What is the Basic Standard Of The Metric System?

[Truckman]

Winter came on a Thursday afternoon here last year...It was gone by lunch the next Saturday...I remember there being dust on my jacket collar when I got it out of the closet......Ben

[wacojoe]

Scientists are about to change what a kilogram is. That’s massive.

https://www.washingtonpost.com/news/...=.5710393bcb32

[Dave Grubb]

Frankly my good man---I don't give a damn----I'm keeping mine at 2.2 pounds---my slide rule does not allow me to work at 34 decimal places of accuracy

All kidding aside---I'm so anal I find the very interesting

[Sandman]

Because of habit.. prices in most Canadian groceries will officially list an item by metric units .. Price per kilogram or liter.. and then as a side note price per pound or gallon.. The baby boomers grew up before metric..

At some Canadian delis if you order a pound of something you will receive half of a kilo (500 grams.. 1.1 lb)

[Billy_Rightwing]

Poke here.

[Bernhardt]

Silly me, and here I thought a kg was based on 1000cc of pure water at STP(standard temperature and pressure). Not by it's weight, but by the mass that fits into that volume.

[TriGuy]

I have always preferred using the metric system. It is so much simpler to use than the US system when inter-converting things like weight per volume etc.

[wacojoe]

Silly me, and here I thought a kg was based on 1000cc of pure water at STP(standard temperature and pressure). Not by it's weight, but by the mass that fits into that volume.

Silly me, and here I thought a kg was based on 1000cc of pure water at STP(standard temperature and pressure). Not by it's weight, but by the mass that fits into that volume.

I always was taught the metric system devolved from one basic immutable standard too, and that was the recognized length of a meter as discussed in the original post. But then the question is, "What is a standard meter?" From that comes 1/100 of the meter — a centimeter, then a cubic centimeter (from which all volumes are derived), then the mass (weight) of pure water at a standard temperature contained in a cc from which all weights & mass are measured. Quite elegant and rational, but the primary standard of a meter must be maintained, agreed and measured.

That is the reason for this thread, and why I find the subject interesting. The newest article in #7 above does not say it, but I am guessing that the 1889 platinum and iridium cylinder maintained as the standard kilogram is a stand-in for the theoretical pure water measure of that mass because it is more stable to maintain, but it is not explained in the article. Plank's Constant blew right past me though.

[Dave Grubb]

Because of habit.. prices in most Canadian groceries will officially list an item by metric units .. Price per kilogram or liter.. and then as a side note price per pound or gallon.. The baby boomers grew up before metric..

At some Canadian delis if you order a pound of something you will receive half of a kilo (500 grams.. 1.1 lb)

Canada is officially bimensuric, meaning there are aspects of both Imperial and SI (metric) systems.

They are not alone in that. For example, don't go into a British Pub and order a half liter of beer.

I go both ways In somethings I think in metric and have to mentally convert to Imperial when speaking to someone rooted (and stuck) in Imperial units. In somethings I still think in Imperial units and have to mentally convert to SI as needed.

My personal preference is to be completely metric, it makes far more sense.

[Bernhardt]

I'm sure the block is a stand in. What they're looking for with plank's constant is something that is even less variable than the pure water block in case the conditions are off a little bit when measuring. They did the same with the second by basing it on being defined by the number radiation periods of cesium 133.

The numbers won't be nice and round in the new definitions since the definitions are being "reverse" engineered to meet what the old definitions, which were pulled out of thin air, say things are. They're not trying to change what a second, meter, or kg are - just the basis of the legal definition.

[dmd]

"symmetrically placed in the same horizontal plane at a distance of 571 mm from each other"

OK.. If they are using this to define a meter, how do they know how long 571mm is?