Perfection

[Murff]

It's all in the title...

http://news.yahoo.com/s/nm/20070615/sc_nm/australia_spheres_dc_1;_ylt=Aohixj1hbuMvN9MmSPjrmE ME1vAI

[01101001]

It's all in the title...

http://news.yahoo.com/s/nm/20070615/sc_nm/australia_spheres_dc_1;_ylt=Aohixj1hbuMvN9MmSPjrmE ME1vAI

The news article is titled The grind's almost over to forge two perfect balls (http://news.yahoo.com/s/nm/20070615/sc_nm/australia_spheres_dc_1;_ylt=Aohixj1hbuMvN9MmSPjrmE ME1vAI) and it's about new standard-kilogram objects:

They will be the earth's roundest spheres, crafted by Australian scientists as part of an international hunt to find a new global standard kilogram.

Ever since scientists discovered that the current standard -- a bar of platinum and iridium held in a French vault since 1889 -- was slowly deteriorating, the search has been on for a replacement.

Edit: Discussed in topic The kilogram, international mass unit (http://www.bautforum.com/showthread.php?t=59353)

[Nicolas]

Somehow, the title attracted me :).

"The aim is not to change the value of the kilogram, but to ensure its stability for all future times," Giardini said. "It will no longer depend on an actual physical object and this is going to allow us to relate the mass to the individual atoms."
So they are making a physical object (two actually, I assume to average out?) from which they will determine the volume, mass, and number of molecules. With that known, they'll never need a physical reference kilogram again.

My question then is, why not simply measure only the molar properties of pure, single crystal silicon, and calculate the properties of a theoretical perfect sphere from that? Is that too hard, why is there a need for a real object?

(btw Belgian scientists will also be working on it. Which is very justified indeed, since we're the country that sells chocolates per kilogram!)

[Murff]

I was making a joke with the title, but the article was pretty interesting. I never knew about the bar in France they had kept for so long!

[Captain Kidd]

Why spheres? Well I can guess why, but still the first thing I thought of was the press conference where they bring out the sphere.
PR rep: And here we have the physical representation of 1 kilogram.
[ PR rep sets balls down onto table ]
[ To everyone's horror, the balls roll off the table and fall to the floor, shattering. ]
PR rep: Nevermind

[Damien Evans]

Somehow, the title attracted me :).


So they are making a physical object (two actually, I assume to average out?) from which they will determine the volume, mass, and number of molecules. With that known, they'll never need a physical reference kilogram again.

My question then is, why not simply measure only the molar properties of pure, single crystal silicon, and calculate the properties of a theoretical perfect sphere from that? Is that too hard, why is there a need for a real object?

(btw Belgian scientists will also be working on it. Which is very justified indeed, since we're the country that sells chocolates per kilogram!)

So does Australia

[Nicolas]

Ok then, because the average Belgian eats chocolates per kilogram. :D

(note that I say chocolatessss, not chocolate, which would be more relevant in defining the metric ton ;))

[Damien Evans]

Ok then, because the average Belgian eats chocolates per kilogram. :D

(note that I say chocolatessss, not chocolate, which would be more relevant in defining the metric ton ;))

I must be the average Belgian then :)

[sarongsong]

It's all in the title...How is that?
Thanks, 01101001!

[Maksutov]

"We have developed technology so that we can see what we are getting, whether they are slightly oval or flat. We are trying for an accuracy of two parts in 100 million," Giardini said.One wonders what kind of precision they're trying for...

:think:

[LurchGS]

Somehow, the title attracted me :).


So they are making a physical object (two actually, I assume to average out?) from which they will determine the volume, mass, and number of molecules. With that known, they'll never need a physical reference kilogram again.

My question then is, why not simply measure only the molar properties of pure, single crystal silicon, and calculate the properties of a theoretical perfect sphere from that? Is that too hard, why is there a need for a real object?

(btw Belgian scientists will also be working on it. Which is very justified indeed, since we're the country that sells chocolates per kilogram!)

I would suggest that most of the scientific world would be just as happy with that kind of definition, but the average Joe likes to point at something he can see.

As for two - man, you ALWAYS make a spare.

Just curious: since that bar of platiridium is coming apart (they make it sound like rust - it's not really that bad), how are they going to know what it massed in 1889? Or, rather, how are they going to find out the difference between its 1889 mass and it's current mass?

and even further into the depths of what I call my mind.. these two spheres are just big crystals... if you whack them together, they'll make sounds.. If you do it right, they might produce a melody. You know, Music of the Spheres...