Roundest Object In the World Created 509
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."
Wishing... (Score:4, Funny)
Re:Wishing... (Score:5, Insightful)
I don't know what kind of ero-manga you've been reading (Ok, perhaps I do...), but real boobs aren't spherical. Especially not ones that would be anywhere near being considered 'perfect'.
Re:Wishing... (Score:5, Funny)
Re:Wishing... (Score:5, Funny)
Re:Wishing... (Score:5, Informative)
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.
Re:Wishing... (Score:5, Insightful)
I do however, wish to go on the record that I fully support scientific efforts to find/create the perfect breasts
If all women had scientifically 'perfect' breasts then those perfect breasts would get pretty boring, unless the scientific process took into account many different factors and created different breasts for each person. I think 'perfect' is all down to personal preference.
There is beauty in many different breast shapes, though everyone will have their preferences. I think any slashdotter with access to any kind of breasts would be pretty happy. Apart from the female ones, they probably aren't too fussed.
Re:Wishing... (Score:5, Funny)
There is beauty in many different breast shapes, though everyone will have their preferences. I think any slashdotter with access to any kind of breasts would be pretty happy. Apart from the female ones, they probably aren't too fussed.
Sadly, I suspect that a great many slashdotters have breasts. Male or female...
Re:Wishing... (Score:5, Funny)
They are Dalek-bumps, you insensitive clod!
Re:Wishing... (Score:4, Funny)
Re:Wishing... (Score:5, Funny)
That explains how they can cope with living in their parents basements - if I had a decent set of breasts I could amuse myself for hours on end!
And you call yourself a man! (Score:3, Insightful)
If all women had scientifically 'perfect' breasts then those perfect breasts would get pretty boring
Where has your penis gone? Breasts getting boring? What kind of silly, nonsensical, jibber-jabber is that?
Breasts NEVER get boring! I love my wife's breasts as much today as the day I married here!
Actually, come to think of it, it'd be pretty awesome for all women to have the same sized breasts. That's a whole level of insecurity that men wouldn't have to deal with any longer.
Re:And you call yourself a man! (Score:4, Interesting)
Well, I mean from a purely physical point of view, the world is a lot more interesting (though sadly sometimes in a negative way, as you point out) because of physical differences. I find amusement in different breast shapes. I'm sure I'd be happy with one set of breasts attached to a special someone, but while I'm single I can honestly say that I quite enjoy the variety!
I'm sure you do love your wife's breasts, but that is presumably mostly because they are a part of your wife and you love her. They also are 'your' personal set of breasts so aesthetically you will also come to find them even more pleasing because of this.
People subconsciously come to prefer things that they own - they tested it on people with short term memory loss, getting them to rate some paintings on an aesthetic scale, then 'gave' them one of the paintings, came back later when the people had forgotten about the whole thing, and then asked them again to rate the paintings, and people rated the ones they were given as higher than before. I can't find a reference for this (I have a feeling it was in Robert Anton Wilson's Prometheus Rising but despite that being about the human brain I'm not sure how it fits into that context, so maybe I read it elsewhere), so take it with a pinch of salt if you will.
Personally I can vouch for that theory though, as I never used to find medium-smaller breasts interesting until I went out with someone who had fairly small breasts. Yes, she had a freakin awesome ass, but I learned to love her breasts too. I also tend to find women more attractive if I like their personality, and consider even good looking women to be 'ugly' overall if they are evil bitches.
Re:Wishing... (Score:5, Informative)
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.
Re:Wishing... (Score:5, Funny)
Re:Wishing... (Score:4, Funny)
7337 neologism
Your misspelling (misnumbering?) of 1337 is strangely appropriate.
Re: (Score:3, Informative)
Actually, "eromanga" is a plain japanese word and not any kind of neologism. It just means "porn manga".
"Hentai", however, is a western neologism that is not used in Japanese.
Re: (Score:3, Funny)
What is teet?
What you walk on when your feef hurt.
Exactly (Score:4, Informative)
(NSFW)
http://images.fok.nl/upload/050701_30560_howtodrawboobsfok.jpg [images.fok.nl]
Re: (Score:3, Interesting)
CmdrTaco did. Look at the dept. line.
Re:Wishing... (Score:5, Funny)
Re:Wishing... (Score:5, Funny)
Re:Wishing... (Score:4, Funny)
Dude. Have some standards.
Slashdotters are desperate but come on... a 7 digit UID? I think even having boobs might not quite save you from that to put you in the eyes of the nerds. :)
Re:Wishing... (Score:4, Funny)
I have read "Roundest Object In the World Created " and immediately thought "CowboyNeal".
Re:Wishing... (Score:5, Funny)
Re: (Score:3, Funny)
Yea, but I've seen more worst cases of grammatical error on Slashdot.
Re:Wishing... (Score:4, Interesting)
Honestly, as a married man I don't understand why anyone would think that...
My first thought was of more efficient ball bearings. Such perfect ball bearings alone could reduce world-wide energy usage by a large percentage. Technology like this is the truly "green" tech that we need to proliferate in addition to the other forms we are currently working on.
Re: (Score:3, Interesting)
The married guy thinks of balls.
I'm not sure what kind of commentary that is on our social structures...
I, for one, am married, and that means I think of boobies *more* often. Of course, now, some of the time I'm wondering how much milk they hold. Which doesn't really help when we're discussing solid spheres.
Re:Wishing... (Score:5, Funny)
> Honestly, as a married man I don't understand why anyone would think that...
>
> My first thought was of more efficient ball bearings
Thanks. I've printed this comment out and plan to show it to my friends when they bug me about why I'm not married.
Vague AC/DC Reference (Score:5, Funny)
Deiseil or widdershins
What matters is their smoothness
Reflects what's on your chins.
Burma Shave
The hubris of man (Score:5, Funny)
In other news... (Score:5, Funny)
In a press release today, Sir Mix-A-Lot is quoted as saying that, by viewing this object, "You get sprung", as well as "[wanting to] pull up tough" because of the perfect shape of the object.
He was later quoted as saying that "I like'em round and big, And when I'm throwin a gig, I just can't help myself". Clearly, he is an aficionado for perfectly round objects.
* my captcha was "beating", which is what I deserve for the 90's reference.
Re:The hubris of man (Score:5, Funny)
No mere human will never be able to accomplish what God did with Jennifer Lopez's ass.
Perhaps not, but we are interested in pinning down the exact measurement of the kilogram, not the metric ton.
Re: (Score:3, Funny)
This thread is like a couple of janitors on break discussing the merits of the 2008 models according Yachting magazine.
They might have the dinghies, but they'll never use them with the objects of discussion.
anyone (Score:3, Insightful)
Re:anyone (Score:5, Funny)
Does anyone here want to inform CmdrTaco that boobs shouldn't be perfectly spherical, and in fact, it's preferable if they're not?
It's not his fault. He watched a lot of Baywatch. He doesn't know any better.
Finally (Score:5, Funny)
No one will be able to claim that a game of pool, snooker or soccer was won because the ball wasn't round enough...
Re:Finally (Score:5, Funny)
What's the problem? (Score:4, Interesting)
Of course, I'm no experimental physicist, but if I were to guess, I might suggest the fact that the binding energy (and thus the mass) might change with force-field fluctuations in the vicinity, but I think that problem should be solvable by defining the proper environment for measuring.
Does anyone know?
Re:What's the problem? (Score:5, Informative)
That's precisely what they are trying to do.
Re: (Score:3, Informative)
If it isn't possible to consistently construct and measure the spheres (or some other object), then the a number of atoms isn't particularly more useful for calibration (which is the whole point) than the old standard.
Re: (Score:3, Informative)
Re: (Score:3, Insightful)
That is exactly precisely what they are trying to do.
They are not making a physical standard. They are attempting to get away from one. The desire is to specify a kilogram as a specific number of a specific type of atoms, but what is that number? In order to do that, they need to create something that both:
1. has a measureable mass that is equivalant to the current kilogram to the _greatest_ precision it is possible to measure with todays equipment. (with a fair amount of leeway)
2. has the property that yo
Re:What's the problem? (Score:5, Informative)
Re:What's the problem? (Score:4, Funny)
That is what they are doing. They are defining the kilogram as X silicon atoms.
Oh God! We're back to the earlier boobies thread again...
Re:What's the problem? (Score:5, Informative)
You can't calibrate a scale by telling it your theoretical model - at some point there actually has to be a physical thing.
Re: (Score:3, Interesting)
Re:What's the problem? (Score:5, Funny)
why not use, say, electrons, as in 1kg=weight of 1.1xxxe30 electrons (at rest)?
They tried that, but when they charged their terafarad capacitor with 1e30 electrons so that they could calibrate their scale, somebody accidentally grounded it and the massive arc of current blew the roof off of the lab.
Re:What's the problem? (Score:4, Interesting)
That's in fact what this is doing. The silicone balls are intended to be calibrated according to a fixed value of Avogadro's number, rather than the Avogadgro number being defined according to the standard. Given this, it would be possible for a researcher anywhere in the world to recreate their own standard.
However, given that milling carbon into a monocrystalline structure is expensive (think 1kg diamond), they are using silicon instead. Thus, the KG would be defined in terms of the number of silicon atoms. They have yet to decide (as far as I know) whether to use naturally occurring silicon, or to remove all the isotopes and only use 28Si. This would, effectively, create a new number, redefining Avogadro's number as:
Avogadros number = New Constant * (mass(12C) / mass(28Si))
Re:What's the problem? (Score:5, Informative)
My other summary was a bit off, got the process a little backwards.
Re:What's the problem? (Score:5, Informative)
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 [wikipedia.org]
Re:What's the problem? (Score:4, Interesting)
In fact, this change in the kilogram is coupled with a change in avogadro's constant to make one immutable and the other exact!
Re:What's the problem? (Score:5, Interesting)
Also, nitpicking but... one kilogram = 10^15 picograms, always.
Re: (Score:3, Interesting)
It *is* based on measurable quantity... (Score:4, Funny)
A kilogram is defined as exactly 2.20462262 pounds of pure water at pressure of 100 kPa (1 bar) and a temperature of 273.15 K. :)
Re:It *is* based on measurable quantity... (Score:5, Funny)
So how do you define a pound?
My driver's license (a legal document!) says that I weigh 185 lbs. So, 1 lb is defined as my weight divided by 185.
Therefore, 1 kg = 2.20462262 * (1 gnick-weight) / 185. Was that so hard? A measurable quantity.
The only problem I see is that I don't to live out my days on some shelf in France.
manufacturing problems (Score:5, Informative)
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.
Re: (Score:3, Insightful)
Hmm, well, if I remember physics at all, gravity would be an even bigger bitch to measure. Really, it's a very weak force. It only does anything measurable for _huge_ masses. You know, stars, planets, etc. The space curvature is observed around stars and the like. Measuring it around a 1 kilo sphere, well, you're probably worse off than counting atoms.
Plus, if you think about it, it also doesn't help that we're already in a huge gravity well. So it's a bit like measuring the brightness of a lightbulb, near
Re: (Score:3, Informative)
I've never really understood the problem with creating a more stringent definition of the kilogram.
Others have pointed out that they are doing more or less what you advocate, but let me address the more general issue.
Remember that the definitions for the fundamental units are intended, above all, to be *practical*. In other words, the goal is to make the definition as easy as possible for a competent scientist/engineer anywhere in the world to reproduce in order to calibrate some instrument. All the funda
Cleanroom? (Score:5, Insightful)
The picture in the article shows the sphere being handled in what obviously isn't a cleanroom. Won't that mess up its surface?
Re:Cleanroom? (Score:4, Funny)
Just wipe it off with some kleenex.
Re:Cleanroom? (Score:4, Insightful)
Just wipe it off with some kleenex.
Different kind of "balls", so what works for you won't work for them.
Re:Cleanroom? (Score:5, Informative)
The picture in the article shows the sphere being handled in what obviously isn't a cleanroom. Won't that mess up its surface?
I'm sure they don't cart the real ones around for press tours.
Comment removed (Score:5, Funny)
Metric... (Score:5, Funny)
Re:Metric... (Score:4, Funny)
Perhaps it's due to the changing masses of ducks? I'm just sayin'...
Re:Metric... (Score:5, Interesting)
It gets worse. US standards are based on metric standards. (For instance, the inch is defined as 25.4 mm.) You're basically using a French system!
Re: (Score:3, Informative)
Easy. At some point in time some people decided to base the US system on the metric system. There was a time of course when the US system was standalone, but then came a situation when these people had to refine this system and they made the choice to base it on the metric one.
Re: (Score:3, Funny)
The pound is no more equivalent to the kilogram than Disney dollars are equivalent to US dollars.
Ah Ha! Take that! (Score:5, Funny)
So I'm not getting fatter, it's the kilogram that's getting slender!
You know, roughly (Score:5, Funny)
"First we create a perfect sphere, then we count the number of atoms exactly - and we get a kilogram standard!"
"Alright... so how big do we make this sphere?"
"Oh you know.. roughly 9 cm, give or take."
just add water (Score:5, Interesting)
Re: (Score:3)
Re:just add water (Score:5, Informative)
Because its 1 liter of pure h2o at 4 deg C -at the sea level-, (remember, pressure isn't the same at the top of a mountain than it is at the bottom...and it changes everything). It is also not universal... if the earth was to go boom, (and somehow live), we'd lose our reference.
That is in opposition to, let say, a meter, which is a fraction of the distance light travels in a specific amount of time. Fairly universal. (I beleive it USED to be a fraction of the earth's size... which was quite bad too).
Re: (Score:3, Funny)
if the earth was to go boom, (and somehow live), we'd lose our reference.
I think in that case, we're gonna have other things to worry about than knowing the exact measurement of 1kg
pi (Score:4, Funny)
Does this also pin down the value of pi? I mean, they know exactly how many silicon atoms are on the surface of the sphere, and they know exactly how many atoms there are from the center to the surface.
hmm.
Re:pi (Score:4, Insightful)
Pi describes an idealized construction. Physical manifestations are imperfect to the extent that they don't match pi, not the other way around.
I beg to differ (Score:4, Funny)
The roundescht object in the world isch your mother, Trebek.
Gravity Probe B has more Perfect Spheres (Score:5, Interesting)
Kilogram Silicon Spheres
"If you were to blow up our spheres to the size of the Earth, you would see a small ripple in the smoothness of about 12 to 15 mm, and a variation of only 3 to 5 metres in the roundness"
Gravity Probe B Spheres
http://www.nasa.gov/mission_pages/gpb/index.html [nasa.gov]
"If these ping pong-sized balls of fused quartz and silicon were the size of the Earth, the elevation of the entire surface would vary by no more than 12 feet"
Re:Gravity Probe B has more Perfect Spheres (Score:4, Funny)
I can't believe no one has posted this... (Score:4, Interesting)
http://www.kyokyo-u.ac.jp/youkyou/4/english4.htm?
making spherical mud balls. I've had this bookmarked in del.icio.us for a long time
Precisely, roughly, about a kilo. (Score:4, Funny)
...has created the most perfect spheres ever made...
...roughly 9cm...
That precise eh?
Simple (Score:4, Funny)
How much more round could it be? (Score:5, Funny)
The answer is none.
None more round.
Definition of the kilogram? (Score:5, Funny)
It's 1024 grams, right? Easy definition.
A Metrologists comment... (Score:4, Informative)
Re: (Score:3, Informative)
Crystal growth is often spherical. And very controlled crystal growth is a method to get a very uniform object without (many) defects.
Is crystal growth really the reason why? (Score:5, Interesting)
Is this really the reason why it's a sphere? Crystals don't PRECISELY grow into a sphere do they? Won't they still need to shave or polish it to get it to the exact radius? And then they'll need to calculate the number of atoms using Pi, an irrational number!
Why don't they make it a cube and find a length that is close enough (cubed) to give them the approx. right number of atoms and then make THAT the standard? They'll then have an EXACT number of atoms making up each length. It should be easier to cut or shave off the requisite number of atoms to maintain it, a (perfectly) flat surface seems much easier to maintain than a 3D curved surface. In fact if they make it just a little too small they could probably even ADD to the cube in single atomic layers using vapor deposition!
Obviously brighter minds than mine have thought this through more thoroughly, so really, I'm curious: why is it a sphere?
By the way, maybe this is a good use for the ISS, to keep the 1kg reference MASS somewhere it won't be distorted by gravity, not kept at any particular country for measurement and you can keep it in a high quality vacuum for free! (A little expensive to get to though).
Re: (Score:3, Informative)
I'm not sure if you were being facetious or not when you were talking about pi being irrational, but its value is known to billions of decimal places. I doubt it will introduce any additional uncertainty.
A cubes edges might chip easily (Score:3, Interesting)
For the specification they are trying to achieve, even a little chip from a corner would be a tremendous error. It's a lot tougher to damage a sphere that way. Of course you can damage both from dropping them.
I too think eventually this physical weight will be replaced by a known voltage/wattage on a scale to counteract a force, although for practicality purposes, having a physical object is probably much easier to use in daily situations.
Polishing the perfect sphere is easier (Score:4, Informative)
I think the reason why they made it a sphere is because a sphere is defined by one parameter only, its diameter. To make a perfect sphere all you need is to make sure it has exactly the same curvature everywhere. Now, let's see what it takes to make a perfect cube:
1) each of its six faces must be perfectly plane
2) each of its twelve edges must have exactly the same length
3) each of its twelve angles must be exactly ninety degrees
Just to illustrate how difficult this is, I once read this anecdote about Wernher von Braun: when going through his mechanical engineering course in Germany, one of the professors gave each student an irregular lump of iron. The assignment would be to create a cube, as perfect as possible, from that lump. The size of the resulting cube didn't matter but, naturally, if it was a very small cube it meant the student had a tough job getting it right.
Re:Polishing the perfect sphere is easier (Score:4, Informative)
On the contrary, it is quite simple if you use interferometry. Put the sphere on top of a small flat piece of glass. Illuminate it with monochromatic (laser) light. The light reflects both from the glass and from the sphere; depending on the distance between the glass and a point of the sphere, there will be constructive or destructive interference. It's straightforward to measure the curvature across a square cm with better than 150 nm accuracy (you can do it at home by putting to glass plates on top of each other), and with some tricks even more accurate. See Wikipedia: Newton's rings [wikipedia.org]. There are variations on this principle with better accuracy; they can make telescope mirrors of more than a meter with less than 100 nm deviation from the ideal surface.
Re:Is crystal growth really the reason why? (Score:4, Insightful)
If the mass of a sphere containing (x) atoms of silicon-28 isn't the same as the mass of (insert favorite shape here) containing (x) atoms of silicon-28, we've got problems...
Re: (Score:3, Informative)
number of atoms = (volume * density) / mass of silicon atom
With the volume of a perfect sphere simply being
Pi*r^3 (I think)
It's also much much easier to test for the perfection of a sphere over any other geometric shape. All you do is spin it with slight axis rotation while a laser is pointed at it, and measure the distance.
Re: (Score:3, Funny)
Re:Changing Mass? (Score:4, Interesting)
Its shrinking. Losing incredibly small pieces over long periods of times. No object can realistically stay -exactly- the same forever.
Re:Double Dupe (Score:5, Informative)
Not a dupe - a follow-up.
The first article mentions only the weight loss of the original kilogram, the second article follows up on that mentioning a perfect sphere is going to be made. The current article follows up on that, announcing the actual creation of this sphere.
Now the fourth article in this series should be the announcement of the number of silicon-28 atoms needed to create exactly one kilogram.
On the other hand, isn't the exact mass of atoms known? Then it should be easy to say "this number of atoms is exactly one kilogram". The creation of the sphere being an exercise left to the reader.
Re:Energy is Rounder than Matter (Score:5, Interesting)
Keep in mind that the Joule is a composite SI unit, and is itself dependent on the mass of the kilogram. Unless you can calibrate the energy measurements (exactly what they are trying to do) you end up with a circular definition.
Re: (Score:3, Informative)
I hope someone with more knowledge than I do answers, but I'll try to give my best answer, from the understanding I've gleaned so far from my Engineering Physics courses at the University I'm attending. . .
I think, at an atomic level, atoms don't actually touch. When they get close enough, I think the internal atomic forces cause them to repel each other based upon field-forces (field forces are things like magnetism, or gravity, where no contact is required for things to act upon each other), or, for some
Re: (Score:3, Informative)
This answer is mostly correct, but it should be noted that the primary force that keeps atoms apart is the electromagnetic force. At large distances an atom appears neutral being made up of an equal number of positive and negative charges. However since the negative charges (i.e. electrons) are on the outside and the positive charges are on the inside (i.e. protons), when atoms get close to each other the repulsive force between the negative charges is over a shorter distance and is thus stronger than th
Re: (Score:3, Funny)
Problem being that if the balls were touching - well, it would be gay. Consequently, the answer is unimportant.