Saturday, August 22, 2009

Meet the new kilogram. Same as the old kilogram?

If you think academic standards are troublesome, take a look at this story about our favorite standard for mass:

The kilogram has a weight-loss problem

And settle down: I know there's physics foul in the headline, itself. It's good that you noticed, but go ahead and take in the substance of the story.

Units of measure continue to evolve. Once the province of royal body parts, then Earth and water, we seek now to establish units relative to universal constants.

And it is good.


Joseph Smidt said...

Yeah, I've often mused about about what will happen as the mass of that object changes ever so slightly. Great post!

stevieray said...

This issue "weighs" heavily on my mind but I'm just going to wait for the Watt Balance APP.

Eric W. said...

I seems like there ought to be a less volatile way of defining a certain mass than taking an ice cream scooper and saying "yup, that's a kilo, bag it and ship it." The meter is defined in terms of the distance traveled by light during a certain time; the second is defined by the duration of a certain number of periods of radiation emitted by a caesium atom; isn't there some way you could define a mass using some universal phenomena that doesn't change?

But what do I know, I don't have a PhD.