These definitions seem to be attributed to Donald Rumsfeld, former US Secretary of Defense. The attribution is usually derogatory, e.g. “Rumspeak”. But I think its great …
Known knowns – things we know we know
Known unknowns – things we know we don’t know
Unknown unknowns – things we don’t know we don’t know
Rumsfeld would add another relevant, telling category later: the unknown known, the kind of thing you think you know, based on information that seems solid but which in reality isn’t very solid at all. It’s the thing you think you know but that you actually do not.
Here is a video of Rumsfeld describing his uncertainty principle.
Iori Tomita began making transparent specimens while working as a fisherman. This has evolved into a project, the New World Transparent Specimens, which is as much art as it is science.
The method of making transparent specimens — enzymatically turning the protein transparent, dyeing the bones magenta and dyeing the cartilages blue — was established for scientific purposes to study the skeletal system. Tomita has taken the process and turned the result into art imitating life … or life imitating art … or the art of life. Whatever. Beautiful stuff.