New definition of the kilogram will change how we weigh everything

[ShawnDriscoll]

Probably won't affect the d-ton though.

 

[mike wightman]

Would that be the 14 cubic metre displacement ton, based on the volume occupied by one metric ton of liquid hydrogen, the 500 cubic feet displacement ton also based on the volume occupied by one metric ton of liquid hydrogen or the 13.5 cubic metre displacement ton based on the size of a deck plan square on ship deck plans :devil:

 

[Adam Dray]

My browser doesn't seem to be displaying the web link:

https://www.pbs.org/newshour/science/its-a-massive-change-scientists-redefine-the-kilogram (web article, medium length)

Summary:

The kilogram is currently "based on the exact weight of a golf-ball-sized chunk of platinum and iridium stored under three glass bell jars in a vault in an ornate building outside of Paris." This defines mass internationally.

This standard chunk of metal has lost a tiny bit of material, and people don't know why. This makes the universe "heavier," by our lame definition.

Today (11/16), scientists meet in Versailles, France, to discuss a new definition.

Maybe a "Kibble balance," which uses magnetic/electrical measurements and laser interferometers to get at a measure of mass in a sideways fashion.

The new kilogram will be announced on World Metrology Day this year, May 20, 2019.

 

[aramis]

the difference will be negligible for all but the most scientific uses.

 

[whartung]

the difference will be negligible for all but the most scientific uses.

Yea I pretty much still plan on using my bathroom scale and the ones at the store next to the oranges myself.

 

[btoadflax]

I guess they should have put a fourth bell jar over the thing...

 

[Timerover51]

They changed the definition of a kilogram? Since I am still a pound and ounces guy, any change will be very minor, if even noticeable.

 

[Ulsyus]

the difference will be negligible for all but the most scientific uses.

In effect they're moving from an analogue to a digital method, one that doesn't rely on a physical item that's maintained in a vault.

 

[robject]

I suggest the kilogram be slightly adjusted downwards, to exactly 2 pounds

While I'm spamming, I also think we should modify the foot to be exactly 30 centimeters long.

...

What?

 

[mike wightman]

In which case lets set Planck's constant to 7x10^-34

Nothing bad can happen...

 

[Ulsyus]

In which case lets set Planck's constant to 7x10^-34

Nothing bad can happen...

Don't let Science tell you something that cannot be more palliatively determined by a committee of socially acceptable individuals!

 

[robject]

"palliatively determined". I like that.