Edwards air show B-1 speed record attempt

On Thu, 23 Oct 2003 21:24:18 -0700, (Harry
Andreas) wrote:

In article , Peter Kemp
peter_n_kempathotmaildotcom@ wrote:

Especially living in the US as I currently do, it drives me nuts to
work in mm, inches and U just to get a single box to fit a rack.

Whoever thought of U as a unit of measurement really needs to suffer
in a major way. The sooner racks become standardised on a metric
measurement, the happier I'll be.

Hate to break it to you, but the U is a metric spec.

What are u talking about? What is this U as a unit of measure?
Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"Jim Battista" wrote in message
.. .
"Keith Willshaw" wrote in
:


"Jim Battista" wrote in message
.. .
"Keith Willshaw" wrote in
:

The SI system is simplicity itself

A cu metre of water masses 1 Kg - simple

But that's, at one level, stupid.

If you cant be civil this ends now.

Sorry.

Not you that's stupid, the system. It's broken at a basic level --
you should never have to remember anything, which requires 1 to 1 to
1 conversions. Meters lead to liters lead to grams lead to calories
and newtons, all based rigidly off a better-defined meter.


Ok

You are forgetting the historical context of the system I think

The metric system came about because the French pre-revolutionary
system of weights and measures were chaotic. In Britain (and of course
its colonies) the systems of measurement had been standardised.
One of the first of these standard measures was the yard.
There was a standard yard held centrally and all others were subsidiary
to that. The name of this measure has been incorporated in the
language , it was of course the 'Yardstick'

The French needed some system that could be the standard for
trade within France and the other continental nations, the basic unit
of length had to be something usable in trade and people dont
buy cloth, rope or string in mm portions so they adopted a form of
standardised yard.

You also have to consider the technical limitations of the late 18th
century. Adopting something as small as todays mm or gramme
as standard measures would have caused great problems when
producing secondary standards for regional centres and scaling
up would be a problem.

Keith

Jim Battista wrote:


Not you that's stupid, the system. It's broken at a basic level --
you should never have to remember anything, which requires 1 to 1 to
1 conversions. Meters lead to liters lead to grams lead to calories
and newtons, all based rigidly off a better-defined meter.


I agree that there are some "anomalies" in the SI, like e.g. the basic
(as in "used when deriving other SI units") unit of mass is
"kilogram", while all other basic units are non-prefixed. Still,
1-to-1 conversion factors between units (called "coherent units" IIRC)
are the basic idea behind SI, and are very common - e.g. you need a
force of 1 N to accelerate a mass of 1 kg by 1 m/s^2.

Anyway, if you say SI is "broken at a basic level" because of the
inconsistency involving kilogram/gram/liter/cubic-meter, what do you
call the US/Imperial system? "Utterly and fundamentally broken by
design" ;-) ??

Andreas

On or about Thu, 23 Oct 2003 21:24:18 -0700,
(Harry Andreas) allegedly uttered:

In article , Peter Kemp
peter_n_kempathotmaildotcom@ wrote:

Especially living in the US as I currently do, it drives me nuts to
work in mm, inches and U just to get a single box to fit a rack.

Whoever thought of U as a unit of measurement really needs to suffer
in a major way. The sooner racks become standardised on a metric
measurement, the happier I'll be.

Hate to break it to you, but the U is a metric spec.

1U = 44.45mm = 1.75 inches. It may be definable in terms of mm, but
since it generally applies to 19 inch racks (ugh) I consider it an
imperial measure.

Roll on the replacement by V = 50mm :-) in the 500mm rack (500 mm wide
AND deep).

Oh, and Gene, a U is a unit used to measure the height of equipment in
"standard" 19inch racks of equipments, be they computers, radios, or
any other technical equipment.

Of course, even standard 19 inch racks are not standard, they come in
lots of non-standard depths - which can be a real arse when you fly
somewhere for an installation to discover the rack is particularly
shallow and now you can't close the door :-)

---
Peter Kemp

Life is short - Drink Faster

On Fri, 24 Oct 2003 06:12:29 -0400, Peter Kemp
peter_n_kempathotmaildotcom@ wrote:

On or about Thu, 23 Oct 2003 21:24:18 -0700,
(Harry Andreas) allegedly uttered:

In article , Peter Kemp
peter_n_kempathotmaildotcom@ wrote:

Especially living in the US as I currently do, it drives me nuts to
work in mm, inches and U just to get a single box to fit a rack.

Whoever thought of U as a unit of measurement really needs to suffer
in a major way. The sooner racks become standardised on a metric
measurement, the happier I'll be.

Hate to break it to you, but the U is a metric spec.

1U = 44.45mm = 1.75 inches. It may be definable in terms of mm, but
since it generally applies to 19 inch racks (ugh) I consider it an
imperial measure.

Roll on the replacement by V = 50mm :-) in the 500mm rack (500 mm wide
AND deep).

Oh, and Gene, a U is a unit used to measure the height of equipment in
"standard" 19inch racks of equipments, be they computers, radios, or
any other technical equipment.

Of course, even standard 19 inch racks are not standard, they come in
lots of non-standard depths - which can be a real arse when you fly
somewhere for an installation to discover the rack is particularly
shallow and now you can't close the door :-)

Is that really half of the width of a 3½ inch diskette? That standard
size is 90.0 mm, not 88.9 mm.

In other words, was Harry Andreas telling you that this standard size
isn't really 1.75 mm = 44.45 mm, but rather 45 mm = 1 98/127 in or
about 1.77 in? That's what it sounds like to me, but I don't know if
that is the case or not.

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

"Keith Willshaw" wrote in
:

The French needed some system that could be the standard for
trade within France and the other continental nations, the basic
unit of length had to be something usable in trade and people dont
buy cloth, rope or string in mm portions so they adopted a form of
standardised yard.

Yah. I'm just wishing they'd adopted a standardized tenth of a yard.
Ie, adopting what we call a decimeter as a plain meter.

Then the coherent factors stuff would have worked out well enough --
liters would be the same, and grams would be what we call kilograms
now.

It would also have the benefit of making people 12-20 meters tall.

--
Jim Battista
A noble spirit embiggens the smallest man.

"Gene Nygaard" wrote in message
...
On Thu, 23 Oct 2003 12:46:36 -0700, "Tarver Engineering"
wrote:

snip
Why not "pounds", like an aircraft?

Because there are too many engineers too stupid to understand the
simple fact that those pounds are, by definition, units of mass
exactly equal to 0.45359237 kg.

I find it unlikely that there are many engineers that can not operate a
calculator. In fact, the calculator is the end of any need to change to si
units, as si is a slide rule reality.

If we were using drays, I'd calculate in slugs of mass.

The
fact that they are canceling out two units that aren't the same thing,
even if they are both called pounds. While seconds are a base unit in
SI, those "seconds" are not the SI units of specific impulse.
Specific impulse in SI is in units of N·s/kg, or the equivalent m/s.

I think the "law of the wall" demonstrates that unit balancing is not in the
pervue of an aerospace engineer.

There are some engineers that go against what is common practice and attempt
to build in units for political correctness. It is also evident that using
alternate units was the cause of the loss of this vehicle and the Glimini
Glider. Childish political correctness, on the part of some, has now caused
two serious incidents.

On Fri, 24 Oct 2003 08:15:17 -0700, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Thu, 23 Oct 2003 12:46:36 -0700, "Tarver Engineering"
wrote:

snip
Why not "pounds", like an aircraft?

Because there are too many engineers too stupid to understand the
simple fact that those pounds are, by definition, units of mass
exactly equal to 0.45359237 kg.

I find it unlikely that there are many engineers that can not operate a
calculator.

Show me a calculator that will figure out *which* pounds are being
used, so that they get converted correctly.

You also underestimate the effects of systematic miseducation. The
mere existence of a conversion factor from pounds to kilograms on a
calculator isn't going to undo the fact that some favorite teacher has
drummed into someone's head the notion that pounds are always units of
force and not units of mass, so you can't really convert between
pounds and kilograms. In fact, in today's screwed up world, there are
a number of textbooks which tell you just exactly that.

In fact, the calculator is the end of any need to change to si
units, as si is a slide rule reality.

Any time you make a conversion, at least other than by factors that
are exact powers of 10, you lose something.

Any time there is a need to make conversions, it is an opportunity for
all sorts of other errors, including misentry of the numbers into the
calculator, transposition of digits in copying the result, or
whatever.

If we were using drays, I'd calculate in slugs of mass.

The
fact that they are canceling out two units that aren't the same thing,
even if they are both called pounds. While seconds are a base unit in
SI, those "seconds" are not the SI units of specific impulse.
Specific impulse in SI is in units of N·s/kg, or the equivalent m/s.

I think the "law of the wall" demonstrates that unit balancing is not in the
pervue of an aerospace engineer.

There are some engineers that go against what is common practice and attempt
to build in units for political correctness. It is also evident that using
alternate units was the cause of the loss of this vehicle and the Glimini
Glider. Childish political correctness, on the part of some, has now caused
two serious incidents.

Your conclusion differs from that of the incident investigation board,
and it differs from the conclusions of NASA's Inspector General report
on NASA's use of the metric system.

Same with the Gimli glider. Why in the world were U.S. gallons ever
involved in that improbable, couldn't-be-written-as fiction string of
errors, when you had a Canadian airline on a domestic flight? It's a
lot easier to mix up gallons and gallons than it is to mix up gallons
and litres.


Gene Nygaard
************************************************** *
At the present time, however, the metrical system
is the only system known that has the ghost of a
chance of being adopted universally by the world.
-- Alexander Graham Bell,1906

"Gene Nygaard" wrote in message
...
On Fri, 24 Oct 2003 08:15:17 -0700, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Thu, 23 Oct 2003 12:46:36 -0700, "Tarver Engineering"
wrote:

snip
Why not "pounds", like an aircraft?

Because there are too many engineers too stupid to understand the
simple fact that those pounds are, by definition, units of mass
exactly equal to 0.45359237 kg.

I find it unlikely that there are many engineers that can not operate a
calculator.

Show me a calculator that will figure out *which* pounds are being
used, so that they get converted correctly.

Aircraft already have units of measure. Why use different units? Why is
anyone working in NASA Operations that does not know aircraft units?

What you write is a non-sequitur.

You also underestimate the effects of systematic miseducation. The
mere existence of a conversion factor from pounds to kilograms on a
calculator isn't going to undo the fact that some favorite teacher has
drummed into someone's head the notion that pounds are always units of
force and not units of mass, so you can't really convert between
pounds and kilograms. In fact, in today's screwed up world, there are
a number of textbooks which tell you just exactly that.

Why change from the units of aerospace to some other arbitrary set of units
in the first palce? In my 20 20 hindsight I can say for a fact that
attempting to apply si units to aerospace has come at the cost of confusion
and we are very fortunate to have avoided toumbstones.

In fact, the calculator is the end of any need to change to si
units, as si is a slide rule reality.

Any time you make a conversion, at least other than by factors that
are exact powers of 10, you lose something.

Perhaps, but not enough to matter from an engineering, of operational
standpoint.

Any time there is a need to make conversions, it is an opportunity for
all sorts of other errors, including misentry of the numbers into the
calculator, transposition of digits in copying the result, or
whatever.

In that case, why stray from what already works and play silly SI games?

snip
Your conclusion differs from that of the incident investigation board,
and it differs from the conclusions of NASA's Inspector General report
on NASA's use of the metric system.

Same with the Gimli glider. Why in the world were U.S. gallons ever
involved in that improbable, couldn't-be-written-as fiction string of
errors, when you had a Canadian airline on a domestic flight? It's a
lot easier to mix up gallons and gallons than it is to mix up gallons
and litres.

Aircraft buy fuel by weight, so the best I can say for the Gimili Glider
report is that they have to be kidding. At the very least the board has
maintained plausable deniabiliy.

"phil hunt" wrote in message
. ..
On Thu, 23 Oct 2003 12:46:36 -0700, Tarver Engineering
wrote:

Which gallon US or Imperial ?

Either would do; in my figures below i was using Imperial gallons
(because I know how big they are).

Why not "pounds", like an aircraft?

Pounds aren't as unit of volume.

Immagine that.