xkcd: Metric Tip
https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional units
number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O gauge).
Mixing dimensional units is a very bad thing for programmers, we will
screw it up.

Explained at:
https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

Lynn


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 6 Nov 2025 13:21:38 -0600, Lynn McGuire
<lynnmcguire5@gmail.com> wrote:

xkcd: Metric Tip
https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional units >number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O gauge). >Mixing dimensional units is a very bad thing for programmers, we will
screw it up.

Explained at:
https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

As I believe one of the Mars missions demonstrated disasterously when
the bits written in the USA to handle the landing took over from the
bits written in Europe. Or something like that.
--
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/6/2025 2:21 PM, Lynn McGuire wrote:

xkcd: Metric Tip
ÿÿ https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional units number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O gauge). Mixing dimensional units is a very bad thing for programmers, we will
screw it up.

Explained at:
ÿÿ https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

OK, I'll bite:

What's the difference between the two?

pt

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/7/2025 11:24 AM, Paul S Person wrote:

On Thu, 6 Nov 2025 13:21:38 -0600, Lynn McGuire
<lynnmcguire5@gmail.com> wrote:

xkcd: Metric Tip
https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional units
number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O gauge).
Mixing dimensional units is a very bad thing for programmers, we will
screw it up.

Explained at:
https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

As I believe one of the Mars missions demonstrated disasterously when
the bits written in the USA to handle the landing took over from the
bits written in Europe. Or something like that.

Mars Climate Orbiter, 1999.

It failed by diving too far into Mars' atmosphere in an aerobraking
maneuver.

From Wikipedia:

"Specifically, software that calculated the total impulse produced by
thruster firings produced results in pound-force seconds. The trajectory calculation software then used these results ? expected to be in newton-seconds (incorrect by a factor of 4.45) ? to update the predicted position of the spacecraft."

pt

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/7/2025 12:34 PM, Cryptoengineer wrote:

On 11/6/2025 2:21 PM, Lynn McGuire wrote:

xkcd: Metric Tip
ÿÿÿ https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional
units number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O
gauge).

OK, I'll bite:

What's the difference between the two?

Not my field, but gauge pressure is relative to ambient atmospheric
pressure; absolute pressure is relative to vacuum (think of a barometer).

--
Mark Jackson - https://mark-jackson.online/
To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally
treasonable to the American public. - Theodore Roosevelt

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Lynn McGuire <lynnmcguire5@gmail.com> schrieb:

xkcd: Metric Tip
https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional units number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O gauge). Mixing dimensional units is a very bad thing for programmers, we will
screw it up.

I recently heard that the US amost got metric units, but the people
who were sent to revolutionary France to get measures of the meter
and the kilogram were caught by pirates, and thus it didn't happen.

Not sure if this story is true or not.

On the other hand, this would have deprived us of a sketch
that I find so hilariously funny that I keep re-watching it:
"Washington's Dream", https://www.youtube.com/watch?v=JYqfVE-fykk .
Any US engineer, or any engineer working with somebody from the US,
should be obliged by law to watch it :-)
--
This USENET posting was made without artificial intelligence,
artificial impertinence, artificial arrogance, artificial stupidity,
artificial flavorings or artificial colorants.

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/7/2025 11:34 AM, Cryptoengineer wrote:

On 11/6/2025 2:21 PM, Lynn McGuire wrote:

xkcd: Metric Tip
ÿÿÿ https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional
units number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O
gauge). Mixing dimensional units is a very bad thing for programmers,
we will screw it up.

Explained at:
ÿÿÿ https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

OK, I'll bite:

What's the difference between the two?

pt

From a friend: "Wouldn?t mH20a (meters of H20 absolute) be more
consistent?"

Consistency is not my middle name. Our pressure dimensional units now
are ?psia?, ?psig?, ?atm?, ?mm Hg?, ?bar?, ?kg/cm2?, ?kg/m2?,
?dynes/cm2?, ?g/cm2?, ?Pa?, ?kPa?, ?atmg?, ?barg?, ?kg/cm2g?, ?kg/m2g?, ?dy/cm2g?, ?g/cm2g?, ?Pag?, ?kPag?, ?MPa?, ?MPag?, ?inH2O?, ?inH2Og?,
?mmH2O?, ?mmH2Og?, ?mH2O?, and ?mH2Og?.

The only trailing a that we have is psia since psi is really a delta
pressure unit. Pa stands for Pascals. Many of the other pressure units
such as atm and mmHg are defined to be absolute pressure by old customs.

Having a trailing a on the absolute pressure units would be better.
Where were you over the last 56 years ? I now have these strings
embedded in my software in thousands of hands, never to be changed now.

Lynn


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/7/2025 11:34 AM, Cryptoengineer wrote:

On 11/6/2025 2:21 PM, Lynn McGuire wrote:

xkcd: Metric Tip
ÿÿÿ https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional
units number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O
gauge). Mixing dimensional units is a very bad thing for programmers,
we will screw it up.

Explained at:
ÿÿÿ https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

OK, I'll bite:

What's the difference between the two?

pt

BTW, 0 psig = 14.696 psia at sea level.

At Pike's Peak, 0 psig = 9.28 psia due to the elevation change (14,115
feet, 4,302 meters, above sea level).

Lynn



--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Cryptoengineer <petertrei@gmail.com> wrote:

On 11/6/2025 2:21 PM, Lynn McGuire wrote:

xkcd: Metric Tip
ÿÿ https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional units
number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O gauge).
Mixing dimensional units is a very bad thing for programmers, we will
screw it up.

Explained at:
ÿÿ https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

OK, I'll bite:

What's the difference between the two?

14.7 psi. Or about a bar.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Lynn McGuire <lynnmcguire5@gmail.com> wrote:

Having a trailing a on the absolute pressure units would be better.
Where were you over the last 56 years ? I now have these strings
embedded in my software in thousands of hands, never to be changed now.

What about inches of water, inches of mercury, millimeters of mercury, millimeters of water, psf, and torr? And we use dBtorr sometimes too.

I once worked in a facility with a gauge marked lb/cm2 and I never did
figure out how they wound up with that one.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Scott Dorsey wrote:

Lynn McGuire <lynnmcguire5@gmail.com> wrote:

Having a trailing a on the absolute pressure units would be better.
Where were you over the last 56 years ? I now have these strings
embedded in my software in thousands of hands, never to be changed now.

What about inches of water, inches of mercury, millimeters of mercury, millimeters of water, psf, and torr? And we use dBtorr sometimes too.

I once worked in a facility with a gauge marked lb/cm2 and I never did
figure out how they wound up with that one.

The classic measure of speed, of course is in furlongs per fortnight.


William Hyde



--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 8/11/25 07:01, Thomas Koenig wrote:

I recently heard that the US amost got metric units, but the people
who were sent to revolutionary France to get measures of the meter
and the kilogram were caught by pirates, and thus it didn't happen.

Not sure if this story is true or not.

On the other hand, this would have deprived us of a sketch
that I find so hilariously funny that I keep re-watching it:
"Washington's Dream", https://www.youtube.com/watch?v=JYqfVE-fykk .

This would have been quite funny to read. However, slave owner
Washington's dead pan delivery made this brilliant comedy. I enjoyed
part 2 just as much. Thank you.

Any US engineer, or any engineer working with somebody from the US,
should be obliged by law to watch it :-)

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/8/25 13:20, Scott Dorsey wrote:

Lynn McGuire <lynnmcguire5@gmail.com> wrote:

Having a trailing a on the absolute pressure units would be better.
Where were you over the last 56 years ? I now have these strings
embedded in my software in thousands of hands, never to be changed now.

What about inches of water, inches of mercury, millimeters of mercury, millimeters of water, psf, and torr? And we use dBtorr sometimes too.

I once worked in a facility with a gauge marked lb/cm2 and I never did
figure out how they wound up with that one.
--scott

Engineers.

bliss

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Scott Dorsey <kludge@panix.com> schrieb:

Lynn McGuire <lynnmcguire5@gmail.com> wrote:

Having a trailing a on the absolute pressure units would be better.
Where were you over the last 56 years ? I now have these strings
embedded in my software in thousands of hands, never to be changed now.

What about inches of water, inches of mercury, millimeters of mercury, millimeters of water, psf, and torr? And we use dBtorr sometimes too.

There is one duplicate in that list :-)
--
This USENET posting was made without artificial intelligence,
artificial impertinence, artificial arrogance, artificial stupidity,
artificial flavorings or artificial colorants.

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Bobbie Sellers <blissInSanFrancisco@mouse-potato.com> wrote:

On 11/8/25 13:20, Scott Dorsey wrote:

I once worked in a facility with a gauge marked lb/cm2 and I never did
figure out how they wound up with that one.

Engineers.

Yes, clearly. There's some number that is easiest to calculate with those units so that's the unit they use. But what is that number and why is it easiest to calculate that way? There is a story here and I bet it turns
out to be an interesting one.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Scott Dorsey <kludge@panix.com> schrieb:

Bobbie Sellers <blissInSanFrancisco@mouse-potato.com> wrote:

On 11/8/25 13:20, Scott Dorsey wrote:

I once worked in a facility with a gauge marked lb/cm2 and I never did
figure out how they wound up with that one.

Engineers.

Yes, clearly. There's some number that is easiest to calculate with those units so that's the unit they use. But what is that number and why is it easiest to calculate that way? There is a story here and I bet it turns
out to be an interesting one.

Ah, pound force... why does lb/lb have the dimension of length/time
squared? Or is it times squared/length? Or one?

Fun story: While I was studying and had just finished technical
mechanics, my father, who was a mechanical engineer, asked me
for some beam theory calculations that he needed for something,
I forget why.

I stared calculating in the units I had been thought - decimal
units based on SI (force Newton, Length m, Density kg/m^3, but
beam cross-section based on mm with the appropriate conversion)

My father looked at the caclulations and became a little agitated.
He told me that, finally, he had understood where to put the
constant of gravity (he had learned with kg force, or maybe kp),
and having seen my calculation, he had immediately understood it
and promptly un-learned the old way he had been tought. The only
problem he saw was that he still knew figures like the strength
of steel in the old measurement system.

At work, I use MathCad a lot, and I rarely hand out a calculation
in Excel whose dimensions weren't checked previously that way.
It also helps a lot with discussions with US colleagues :-)

--
This USENET posting was made without artificial intelligence,
artificial impertinence, artificial arrogance, artificial stupidity,
artificial flavorings or artificial colorants.

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Titus G <noone@nowhere.com> schrieb:

On 8/11/25 07:01, Thomas Koenig wrote:

I recently heard that the US amost got metric units, but the people
who were sent to revolutionary France to get measures of the meter
and the kilogram were caught by pirates, and thus it didn't happen.

Not sure if this story is true or not.

On the other hand, this would have deprived us of a sketch
that I find so hilariously funny that I keep re-watching it:
"Washington's Dream", https://www.youtube.com/watch?v=JYqfVE-fykk .

This would have been quite funny to read. However, slave owner
Washington's dead pan delivery made this brilliant comedy. I enjoyed
part 2 just as much.

Apart from the scene with the hot dog (great!), most of the
idiosyncrasies of English speared in that sketch are common to
UK and US English. For the "beef/cow" difference, the French-
speaking Norman nobility is to blame. They were the ones who saw it
on the tables and ate the meat (boef), the Anglo-Saxon farmers were
the ones who handled the animals, hence the Germanic name "cow".

Thank you.

You're welcome.
--
This USENET posting was made without artificial intelligence,
artificial impertinence, artificial arrogance, artificial stupidity,
artificial flavorings or artificial colorants.

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Sat, 8 Nov 2025 16:20:27 -0500 (EST), kludge@panix.com (Scott
Dorsey) wrote:

Lynn McGuire <lynnmcguire5@gmail.com> wrote:

Having a trailing a on the absolute pressure units would be better.
Where were you over the last 56 years ? I now have these strings
embedded in my software in thousands of hands, never to be changed now.

What about inches of water, inches of mercury, millimeters of mercury, >millimeters of water, psf, and torr? And we use dBtorr sometimes too.

I once worked in a facility with a gauge marked lb/cm2 and I never did
figure out how they wound up with that one.

Bing is your friend:

A pound per square centimeter (lb/cm?) is a non-metric measurement
unit of surface or areal density. The surface density is used to
measure the thickness of paper, fabric and other thin materials.

<https://www.aqua-calc.com/what-is/surface-density/pound-per-square-centi meter>

So, did the facility (by any chance) work with/produce thin materials
whose thickness needed to be measured?
--
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 11/7/2025 4:14 PM, Lynn McGuire wrote:

On 11/7/2025 11:34 AM, Cryptoengineer wrote:

On 11/6/2025 2:21 PM, Lynn McGuire wrote:

xkcd: Metric Tip
ÿÿÿ https://www.xkcd.com/3164/

No, no, no, no.

I write software for a living and just added pressure dimensional
units number 25 and 26, mH2O (meters of H2O) and mH2Og (meters of H2O
gauge). Mixing dimensional units is a very bad thing for programmers,
we will screw it up.

Explained at:
ÿÿÿ https://www.explainxkcd.com/wiki/index.php/3164:_Metric_Tip

OK, I'll bite:

What's the difference between the two?

pt

BTW, 0 psig = 14.696 psia at sea level.

At Pike's Peak, 0 psig = 9.28 psia due to the elevation change (14,115
feet, 4,302 meters, above sea level).

Thanks! I'm pretty sure you mentioned this a few years ago, but it
slipped my memory.

This all brings to mind the World's Nerdiest Joke:

Einstein, Heisenberg, Pascal and Newton are playing hide and seek.

Einstein covers his eyes and begins counting. While Heisenberg and
Pascal run off and hide, Newton takes out some chalk and marks a square
on the ground with a side length of exactly 1 meter, then sits down
inside the square.

When Einstein is finished counting and opend his eyes, he yells,
"I've see you, Newton, and you're terrible at this game!"

Newton replies "No, Einy. You see one Newton per square meter.
You've found Pascal."


pt


--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Paul S Person <psperson@old.netcom.invalid> wrote:

Bing is your friend:

A pound per square centimeter (lb/cm=B2) is a non-metric measurement
unit of surface or areal density. The surface density is used to
measure the thickness of paper, fabric and other thin materials.

Bing is definitely not my friend. For one thing, it's not a non-metric measurement, it's partially metric. And it's a very curious way to measure surface density.

You might want to do that if you have a material that is measured in metric units, but whose total mass is measured in American units. That's what I'd like explained.

So, did the facility (by any chance) work with/produce thin materials
whose thickness needed to be measured?

No, it was a wind tunnel. But I think the basic source again was
measuring density of something derived from mixed units.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Mon, 10 Nov 2025 10:03:48 -0500 (EST), kludge@panix.com (Scott
Dorsey) wrote:

Paul S Person <psperson@old.netcom.invalid> wrote:

Bing is your friend:

A pound per square centimeter (lb/cm=B2) is a non-metric measurement
unit of surface or areal density. The surface density is used to
measure the thickness of paper, fabric and other thin materials.

Bing is definitely not my friend. For one thing, it's not a non-metric >measurement, it's partially metric. And it's a very curious way to

measure

surface density.

Ah. Semantic goo again. You are taking "non-metric" to mean that it
has no metric components at all, when here it is used to mean the
opposite of "metric" (where all components are metric).

Instead of a simple dichotomy, you prefer a range.

You might want to do that if you have a material that is measured in

metric

units, but whose total mass is measured in American units. That's what

I'd

like explained.

Fair enough. I couldn't find one, but then, I'm not really good at
searching on computers.

So, did the facility (by any chance) work with/produce thin materials
whose thickness needed to be measured?

No, it was a wind tunnel. But I think the basic source again was
measuring density of something derived from mixed units.

--
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"

--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)