…reading the following sentence causes me to question my dorky credentials:
A [re-]definition [of the kilogram] based on Planck’s constant could mean scientists would determine a certain number of photons of light of a certain frequency would correspond to a kilogram.
To which I can only say “huh?” I mean, I realize that photons have mass, at least in theory, else a solar sail could never work, but, uh… I don’t know, I just can’t wrap my brain around that sentence. Maybe I should get more sleep and drink more coffee. 
Anyhow, the article on redefining the kilogram is interesting. I had no idea its origin was so arbitrary.
(þPaul Hsieh)