This might not mean a lot to an American, but Canadians might be interested to learn that the kilogram is getting a new definition.
For World Metrology Day -- the annual observation of scientific measurements -- they're redefining the metric weight.
Until now one kilogram weighed as much as the prototype kilogram, a hunk of platinum-iridium alloy kept in France.
The problem is, over time, that hunk has lost weight equivalent to a human eyelash.
So from now on, the kilogram will be based on an equation called the Planck constant, which will never change.