Halloween began as an ancient pagan Irish fall festival, Samhain: pronounced Samantha and sometimes abreviated to Little Sam---not that there ever was a Great Sam. The Scottish and English claims to have originated the festival are complete fictions.
The Christian missionaries (you know St. Patrick and the boys) not wanting to miss out on a good thing---dressing up and trick-or-treating---liberated Samhain from the pagan calendar and added to the Christian calendar as the Eve before All Hallows (or All Saints) Day. The day is little remembered---but will be much better known when the Saints come marching in---but the Eve has take on a life of its own as Hallows eve or Halloween.
Spooky Field.
This is a pure physics in-joke. I saw it on a blackboard---which oddly enough was green---in 2006 and liberated it for myself. But the anonymous original had a sly je-ne-sais-quoi that I've not been able to capture.
Dante & Virgil in Hell.
They are right at home.