Alien practical joke?

[nancylebov]

http://www.abc.net.au/news/stories/2007/09/16/2033951.htm

A riddle: When is a kilogram that is no longer a kilogram still a kilogram?

Answer: When the chunk of metal that serves as the official international standard for the kilogram, under triple lock-and-key in France since 1889, inexplicably sheds a little weight.

As far as I can tell, all the obvious explanations have been looked at, and the official kilogram is being compared to other kilograms made at the same time in the same way and stored under the same conditions, so it isn't a matter of gravity changing or somesuch.

I don't know if anyone has checked for the shape of the missing 50 micrograms--that might provide a clue, nor do I know what it would take to knock 50 micrograms off platinum.

Sometime before 2010, he said, the mysteriously shrinking cylinder will be replaced with a new-and-improved model, a perfect sphere measuring 93 millimetres in diameter and made of pure silicon-28.

"The advantage of silicon-28 is that it is stable. The mass does not change over time," said Dr Davis.

So if the silicon sphere starts shrinking too, I guess that's more reason to think it's aliens.

Any other examples of intractable weirdness?

Comments

[mishalak.livejournal.com]

Well if I was one of the scientists wondering about it I would do every non-destructive test I could think of. Any test. Measure the radioactivity vs. the other standard weights. Test the surface it has been sitting on with mass spectroscopy. Test the air around it. Try to find a chemist to check and see if there might be some unanticipated long term catalytic action. Heck, if there is no danger of inducing radioactivity put it through an X-ray to see if it really is made out of what we think it is made out of.

[nancylebov.livejournal.com]

And do a careful examination of the surface in case a little bit got knocked or corroded off.

[mishalak.livejournal.com]

Oh and the BBC has a nice article with a idea I had not considered. Perhaps the other kilos are gaining due to atmospheric mercury or the hydrogen from the solvents used to clean them. Since they are handled more often than the international standard kilogram.