Four base units of measure in the metric system about to be changed

Officials with the General Conference on Weights and Measures (CGPM) have announced that at a meeting to be held next week, four of the base units used in the metric system will be redefined. The four units under review are the ampere, kilogram, mole and kelvin.

Currently, the kilogram is officially defined as the mass of a cylinder made of a platinum-iridium alloy housed in a bell jar in France—it has been removed from its protected spot every 40 years to serve as a calibration tool for other weights. But according to officials with CGPM, its days are numbered. This is because the 60 member nations that make up the body will be voting to change to a system in which the kilogram will be defined indirectly—by using the Planck constant.

phys.org, Nov. 9, 2018 - Four base units of measure in the metric system about to be changed.

WHAT!???!!

I understand that the kilogram is slowly evaporating away. I can see a need for getting out in front of the sample weighing less than it does now. But the other three? How does changing an ampere make measurements any better? And what about a mole? I spent an awful lot of time learning that mol is 6.02214179 * 10^23 atoms (Avogadro's Number) and now they want to change that?

What gets me is Lord Kelvin's scale! Absolute zero. Where all movement stops. What happened? Somebody figure out how drop below absolute zero? I know we are micro K with lasers and magnetic cooling. But now the definition of what a Kelvin is will be different?

What gives? Anybody else shocked by this? Are we so advanced that our equipment has to be defined by quantum mechanics?

I am just stunned. I am not sure about anything anymore. I think I will go have a pint at the pub!

a reply to: TEOTWAWKIAIFF
As long as they're not changing the Erg.
I still remember the definition I learned at school, because it's just such a beautiful mystic poem;
"An erg is the work done
When one dyne
Moves one centimetre
In its own direction".
I wonder what it means.

a reply to: DISRAELI


For crying out loud. I barely survived the switch from Daylight Savings time!!

i am sure many changes are only enacted to give the people " in charge " something to do

a reply to: ignorant_ape


I am an American. We don't even use the metric system (well, some places selling these dried flowers seem to use grams a lot), and I am upset!

Hi! I am Troy McClure. You may remember me from such educational films such as, Lead Paint: Delicious but Deadly; and, Here Comes The Metric System...

a reply to: TEOTWAWKIAIFF

The metric system we used was plagurised from ancients. Them units can be used to make meaning of profound structures that for all reasons of explanation should not exist. Make up new units to make it much more difficult for people to demonstrate mathematic rationale.

The adjustments are relatively minor and won't affect that math.

a reply to: TEOTWAWKIAIFF

Its used in engineering and scientific disciplines.

So now we are moving from object to virtual and that leaves us with nothing to crosscheck in the physical world.

I understand that they all fall together because they are coupled in their initial definitons and measurements.


But what about time? The second, minute etc is also oriented in the timespan of a year/day, and that is defined by the physical movement relationship between earth and sun and the earths rotation.

Or does this not count because minutes, hours and seconds are fillers to divide the unit "day"? Questions over questions...

Interesting fact about the metric system, it’s based on water.
1 square centimetre of water equals 1 millilitre and weighs 1 gram.

Makes way more sense than the armpit to finger measurement of some king that Americans use, get with the programme yanks the metric system is the way forward and I’m sick of trying to figure out how many kilos you guys weigh.

a reply to: IkNOwSTuff

Metric system FTW!!!!

a reply to: TEOTWAWKIAIFF

Sounds like a globalist plot to me.

Well if they're not using that kg of platinum/iridium alloy anymore I've got a stack of paper that needs weighing down....

a reply to: TEOTWAWKIAIFF

I don’t understand how they can change the ampere, not without changing volts and Watts too. As volts/resistance equals amps, or amps x volts gives us watts.

What am I missing here?

a reply to: TEOTWAWKIAIFF

It appears to me that "they" aren't necessarily changing the value of those four measurements, but the manner in which they are measured. Perhaps I'm reading that wrong, but it looked so to me.

a reply to: surfer_soul
They will change the way the unit ampere is referenced with.

Because I´m bad in english, here is the wiki article.

The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed one metre apart in vacuum, would produce between these conductors a force equal to 2×10−7 newtons per metre of length.

Here you see that the ampere is defined via cross-reference to length.

Since the meter won´t be measured physically anymore on an object but rather calculated with the help of the planck length, all the units that use the meter to define itself, now have a virtual reference point.

There is a bar in Paris that is exactly 1m long pert definition. The true and only meter stick. It´s made of material that won´t stretch or contract much on temperature changes. This is bar is/has been used to calibrate other equipment. It served us as an reference point and it´s protected.

If you would sneak in over night an cut it shorter and nobody would notice... Imagine the consequences.

Ampere will still be around, it´s just referenced differently.

It's an interesting subject.

It does make more sense to make things a bit more simple and accurate.

The kg is dubious. For me.

Mass and weight are different things.

So. 1kg placed in a vault in France. Weighs more than the same object at a higher altitude or a nearer to the equator position.

a reply to: blackcrowe
It was the only know way, since they could measure gravity, but not measure local changes in gravity with their crude equipment. Today we have satellites that do that for us.

www.space.com...

a reply to: verschickter

Exactly.

It will make it an accurate measure.

Also TEOT.

I am an American. We don't even use the metric system (well, some places selling these dried flowers seem to use grams a lot), and I am upset!

Your money is in metric.

originally posted by: TEOTWAWKIAIFF
a reply to: ignorant_ape


I am an American. We don't even use the metric system (well, some places selling these dried flowers seem to use grams a lot), and I am upset!

Hi! I am Troy McClure. You may remember me from such educational films such as, Lead Paint: Delicious but Deadly; and, Here Comes The Metric System...

We do in healthcare.