What bothers me about this specific question, apart from it being dated, is that it breaks the rules of these kind of riddles. They’re implied to be in a sort of frictionless sphere universe, the whole preposition is silly except as an abstract puzzle. To then rely on the physical properties of real lamps is cheating. You’re supposed to ignore all the real-world aspects of the setting except that one.

Capital “I”? Heathen!

unstable-final-release2-usethisone

It’s a joke on the “main” name vs. the main() function. That’s normally considered the entry point, but really _start() is the OG entry, used by the runtime to do setup before calling main().