File :-(, x, )
Anonymous
What has science done?
The Ur-Kilogramm.
Made of iridium and platinum.
>> Anonymous
     File :-(, x)
For unknown reasons it is loosing mass every year.
0,00005 gramm, which is a catastrophe.

So they are looking for alternatives.
This silicium crystal could be one.
They are trying to count the atoms.
>> Anonymous
>>152926
Why is this a catastrophe?
>> Anonymous
>>152929
Because it is still the standard for every other kilogramm in the world.
It is compared with exact copies every other year for clarification.
Now imagine what horror it is for physicists if the original one is not exact and gets worse every year.
>> Anonymous
what purpose has that thing anyway?
>> Anonymous
>>152931
It's the definition of exactly one kilogramm.
Every physical calibration has to be in compliance with this one.
Every weighing machine on the planet has to calibrated in compliance with it.
>> Anonymous
They'll redefine it soon. I think this must be just about the last of the units still tied to a physical object. They used to have a rod 1 metre long, now a metre is defined as some function of the wavelength of orange light.
>> Anonymous
>> For unknown reasons it is loosing mass every year. 0,00005 gramm, which is a catastrophe.

I guess on days like this (when they made the measurement) it really sucks to be a scientist.
>> Anonymous
>>152948

A metre is defined as the length of the path travelled by light in a vacuum during 1/299,792,458th of a second, and a second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of caesium-133.

Kinda makes a lump of metal look like a pretty dodgy standard for measurement.
>> Anonymous
I was doing some ye olde surveying the other day and we had to compare our 50m tape to their "precise standard".... another fucking 50m tape!
>> Anonymous
Shove some sugar packets under it
>> Anonymous
>>152943
thought they changed it to 0.1m^3 of pure water at STP?
>> Anonymous
penis
>> Anonymous
what the difference? im confused as to why this is a bad thing
>> Anonymous
::sigh:: my new physics books is now obsolete.
>> Anonymous
OMG it's so cute!
I want a pet kilogram.