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Big Test Coming Up For Kilogram Redefinition (ieee.org)
szotz writes: Electromechanical balances have got to be better than an aged lump of platinum and iridium right? Teams are working to get kilograms measured and shipped to Paris in time for a test to see whether the technology (along with another that uses ultrapure silicon spheres) is now ready to redefine the kilogram. Why is this redefinition interesting? Because it's about using physics to overcome one problem with weight standards based on tightly held exemplars in standards bodies' inner sanctums: the mass of those exemplars can change, however subtly, introducing uncertainty and confusion. From the article: The world's metrologists aim to change this state of affairs in 2018 by fixing the kilogram to the Planck constant, a fundamental physical constant. That shift would, at least in principle, allow any laboratory to "realize" the kilogram from scratch with a series of experiments and specialized equipment. But for that scheme to work, the kilogram derived by one laboratory must be the same as those derived by others.
So really it is just a global scientific test of who's is bigger.
Sounds like they won't be needing that kilo of platnium anymore... Send it to me please.
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hey, that's cool. the planck constant can not and will not ever, ever possibly change. right, literally everyone alive now and in the foreseeable future?
*hell freezes over*
hello?
"Stratigraphically the origin of agriculture and thermonuclear destruction will appear essentially simultaneous" -- Lee
I don't get it why you always keep confusing those two. The one for implants is called silicone.
Capito?
Why the planck constant then? Why not e, or (pi), or any other constant, for that matter? If you're going to change the definition, isn't it just a matter of choosing the close enough factor?
By the way, I'm asking. I am ignorant about this.
The fundamental distinction between math and physics is measurement. We need to base the physical constants on something measured from the universe we're interested in.
As a simple example, mathematics defines and explores 3 basic forms of geometry: Euclidean, hyperbolic, and elliptic.
The distinction between these is based on the curvature of space as defined by the behaviour of parallel lines: if parallel lines eventually meet, then space has positive curvature like the surface of a sphere. If parallel lines diverge, then space has a negative curvature like the surface of a saddle. And if parallel lines stay parallel, then space has zero curvature and is Euclidean.
Three equally valid forms of geometry, but which one does the universe have? To choose the correct model, we have to measure the actual universe.
The same is true with the fundamental physical constants. There's any number of ways to base our measurements on pure math, but these don't necessarily reflect the reality we live in.
To do that, we need to take a measurement.
This is a massive development.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
Weight Watchers International weighted in on the discussion requesting the new kg to be defined at twice the weight of the current kg ("Yes Sandy, I lost half of my weight in the blink of an eye!"), while grocers all over the planet petitioned to divide the current value by four.
So better to stay with our standards! They prove to be better, as we are number 1! USA! USA!
Bonus: as we have at least two standards, we can keep to the other when one fails.
Somebody should go down to the hardware store and get some ball bearings, just to fuck with them.
All kilograms are equal
but some are more equal than others.
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Isn't a litre 1kg of pure water at normal room temperature and normal atmospheric pressure, so presumably that will change if the definition of 1kg changes?
I don't know why they don't switch a litre to being 1000cc. For most purposes 1000cc is close enough to a current litre that it won't make any difference, and 1000cc would give the litre a more precise definition than it currently has.
Trump can't save the west but he can fight its death.
I hope he wins. We need more Putins and Orbans and Trumps.
I bet they're going to change the definition from 1 kg = 1024 grams to 1 kg = 1000 grams. And we'll probably have to write "kig" too to make sure we don't get confused about the old definition.
So glad to be living in the US, where we do not use this satanic SI weight measure and all the attendant confusion.
And have Bill Gates switch off the internet to save your children.
The unit formerly known as the "pound" shall now be called the "kilogram". The prices will be adjusted accordingly.
Plot twist: The Planck constant turns out to be changing slowly.
So it'll be 999.000000001 grams or something?
Maybe they'll redefine gram one of these days
...the Imperial system of weights and measures is bad because it's "arbitrary".
-Styopa
That's a researchable fact. Trump supporters don't like those.
If Trump wins (shudder), don't be surprised if the inauguration is moved to halftime at the Superbowl.
This proves it even better. The kilogram is fake and so is constant "g" for gravity. It's just a matter of "deciding" your own personal truths.
The US approach is silly. The apparatus must be isolated from the environment to such a degree that it is impractical. Oner must monitor and dissuade wildlife a quarter mile away from the apparatus to get useful measurements. In essence the US approach is not to make a standard but a very impractical scale. The German approach is not so touchy. There is nonsense about only one Australian guy being able to form the spherical reference but that is ridiculous cult of personality. The German approach is both defined by a physical description and produces an actual physical kilogram reference. The US approach has the wow factor of a physical constant used to define the kilo but who cares? The US approach would result in inconsistent kilos if adopted. Anything that touchy is not suitable as a definitive reference.
It should be defined by Pope Francis
He used to be a chemist, and is infallible.
is this one: https://www.youtube.com/watch?v=ZMByI4s-D-Y
Use the D1 discussion system. It still works just fine, and it has both a dropdown and a "confirm" button. Find it in your account options under 'Discussion'.
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
It's more than 2.2 times better..
e and pi are ratios. What is interesting to think about is that pi could be argued to be variable depending on space-time (ex: variations in ratio of circumference to diameter for a given circle could indicate variances in local space-time--if the measuring devices is somehow unaffected [or affected differently in a known, correctable way] by those local variations).
What about Planck mass? https://en.wikipedia.org/wiki/Planck_mass
We still use the pound in the US of fucking A.