Darling, they’ve redefined the kilogram.
Once it was a thing. A real thing:
a platinum-iridium cylinder
weighing 2.2 pounds. A thing they kept
in France in a high-security vault. A thing
they could compare to other such weights
kept in vaults all around the world.
As if to lock a thing up is to keep it
from changing. Forever.
Now we know better.
Every thing changes. It’s the nature
of things. Even prototypes lose atoms,
no matter how sterile the room
in which they’re kept.
The loss may be only the weight
of a single eyelash that no longer
bats itself at time.
Over time, it matters.
Now, understanding the volatile nature of things,
they’ve made the kilogram an idea—
a simple truth—by tying its definition
to Planck’s constant. How the world loves
a constant.
Darling, know that I am a thing.
I have wanted to be constant,
unwavering, true, but I lose things.
I gain things. I change innumerable
times a day. I am never the same woman
as I was yesterday. Each time we speak,
I swell, I leak. I will always love you
not the same. There is more at work than gravity.
It’s the way the heart is made.
I want to make you promises.
Like constancy. Like forever.
I promise that I’ll change.
Like the old kilogram. Like weather.
https://www.cnn.com/2018/11/13/world/kilo-measurement-scli-intl/index.html