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 Scientists present their argument for doing away with the kilogram 239 More: Asinine
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24411 clicks; posted to Main » on 27 Feb 2005 at 11:23 AM   |  Favorite    |   share:    more»

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BigJoeJo: I remember from simple engineering class that a 1 pound mass would exert a 1 pound force at 1 times the force of gravity.

Alternatly, 1 Kilogram exerts 9.8 Newtons at 1 times the force of gravity. SImple eh?

right now the KG is just some lump of stuff

More importantly, it's a lump of radioactive stuff. It's weight is slowly decreasing as it throws off the occasional neutron.

when can i start buying metric eggs in the grocery store?

phife

Thanks, but could this system be used practically in everyday life?

MrNeutron: BigJoeJo: I remember from simple engineering class that a 1 pound mass would exert a 1 pound force at 1 times the force of gravity.

Pound is a measurement of force, not mass. Use slugs.

Hot Panda Milk: could we use these for new measurement standards?

Sure, you be the first to ask your girlfriend if she weighs 1.6 Olsens or not.

Oprahs on the other hand might have a more positive effect.

When Canada was going through the metric debate, I had an Italian boss who did construction. Spreading his arms, he said "If you need a piece of wood this long, it doesn't matter if it's in millimeters, inches or cubits".

For most day to day household measuring, you can get by on any measurement system you want to employ.

But for scientific measurement, there has to be empirical standards which can be communicated around the globe, no matter which cultural measurement background someone comes from.

Myself, I use metric for temperatures below zero and inches for short measurements. For some reason I use farenheit above zero and kilometers for long distance.

phife
Planck's constant was discovered around the turn of the century by (you guessed it) german physicist Max Planck. It originally related a photon's energy to its frequency (the foundation of quantum mechanics), and has since found countless applications in modern physics. It's super-duper tiny, on the order 10^-34 in SI (metric) units

Planck length and time are extremely small, the mass unit is pretty tiny, the energy unit is pretty large, and things like pressure are gargantuan. For day-to-day measurement, you'd want scaled units. If you scale the base units by some power of ten to get them in the right ballpark for easy use, the derived units will be okay.

MrNeutron

Ok, can you clearly explain the differences between slug, pound-force and pound-mass? By the time you figure it out, I'm done with my calculation...

MrNeutron:

BigJoeJo: I remember from simple engineering class that a 1 pound mass would exert a 1 pound force at 1 times the force of gravity.

Alternatly, 1 Kilogram exerts 9.8 Newtons at 1 times the force of gravity. SImple eh?

That's because "pound" is a unit of weight, not mass. A 1 pound mass is not the same on the moon.

For pressure, PSI (pound per square inch) is much easier to use and mentally image than the pascal (newton per square meter).

While they're doing this, they should make a differentiation between mass (measured in Kg in SI units) and weight (also measured in Kg in SI units). At least in the Imperial system we know that the mass is slugs and weight is pounds. They should have a different word for the weight of a 1 Kg (mass) object in a 1 g field.

The mass of the lump of platinum in Paris is supposed to equal the mass of a 10 cm cube of water at maximum density--about 3.9 C. That makes a lot of things easy for chemists. Whether they count the number of molecules in the cube or figure how many wavelengths of whatever light make up the sides of the cube isn't important, as long as the relationship remains the same.

I still don't understand why the US won't switch to the metric system. I guess it's some sort of national identity or something. "Yeah, I'm from the US" "Whoa, you mean that country with the mad crazy measurements?" "That's the one!" ...

But for all of those people going on about how the metric system doesn't work, doesn't matter, etc. Well, here's a few examples. As far as I know, all of these are more or less imperial measurements. I will accept corrections. :)

Fluid measurements
1 teaspoon = 0.166666667
1 tablespoon = 4 teaspoons
1 cup = 16 tablespoons
1 pint = 2 cups
1 quart = 4 cups
1 gallon = 4 quarts
1 gallon = 128 fluid ounces

Weight
1 ounce = 0.0625 pounds
1 pound = 16 ounces

Distance
1 inch = 0.0833333333 feet
1 foot = 12 inches
1 yard = 3 feet
1 mile = 5280 feet

Okay, I think that's about it. So, those of you out there who champion the imperial system (which, if I'm not mistaken, isn't even American in origin), explain to me the rhyme or reason behind it. I know that some of the things are based on 12, though not all of them are. What is the advantage to this over using the metric system? What is so hard about learning the metric system? If they stopped fiddling with conversion (i.e., buying gas in liters and trying to figure out how many gallons go in your tank, having speed limits in kilometers per hour and having to figure out how many miles per hour that is, etc.) it'd be much simpler.

/Lives in the US
//Grew up with imperial system
///Converts most things to metric and uses that when possible because it makes at least 10 times (pun intended) more sense

Theseus

At this very moment in colleges and universities across the United States, science and engineering majors are learning how to do calculations in metric, and it is SO much easier than the unwieldy U.S. system.

Northern

The US system is assinine. We are behind in weights and meaurements by decades for most of Africa for crying out loud.

How, precisely, are Imperial Units a U.S. system?

freznel
Mass does not increase with temperature, you might be thinking of volume or pressure as with the ideal gas law. The mass of an object is something that never changes unless more mass is given or mass is taken away from the object. What they want to do is break away from the "old hunk of metal" approach to mass and use a universal constant approach.

pandabear:

While they're doing this, they should make a differentiation between mass (measured in Kg in SI units) and weight (also measured in Kg in SI units). At least in the Imperial system we know that the mass is slugs and weight is pounds. They should have a different word for the weight of a 1 Kg (mass) object in a 1 g field.

Mass: Kilograms
Weight: Newtons (not Kg!)

*not hard*

err, after teaspoon, that's supposed to be fluid ounces

How, precisely, are Imperial Units a U.S. system?

We got it as a hand-me-down when England didn't want it anymore.

Mystic

You're using the Yankee Trader measurement system:

1 pint = 2 cups
1 quart = 4 cups
1 gallon = 4 quarts
1 gallon = 128 fluid ounces

The British system, used almost everywhere but the US, has the following:

1 pint = 2 cups
1 quart = 4.5 cups
1 gallon = 4 quarts
1 gallon = 160 fluid ounces

/no disrespect. Just showing how asinine the Imperial system is.

2005-02-27 12:25:29 PM
moonduck

How, precisely, are Imperial Units a U.S. system?

Well, take away one-fifth on volume measures to give to the king, don't use the stone measure for weights, and you have the US version of the Imperial system. Some other units vary by tiny amounts because the standards vary from England to the US.

A pint's a pound the world around.

//////just to interject

Nanuk-the White Bear

The British system, used almost everywhere but the US, has the following:

1 pint = 2 cups
1 quart = 4.5 cups
1 gallon = 4 quarts
1 gallon = 160 fluid ounces

/no disrespect. Just showing how asinine the Imperial system is.

Haha, none taken. I definitely welcomed corrections. I did not know that there was actually a difference there, so I learned something new today. It does illustrate how asinine the Imperial system is, however. Thanks for the comment. :)

phife: /Finally, a thread that validates my physics education

Funny, I was just thinking the same thing...

As a Floridian living abroad, I have to admit I do like the metric system.

celsius/fahrenheit -> now this one is really annoying because I often screw this up and when you tell a story and say "it was a hundred degrees outside" and neglect to mention you're talking Fahrenheit, people tend to look at you funny

mph/kph -> don't really care either way
mass -> same, 1kg is 2.2 pounds = 35 oz. - really no problem there
length -> same, 1m = 3.2 ft.; 1 mile = 1.6 km

Plus, I really don't need to do exact conversions (if I did, I'd use my cell phone or PDA). I just need to have a general idea of what 1kg feels like.

2005-02-27 12:27:54 PM
Tupuli

Mass: Kilograms
Weight: Newtons (not Kg!)

*not hard*

When's the last time you ordered a Newton of salami at the deli? Ever seen a balance in a lab calibrated in Newtons?

Newtons are force, which is mass x acceleration, regardless of the source of the acceleration. 1 N = 1 Kg x m / s^2. 1 Kg of weight (as salami) assumes that there is an acceleration of 9.806 m / s^2.

mystic1423:

The British system, used almost everywhere but the US, has the following:

1 pint = 2 cups
1 quart = 4.5 cups
1 gallon = 4 quarts
1 gallon = 160 fluid ounces

And you wouldn't believe the freakin' confusion it causes me at work. We build containers. American customers order in Gallons (US Gallons), Canadian customers who are over the age of 40 order in Gallons (Imperial Gallons)...

You wouldn't believe how many people have no idea what we are talking about when we ask "Imperial or US Gallons?"

America is just inching its way into the metric system, that's all.

Mass does not increase with temperature

Actually, it does. Temperature does raise kenetic energy, and kenetic energy increases mass, because mass is energy. However, the relativistic correction isn't even calculable at any temperature possible in the universe. Only velocity can measurably change mass. However, and interesting trick is that mass units still work the same way with the mass correction in effect.

In order to measure the mass of something moving fast enough for velocity to measurably effect it's weight (around .8 or .9c), the measuring device has to move the same speed. The mass effect is relative, so the scale will still measure the object's mass the same as it would be measured if it were at rest, because the relative velocity is 0.

My conspiracy theory is that the metric system is the begining of the new world order.

/Looks for tinfoil hat

Ever seen a balance in a lab calibrated in Newtons?

Balances measure mass. The point of using a balance instead of a spring scale is that the balance will measure a kilogram as a kilogram in any gravity (except 0, it's kind of hard to balance things that won't stay on the tray).

Newtons are force, which is mass x acceleration

Weight is a force. Mass is an intrisnic property of that object, weight is an effect of gravitational accelleration applied to that object. There's a reason that the Imperial system measures all forces in pounds, because pound is a unit of force.

What is the advantage to this [imperial] over using the metric system?

It's already in place and understood by those using it

What is so hard about learning the metric system?

Not hard at all, but if no one around you uses it, what's the point?

If they stopped fiddling with conversion (i.e., buying gas in liters and trying to figure out how many gallons go in your tank, having speed limits in kilometers per hour and having to figure out how many miles per hour that is, etc.) it'd be much simpler.

Seriously, what in the hell are you talking about? Who's converting what?

pandabear:

This is what you said originally:

While they're doing this, they should make a differentiation between mass (measured in Kg in SI units) and weight (also measured in Kg in SI units). At least in the Imperial system we know that the mass is slugs and weight is pounds. They should have a different word for the weight of a 1 Kg (mass) object in a 1 g field.

Which is wrong because weight is not measured in Kg.

When's the last time you ordered a Newton of salami at the deli? Ever seen a balance in a lab calibrated in Newtons?

Scales can only measure force. So yes, all scales are calibrated in Newtons.

Newtons are force, which is mass x acceleration, regardless of the source of the acceleration. 1 N = 1 Kg x m / s^2. 1 Kg of weight (as salami) assumes that there is an acceleration of 9.806 m / s^2.

Newtons are also units of weight numbnuts.

It seems you know enough to be dangerous, but not enough to be correct. Please quit spreading misinformation until you become more knowledgeable.

Seffner

It's true ,they arn't constant.
Just use a movie or T.V. show for reference.
for example you could express your weight as .8 Color Purple Oprahs or 3.2 New York Minute Olsens.

Darnit! My car gets 50 rods to the hogshead, and that's the way I likes it!!!

/raised metric
//finds imperial arsinine

Ouroborus
Seriously, what in the hell are you talking about? Who's converting what?

From the people I've talked with who were around when they first tried to convert the US to the metric system, as well as those since then I've talked about it with, it's gone something like this. "Okay, so now you buy gas in liters and your car holds 30 liters." "So how many gallons is that?" "It doesn't matter. You buy it in liters and you know to fill your car up requires 30 liters." "So how many gallons do I buy?"

Perhaps my experiences have been different than others in discussing such things, but that's how it's been with anyone I've talked to about the metric system who was interested in the preservation of the US variant of the imperial system.

Also as an amateur radio operator, I'm glad we refer to the different bands by their metric names. "Yep, yep, Jim and I had a nice QSO yesterday on the 32.808 foot band. I can't wait until tonight to try to talk to Bob over on the other side of the country using the 229.658 foot band."

Is there such thing as a metric cookbook? Or do the chefs in France still use the tablespoon and teaspoon to measure ingredients in their cooking?

Aaaaaand I'm an idiot.

////Must not kill the happy canadian

When's the last time you ordered a Newton of salami at the deli?

Well, you're paying for a specific MASS of salami, not weight. You shouldn't expect to get six times the amount of salami if you're on the moon when you buy it.

As an aside, can you buy digital balances for labs? i.e. instruments that compensate for local variances in gravity?

This thread is so nerdy...I love it!

wtf is this headline supposed to mean? they're not eliminating it, they're attempting to fix it to a constant, which is a bright idea.

I don't see how the F system is more precise or accurate than the C system. They can both record the exact same temperatures with the same degree of accuracy and precision.

Sonofa... I'm going to have to get all new bags for my drugs now...

/sarc
tlenon

matrix29

2005-02-27 08:22:03 AM Kilmore_Trout [TotalFark]
I agree. I have a couple stones that work fine, though the pole seems to change size with repeated measurement.

Cues penis joke in...
3...
2...
1...

Hey Poopy Von Fecalstein....that WAS the penis joke.

2005-02-27 12:52:40 PM
Tupuli

Which is wrong because weight is not measured in Kg.

My point precisely. In everyday life, we call the force produced by a one kilogram mass in earth's gravity a Kilogram, not 9.806 Newtons. We say a lump of salami _weighs_ 500 g. We say a person weighs 70 Kg.

Scales can only measure force.

Of course they do.

So yes, all scales are calibrated in Newtons.

But they read in Kilograms, and ignore that pesky 9.806 m/s^2. That was my initial point precisely. It is usual with the Imperial system to call weights, which, as you pointed out, are forces, pounds. The unit of mass in the Imperial system is only used for mass. OTOH, It is usual with SI for scientists to measure forces with Newtons, and for everyone else to assume the acceleration is 1 g and call the resultant force some number of grams equal to the actual weight divided by the acceleration due to gravity.

It seems you know enough to be dangerous, but not enough to be correct. Please quit spreading misinformation until you become more knowledgeable.

It seems that you prefer ad hominem attack to understanding the point. I'll type my thesis again slowly for you.

In the Imperial system, we use the same word for force and for weight as an everyday measure and there is little possibility of confusion, as the unit of mass is only used for mass.

In SI, we use the unit of mass not only to describe mass, but to describe everyday weights, except for scientists, which therefore causes confusion, because a "weight" of 1 Kg exerts a downward force of 9.806 N.

Now if we called 500 g of salami 4.9 N of salami, I wouldn't have a problem, but we don't. BTW, as far as "knowing enough," I'm sure I do know enough to realize that you missed my point entirely.

/Lived in SI and Imperial countries
//Studied chemisty in both, too.
///Now make textbooks for a living--so I'm passing this misinformation on.

bah. AS soon as everyone accepts the smoot system, the world will be a better place.

sooooooooo,should i start freakin out now???

Modulous

My guess is what people meant to say is that Farenheit has greater resolution without resorting to decimalization. Most people like to get the temperature in integers, and in Farenheit, that can be more accurately done.

I'm confused, often.

the former measures the amount of carbon-12 atoms in 0.012 kg of that element

Isn't that a circular reference?

Exits singing, I love you, a bushel and a peck...

"Lord It's Hard To Be Happy When You're Not Using The Metric System" -Atom and his package

12 inches per foot two pints per quart why don't we make it easy?
The English system of measurement must be laid to history. We can use units of 10 and convert with ease like all the other countries.
I am in command yes I am taking a stand from this disease we must be free.
good god!

[chorus]
You're drunk with your tradition that has no validity while I'm intoxicated with smarts and metrics come drink a decaliter with me.
We want metrics
We want it now
We know can win
I weigh 170 pounds that's 90 kilograms
see metrics can even make you thin
[/chorus]

all cool things are in metrics for example here's just one "I've got my 9" well that's 9 millimeters, sounds cooler than "my point two something inches gun".
The proverbial (if not existent) 'they' will call me communist
they'll call me scum
but its worth it Canadians will think we are smart or at least they will think we are not as dumb.

[chorus]

the revolution is here!
we must overcome at last !
as we symbolically stick their farking 'foot' up their farking ass!!! GUITAR!!

[guitar solo]

[chorus]

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