Subject: Re: A case against nuclear energy?
From: Dennis Nelson
Date: Fri, 17 Jan 1997 17:20:53 -0800
steve perryman wrote:
>
> Greg Chaudion wrote:
>
> Who's defending evil? What's the death of a few civilians compared to
> all life on the planet? It may sound cruel, but given the choice I would
> sacrifice a few (yes, even myself) if I was absolutely sure that it would
> preserve more life than it would destroy.
And just how would you be "absolutely sure that it would preserve more life
than it would destroy?" There's the rub. You have to place yourself in
a position of wisdom and knowledge of which you are incapable. This is
precisely the problem as it occured before. A few arrogant morons got
together in secret and convinced themselves that they knew what was best
for the rest of us, and then committed all manner of evils in carrying out
their plan. Very few of them ever acknowledge that they were wrong and most
present elaborate, however fanciful, after the fact rationalizations as to
why what they did was the right thing to do.
> Of course, nuclear testing is a... dubious, at best, method of
> heroism, but in the long run the arms race ultimately prevented a
> full-scale nuclear exchange. It is almost perverted, but if we hadn't kept
> up with the Soviets in weapons tech, they would have almost surely
> attacked when they felt in a superior position.
I maintain that the US was always ahead of the Soviets, and the Soviets were
the ones trying to keep up. Whoever was ahead, trillions of dollars which
could have been spent to improve the life of people, and protect the environment
in both countries were literally pissed down the corporate welfare rat hole in
both countries and into the pockets of the warmongers.
Dennis Nelson
Subject: Re: Missing Plutonium
From: Dan Evens
Date: Fri, 17 Jan 1997 17:04:09 -0500
Alan "Uncle Al" Schwartz wrote:
> The toxic radiological hazard from ingestion is incredible. The weapon
> forthcoming would not be a nuclear device, it would be a bunch of aerosol
> cans. Think about infiltrating a deodorant manufacturer.
Not all that incredible. If it is plutonium oxide, it is roughly
as chemically poisonous as caffeine. You don't see too many terrorists
hijacking coffee shipments and threatening to blow them up.
Radiologically, the radioactive isotopes of iodine are far more
troublesome because they are heavily concentrated by many orgranisms,
including humans.
The mythology surrounding plutonium as "most toxic substance" is
based on the so-called "hot particle theory." This is the notion
that a lethal dose of plutonium is the amount which, if it held
still in one place in a human lung, would cause cancer. This
notion is clearly false as such small particles DON'T hold still.
There is also the "Is there something in this room?" counter
argument. The hot particle theory says a lethal dose in the lung
is about 4 x 10^-12 grams. Since about 3 x 10^9 grams have
been dispersed into the atmosphere by nuclear weapons testing,
which would be more than 100 million lethal doses per human
on the Earth if the hot particle theory were correct.
So, is there anybody alive in the room you are in? And do
they inhale air?
(Reference: D.P. Geesaman, UCRL-50387 and Addendum, Lawrence
Livermore Laboratory, 1968 for the hot particle theory, and
_The Anti Nuclear Game_ by Gordon Simms, University of
Ottawa Press, 1990, for the rebuttal.)
This is not to say that plutonium is completely safe. It
is poisonous, and it is radioactive. However, you ought
to keep in perspective just how radioactive and how
poisonous it is. As these things go, we handle much
worse substances on a routine basis. And, as material
for a terrorist action, it is largely psychological.
At least in the range of 80 grams which is much to
small to make a critical mass.
--
Standard disclaimers apply.
I don't buy from people who advertise by e-mail.
I don't buy from their ISPs.
Dan Evens
Subject: Re: New Bad Astronomy Addition (1/7/97)
From: "Peter Diehr"
Date: 17 Jan 1997 23:56:55 GMT
Twisted STISter wrote in article
...
> In article <5bfoo6$kof@hermes.ucd.ie>,
> Kevin McLaughlin wrote:
> >Glen Moore (glen_moore@uow.edu.au) wrote:
> >: Phil
> >:
> >: You write
> >: "There is a new addition to my Bad Astronomy page:
> >:
> >: "The Moon appears larger on the horizon because
> >: you are comparing it to foreground objects."
> >:
> >: I don't believe that this is a very good example of 'bad'
astronomy.
> >:
> >: I think that that the above statement could be interpreted as
another
> >: way of expressing what you believe to be the 'correct'
explanation of
> >: the phenomenon i.e. that the horizon is perceived to be more
distant
> >: than the zenith.
> >:
> >: gkgm
> >: Science Centre
> >: Wollongong, Australia
>
> >i have been told it is an effect of the light travelling through
a
> >thicker atmosphere which is also a different shape to that
through which
> >you view the moon when overhead. though this would produce a
distortion
> >along one axis only, i would have thought.
>
> As light goes through the atmosphere, it gets bent. Near the
horizon,
> there is a longer path length through the air due to the curvature
> of the Earth, so light is bent more than it would be if it came
from
> the zenith. HOWEVER, the effect is the opposite of what you want--
> it compresses the disk of the Moon (or the Sun) vertically, making
the
> Moon look squashed. The horizontal component remains the same. So
> refraction by air not only cannot be the cause of the illusion,
but
> actually acts to negate it somewhat!
>
> As for the first person's reply, I have seen a study (I have no
reference,
> sorry) that shows that the explanation given by the link in my Bad
Astro
> page is actually the best explanation. As an example, recently I
was
> looking at the Moon when it was high in the sky, but I was still
looking
> through some large oak trees across the street. Even though the
Moon
> was easily seen through the trees, and thus easily comparable to
them, the
> Moon looked to be the same size as always. Yet I know the Moon
> looks tremendously bigger when it is rising, so comparing it to
> foreground objects *cannot* be right.
>
> As an aside, recently while out on a walk I saw the Sun set
centered
> perfectly on the street I was on. I was at the bottom of a small
hill
> and had to actually raise my head a bit to see it. The Sun was a
> fantastic magenta in color, and looked larger than I have ever
seen
> in my life. I have no ready explanation for why it looked so big,
> except to say that it had been a long time since I had seen a
sunset,
> and so it impressed me quite a bit.
>
> --
(1) The atmospheric effects upon the apparent size of the moon are
very
slight ... this was remarked upon above.
(2) So we can write off the observations as due to perceptual
factors.
(3) Since the only obvious factor is that there are objects of
_known size_
in the foreground, it is reasonable to conclude that the explanation
given
in the quoted statement at the top is probably correct.
Now let me give you a way to verify that the apparent size of the
moon at
the horizon is perceptual .... we do an experiment where the moon is
fully
blocked by an object of known angular size.
Take a coin (a 25 cent piece is perfect), and a meter stick. Hold
the meter
stick in such a way (tucked to your chin, for example), so that you
can
aim your eye (one eye only, please!) along the stick, and place the
coin
so as just block the full moon.
This gives you a distance from your eye to the coin. You could now
do some
calculations, but that isn't necessary, since all we want to do is
show that
the angular size of the moon doesn't change as the moon rises (or
sets).
So take a measurement when the moon is at the horizon, and again a
few
hours later. Do this on the same day, since the distance from the
earth to
the moon does change during the course of the year.
What will the results be? You should get the same distance at both
times.
That's what I've found when I've done it.
Best Regards, Peter
Subject: Re: PH.D.s are useless
From: meron@cars3.uchicago.edu
Date: Fri, 17 Jan 1997 20:13:38 GMT
In article <19970117105000.FAA06393@ladder01.news.aol.com>, lbsys@aol.com writes:
>Im Artikel , meron@cars3.uchicago.edu
>schreibt:
>
>>Teller committed the unspeakable horror of insisting that "He who
>>wants peace should prepare for war" thus making him the favorite
>>whipping boy of wishful thinkers around the world :-)
>
>C'mon, Mati, you know more about it ;-). Teller did not only invent the
>Super (I mean the feasable one, no one could have thrown a supercooled
>device from a B52 :-), which is bad for itself
True, and the Russians invented it independently, in fact they had it
before the US did. So, would the world have been a better place
without Teller?
(would you work for the national weapons program?)
Depends on the time and situation. If asked during the 40s or 50s, my
answer would've been "yes". Nowadays, given the current geopolitical
situation, if would've been "no". The are no clear cut, invariant
answers to this question.
>but also is a well known right winger, who pleaded for using the bomb
>on the commies
Well, he had his childhood experiences with the commies (the bloody
communist takeover attempt in Hungary in 1921, or maybe 22) at that
set his attitude for life. He saw them as a scourge no less then
Hitler was and, belonging to a generation which learned first hand
what are the consequences of letting scourges grow unchecked, he
considered it necessery to do something about it. While I by no means
identify with his attitude, I can see where it is coming from and
understand it.
and in his later years was all for star wars (which
>really makes him look more stupid than ever: with his brains he should
>have seen the non-feasability of the project, but politics was dearer
>to him then).
That much is true. Though I think that, regarding star wars, it was
more of just softening of the brain (age?) since, while politics was
dear to him (always, not only then) I doubt that he would throw his
scientific reputation behind something he knew is unworkable. Anyway,
lots of physicists get involved with nonsense when they get older.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
Subject: Re: Current to heat filament ?
From: John
Date: Fri, 17 Jan 1997 18:59:49 -0500
HeikoFy wrote:
>
> Hi!
> What current is necessary to heat a filament with a specific electrical
> resistance; diameter and length (full length, not as a helix) are given
> (e.g.
> in a tube) ?
>
> Thanx for any answer !!!!
>
> Heiko
> heikofy@aol.com
HeikoFy wrote:
>
> Hi!
> What current is necessary to heat a filament with a specific electrical
> resistance; diameter and length (full length, not as a helix) are given
> (e.g.
> in a tube) ?
>
> Thanx for any answer !!!!
>
> Heiko
> heikofy@aol.com
Hi Heiko,
There are two difficulties with your problem.
1). Resistance is a function of temperature.
2). The temperature of the wire depends on the power per unit volume
and the thermal heat transfer paths available.
The following ramble may help with about 1.2 of the difficulties.
-----
1).
The *simple* formula for the resistance of a wire is
R = p*L/A
where p is resistivity,
L is the length,
A the cross sectional area.
If L is in cm and A in cm^2 then p is in ohm-cm.
The complication arises when the wire heats because the resistivity of
most conductors increases with temperature.
A formula for resistance vs temperature is
R_T=R0*(1+a0*T)
where R_T is resistance at temperature T degrees centigrade,
R0 is resistance at temperature 0 degrees centigrade,
a0 is temperature coefficient of resistivity ohms/degree
centigrade.
Filaments in incandescent lamps and vacuum tubes operate in the region
of 1000 degrees centigrade and the temperature coefficient of
resistivity
is around 0.003 for many metals. So the hot resistance can be around
four
times the cold resistance.
Ohm's law then gives the current as
I = R/E.
Hence the cold current could be four times the hot current.
This sort of answers your question as to the current.
----
The heating is by Joule's law where the heat units vary with R*I^2 and
time.
You didn't mention the temperature you wanted in the wire. I'm
glad.
----
Ref.
"Mark's Standard Handbook for Mechanical Engineers" 7th edition
Theodore Baumeister, Editor-in-Chief
McGraw-Hill Book Co, 1967
sect 15, page 6 for resistivity stuff and
sect 15, page 13 for Joule's Law
----
I hope this starts you on the way to a solution.
Regards,
John
This reminds me of an old story. The seven year old boy asks his father,
"Where did I come from?". The father delivers a nervous two hour lecture
on the birds, the bees and Misty their pregnant cat. When he finishes
the kid says, "Yeah, I know all that!! My buddy, Jimmy comes from
Chicago,
I just wondered where I came from."
Subject: Re: Happy Birthday, HAL 9000!
From: Brian J Flanagan
Date: Fri, 17 Jan 1997 14:58:44 -0600
HAL:
Happy Birthday, indeed.
I found those references you wanted:
Carnap, *The Logical Structure of the World*, p.92
"Physical Objects are Reducible to Psychological Objects and Vice Versa
Statements about physical objects can be transformed into statements
about perceptions (i.e., about psychological objects). For example, the
statement that a body is red is transformed into a very complicated
statement which says roughly that, under certain circumstances, a certain
sensation of the visual sense ('red") occurs.
Statements about physical objects which are not immediately about sensory
qualities can be reduced to statements that are . . . For every
psychological process, there is a corresponding "parallel process" in the
brain, i.e., a physical process. There is a univocal correspondence
between each property of the psychological process and some (even though
entirely different) property of the brain process. Thus, every statement
about a psychological object is translatable into a statement about
physical objects. Since the correlation problem of the psychophysical
relation . . . has not yet been solved, the present state of science does
not allow us to indicate a general rule of translation."
(BJ: It remains true that the "correlation problem" has not yet been solved,
though Mach showed us the way: "A color is a physical object as soon as
we consider its dependence, for instance, upon its luminous source, upon
temperatures, upon spaces, and so forth." Well! If color can be readily
translated into the realm of the physical by such simple considerations,
that would certainly seem to take us a long way toward a solution of the
correlation problem. Mach's argument applies with equal force to sound,
to hot & cold, and to all the other secondary qualities. If all these
qualities are indeed physical properties, then we can proceed in good
conscience to *coordinate* the secondary qualities with (say) the physical
field properties with which they regularly covary - as when light at 580
nm is coordinated with yellow, e.g. Difficulties remain, to be sure, but
we have overcome, with Mach's help, the single greatest ontological
hurdle: We can readily translate talk of "mental" colors and sounds and
so forth into talk of "physical" field properties. Indeed, we might,
following the lead of Schrodinger and Feynman, assign a color to a vector
and then, going further, explicitly coordinate that color vector with the
state vector of the photon at 580 nm.
But let's put this argument to the side for a moment and beat a quick
retreat back to respectable science with Eugene Wigner's "Physics and
the Explanation of Life," in *Foundations of Physics*, vol. 1, 1970, pp.
34-45.)
"What we are interested in is not only, and not principally, the motion
of the molecules in a brain but, to use Descartes' terminology, the
sensations which are experienced by the soul which is linked to that
brain, whether pain or pleasure, stimulation or anxiety, whether it
thinks of love or prime numbers. In order to obtain an answer to these
questions, the physical characterization of the state of the brain would
have to be translated into psychological-emotional terms.
It may be useful to give an example from purely physical theory for the
need for such a translation. The example which I most like to present
derives from the classical theory of the electromagnetic field in vacuum,
that is, the simplest form of Maxwell's equations. These give the time
derivative of the electric field E in terms of the magnetic field H, and
the time derivative of the magnetic field in terms of the electric field."
(Wigner then goes on to sketch how this translation is performed,
starting from the equation for the source-free magnetic field and
proceeding through a standard "translation" equation to find the electric
field E from the magnetic field H. We omit the slight details involved
because this all standard stuff. The point is that, starting with the
equation for the magnetic field, one can, by means of a complicated
translation equation, arrive at the formula for the electric field.)
"The translation equation is also more complicated than the set of
equations, in this case Maxwell's equations, which uses both concepts:
the one which turns out to be the more relevant one, that is, E, along
with the other, H, which does suffice for the formulation of the time
dependence. It is unnecessary to remark that, in the preceding
illustration of a future theory of life, H plays the role of the purely
physical variables, E plays the role of the psychological variables. In
this illustration, the use of both types of variables in the basic
equations is much preferable to the use of only one of them - the problem
of translation does not arise in that case...."
(BJ: OK, now let's think about Wigner's "first alternative" for a moment. We
shall come back to it later. Note though that E and H coexist, covary and
are best understood as dual aspects of a more complete and symmetric
object, the EM field.
Perhaps, then, we can reason by analogy and ask whether "the use of both
types of variables [tho' now we mean the "mental" & "physical" variables]
in the basic equations" will prove to be "much preferable to the use of
only one of them" and whether "the problem of translation does not arise
in that case...." Following Mach, we can readily treat "mental"
colors and so forth as being on the same footing as those "physical"
variables with which they coexist and covary.)
"Let us now turn to the assumption opposite to the "first alternative"
considered so far: that the laws of physics will have to be modified
drastically if they are to account for the phenomena of life. Actually, I
believe that this second assumption is the correct one. . . .
Can arguments be adduced to show the need for modification? There seem to
be two such arguments.The first is that, if one entity is influenced by
another entity, in all known cases the latter one is also influenced by
the former. The most striking and originally the least expected example
for this is the influence of light on matter, most obviously in the form
of light pressure. That matter influences light is an obvious fact-if it
were not so, we could not see objects. The influence of light on matter
is, however, a more subtle effect and is virtually unobservable under the
conditions which surround us. . . . Since matter clearly influences the
content of our consciousness, it is natural to assume that the opposite
influence also exists, thus demanding the modification of the presently
accepted laws of nature which disregard this influence.
The second argument which I like to put forward is that all extensions of
physics to new sets of phenomena were accompanied by drastic changes in
the theory. In fact, most were accompanied by drastic changes of the
entities for which the laws of physics were supposed to establish
regularities. These were the positions of bodies in Newton's theory and
the developments which soon followed his theory. They were the
intensities of fields as functions of position and time in Maxwell's
theory. These were replaced then by the outcomes of observations (the
perceptions referred to before) in modern microscopic physics, that is,
quantum mechanics. In the development which we are trying to envisage,
leading to the incorporation of life, consciousness, and mind into
physical theory, the change of the basic entities indeed appears
unavoidable: the observation, being the entity which plays the primitive
role in the theory, cannot be further analyzed within that theory.
Similarly, Newtonian theory did not further analyze the meaning of the
position of an object, field theory did not analyze further the concept
of the field. If the concept of observation is to be further analyzed, it
cannot play the primitive role it now plays in the theory and this will
have to establish regularities between entities different from the
outcomes of observations. An alteration of the basic concepts of the
theory is necessary."
BJ: Our only objections to the above would be met by two changes:
(1) Removing "observation" from its privileged status as a special kind of
interaction; and
(2) Adding the secondary qualities or properties to the official list of
undefined primitives of the theory.
Then all shall be well.
Subject: Re: twin paradox
From: Larry Richardson
Date: Fri, 17 Jan 1997 13:42:57 -0800
Ken Fischer (carnold@kiva.net) wrote:
> I am very discouraged considering the number of
> different opinions regarding the twin paradox.
> I agree that there is no apparent reason that
> relative velocity should make one clock slow, I don't
> even understand how to decide which clock should run
> slow because I don't know which one is moving, because
> I don't know what not moving would be.
> But I think there is merit in the concept of
> velocity causing time dilation, and I think maybe the
> only reference point to index as zero velocity is the
> center of mass of the closest massive body, or the
> massive body the space ship starts out from.
Ken, the velocity is always with respect to a selected observer. Assuming
you are familiar with Minkowsky-type maps, that observer owns the perpendicular,
Euclidean axes and is assumed to be at rest, and the object of observation
owns the skewed axes and is assumed to be in motion. A clock at rest in
either frame will appear slow to an observer in the other frame because for
an arbitrary value on either clock the time coordinate value will be larger
using the other frame's coordinate system, so an observer in either frame
always sees a greater time on their own clock than they see on the other
frame's clock.
> This does allow me to wonder if then the ticks
> of a clock would vary according to some formula using
> the speed of light as a maximum velocity, but I still
> feel that an observer with the clock will still have
> 60 heartbeats per minute as usual.
There is no need to assume that either clock ticks abnormally - the apparent
slownesses can be attributed to the observer's perspective (in the case of a
map, that translates to the geometry of the map) without requiring changes
in anything intrinsic to the observed moving clock itself.
> I have seen about equal opinions for acceleration
> and velocity as the cause of time dilation. I think
> the velocity is the most basic cause, but I still am not
> convinced that the math used in the twin paradox really
> is valid and correct, because I think the distance
> traveled is not a linear function of velocity, and
> I think the formulation used does not take this into
> consideration.
Distance values have the same inter-frame relationship as do time values -
the other frame's distance intervals are observed to be smaller than they
are measured to be in their own frame. From the observer's perspective,
the moving clock is registering small changes while traversing large
distances in the observer's frame. The reason that the moving frame does
not measure itself as exceeding light-speed is that a given distance in
the observers' frame is measured to be shorter using the moving frame's
coordinate system (Lorentz-Fitzgerald distance contraction). Consequently,
a traveller can leave any location in a specified frame and then return to
that location later with less clock advancement than for a clock that remains
at that specified location. Some means of establishing the required relative
motions must be utilized, and that will usually be acceleration, but any
means of changing the velocity relationship is sufficient (gravitational
influence, universal expansion?).
LR
Subject: Re: Learning, who cares?
From: Anonymous
Date: Fri, 17 Jan 1997 15:42:39 -0600
Alan "Uncle Al" Schwartz wrote:
>
> "Michael D. Painter" wrote:
> >I've held for some time that our culture does not put much importance on
> >education. Bake sales are for bands or soccer, never books or science.
> >
> >Many of the people here add fuel to this belief.
> >
> >A teacher gives a class an assignment designed to make them think, to learn
> >to solve problems.
> >Rather than do this the student asks someone for the answer and the people
> >here do it for them.
> >How to keep an ice cube frozen for 5 hours is the latest.
> >With luck the kid will grow up and work at McDonald's.
>
> Less than 1% of the population is needed to create and sustain the
> aggressive science (discovery), technology (reduction to practice), and
> engineering (production) which underlies civilization. You'd like most
> of the balance not to be susceptible to Dead Psychic's Hotline. If you
> seize that top 1% you get America. Lose it and you have Haiti.
>
> When Sputnik went up in the mid-50s America went absolutely apeshit.
> Pundits envisioned football fields of nerds debugging octal computer
> code and hunched over drafting tables. The five to seven year blast of
> full emeregency military power achievement-based education so motivated
> fueled an entire generation of violent progress (and compiled computer
> languages). We don't do that anymore - it is discriminatory.
>
> We are here to winnow the chaff looking for the odd grain that it might be
> planted in a fertile field. A paltry 1% will do it. Pray that they are
> forthcoming.
>
> Have you ever been behind the counter at McDonalds? The cash register
> keys don't have numbers. They have pictures. One wonders how the
> graphics will be translated into Ebonics so as not to oppress the
> sensibilities of ethnic cognition.
>
> --
> Alan "Uncle Al" Schwartz
> UncleAl0@ix.netcom.com ("zero" before @)
> http://www.ultra.net.au/~wisby/uncleal.htm
> (Toxic URL! Unsafe for children, Democrats, and most mammals)
> "Quis custodiet ipsos custodes?" The Net!
I don't think that's right. A moderate percentage of people in many
countries, although they are usually older people, can not read or write
at any level, much less the 'eighth grade' level that they use here to
define illiteracy. Sizable percentages of people live on farms there,
to simply produce food by inefficient methods, rather than the smaller
percentage here. The number and type of factories in relation to the
population, and fecundity of the populace, cheapen labor, and thus
encourage inefficiency. Also in the U.S. there are millions of techs,
who both fix gadgets and machinery and make them, and report defects on
the line, and sell them and do other things. When they do these things
efficiently, a lot of other people can do different things as well. A
lot of the upper 1% in many of these countries are about as smart as we
are here, and many live as well as we do. But if you are talking about
civilization you've got to talk about the bottom 99%, because the 1%
simply won't do it.
