Mishna B'rura 264:1 says: The reason for the invalidity of [certain] wicks and oils [for the Shabas lights] is that they do not shine well and we're afraid he may tilt the lamp so the oil within ...
Background: Among the things one may not move on Shabbat (Muktzah) is a utensil which is primarily used for a forbidden activity on Shabbat (a classic example is a hammer). This is called a "Keli ...
I'd be very interested to know if anyone has definitive advice on which types of light bulbs are considered an issur d'rabbanan (Rabbinic prohibition) vs an issur d'oraita (Torah prohibition) to turn ...
May one activate a glow stick on Shabbos? (In other words, is there a prohibition on activating the chemical reaction which produces the light in a glow stick?)
What is the problem with shaking one of the no battery/shaking flashlights which is on on shabbos?