OK, for the confused:
They are making reference objects that can be put on precise scales to calibrate the scales.
You can’t do that by making something, and rubbing off bits until it weighs the right amount, because you need a scale to weigh it, and that scale needs to be calibrated.
So you make something of a material that of a known density, and make it to a known volume. You choose a sphere because its volume can be measured by only one measurement (diameter).
Of course, you need to calibrate the “”calipers” you measure it with, but that kind of calibration is absolute, with devices that use known wavelengths of certain atomic vibrations. They count the number of wavelengths across the diameter.
Then, you put the ball on the “mother” scale, and cabibrate the scale. That can be used to weigh test items that are sent in from other precision scale owners, so they can be told how much their sample weighed. Or, the balls may be taken on tour, rented out. (Precision instrument calibration is a big business.)
You see, brilliant scientists and engineers rarely do things that are dumb. It’s just that news reporters can make smart stuff sound dumb with inadequate reporting. Like here, when they take down other people’s quotes and explanations, instead of actually explaining the concept.
I’m not confused, just sarcastic.
Thank you.
And on a related note, I really wish the US would have adopted the metric system. Seriously! It just makes sense.
Yes, but it still depends on an “actual physical object”.
the balls may be taken on tour, rented out.
I hear Bill is doing that, and now Hillery! wants them back
in time for the campaign.
“Or, the balls may be taken on tour, rented out.”
I thought that was illegal in most states????