Microgravity parable

On 9 Oct 2003 18:09:48 -0700, in a place far, far away,
(Stuf4) made the phosphor on my
monitor glow in such a way as to indicate that:

The main point of focus has been that the concept of gravity is
distinct from the concept of acceleration. While the force of gravity
causes acceleration, many accelerations are not caused by the force of
gravity.

Which is irrelevant to your lunatic theory that space engineers and
scientists don't understand the theory.

Perhaps you'd like to offer an explanation as to why astronauts are
quoted as speaking about "no gravity" in orbit, or why NASA scientists
advertise facilities with "low gravity".

Because they're using shorthand to make concepts comprehensible (if
not entirely accurate) to laypeople.

Your theory that they actually don't understand the physics is,
frankly, laughable.

--
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interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
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In sci.space.policy, on Wed, 08 Oct 2003 13:51:30 -0500, Joe Strout
sez:

` In article ,
` (Stuf4) wrote:

` And when astronauts came back from space, they would be crystal clear
` that while they floated around, with their bodies having no relative
` acceleration in relation to their spacecraft, gravity never came
` anywhere close to zero at any point in their trip. They *never*
` experienced zero gravity. They experienced zero acceleration.

` Traveling at constant speed in a straight line, were they?

Travelling in a straight line following a "geodesic" (what's a
geodesic called when you're not on geos?) of spacetime. -GR

--
================================================== ========================
Pete Vincent
Disclaimer: all I know I learned from reading Usenet.

From Rand:
The main point of focus has been that the concept of gravity is
distinct from the concept of acceleration. While the force of gravity
causes acceleration, many accelerations are not caused by the force of
gravity.

Which is irrelevant to your lunatic theory that space engineers and
scientists don't understand the theory.

Perhaps you'd like to offer an explanation as to why astronauts are
quoted as speaking about "no gravity" in orbit, or why NASA scientists
advertise facilities with "low gravity".

Because they're using shorthand to make concepts comprehensible (if
not entirely accurate) to laypeople.

It would be very easy for NASA to speak of zero-g to communicate the
concept of acceleration. Instead they mistake "g" for "gravity" and
the result is *incomprehensible* because it makes no sense at all.

But NASA *does* make the effort to educate the public on the
distinction between "zero-" and "micro-". This makes it all sound
more scientific and probably helps shake dollars out of the DC tree,
but NASA missed the forest on this one.

Your theory that they actually don't understand the physics is,
frankly, laughable.

I started talking about this topic early on after joining this forum.
I remember giving them all the benefit of the doubt, but the more I
looked into the matter, the more disappointed I became.

Lack of comprehension is only one possible explanation as to why NASA
persists in using anti-scientific terminology. But I'm at a loss for
finding an alternate explanation that would seem more probable.


~ CT

(Stuf4) wrote in message
From Joe Strout:
(Stuf4) wrote:

And when astronauts came back from space, they would be crystal clear
that while they floated around, with their bodies having no relative
acceleration in relation to their spacecraft, gravity never came
anywhere close to zero at any point in their trip. They *never*
experienced zero gravity. They experienced zero acceleration.

Traveling at constant speed in a straight line, were they?

Umm, Joe, in rereading what I originally wrote (as quoted) you can see
that it was explicitly stated:

"...their bodies having no relative acceleration in relation to their
spacecraft..."


~ CT



Thanks for the correction! I meant to say...

They experienced zero acceleration *relative to their spacecraft*.

(Or micro accel, to be more exact.)


~ CT

stmx3 wrote...

(Some interesting stuff three times)

I occasionally get that multiple-posting glitch with Outlook Express. On
some level, I'm glad to see it on Netscape mail as well

- Peter

Peter Smith wrote:
stmx3 wrote...

(Some interesting stuff three times)

I occasionally get that multiple-posting glitch with Outlook Express. On
some level, I'm glad to see it on Netscape mail as well

- Peter



Yes...I found it unusual. Actually, I think it was my own fault. I hit
"Reply All" but it wouldn't send because Stuf4's email address wasn't
recognized. I removed the 'spamblock' from the address, tried to send
again, but nothing happened. Finally, I removed his email address
altogether and voila! 3 posts!

Or maybe the forum was trying to emphasize my post?

Stuf4 wrote:
From stmx3:
snip
http://spacelink.nasa.gov/Instructio...ce/.index.html

Note - this is a NASA educational website.
(If you can't reconstruct the link, try http://tinyurl.com/qbv6 )

"*Microgravity* literally means very little *gravity*. Another way to
think of 'micro-' is in measurement systems, such as the metric system,
where micro- means one part in a million or 1 x 10^-6 g. Scientists do
not use the term microgravity to accurately represent millionths of 1 g.
The microgravity environment, expressed by the symbol mu-g, is defined
as an environment where some of the effects of gravity are reduced
compared to what we experience at Earth's surface."


I could go on. Google gave me 340,000 returns on "microgravity". But,
it doesn't matter because you choose to look through filtered glasses
where you see only what you want to see.

Some of the articles above explicitly acknowledge that "microgravity"
doesn't mean there's no gravity in a freefall. That is what *you* think
it means.


...and the view I hold is in agreement with a quote that you yourself
provided:

"*Microgravity* literally means very little *gravity*."


Yup. I didn't leave that out. I want to be as objective as possible
and I don't go into selectively editing quotes or take them out of
context. There were a few more you could have grabbed hold of and
pointed out their support for your position.

Of course, if you stopped reading after the first sentence of that
quote, you would walk away with the wrong definition of microgravity.
And that quote can be confusing. But it later gives the proper def. of
microgravity...it just doesn't do a good job at contrasting the two
meanings (i.e. the literal translation and the vernacular usage)

[snip]

Stuf4 wrote:
[snip]


Lack of comprehension is only one possible explanation as to why NASA
persists in using anti-scientific terminology. But I'm at a loss for
finding an alternate explanation that would seem more probable.


~ CT

If you cannot rationalize in your own mind why "microgravity" is used,
without resorting to your brand of off-the-wall explanation (lack of
comprehension among the scientific community), then you must find life
very hard. I've tried very hard to provide an explanation, but you deem
it to be improbable and prefer your viewpoint above all else.

I recommend you stay away from the Annals of Improbable Research, even
though their conclusions pale in the face of yours.
http://www.improbable.com/ig/ig-top.html

Stuf4 wrote:
This supports the view that people
*do* know the difference and they just use the bogus terms anyway.

So do you know subscribe to the accepted opinion that NASA astronauts
and scientists understand that the effects of Earth's Gravity is not
zero...not even micro...in LEO?


Along the lines of:

"...what I said was "no gravity"...but you know what I meant."

Yup. That's what they do.


~ CT

Stuf4 wrote:
[snip]


It would be very easy for NASA to speak of zero-g to communicate the
concept of acceleration. Instead they mistake "g" for "gravity" and
the result is *incomprehensible* because it makes no sense at all.

But NASA *does* make the effort to educate the public on the
distinction between "zero-" and "micro-". This makes it all sound
more scientific and probably helps shake dollars out of the DC tree,
but NASA missed the forest on this one.

Actually, NASA goes further and makes the point that objects in freefall
are still subject to the Earth's gravitational pull, which is not zero
and is not micro. They even define what a microgravity environment is.
I've cited references for your benefit.



Your theory that they actually don't understand the physics is,
frankly, laughable.


I started talking about this topic early on after joining this forum.
I remember giving them all the benefit of the doubt, but the more I
looked into the matter, the more disappointed I became.


Actually, you opened this can of worms by saying

"(But I'm amazed at how NASA talks about promoting science yet has no
qualms about referring to weightlessness by that completely bogus term
"microgravity". I'd go so far as to call that *anti-science*.)"

So, I'm assuming this was made long after your "age of disappointment".
All benefit-of-the-doubt has been removed.


Lack of comprehension is only one possible explanation as to why NASA
persists in using anti-scientific terminology. But I'm at a loss for
finding an alternate explanation that would seem more probable.

After responding to this earlier and reading your other posts, let's
add: "They don't care enough to speak accurately." as another possible
explanation which you should find more probable.


~ CT