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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: decimon
The kilogram's uncertainty could affect even countries that don't use the metric system it is the ultimate weight standard for the U.S. customary system, where it equals 2.2 pounds. That is only approximately true. To eight significant figures, a kilogram equals 2.2046226 pounds.
Of course, that would be 2.6792289 troy pounds.
To: Recovering_Democrat; Ramius; decimon
Right, that's a loss of way too much energy. Even radioactive decay can't be the problem here, because the kg cylinder would have lost ~10
-4 moles of alpha particles. The thing couldn't possibly be that hot, or differ from the others. Differences in hydrogen content are also out, because this is a low solubility alloy and they're all stored the same atmosphere(or vacuum. The difference would have to be on the order of the alpha particle loss.
I think the problem with the cylinder in Paris is that it has different and changing magnetic properties for some reason. Since a mass, or energy loss is out, the only force left is the magnetic force, in the Earth's field and that of the surrounding balance. They account for that, but they'll have to look closer. The link is technical, but shows how they attempt to weigh them in different orientations. They may have assumed that the magnetic properties are the same, but they're not.
102
posted on
09/12/2007 7:45:04 PM PDT
by
spunkets
("Freedom is about authority", Rudy Giuliani, gun grabber)
To: spunkets
Hmmm... Magnetic forces. Interesting idea.
103
posted on
09/12/2007 7:58:30 PM PDT
by
Ramius
(Personally, I give us... one chance in three. More tea?)
To: ccmay
Of course, these are personal call signs and they “belong” to the pilot. So they travel with them from squadron to squadron. If there is a conflict, I imagine the junior pilot gets a new call sign. But, as your father's example illustrates, these call signs are pretty unique and the likelihood of two that were exactly the same being in service at the same time - much less in the same squadron - is probably pretty low.
As I’m sure you know, squadrons also have aircraft call signs (usually made up of the squadron identification letters and the last digit or two of the aircraft tail number). These, of course, remain with the squadron and the aircraft.
My father served in England as a B-24 bomber crewman with the U.S. 8th Air Force. Flew 120+ missions (no 25 mission limit for pre-war regular Army soldiers) ranging all over western and northern Europe (including some up to Norway). However, lately I’ve begun to suspect he might also have been in one of the B-24 squadrons “loaned” to 15th Air Force to help carry out the mass raids on the Polesti refineries in Romania.
Unfortunately, it is impossible to check. He passed away in 1975 at the age of 56 and the St. Louis archives fire of the 1950's destroyed a great number of the stored service records of 8th Air Force personnel, including my father's.
104
posted on
09/12/2007 9:43:17 PM PDT
by
Captain Rhino
( Peace based on respected strength is truly peace; peace based on weakness is ignoble slavery)
To: Oberon
Yep.
All of the others are heavier by a fingerprint...
Hmmm.
To: Cicero
Thats what you get when you base all of the worlds measurements on the French Enlightenment. Apropos of nothing, I believe the United States Constitution is inspired (almost to the point of plagiarism) from the writings of one Charles de Secondat, baron de Montesquieu.
106
posted on
09/13/2007 7:52:07 AM PDT
by
Alter Kaker
(Gravitation is a theory, not a fact. It should be approached with an open mind...)
To: decimon
I have got to get on this weight loss program. I could lose 20 pounds in ... only about 23 billion years!
To: 6SJ7; AdmSmith; AFPhys; Arkinsaw; allmost; aristotleman; autumnraine; Beowulf; Bones75; BroJoeK; ...
108
posted on
04/15/2013 7:34:33 PM PDT
by
SunkenCiv
(Romney would have been worse, if you're a dumb ass.)
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