When you say something really stupid, or you are excepted to know something but you don't, a friend may exclaim that you deserve a slap for you ignorance. The phrase is usually followed by a harsh, quick, blow to the cheek. Sissy crying may follow along with a "WTF? Why'd you do that, man?"

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.