stephen Forbes wrote:

 > So what if its simplified. It still totally contradicts what you keep
 > saying and backs up what I have been saying all along. Its also a NASA
 > site and they like to have a reputation for accuracy, remember rocket
 > scientists work there.
 >
 > Its time for you to grovel for my forgiveness.

Do you really think that your physics analysis is sufficient to be
validated by a child? Because that's what you're in effect doing when
you reference this obvious children's page as proof that you're right.

--
__ Erik Max Francis && max.RemoveThis@alcyone.com && <a style='text-decoration: underline;' href="http://www.alcyone.com/max/" target="_blank">http://www.alcyone.com/max/</a>
/ \ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
\__/ Black vinyl man with black plasticized imagination
-- Nik Kershaw<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

"Erik Max Francis" <max.DeleteThis@alcyone.com> wrote in message
news:4148CF6D.791CEACE@alcyone.com...
 >
 > Do you really think that your physics analysis is sufficient to be
 > validated by a child? Because that's what you're in effect doing when
 > you reference this obvious children's page as proof that you're right.

Ooooh, this is getting really weird now.

Have a great day!

Ami
"Nothing is so bad that with a little thought, you couldn't make worse."<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

In article <4148CF6D.791CEACE.TakeThisOut@alcyone.com>, max.TakeThisOut@alcyone.com (Erik Max
Francis) wrote:

 > Stephen Forbes wrote:
 >
  > > So what if its simplified. It still totally contradicts what you keep
  > > saying and backs up what I have been saying all along. Its also a NASA
  > > site and they like to have a reputation for accuracy, remember rocket
  > > scientists work there.
  > >
  > > Its time for you to grovel for my forgiveness.
 >
 > Do you really think that your physics analysis is sufficient to be
 > validated by a child? Because that's what you're in effect doing when
 > you reference this obvious children's page as proof that you're right.
 >

Well as your intellect is obviously below kindergarden level, perhaps a
children's page was too complicated for you to understand.

Stephen

<a style='text-decoration: underline;' href="http://www.cix.co.uk/~sforbesa" target="_blank">http://www.cix.co.uk/~sforbesa</a><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

steve RemoveThis @antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote in message news:<memo.20040916001455.8557C RemoveThis @sforbesa.compulink.co.uk>...
 > In article <20040914215210.01852.00000746 RemoveThis @mb-m13.aol.com>,
 > anim8rfsk RemoveThis @aol.comNOSPAM (ANIM8Rfsk) wrote:
....
  > > "To which Larry replied:
  > >
  > > I should have drawn pictures. I've pictured them standing straight up
  > > from the rim. That doesn't work, does it? We don't want to impede the
  > > flow of the solar wind, just compress and fuse and release. So we'd
  > > better mount them OUTSIDE. Otherwise they'll be spraying hot helium at
  > > the Ringworld environment!
  > >
  > > End of quotation."
  > >
  > > Whoooo-hooooooooooo
  > >
  > > thanks!!!
  > >
  > >
 > ...and it doesn't bother you that the above has the jets firing away from
 > the sun and "Engineers" has them firing towards the sun??? A total
 > contradiction? It bothered me!

I answered that question at the time of the original attitude jets
discussion, though never to your satisfaction. I don't care to re-hash
my arguments; Google if you wish to review them.

It certainly bothered me that you cited Niven's message, quoted above,
as supporting your preferred location for the jets, which was on the
inside, the one possible location that the cited text doesn't even
mention.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

"Stephen Forbes" <steve.DeleteThis@antispam.sforbesa.cix.co.uk> wrote in message
news:memo.20040916001453.8557A@sforbesa.compulink.co.uk...
 > In article <2qq9ovF124ddbU1.DeleteThis@uni-berlin.de>, gieljanBZZdeBZZvries.DeleteThis@planet.nl
 > (Gieljan de Vries) wrote:
 >
 > I don't actually expect you to ever understand this as its way beyond your
 > capabilities.

Indeed. I hold a master's degree in the field. Guess that makes me incapable
of wrapping my head around crackpot science like yours.

*plonk*<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

steve.RemoveThis@antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote in message news:<memo.20040916001455.8557D.RemoveThis@sforbesa.compulink.co.uk>...
 > In article <8b42afac.0409142024.65ed269e.RemoveThis@posting.google.com>,
 > kuyper.RemoveThis@wizard.net (James Kuyper) wrote:
 >
  > > steve.RemoveThis@antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote in message
  > > news:<memo.20040914211658.19947D.RemoveThis@sforbesa.compulink.co.uk>...
....
  > > If you used the numbers and formulas you've presented here, the
  > > conclusions you've drawn are not supported by those numbers.
  > >
 >
 > Only because you refuse to acknowledge the possibility that I might
 > actually be right and you are basing your opinion on that.

Sure, there's a possibility that you might be right. There's also a
possibility that the Flat Earthers might be right. I'm even willing to
say that your chance of being right is slightly larger than the chance
that the Flat Earthers are right. However, my assessment of the
numbers and arguments you've presented is that some of your numbers
are valid, some of the phenomena you describe will happen, but that
the time scales associated with those phenomena are many orders of
magnitude longer than your incorrect estimates.

If you're presenting the same numbers and arguments to Niven, by
definition they must contain the same flaws; if they didn't, they'd be
different arguments.

  > > I thank you for the vote of confidence, but I myself would never make
 >
 > I was being sarcastic about your point of view.

I'm sorry, I guess I was being too subtle. I knew that you were being
sarcastic, and my response was intended to be equally sarcastic.

  > > such a claim. We're quite capable of making mistakes, and so is Larry.
  > > I we all agree on something within our shared domain of competence,
  > > there's a pretty good chance that it's true, but I'd never claim our
  > > opinion was incontrovertible. ^^^^^^^^^^^^^^^^^^^
 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 > If only that was true, this message would be unnecessary.

Please cite the text wherein I make a claim of infallability. All I've
ever claimed is that I'm right, and that you're wrong, because my
evidence is correct, and my arguments validly use that evidence to
support my conclusion, while the same is not true for you. I've never
claimed that I'm necessarily right, just that I am right.

 > Just because you are in a majority, it doesn't make you right. I learnt

I didn't suggest otherwise. Being in the majority has nothing to do
with it. The key phrase was "within our shared domain of competence".
Whenever anyone has an opinion on a subject that is within that
person's domain of competence, it's disproportionately likely to be
true (while still possibly being false): that's what competence means.
When a group of people, with a shared domain of competence, are all in
agreement, it's even more likely to be true. Yet no matter how many
people who should be competent agree on an issue, that doesn't mean
that the lone dissenter is wrong. What matters is the evidence and
supporting arguments. "likely to be true" is always trumped by "proven
false", no matter how high the likelihood is

The problem is that your evidence and arguments don't support your
conclusion. Everything else I say about it is merely supporting
arguments.

  > > No. If he agrees with an incorrect conclusion, he must be wrong,
  > > whether the conclusion is from you or from me or from Erik or from
  > > Jesus. You are simply a much more prolific generator of incorrect
  > > conclusions than we are. I'm not sure why - it's a bit of a puzzle to
  > > me how you manage to be so consistently wrong.
 >
 > Its called mindless stupidity on your part as I am not a prolific
 > generator of incorrect conclusions. It is only you 3 always saying i'm
 > wrong regardless of what the post is about. I have on numerous occasions
 > proved the truth of my conclusions in the face of blatent lying from the 3
 > of you. When it comes to me all you ever do is lie and i'm sick of it.

I know we've never convinced you of the errors you've made; but that's
not because our evidence is wrong or our arguments invalid.

  > > Is there a selection
  > > effect going on here? Do we only notice you when you're wrong? You
  > > obviously know a fair amount about science, but you somehow manage to
  > > always misapply that knowledge.
 >
 > How are you so sure that I am always wrong?

I'm not sure. I'm hoping that you aren't. I look forward to the day
when you post a comment that's both interesting and valid. It seems to
me that you couldn't always be wrong, or you wouldn't still be alive.
Making a wrong decision when driving a car, for instance, can be
fatal. However, I can't remember you ever arguing for a correct point
of view in this newsgroup. That doesn't mean it hasn't happened. For
one thing, recently there was a multi-year gap in my recreational
usenet access, and you might have said something right during that
gap. I'm just saying that I can't remember ever seeing it.

....
  > > I wouldn't hold my point of view if I didn't think it was the correct
  > > point of view. If I thought some other point of view was the correct
  > > one, I'd adopt it as my own.
 >
 > Really? somehow I don't believe you would ever admit to adopting anything
 > I say.

Believe what you wish; if you go on Google, you'll find that I've
admitted error and adopted the opposing point of view in arguments
I've had with other people in other newgroups. I don't do it very
often, but I've got such a long and prolific posting history that even
such a rare occurance has come up many times.

You actually have said some things I've adopted. Some of the points
you made in the attitude jets discussion were valid, and I
acknowledged that fact at the time. However, you didn't have enough
valid points to change the main conclusion.


  > > Right now, the only arguments I've seen for
  > > the opposing point of view are your invalid arguments.
 > ^^^^^^^
 > How are you so sure they are invalid? Answer, because thats the only
 > situation you ever consider.

I'm sure that they're invalid because I've read them, understood them,
and identified the flaws in them. How do you ordinarily go about
identifying invalid arguments? Do you do something different from
that?

  > > If Niven really
  > > is agreeing with you in a quantitative sense, and not merely in a
  > > qualitative sense, then the most plausible conclusion is that he's
  > > been misled by your incorrect arguments. It's also possible that
  > > you're right, we're wrong, and Niven recognised that fact, but that's
  > > a far less plausible explanation.
 >
 > Again, you don't even consider that you being wrong is even likely. I find

Correct, I don't consider it likely. It would be inconsistent with the
available evidence to think that it was likely. You have clearly
presented evidence and arguments that do not support your conclusions.
You have a long history of doing the same thing in the past. It's
possible that I'm misjudging your evidence and arguments, or
misunderstanding your conclusions, but why in the world should I think
that it's likely?

   > > > BTW I came across this Nasa site. Enjoy your humble pie!
<font color=brown>   > > > <a style='text-decoration: underline;' href="http://science.msfc.nasa.gov/ssl/pad/sppb/edu/magnetosphere/mag4.html</font" target="_blank">http://science.msfc.nasa.gov/ssl/pad/sppb/edu/magnetosphere/mag4.html</font</a>>
  > >
  > > So what? I'm not talking about a situation where there's no protective
  > > magnetic field. I'm talking about a situation where generation of such
  > > a field is a comparatively trivial engineering detail.
  > >
 >
 > Ahhh a conflict in your point of view.
 >
 > Above you are talking about Niven "wrongly" agreeing with me about the
 > instability of the Ringworld's atmosphere by the solar wind, and then you
 > start describing how to create a protective magnetic field to stop the
 > very same solar wind destabilising the atmosphere.

There's no conflict. I'm said that Niven would be wrong, if he accepts
your estimates of the speed with which those phenomena would occur.
It's not clear to me from the text that you quoted whether or not he
even knows of those estimates, much less agrees with them.

However, it's also quite true, and no contradiction to that statement,
that the existence of a protective magnetic field is helpful, and
without it the loss of atmopheric water from the Earth's atmosphere
would be much greater. Your error consists in having reached the false
conclusion that no such field can be provided on the Ringworld.

 > You're trying to have it both ways with me both right and wrong about the
 > exact same thing. Besides the NASA site says quite clearly that I was
 > right about needing a magnetic field to protect Earth's atmosphere from
 > the ravages of the solar wind and you 3 guys are, to quote JesusX
 > correctly this time, horribly horribly wrong!

I never said it wasn't helpful. So there's no contradiction. I was
concentrating on the atmosphere as a whole, which isn't very
vulnerable, but it's certainly true that the Hydrogen (and therefore
the water content) in the atmosphere is far more vulnerable than the
atmosphere as whole. However, to counter this, there's also the fact
that the solar wind consists of hydrogen, and unlike the Earth, the
Ringworld is well shaped to capture and hold that hydrogen.

Therefore, while the solar wind might strip some of the hyrdrogen
away, it's sort of like trying to empty a pool by knocking the water
out of the pool with a garden hose. A high-powered fire hose could
give the water in a small inflatable wading pool enough velocity to
knock most of it out of the pool, including the water that came from
the fire hose. However, the case of the Ringworld is more like trying
to use a stream of water from a garden hose to knock the water out of
a lake. You've never properly acknowledged the extreme weakness of the
cause you're proposing, compared to the size of the effect that you're
suggesting.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

"Gieljan de Vries" <gieljanBZZdeBZZvries RemoveThis @planet.nl> wrote in message
news:2qsrsvF13bibrU1@uni-berlin.de...
 > "Stephen Forbes" <steve RemoveThis @antispam.sforbesa.cix.co.uk> wrote in message
 > news:memo.20040916001453.8557A@sforbesa.compulink.co.uk...
  > > In article <2qq9ovF124ddbU1 RemoveThis @uni-berlin.de>,
gieljanBZZdeBZZvries RemoveThis @planet.nl
  > > (Gieljan de Vries) wrote:
  > >
  > > I don't actually expect you to ever understand this as its way beyond
your
  > > capabilities.
 >
 > Indeed. I hold a master's degree in the field.

"Of physics", of course. Today's important lesson: only post after a cup of
coffee.

 > Guess that makes me incapable
 > of wrapping my head around crackpot science like yours.
 >
 > *plonk*<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

steve RemoveThis @antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote in message news:<memo.20040916001457.8557E RemoveThis @sforbesa.compulink.co.uk>...
 > In article <8b42afac.0409142004.16415603 RemoveThis @posting.google.com>,
 > kuyper RemoveThis @wizard.net (James Kuyper) wrote:
 >
  > > steve RemoveThis @antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote in message
  > > news:<memo.20040914211657.19947C RemoveThis @sforbesa.compulink.co.uk>...
   > > > In article <8b42afac.0409140657.42e87ca4 RemoveThis @posting.google.com>,
   > > > kuyper RemoveThis @wizard.net (James Kuyper) wrote:
 > ...
   > > > > Call it obvious, if you wish, but I don't see any basis for those
   > > > > assertions. What would cause those burn marks? Charged plasma
   > > > > spirals
   > > > > around magnetic field lines. If you choose the intensity of the
   > > > > magnetic field properly, the radius of the spirals will be just
   > > > > large
   > > > > enough to divert the solar wind away from the Ringworld and into a
   > > > > region where the magnetic field is weak enough that the radius of
   > > > > the
   > > > > spiral increases to infinity, thereby releasing the charged
   > > > > particles.
   > > >
   > > > This actually has me confused. You want to form a uniform vertical
   > > > magnetic field across the width of the Ringworld.
  > >
  > > It can't be uniform because the Ringworld is a cylinder of finite
  > > length. As a general rule, edge effects make it impossible for an
  > > electromagnetic field to be exactly uniform. However, it doesn't have
  > > to be perfectly uniform for this approach to succeed.
  > >
  > > HOW??? Please answer
   > > > this question. I cannot see the superconductor grid doing this, I can
   > > > only see horizontal field lines above the grid and vertical lines in
   > > > the middle of each hexagon. Are you only going to use 1 in every 7
   > > > hexagon because even that won't form a uniform field.
  > >
  > > It's pretty simple. Choose the region within which you want to set up
  > > a nearly uniform field with a primarily vertical orientation. Route
  > > the electric current through the hexagaon grid on a path that follows
  > > as closely as possible the perimeter of that region. The resulting
  > > horizontal current loop necessarily produces a magnetic field that is
  > > primarily vertical throughout the region inside the current loop, and
  > > for a considerable distance above and below the current loop.
 >
 > So, you are setting up an enormous loop which encompasses lots of
 > hexagons. Basically 597 huge loops 20 hexagons across.

Sure - covering a lot of area requires including a lot of hexagons. I
didn't remember that Niven had given a specific size for the hexagons,
but I see no reason why your numbers couldn't be correct, nor are they
a problem for my hypothesis.

 > ... There are some
 > obvious problems where the loops touch, where the field is horizontal not
 > vertical. This problem will remain as long as there is more than one loop.

The loops touch, and the field is horizontal, only in the region
between day-streams, where there is little solar wind because it's
been blocked by the shadow squares. That was an essential component of
my design.

   > > > > Not when the main component of their velocity of the protons is
   > > > > anti-spinward, and the radius of the spiral is adjusted to be on the
   > > > > order of 1 million miles. Then the spiral will simply divert the
   > > > > flow
   > > > > either to port or starboard.
   > > > >
   > > >
   > > > What strength of field? This is your baby so its up to you to justify
   > > > this with numbers and patterns. I can't see it working, please prove
   > > > me wrong.
  > >
  > > That's trivial enough - I assumed you were familiar with the formula.
  > > In the appropriate units, it takes the form B=m*v*c/r*q, where 'm' is
  > > the mass of the charged particle, v is the component of it's velocity
  > > transverse to the the magnetic field, c is the speed of light, r is
  > > the radius of the spiral, and q is the charge of the particle. I don't
  > > see much point in plugging actual numbers into that equation; we've no
 >
 > You really should put numbers in and balance it with the current required
 > to produce that field in your coil.

You know of some particular limit on that current? I don't. Without a
limit, I don't see why it matters what the current required is.

  > > information about the limits on the superconductor being used, and
  > > therefore no basis for saying that any particular magnetic field
  > > strength is unattainable. I will point out that the radius of the
  > > spirals in the Earth's magnetic field is immensely smaller than 1
  > > million miles, and the required field strength is inversely
  > > proportional to the spiral radius. As a result, the field required to
  > > keep the Ringworld safe is much weaker than the one needed to keep the
  > > Earth safe.
 >
 > Not when your dealing with the Ringworld it isn't. The Earth's main
 > defence is a field at right angles to the path of the solar wind and that
 > only needs a relatively weak field. You're trying to produce a uniform
 > field parallel to the path of the solar wind

No, as you yourself have pointed out, the solar wind is coming in with
an anti-spinward velocity of 770 mi/sec. Therefore, it's not parallel
to the field. If it were parallel, the approach I described wouldn't
work.

 > stronger field as you will have to cope with the _inverse cube law_ for a

Keep in mind that fields decline according to the standard force laws
only for distances that are large compared to the dimensions of the
source of the field. The source of this magnetic field is a current
loop a million miles wide and millions of miles long; the inverse cube
law will be significant only for distances much larger than a million
miles.

  > > If it seems counter-intuitive that such a tiny field is sufficient,
  > > keep in mind that the mechanism I describe requires that this very
  > > weak magnetic field must remain at least moderately uniform over
  > > millions of miles; the total energy of that volume of magnitic field
  > > is enormous, despite the fact that the field itself is quite weak.
 >
 > It can't remain uniform, apart from the dipole effect the middles of your
 > loops aren't likely to have a noticable field present. The coils are so
 > big that they can be treated at single straight wires and you will be more
 > accurate that way.

Who said anything about coils? I was talking about a single closed
loop of current for each day-stream.

 > I know you are going to say something along the lines of "but inside a
 > coil the lines of force are uniformly distributed".

They're uniformly distributed only in an infinitely long cylinder,
bounded by closed current loops. I'm talking about a single closed
current loop, so there's going to be a lot less uniformity. The field
will point upward at the center of the loop. It will get weaker and
tilt away from the vertical toward the edges of the loop. However, it
will never point very far away from the vertical anywhere near the
plane of the loop.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

steve.RemoveThis@antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote in message news:<memo.20040916001454.8557B.RemoveThis@sforbesa.compulink.co.uk>...
 > In article <414786B9.5F7BA3CF.RemoveThis@alcyone.com>, max.RemoveThis@alcyone.com (Erik Max
 > Francis) wrote:
 >
  > > Stephen Forbes wrote:
  > >
   > > > Actually I don't need to as NASA has already done the hard work for
   > > > me.
<font color=brown>   > > > <a style='text-decoration: underline;' href="http://science.msfc.nasa.gov/ssl/pad/sppb/edu/magnetosphere/mag4.html</font" target="_blank">http://science.msfc.nasa.gov/ssl/pad/sppb/edu/magnetosphere/mag4.html</font</a>>
   > > >
   > > > EAT HUMBLE PIE!
  > >
  > > That's a Web page intended for children, Forbes. Didn't you think the
  > > suggestion that Venus' atmosphere might have been "singed" was
  > > simplifying a little?
  > >
 >
 > So what if its simplified. It still totally contradicts what you keep
 > saying and backs up what I have been saying all along.

Erik, as far as I can tell, has never said anything that is
contradicted by that web site. Would you care to identify the
contraction? It points out the usefulness of a protective magnetic
field in retaining an atmosphere with a significant water content.
Arranging a protective magnetic field for the Ringworld is a trivial
engineering detail (compared to the Ringworld itself). So?<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

On Thu, 16 Sep 2004 00:14 +0100 (BST),
steve DeleteThis @antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote:


 >So what if its simplified. It still totally contradicts what you keep
 >saying and backs up what I have been saying all along. Its also a NASA
 >site and they like to have a reputation for accuracy, remember rocket
 >scientists work there.
 >

<de lurk>

<a style='text-decoration: underline;' href="http://www.chron.com/cs/CDA/ssistory.mpl/space/columbia/2378073" target="_blank">http://www.chron.com/cs/CDA/ssistory.mpl/space/columbia/2378073</a>


To highlight an important part of the above article:

[ Earlier this week, reflecting on Columbia's upcoming anniversary,
Wayne Hale, deputy shuttle program manager, sent an impassioned e-mail
to his colleagues at Houston's Johnson Space Center. The subject line
read: "Adjusting our thinking."

"Last year we dropped the torch through our complacency, our
arrogance, self-assurance, sheer stupidity, and through (our)
continuing attempt to please everyone," Hale wrote. "Seven of our
friends and colleagues paid the ultimate price for our failure. Yet
the nation is giving us another chance ... We must not fail." ]

Took me about 30 seconds to find them admitting that, at times,
they're downright incompetent over there. You'd probably be horrified
at all of NASA's failures, if I took the time to hunt down all the
links. I wouldn't necessarily say they have a reputation for
'accuracy'.

From what I've seen of this lengthy debate, it basically breaks down
into a few points.

Some of you say that Ringworld's atmosphere is unstable, and needs
some sort of protection that's not mentioned in the novels. This may
or may not be true.

Some of you say that if a species could create a mostly-indestructible
metal to fashion the Ringworld, and in fact to actually construct such
a mammoth creation, that it should/would be child's play for them to
engineer an automated system that would preserve said atmosphere.

Some of you have also pointed out that Venus, being closer to the sun
than Ringworld, has a higher concentration of Solar Winds attempting
to denude it's atmosphere. It's also been pointed out that Venus _is_
indeed losing it's atmosphere, and that it has no magnetic field.

So, it seems to me that the following is possible:

A) Ringworld is losing atmosphere
B) Ringworld's atmosphere is being lost at a higher rate than Venus,
due to i) increased area of atmospheric-solar wind contact and ii)
lower mass of component atoms/molecules
C) Ringworld's atmosphere is being lost at a lower rate than Venus,
due to weaker Solar Winds
and D) Simply assuming that the creators of the Ringworld either
engineered a method to prevent the loss that is not mentioned in the
books due to lack of knowledge on the part of the characters involved,
or that the scale of time that it would take is so massive that the
creators simply don't care or plan to re-collect and re-seed the
atmosphere before it becomes critically unstable.

For those who may point out, yes I didn't include the option that
Ringworld is not losing atmosphere, as it is irrelevant to the
discussion, really.

If RW is not losing atmosphere, no need for the discussion. If it's
losing atmosphere at a very slow rate, also no real need of
discussion, as it can be safely assumed that either the creators
didn't/don't care, or that it is being maintained behind the scenes,
and the characters in the novels are unaware of this. If venus managed
to keep it's atmosphere for billions of years (random estimate,
although it should have formed an atmosphere at a similar time to
earth, I have no hard data at the moment, and don't care to look), it
should be reasonable that the Ringworld could keep it for a
significant amount of time.

The only time where Ringworld losing it's atmosphere would really
impact the series is if it was losing it's atmosphere fast enough that
the atmosphere would have depleted between the first recorded
continuous habitation of the Ringworld, and Louis Wu's first visit.
Why, you ask? Because it could be assumed that the atmosphere was
added shortly before living beings were added to the Ringworld
(because they _were_ added), and if the atmosphere were unable to
stand until Louis Wu's time, there would have been a quite different
world waiting for him.

If someone wishes to prove once and for all that this is the case, I'd
suggest starting from scratch. Declare your equations, declare the
numbers used (and cite sources), and work the math. Same way they do
it on exams, and also the same way theories are presented in the
scientific community. Commonly known equations and sources are usually
not needed or implied, but I'd recommend stating them all the same,
just to make certain people can follow. It also makes math errors
easier to track down, both by those proving their point, and by those
disproving it. Otherwise, what's the point in arguing about something
that won't happen within the time line of the story? I'm sure LN
doesn't worry about details to that level. He's telling a story, not
proving that RW actually exists.

Of course, feel free to totally ignore me and continue debating the
subject. I'm quite happy to have reading material presented to me on a
daily basis for free.

- Dark
-----
"Wilderness of mirrors, streets of cold desire
My precious sense of honor, just a shield of rusty wire
I hold against the chaos, and the cross of holy fire"<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

Dark2112 wrote:
 >
 > On Thu, 16 Sep 2004 00:14 +0100 (BST),
 > steve.TakeThisOut@antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote:
 >
  > >So what if its simplified. It still totally contradicts what you keep
  > >saying and backs up what I have been saying all along. Its also a NASA
  > >site and they like to have a reputation for accuracy, remember rocket
  > >scientists work there.
  > >
 >
 > <de lurk>
 >
<font color=purple> > <a style='text-decoration: underline;' href="http://www.chron.com/cs/CDA/ssistory.mpl/space/columbia/2378073</font" target="_blank">http://www.chron.com/cs/CDA/ssistory.mpl/space/columbia/2378073</font</a>>
 >
 > To highlight an important part of the above article:
 >
 > [ Earlier this week, reflecting on Columbia's upcoming anniversary,
 > Wayne Hale, deputy shuttle program manager, sent an impassioned e-mail
 > to his colleagues at Houston's Johnson Space Center. The subject line
 > read: "Adjusting our thinking."
 >
 > "Last year we dropped the torch through our complacency, our
 > arrogance, self-assurance, sheer stupidity, and through (our)
 > continuing attempt to please everyone," Hale wrote. "Seven of our
 > friends and colleagues paid the ultimate price for our failure. Yet
 > the nation is giving us another chance ... We must not fail." ]
 >
 > Took me about 30 seconds to find them admitting that, at times,
 > they're downright incompetent over there. You'd probably be horrified
 > at all of NASA's failures, if I took the time to hunt down all the
 > links. I wouldn't necessarily say they have a reputation for
 > 'accuracy'.
 >
 > From what I've seen of this lengthy debate, it basically breaks down
 > into a few points.
 >
 > Some of you say that Ringworld's atmosphere is unstable, and needs
 > some sort of protection that's not mentioned in the novels. This may
 > or may not be true.

One person makes that claim: The same person who has consistently made
bizarrely wrong claims with a total lack of knowledge of physics or
common sense in this newsgroup over the years.

You have one kook claiming something ridiculous, and everyone else
telling him he's wrong, but him blindly continuing on. This hardly
qualifies as a debate.

 > Some of you say that if a species could create a mostly-indestructible
 > metal to fashion the Ringworld, and in fact to actually construct such
 > a mammoth creation, that it should/would be child's play for them to
 > engineer an automated system that would preserve said atmosphere.

I don't recall anyone on the other side saying anything like that. On
the contrary, they didn't say that supertechnologies were required to
retain the atmosphere, they said _nothing additional_ was required to
retain the atmosphere, since the leakage rates would be utterly
trivial. It would take many times longer than the age of the Universe
for the Ringworld, as designed, to lose its atmosphere. The lone
detractor made up a figure of 100 yr for the timescale it would take for
Ringworld to empty itself, and then proceeded to claim the same thing
was happening to Venus, although curiously dodging the point that Venus
has had an atmosphere for longer than 100 yr.

 > Some of you have also pointed out that Venus, being closer to the sun
 > than Ringworld, has a higher concentration of Solar Winds attempting
 > to denude it's atmosphere. It's also been pointed out that Venus _is_
 > indeed losing it's atmosphere, and that it has no magnetic field.

All planets are losing their atmosphere; so is Earth. They're just
doing it at extremely low rates. What was quoted about Venus involved
it losing the _water_ in its atmosphere to space, not wholesale loss of
its atmosphere. Venus has had its atmosphere for billions of years.
It's not losing it anytime soon.

--
__ Erik Max Francis && max.TakeThisOut@alcyone.com && <a style='text-decoration: underline;' href="http://www.alcyone.com/max/" target="_blank">http://www.alcyone.com/max/</a>
/ \ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
\__/ Awards are merely the badges of mediocrity.
-- Charles Ives<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

Dark2112.TakeThisOut@FakeEmail.com writes:
 >Some of you say that Ringworld's atmosphere is unstable, and needs

At this point, I think it's down to Steven. I got what I asked for weeks
ago - smart people telling me where my thinking was flawed. They even
taught me how to fish, and running their math verifies they're right.

 >Some of you say that if a species could create a mostly-indestructible
 >metal to fashion the Ringworld, and in fact to actually construct such
 >a mammoth creation, that it should/would be child's play for them to
 >engineer an automated system that would preserve said atmosphere.

Well, you could certainly make that argument (it's sometimes called the
Wizard's gambit), but where's the fun in that?

 >Some of you have also pointed out that Venus, being closer to the sun
 >than Ringworld, has a higher concentration of Solar Winds attempting
 >to denude it's atmosphere. It's also been pointed out that Venus _is_
 >indeed losing it's atmosphere, and that it has no magnetic field.

Venus is not losing its atmosphere at any significant rate, or it would
have lost it already. There was some discussion about venus losing WATER
out of its atmosphere, but that's not the primary component of it.

 >For those who may point out, yes I didn't include the option that
 >Ringworld is not losing atmosphere, as it is irrelevant to the
 >discussion, really.

It's relevant if the forces acting to preserve the ringworld's atmosphere
are stronger than the ones tending to deplete it, and this seems to be the
case.

 >If RW is not losing atmosphere, no need for the discussion. If it's

I started this mess because I had some wacky ideas about the atmosphere not
becoming coupled to the ringworld's spin, mostly because I wasn't taking
the angular momentum of the atmosphere into account. Another flaw in my
thinking, which I corrected myself later, was over-estimating the altitude
of breathable pressure, thinking incorrectly that it wouldn't look like
Earth's.

 >The only time where Ringworld losing it's atmosphere would really
 >impact the series is if it was losing it's atmosphere fast enough that
 >the atmosphere would have depleted between the first recorded
 >continuous habitation of the Ringworld, and Louis Wu's first visit.

The question wasn't about the novel as such.

 >Why, you ask? Because it could be assumed that the atmosphere was
 >added shortly before living beings were added to the Ringworld
 >(because they _were_ added), and if the atmosphere were unable to
 >stand until Louis Wu's time, there would have been a quite different
 >world waiting for him.

Well, yeah. We're not talking about authorial fiat - it's the science that
was interesting.

 >If someone wishes to prove once and for all that this is the case, I'd
 >suggest starting from scratch. Declare your equations, declare the

The only person who feels that there's a problem is Steven, based on the
solar wind, and it seems to me he's not getting much traction. *
--
* PV something like badgers--something like lizards--and something
like corkscrews.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind 

Dark2112 <Dark2112.RemoveThis@FakeEmail.com> wrote in message news:<t2djk0dbvaftkd02dl755hf6rr7a3v4m9o.RemoveThis@4ax.com>...
 > On Thu, 16 Sep 2004 00:14 +0100 (BST),
 > steve.RemoveThis@antispam.sforbesa.cix.co.uk (Stephen Forbes) wrote:
....
 > From what I've seen of this lengthy debate, it basically breaks down
 > into a few points.
 >
 > Some of you say that Ringworld's atmosphere is unstable, and needs
 > some sort of protection that's not mentioned in the novels. This may
 > or may not be true.

We all agree that the Ringworld's atmosphere is unstable. Some of us
believe that it's roughly as unstable as the Earth's atmosphere;
others of us believe that it's far less stable than that.

 > Some of you say that if a species could create a mostly-indestructible
 > metal to fashion the Ringworld, and in fact to actually construct such
 > a mammoth creation, that it should/would be child's play for them to
 > engineer an automated system that would preserve said atmosphere.

It's not just that they could have done so, but that the
superconductor grid is suitable (though not ideal) to serve that
purpose.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Significance of the solar wind