Richard Harrison wrote:
There was a PBS special here today on "The Method" one of the books
written by Archimedes, a copy of which was recently sold at auction for
2 million dollars.

Very interesting program. Archimedes apparently developed an elementary
calculus involving infinity 300 years before Jesus was born.
--
73, Cecil http://www.qsl.net/w5dxp


Aristotle wrote that the Greek mathematicians didn't have any need for
infinity and never used it. Archimedes said that his "Method" wasn't a
proof but a means of mathematical exploration. He also said that
Democritus used infinitesimal methods before he did. Democritus
was born around 460 B.C. The Babylonians... aw, forget it.
73,
Tom Donaly, KA6RUH

Gene wrote,

On 30 Sep 2003 18:36:50 GMT, (Tdonaly) wrote:

Cecil wrote,

Gene Nygaard wrote:
You can, of course, choose not to call this quantity "weight." You
can call it mass instead, if you want to.

Here's an interesting quote from _University_Physics_ by Young and
Freedman: "On the moon, a stone would be just as hard to throw
horizontally, but it would be easier to lift." It also says weight
is a vector and mass is a scalar.
--
73, Cecil http://www.qsl.net/w5dxp


You better watch out, Cecil, Gene is liable to write a scathing indictment
of your intelligence, integrity, and job fitness, for quoting that. By the
way,

I don't know why I would. I agree with the quoted part. Of course,
though the stone is just as hard to throw, it will likely go farther
before it falls to the ground.

Would you say that a boat is heavy because it is hard to push away
from the dock? What is the relevant factor here--that it is pressing
down with a force due to gravity of 9000 pounds force? Or that it has
a mass of 9000 pounds?

What is the metric equivalent of a ton used for the weight of a U.S.
Navy ship? For example, the tanker USNS Henry J. Kaiser is 27,561
tons deadweight. How much is that is SI units?
Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/



Still playing the old one-note samba are we Gene? You must hold the
record for being the most boring guy at the cocktail party. You still
haven't answered my question about why you keep harping on a
question of elementary physics on a newsgroup devoted to
amateur radio antennas. Is this a new species of troll? Is that
all you know how to talk about? When did you first realize you
had this obsession with mass? Are you over-mass?
With the never ending thread about transmission lines, EH antennas,
mass, and the rest, it's pretty obvious what has happened. There's been
an earthquake; all the pots are cracked. Next, someone from the British
Isles will be writing to say gram scales don't MEASURE mass, they only
INDICATE mass.
Brother.
73,
Tom Donaly, KA6RUH

On Wed, 1 Oct 2003 00:36:15 -0500 (CDT),
(Richard Harrison) wrote:

Gene Nygaard wrote:
"What is the relevant factor here -- that it is pressing down with a
force due to gravity of 9000 pounds due to gravity of 9000 pounds force?
Or that it has a mass of 9000 pounds?

The tonnage of a ship is the weight of the water it displaces.

The force pressing down (normal force) in mechanical problems is
significant when friction is involved.

Force equals mass time acceleration. So, the mass opposes and increases
the force required to get an object moving, or slowed, for that matter.
That includes a ship. It has inertia and requires force to change its
velocity. Drag is imposed on the submerged portion of the hull,
especially when coated with barnacles.

I shipped out of Long Beach in WW-2 on the LSM 472. I returned to San
Francisco on the LSM 94. I was transferred to the LST 604 to take it up
river to Stockton to be decomissioned and scrapped. While at the ship
yard there I witnessed a curious sight. A large merchant vessel was
moved from one berth to another using a small boat with an outboard
motor as the tow boat. River current in the basin was almost nil, yet it
took several hours to move that large ship with the power of only an
outboard motor. It worked! There must have been nothing more powerful
available and there must have been no rush to get the berth swap made.

Point is that it is likely that neither mass nor weight is as important
as current in many situations. How soon you can get up to speed depends
a lot on mass as Newton predicts. That motorboat would have done its
thing much more quickly with a waterskier in tow than it did with a big
merchant ship in tow.

So what is the SI equivalent of those 27,561 tons deadweight for that
U.S. Navy ship?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

Here I thought Arkie was a fundamentalist/traditionalist who fatfingered in
CCCLV divided by CXIII and CXCIII by LXXI on his GO34 in order to insert
constants into his equations.
73, Dave, N3HE

"Richard Harrison" wrote in message
...

SNIP
Archimedes inscribed the largest regular polygon ithat would fit inside
a circle. Next he drew outside the circle a similar regular polygon
touching the circle on all sides and having its sides parallel to the
polygon sides inside the circle. Then he increased the number of sides
of his polygons until they totaled 96. He decided a 96-side,
equal-sided, figure was close enough to a circle for practical purposes.
He also knew that a real circle would have a circumference somewhere
between the circumferences of his inside and outside polygons. Also, the
circumferences of his inside and outside figures were very nearly the
same anyway.

The tape measure must not have yet been invented, so Archimedes must
have measured the sides of his figures with a straight ruler. He used
the sums of the polygon sides to arrive at the circumference of his
figures. From these constructions and measurements, Archimedes arrived
at a figure of 3.1416 for the ratio of circumference to the diameter of
a circle (pi). That`s still close enough for most purposes to this very
day.
SNIP

Best regards, Richad Harrison, KB5WZI

Gene wrote,


So what is the SI equivalent of those 27,561 tons deadweight for that
U.S. Navy ship?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/



I asked first. Why are you spamming the newsgroup with off-topic
posts?
73,
Tom Donaly, KA6RUH

On 01 Oct 2003 14:59:45 GMT, (Tdonaly) wrote:

Gene wrote,


So what is the SI equivalent of those 27,561 tons deadweight for that
U.S. Navy ship?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/



I asked first. Why are you spamming the newsgroup with off-topic
posts?

You seem to be operating under several delusions.

I'm not spamming.

I didn't start this discussion.

The discussion I entered was not off topic here.

You yourself, while you have contributed to the on-topic discussion,
have also been responsible for more thread drift in this thread than
anyone else. Democritus? Good grief! There wasn't anything on-topic
in the message in which you brought him up. What connection do you
find between him and the definition of ohms, and the inaccurate
analogy using faulty defintions of pounds that lead to my entry into
the discussion?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

On Wed, 01 Oct 2003 08:54:56 GMT, Gene Nygaard
wrote:

On Wed, 1 Oct 2003 00:36:15 -0500 (CDT),
(Richard Harrison) wrote:

Gene Nygaard wrote:
"What is the relevant factor here -- that it is pressing down with a
force due to gravity of 9000 pounds due to gravity of 9000 pounds force?
Or that it has a mass of 9000 pounds?

The tonnage of a ship is the weight of the water it displaces.

The force pressing down (normal force) in mechanical problems is
significant when friction is involved.

Force equals mass time acceleration. So, the mass opposes and increases
the force required to get an object moving, or slowed, for that matter.
That includes a ship. It has inertia and requires force to change its
velocity. Drag is imposed on the submerged portion of the hull,
especially when coated with barnacles.

I shipped out of Long Beach in WW-2 on the LSM 472. I returned to San
Francisco on the LSM 94. I was transferred to the LST 604 to take it up
river to Stockton to be decomissioned and scrapped. While at the ship
yard there I witnessed a curious sight. A large merchant vessel was
moved from one berth to another using a small boat with an outboard
motor as the tow boat. River current in the basin was almost nil, yet it
took several hours to move that large ship with the power of only an
outboard motor. It worked! There must have been nothing more powerful
available and there must have been no rush to get the berth swap made.

Point is that it is likely that neither mass nor weight is as important
as current in many situations. How soon you can get up to speed depends
a lot on mass as Newton predicts. That motorboat would have done its
thing much more quickly with a waterskier in tow than it did with a big
merchant ship in tow.

So what is the SI equivalent of those 27,561 tons deadweight for that
U.S. Navy ship?

Let me open it up to everyone, and make it a multiple choice:

1. 245.19 MN
2. 245.19 hectopascals
3. 2.5003 x 10^7 kg
4. 28.003 Gg
5. 2.1892 x 10^8 newtons
6. 28 003 metric tons
7. 25 003 metric tons force
8. to have five significant digits, it depends on the latitude of the
ship
9. all of the above
10. none of the above

Does your answer fit in with Richard Harrison's description above?

Does it fit with what any shipbuilder or any navy uses?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

Gene wrote,


You seem to be operating under several delusions.

I'm not spamming.

I didn't start this discussion.

The discussion I entered was not off topic here.

You yourself, while you have contributed to the on-topic discussion,
have also been responsible for more thread drift in this thread than
anyone else. Democritus? Good grief! There wasn't anything on-topic
in the message in which you brought him up. What connection do you
find between him and the definition of ohms, and the inaccurate
analogy using faulty defintions of pounds that lead to my entry into
the discussion?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/


Nope, you're spamming. The subject you keep harping on has very little
to do with antennas. Evidently, it's so overwhelmingly important to you
that you're willing to hand out gratuitous insults and a never-ending series
of posts to those you perceive as not agreeing with your narrow understanding
of the subject. I'm reminded of Samuel Johnson's friend who only had one
idea in his head, and that a wrong one. While you're not alone here in being
possessed of an overwhelming obsession, at least the obsessions of the others
bear some relation to antenna and transmission line theory. Personally, I
don't much care what you do, but I'm curious as to why you do it. How can
such a small idea trigger such a large obsession?
73,
Tom Donaly, KA6RUH

Raymond Sirois wrote:
"A 60-pound object on earth will have a weight of 10 pounds on the
moon."

That`s about right. Gravitational force on the moon is about 0.16 times
that on earth.

If a mass of 60 pounds is suspended from a weight scale on earth, the
force on the scale registers 60 pounds. As Cecil noted, gravitational
force is a vector. Its direction is toward the center of the mass that
exerts the attraction.

A spring scale free to align itself will measure 60 pounds tension no
matter where the 60-pound pul on it comes from. On the moon the object
with a 60-pound attraction to the earth only exerts a 9.6-pound pull on
the spring scale. The object did not change. The spring scale did not
change. The mass of the moon is much smaller than that of the earth, so
its attraction is proportionally less.

A weight balance scale would behave differently from the spring balance
scale. The balance weights and positions would be almost unaffected by
the change in gravitaional force because the forces on both scale and
balance weights change in the same proportion.

A weight balance scale would usually employ a balancing weight much
smaller than 60 pounds to balance a weight of 60 pounds. The balance is
struck with a smaller weight through leverage..It`s a teeter-totter
with the measured quantity getting the short end of the stick. Balance
remains at the same spot regardless of the gravitational pull on both
ends of the balance beam. It`s the torques which balance. When we change
the gravitational force, we multiply both sides of the balance equation
by the same factor.

The spring balance is calibrated for the force of gravity on a mass
residing near the earth`s surface.

The weight balance is calibrated for the same gravitational attraction
on earth.

On the moon the spring scale indicates about 10 pounds for an earth
weight of 60 pounds. On the moon, the weight balance scale still
indicates 60 pounds, though the gravitational pull is only about 10
pounds.

Best regards, Richard Harrison, KB5WZI

Gene Nygaard wrote:
They are incorrect in the doctor's office, and even more incorrect in
the supermarket or the jewelry store. Like I said, you don't have to
call the quantities used there "weight"--but if you do call them
weight, use the definition which is correct in that context. Don't
misinterpret what is being used there.

Do you know what you're talking about Gene? Cuz I sure don't.

It's generally accepted that weight is a force.

I've shown in this thread from the experts in the field, including
NIST (the U.S. national standards agency) and ASTM (an industry
standards agency) and NPL (the U.K. national standards agency) and the
Canadian Standard for Metric Practice, that this is false.

I don't agree.

All of
these sources and many others tell you that weight is an ambiguous
word, with several different meanings.

What physical quantity do you think a grocery store scale measures?

Problems can arise when
someone claims a mass is a force and vice versa.

I agree.

And so a torque wrench has what kind of units printed on its scale -
mass and distance, or force and distance?

You could, of course, argue that we should all change to your usage.

Many people already have, obviously.

Not very many, surprisingly.

Just the ones who write physics books maybe?

It is much more common to find people
claiming, erroneously, that there is some error in that usage.

You're the first guy I've ever seen making claims about errors in usage.


Like slugs, poundals only exist in one limited purpose system
of mechanical units, mostly used to simplify calculations.

But you'd like us to believe the unit of mass in that system is
ubiquitous and universal, and that everybody is wrong!

73, Jim AC6XG