Heisenberg's
uncertainty
principle

You can know the exact position,
or you can know the exact velocity.
You can not observe both at the same time.
Simply stated, if you have having
a moment with your kitty on your shoulder,
do not reach for your camera.
Her head came up and the moment ended.
I could no longer measure her exact position.
However, I did observe her velocity.
Two seconds after this,
she was on the floor
looking for more food.
So much for moments.