Microgravity parable

[Followup set to sci.space.policy]

Stuf4 wrote:

From Rand:


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.

If people at NASA really thought there was no gravity in LEO, I suspect
that their
design for rockets for interplanetary probes would be much different,
and that
these probes would fail miserably. Since many NASA interplanetary probes do
succeed and that the ones that do fail, do so for unrelated reasons, one
has to
think that they are aware of gravity. If they aren't, then the success
of their probes
is an event as unlikely as this post being written accidentally by my
cat walking
on my keyboard.

Meow.

Alain Fournier

"stmx3" wrote in message
...
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.

Also something Stuffie knows from personal experience, as shown by his posts
here.
--
If you have had problems with Illinois Student Assistance Commission (ISAC),
please contact shredder at bellsouth dot net. There may be a class-action
lawsuit
in the works.

From stmx3:
Stuf4 wrote:

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.

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.

Umm, we *all* prefer our own viewpoint above all else. Otherwise, it
wouldn't be our viewpoint!


~ CT

From Alain Fournier:
If people at NASA really thought there was no gravity in LEO, I suspect
that their
design for rockets for interplanetary probes would be much different,
and that
these probes would fail miserably. Since many NASA interplanetary probes do
succeed and that the ones that do fail, do so for unrelated reasons, one
has to
think that they are aware of gravity. If they aren't, then the success
of their probes
is an event as unlikely as this post being written accidentally by my
cat walking
on my keyboard.

Meow.

(Being in total agreement with everything you've stated here, I take
all of that as excellent reasons for NASA to stop speaking about
zero/microgravity.)


~ CT

From stmx3:
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?

While the evidence might give more weight to that view, it's not
enough to persuade me. So, no. My estimation still weighs toward the
view that people who know the difference would be bothered enough by
it to not use those terms.

Along the lines of:

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

Yup. That's what they do.

This goes back to the parable of the emperors clothes. Everyone with
eyes to see knows that he's naked, but people curiously just play
along with it as though it's perfectly normal.

On top of that, they see the blind subjects tear off their clothes
because they've been told that going around naked is perfectly normal.
Certain to cause problems throughout the winter, if not throughout
the rest of the year as well.

*

This view, if accurate, makes for paramount hypocrisy when NASA
presents itself as an agency that cares about promoting science.


~ CT

In article ,
(Stuf4) wrote:

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?

While the evidence might give more weight to that view, it's not
enough to persuade me. So, no. My estimation still weighs toward the
view that people who know the difference would be bothered enough by
it to not use those terms.

Pretty much everyone who posts regularly to these groups knows the
difference and we're not bothered. Stop extrapolating your views and
feelings to the rest of the world.

--
Herb Schaltegger, B.S., J.D.
Reformed Aerospace Engineer
"Heisenberg might have been here."
~ Anonymous

snip
I'm sure there are lots more references with accurate physics. Hey,
maybe even *NASA* has an accurate webpage on this. I'll check there
and let you know if I find something good.


~ CT

I've found a NASA webpage that comes very close to being accurate:

http://science.nasa.gov/newhome/head...ro-g.plane.htm

Quote:

"What astronauts experience in space isn't really zero-gravity. NASA
scientists call it microgravity or low-g, but it's really free fall or
weightlessness."

I see this quote above to be totally accurate. But later in the page,
there is this fatal error:

"NASA scientists call this microgravity... The term is apt since
Albert Einstein said that acceleration caused by gravity is equivalent
to any other push."

The principle is about _mass_ equivalence, not acceleration
equivalence.

Say that you spin a ball at the end of a tether. It is completely
bogus (vice "apt") to say that you are *increasing gravity* on that
ball. Just the same, it is bogus to say that you are *decreasing
gravity* on a ball that you drop from a tower. There is nothing
"micro" about gravity in a freefall toward the Earth.


~ CT



Full article:
__________________________________________________

Temporary weightlessness

Engineers and scientists experience about 20 to 30 seconds of
weightlessness during each parabola aboard NASA's KC-135 aircraft, an
effective and inexpensive means of testing experiments before they go
to space. Because everything floats, test equipment must be bolted or
taped to the deck, as with the apparatus here for testing liquid
cages.

What astronauts experience in space isn't really zero-gravity. NASA
scientists call it microgravity or low-g, but it's really free fall or
weightlessness.

Gravity goes to the edges of the universe -- it's why planets circle
the sun, stars clump together to form galaxies, and Space Shuttles
stay in orbit.

So what is happening on a spacecraft or when Kornfeld and Antar run
experiments on the KC-135 (as seen at top)?

As a spacecraft orbits a planet, it really falls endlessly in a circle
(or ellipse) that is a delicate balance between the satellite's
forward motion and the planet's gravitational pull. Because everything
is falling together, nothing has weight.

Well, almost no weight. Unless an object is at the precise center of a
satellite's mass, it will try to pull ahead or fall back into a slight
different orbit. And that means that the object will experience a
small amount of acceleration against a wall. And even at the Shuttle's
altitude, a trace of atmosphere is left and gently drags on the
Shuttle which will cause an object to drift inside the Shuttle.

NASA scientists call this microgravity since usually it is equivalent
to about 1/1,000th or less of one Earth gravity (the range depends on
the location in the spacecraft and other factors). The term is apt
since Albert Einstein said that acceleration caused by gravity is
equivalent to any other push.

Free fall can be duplicated, briefly, on Earth, by dropping an object.
Like falling off a cliff, it's not the first step that gets you, or
the long trip down, but the stop at the end.

NASA has drop tubes in which molten droplets of material fall for
about 2 to 3 seconds before hitting a bucket of oil to capture them
safely and cool them off.

For larger experiments, or to train astronauts, NASA uses a KC-135, a
military tanker version of the Boeing 707 jetliner. The pilots guide
these jets on carefully designed parabolic trajectories that resemble
a roller coaster ride.

At the top, the pilot throttles back and noses over, letting the plane
dive to give everyone about 20 to 30 seconds of free fall (actually,
it varies between 0.01 g to 0.001 g; it's not nearly as good or as
long as being in orbit). They do this 40 times on each mission, so
they get about 13 minutes of microgravity time -- at a personal price.

People riding the NASA KC-135 often get extremely sick doing this.
That's why the plane is also called The Vomit Comet.

The things you do for science!

__________________

On Fri, 10 Oct 2003 22:44:43 -0500, Herb Schaltegger
wrote:

Stop extrapolating your views and feelings to the rest of the world.

....Extrapolating? I though the word was ejaculating.


OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

From Herb Schaltegger:
(Stuf4) wrote:

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?

While the evidence might give more weight to that view, it's not
enough to persuade me. So, no. My estimation still weighs toward the
view that people who know the difference would be bothered enough by
it to not use those terms.

Pretty much everyone who posts regularly to these groups knows the
difference and we're not bothered. Stop extrapolating your views and
feelings to the rest of the world.

How ironic that you offer your extrapolation regarding "pretty much
everyone..." while chastising my extrapolation.

This reads as another form of "I'm right/you're wrong", coated with a
heavy tinge of hypocrisy.


~ CT

On 11 Oct 2003 07:47:39 -0700, in a place far, far away,
(Stuf4) made the phosphor on my
monitor glow in such a way as to indicate that:

Pretty much everyone who posts regularly to these groups knows the
difference and we're not bothered. Stop extrapolating your views and
feelings to the rest of the world.

How ironic that you offer your extrapolation regarding "pretty much
everyone..." while chastising my extrapolation.

This reads as another form of "I'm right/you're wrong", coated with a
heavy tinge of hypocrisy.

Unlike yours, there's abundant evidence for his extrapolation. For
instance, I haven't seen any posts agreeing with you, and many
agreeing with us. You continue to stagger along to the offbeat
tatooing of your own drunken drummer.

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
Swap the first . and @ and throw out the ".trash" to email me.
Here's my email address for autospammers: