But isn’t the interesting thing that we thought we had sealed these objects in a way that would prevent them from changing mass, and yet they seem to be changing mass, and in different amounts?
This is an interesting anomaly, much like the Pioneer spacecraft being off-course. There must be an explanation, but surely there are scientists who will not rest until they KNOW that explanation.
Meh. To me, it just doesn't seem like that much of a mystery. Every single man-made process involves tolerances, and when these things were manufactured (and, I suspect, today) we were unable to count the individual platinum atoms that were going into them. We can't make a perfect vacuum, and we were probably less able to make a perfect vacuum back when the prototypes were being created. I'm sure there were quite a few errand molecules floating around in the near-vacuum surrounding each kilogram, and some of them probably settled on them, nestling in interstices between platinum atoms. And remember, we are talking about (in the case of the U.S. kilogram), a difference of 19 parts in a billion
Like ko_kyi, I am far readier to believe that this discrepancy is due to the inevitable imperfection of human manufacturing, storage, and measurement processes than some fundamental flaw in scientific theory.
Flaws in the cosmic chips that undergird our perception of the universe ~ something like that.