宇宙射線

宇 = 于 + 宀 : Yu the Great (yu) just earned her PhD in the space station (Ø3) and is proudly putting on her graduation cap (宀). She was measuring cosmic (宇) rays by investigating the traces they left in a honey jar (于) and is demonstrating her experiment for the camera.

宙 = 宀 + 由 : James II of England (zh) finds that he forgot his cuba libre (由) in the outhouse's bathroom (ou4) during the last party. A lot later he finds that in the glass a whole new universe (宙) has developed. He writes a thesis about it and earns a PhD, proudly wearing a graduation cap (宀).

射 = 寸 + 身 : Sherlock Holmes (sh) is ready for takeoff in the elevator's bathroom (e4) and stands in front of a rocket on a launch pad (mnemonic symbol for 射). As there are many journalists, Sherlock prepared to be extra fancy and wears a tight body suit (身). He winks to the photographers and makes the thumbs up (寸) sign.

线 = 戋 + 纟 : Mnemonic symbol: barbed wire.

线 = 戋 + 纟 : The silk worm wants to use the floating tank in the anthill's bathroom, but there's already Marie Curie inside—and she secured the tank by setting up barbed wire all around it.