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Shrinking kilogram bewilders physicists
Associated Press
| Sep. 12, 2007
| JAMEY KEATEN
Posted on 09/12/2007 2:47:48 PM PDT by decimon
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To: spunkets
41
posted on
09/12/2007 3:06:42 PM PDT
by
Recovering_Democrat
((I am SO glad to no longer be associated with the party of Dependence on Government!))
To: decimon
Global warming causing it to expand and become lighter.
Just a guess ;)
42
posted on
09/12/2007 3:07:08 PM PDT
by
grjr21
To: bajabaja
Yes, but water (with its various isotopes of hydrogen and oxygen) varies slightly in weight from sample to sample (as well as with temperature) and thus they wanted something more stable. Thus, the cylinder reference.
They could define it using the cubic decimeter of water again, using and H-1 as the references, 101325 Pa pressure (assuming said atmosphere is saturated with water) and 277.14 K (the point at which water is most dense) and I think you’d probably be able to get a stable enough standard for it. Of course, that’s just my speculation.
43
posted on
09/12/2007 3:07:08 PM PDT
by
jmyrlefuller
("The Price is Right has given away more money than anyone except welfare"-- Bob Barker)
To: Red Badger
Local gravity may have changed slightly..............I'm not sure if your comment is serious or not, but that's not possible. The scale measured the relative weight of two cylinders and that should stay constant regardless of any hypothetical change in gravitational pull.
44
posted on
09/12/2007 3:07:31 PM PDT
by
Alter Kaker
(Gravitation is a theory, not a fact. It should be approached with an open mind...)
To: decimon
Global warming is causing it to evaporate.
45
posted on
09/12/2007 3:07:34 PM PDT
by
puroresu
O-16 and H-1... wonder why the O-16 got dropped?
46
posted on
09/12/2007 3:08:18 PM PDT
by
jmyrlefuller
("The Price is Right has given away more money than anyone except welfare"-- Bob Barker)
To: Red Badger
Local gravity may have changed slightly..............Hm. True. Never thought of that. :)
47
posted on
09/12/2007 3:09:01 PM PDT
by
Recovering_Democrat
((I am SO glad to no longer be associated with the party of Dependence on Government!))
To: Captain Rhino
Slow release of gases entrained during the original casting process?Ah, another plausible idea. Good, Rhino. (Why did you ever choose THAT name?) :)
48
posted on
09/12/2007 3:09:47 PM PDT
by
Recovering_Democrat
((I am SO glad to no longer be associated with the party of Dependence on Government!))
To: decimon
Radioactive impurities decaying over time?
49
posted on
09/12/2007 3:10:03 PM PDT
by
lesser_satan
(FRED THOMPSON '08)
To: decimon
That’s what you get when you base all of the world’s measurements on the French Enlightenment.
50
posted on
09/12/2007 3:10:12 PM PDT
by
Cicero
(Marcus Tullius)
To: Red Badger
Local gravity may have changed slightly..............I'd go for that explanation.
51
posted on
09/12/2007 3:10:37 PM PDT
by
Tallguy
(Climate is what you plan for, weather is what you get.)
To: Captain Rhino
“Slow release of gases entrained during the original casting process?”
Best explanation yet, IMO. Some of the noble metals can absorb or dissolve astounding amount of hydrogen. Palladium, IIRC, can dissolve 500 times its volume of hydrogen. Platinum, similar. Where would the H come from in a crude furnace of over 110 years ago? Reducing atmosphere in the furnace..?
To: jmyrlefuller
The range of expertise on this board, again, impresses. Thanks for that response.
53
posted on
09/12/2007 3:12:04 PM PDT
by
bajabaja
To: Red Badger
Local gravity may have changed slightly.............. I doubt they're being 'weighed'. More likely placed on a balance beam and compared to the copy.
54
posted on
09/12/2007 3:13:26 PM PDT
by
TC Rider
(The United States Constitution ? 1791. All Rights Reserved.)
To: StevieJ
Nice hookah you got there, Stevie.
55
posted on
09/12/2007 3:18:01 PM PDT
by
decimon
To: Petronski
Doesn’t everybody’s Gram get smaller as she ages? It’s usually osteoporosis. That makes it all the more heinous to kilogram.
56
posted on
09/12/2007 3:18:16 PM PDT
by
Sloth
(You being wrong & me being closed-minded are not mutually exclusive.)
To: Sloth
Grand Matricide?
As opposed to Petty Matricide?
57
posted on
09/12/2007 3:25:27 PM PDT
by
Petronski
(Tribe still -11 . . . Jake Westbrook is a bum.)
To: decimon
maybe there’s a stray fingerprint on some of the copies?
To: decimon
To: Recovering_Democrat
You asked if the mass change could be due to a change in entropy. The Pt-Ir alloy has a stable crystal structure. 50 µg of mass is worth 4.5*109J of energy. An entropy change is a configurational energy change at some temp T. See the problem?
60
posted on
09/12/2007 3:28:52 PM PDT
by
spunkets
("Freedom is about authority", Rudy Giuliani, gun grabber)
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