Building a system of pulleys and winches with a rope and noose attached. Then, waiting for your girlfriend/boyfriend to walk through the door, ambush, and smack them over the head with a frying pan. Then, putting the pulley and winch arrangement into effect, hanging your partner up as they start to awaken from the blow to the head. While they are hanging by their neck, you get an erection and when they are just about to die as a result of asphyxiation, quickly drop them and bum them.

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.