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Roundest Object In the World Created
holy_calamity writes "An international research group has created the most perfect spheres ever made, in a bid to pin down a definition of the kilogram. It should be possible to count exactly the number of atoms in one of the roughly 9cm silicon spheres to define the unit. Currently the kilogram is defined only by a 120-year-old lump of platinum in Paris, but its mass is changing relative to copies held elsewhere. Other SI units have more systematic definitions."
That's precisely what they are trying to do.
Onda Technology Institute
You can define a kilogram in the number of atoms of X element, but you still need a physical object to calibrate your scales against. In this case, I believe they did it by number of silicon atoms. TFA says they went and milled a silicon sphere (purified to only Silicon-28) weighing as close to the current standard as they can get it. Next they're going to measure it (X-rays and the such) to find the density, spacing, and the such and end up getting a number of silicon atoms. This number will now BE the kilogram, and these spheres are going to be the new physical standards. They are suppose to be an improvement in that is it theoretically possible to recreate these spheres should anything happen to them (as we know the amount silicon needed), while it is not possible to recreate the current standards.
My other summary was a bit off, got the process a little backwards.
Ero-manga?
Ero-Manga is the proper term for what most clueless US fanboys call "Hentai Manga."
Specifically, he was pointing out that some Ero-Mangaka ("Hentai Artists") draw breasts as if they were morbidly huge helium filled balloons floating on top of a woman's chest.
All this in an attempt to state that you do not know what good breasts look at, having (apparently?) based your opinion on Japanese ero-manga anatomy.
All this in a completely-missing-the-point of the "Heh, Boobs are Round, Scientists are Horny" joke he was replying to.
... Wow, geeky of me, eh? I do however, wish to go on the record that I fully support scientific efforts to find/create the perfect breasts.
Well, it's sorta like this: a standard is only useful if you have some effective way to reproduce it or measure with it.
1. time. You can essentially just make a MASER, which means basically a cavity which resonates at that frequency. The nice part is that it can be tuned, and even continuously tuned, by just measuring the amplitude of the signal. When you've reached the maximum power, the thing is tuned to that frequency.
2. length. It's measured by Interferometry, so you have a meaningful way to transform a wavelength into any given distance.
At any rate, the transition for these two only happened when someone build a device which could actually measure one second or one metre that way.
3. mass. Well, that's the tricky one. Saying that you define a kilogram as one bazillion silicium atoms is useless unless you can somehow actually produce a lump with that many atoms. As long as we can't actually be sure how many atoms are in there, it would be a useless standard.
These guys claim to have been able to do just that: say with a high degree of confidence that, yep, their spheres contain exactly that many atoms. If they're right, then we're finally ready to move the kilo to that standard.
A polar bear is a cartesian bear after a coordinate transform.
Please don't go around trying to be witty against people who don't just live in Japan, but also speaks the language.
Ero-manga is what they call it. If I wanted to talk about hentai, the really creepy kind of mangas, I'd have called it that.
- These characters were randomly selected.
It's not totally worthless, as the kilogram is the basis for just about all other SI units. It is the only unit that is not defined according to other units, or in relation to a natural property. Thus, its definition is arbitrary, and everybody must agree as to what a kilogram is before the unit has any value as a standard. There's a very nice explanation of the kilogram as a fundamental unit here:
http://en.wikipedia.org/wiki/Kilogram#Importance_of_the_kilogram
I hate printers.