Subject: Re: Speed of air in vacuum tube
From: mfarrington@alpha.ntu.ac.sg
Date: 11 Jan 97 10:47:12 +0800
In article <5b1peh$3to@cdn_news.telecom.com.au>, Trung Doan writes:
> If one end of an evacuated tube is opened (the other end is a hinged
> gate, which opens when air pressure hits it), then would someone please
> tell me what is, or how to calculate, the speed of the air rushing from
> the first end to the second one? Many thanks.
>
> Trung
>
hi trung,
since noyone has even attempted an answer to this, i'll make a start.
my guess is that the upper limit will be the speed of sound - anyone
want to set a lower limit??
peter
Subject: Re: question on liquid statics
From: "David E. Pearce Jr."
Date: Fri, 10 Jan 1997 18:59:29 -0700
Albertino Bigiani wrote:
>
> Hi!
> I hope somebody can help me on the following problem.
> Let's imagine a column of liquid. At the bottom, there is a pression (H)
> equal to dgh, where h is the height of the liquid column. Now, at the
> bottom of the column let's apply a pression P directed upward. What
> pressure will read a manometer applied to the lateral wall close to the
> bottom of the column?
>
> Thanks in advance
>
> Albertino Bigiani
You are not clear on what is happening when you apply the pressure P.
If the column is formed by a closed top tube with a sliding bottom and
the pressure port is in the bottom, the total pressure will be
P+dgh assuming P is the delta P over that required to overcome dgh.
Assuming P is not a delta P but is a total P, and the tube is opened at
the top and the P is greater than dgh, you will push all the fluid out.
Assuming P is less than dgh, the bottom will fall out of the tube, again
assuming an open top.
If the tube is closed with or without gas space in the tube (fully
filled with liquid), the pressure at the port will be P if P is less
than dgh (the liquid will pull a partial vacuum at the top until dgh +
negative pressure from vacuum equals P at the bottom and equal P if
greater than dgh because you will get compression in the liquid if
slightly compressible or the container will grow in volume (acting like
a spring) until the dgh + spring constant plus deflection = P.
If the column is an open top tube with an unmoving bottom and the tube
is not attached to anything, and P is the Delta P above dgh, applying
the pressure P will accellerate the tube until the the dkgh equals P
assuming the tube is weightless. The pressure inside the tube at the
bottom would equal P.
If P is a delta value, the sensed pressure will be equal to P + dgh
except if the tube is free to translate or is open at the top, then it
equals P if translated or Zero if open at the top.
If P is an absolute value, the sensed pressure will equal P.
Subject: ** structure of reality ** article 3
From: gary.forbat@hlos.com.au (Gary Forbat)
Date: 11 Jan 97 22:13:02
31-12-96
revised 1-1-97
Notes on the structure of reality - article 3
(first draft)
by Gary Forbat
Copyright (c) G. Forbat 1996
It may now be convenient to extend and qualify some of the main
concepts derived from the theory. In the previous essays I described
a process of material formation which provides the basis for the
observed material reality. The process operates through a building
procedure which involves a relationship between the physical
magnitudes of structures, that is, the volume they occupy, and the
rapidity of their internal cycles. Moreover, the process is universal,
ranging over an infinity of scale tranformations from the most
miniscule sizes to the most gigantic imaginable, in fact infinite in
both directions.
But it is not a single dimensional process involving only scale. What
is peculiar about the sequence is that the smaller structures of
the micro world are highly dynamic due to an extremely rapid internal
cycle operating to hold it together, and the smaller the structure,
the more dynamic it is. Dynamics refers to the rapidity of the
cyclical pulse. As particles break down to the cyclical funtion of a
number of smaller components, those components will have a
significantly more rapid internal cyclical rate than those of the
larger structure they contribute to forming. The atomic structure,
for instance, comes into being due to the cyclical function of the
electron in relation to the nucleus. The composition of the electron
has not yet been penetrated, but the possibilities are few. Either it
is composed of a very large number of tiny parts, or maybe fewer but
of a much higher dynamicity. The nucleus, on the other hand, is known
to break down to combinations of smaller, but much more dynamic parts
known as 'quarks'. Quarks themselves must reduce to even smaller
components, with cyclical rates of increasingly more rapidity. The
many qualities of quarks testify to a variance of configurations.
The quantum proportions testify to this very nature. With the
process of reduction infinite, so with it is the increase in
dynamicity.
We are fortunate enough to be able to observe two vastly different
aspect of the material process. The micro scales of phenomena present
an integrated view of average behaviour over many billions of cycles.
Imagine how the solar system would look if billions of planetary
cycles were pressed into a single second. Theoretically at least, it
would be possible to simulate the effect by taking a long term video
of the solar system in motion over many billions of years, and then
replaying the tape over a matter of seconds. Undoubtedly we could
make computer image simulations of it much more easily.
Then there is the almost static view of the process presented
by the structures of the large scale in their 'real time' cyclical
movements. Our viewpoint of stellar formations is fashioned from the
workings of the atomic structure, and compared to the speed and
capacity of the functioning of our instruments and sensing apparatus,
the stellar structures are both extremely large and so slowly evolving
as to be almost static. But now, let's venture to reconstruct in its
broadest principles the consequences of this infinite sequence of
structuring, not only to determine the status of our own viewpoint
within it, but to attempt to discover general principles that may be
directly affecting us and we are not yet aware of. Firstly, going up
or down in scale, the specific attributes of structure types that
occur depend on the interactive possibilities afforded on each
particular scale. Solar systems of one type or another, whether
binary or planetary are the almost exclusive forms that may be found
at the scale of the direct interaction between the most massive
atomic conglomerations. At this scale of consideration the universe
can be seen to be interspersed with stellar and planetary matter in
mutual interaction as solar systems. But we know that solar systems,
in turn, almost exclusively congregate in the larger massive
formations of galaxies, occuring in a small number of types. Galaxies
themseves form clusters with unique characteristics types of their own.
On the galactic scale of consideration the universe can be seen as
interspersed almost exclusively by galactic formations. Certainly they
are the only long term stable forms to be found at this scale.
In fact we can apply this principle at any level of magnitude. Thus
the universe is interspersed by atoms at the atomic scale of
consideration but with planetary/stellar matter on a larger scale.
So then, as the process builds to infinity, with each structure type
occuring in forms and attributes appropriate to interaction and
formation possibilities at that scale. Each transformation produces
unique structure types, and there is certainly no likelyhood of the
same structure type occuring at different levels either in the micro
and macro scales.
Both the reduction and its reverse process of expansion runs to infinity,
with the roots of each or any structure traceable in infinite steps
toward smaller scales. But this does not work in the reverse toward the
macro. The reason is that not all structures continue to build outward
forever. Large sections of it terminate at a certain level, as in the
case of the structures that intersperse in our seemingly empty spatial
regions. My findings are that these regions are far from empty.
The entire spatiality in fact contains a fine invisible mist of matter,
structured at its highest level to an interactive fabric to form
a micro infrastructure which sets the framework for the workings of
our atomic based matterial environment. But only those elements
which participate in further building processes to form the atomic
base can get through to build outward to form structures on larger
scales. The rest, indeed a very large portion of micro material,
is lost to further structuring. In this infinite chain of
expansions it should be expected that terminal stages are reached
from time to time. Nevertheless, what remains after each of these
mass terminations is still adequete to reconstruct other equally
thickly populated levels of structures on much larger scales.
So what is the status of our material system amid this infinity of
transformation levels ? On the micro end we observe the process through
a very high integration, but on the macro end it tends toward static.
With the two directions reflecting merely different aspects of a
single process, our observational access results from the circumstances
of our evolution as sensing beings and our relation to the material
interaction that brought it about. We are a direct product of our
micro infrastructure and the atomic base. The question remains
whether ours is the only material environment possible or whether
there may be others ? Perhaps other configurational circumstances can
exist among an infinity of types which produces alternative material
bases.
We need firstly to examine the general circumstances which must be
present for a material environment. Obviously the most evident
is the versatility of our atomic structure. It is extremely stable
and durabile with, stability, regularity, as well as variability in
chemical combination. It is truly like a wonder particle which goes on
to create a tremendously varied and interactive world of material
activity. Surely it would be fairly rare to find a scale level of
structuring where such a useful type of particle is found.
Nevertheless it stands to reason that in a infinite chain of
transformations other similarly efficient structure types are bound
to occur. some may indeed be even more flexible than the atom, or
perhaps somewhat less so, but still able to generate a causal
evolution in its conglomerate forms to create an alternative material
environment rivalling ours. Of course on the micro scales a funtional
world would evolve extremely rapidly compared to ours, and on the macro
scales the events would take on gigantic proportions, evolving very
slowly by our way of looking at it.
G. Forbat
to be continued in the next article
Subject: Re: Finding Citation lists...
From: wpenrose@interaccess.com (William R. Penrose)
Date: Sat, 11 Jan 1997 19:36:19
In article "Arthur E. Sowers" writes:
>Almost every library worth its salt will have ISI's "Science Citation
>Index", and its in the reference section of your campus library, and even
>some large decent public libraries will have it. It comes out yearly.
Rooting through the paper edition is tough work, but it is available and
searchable through library search specialists that have an account with the
Institute for Scientific Information. We pay the one we use about $60 and
hour plus a printing charge. A search for a single author's name (1st or
other author) costs about $15 since it is a very simple search.
SCI is also available on CD ROM and some university and national
laboratory libraries have it. This can be searched painlessly if you have
access, but you generally still need a search specialist.
Bill
********************************************************
Bill Penrose, President, Custom Sensor Solutions, Inc.
526 West Franklin Avenue, Naperville, IL 60540
630-548-3548, fax: 630-369-9618
email wpenrose@interaccess.com
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