Doubt: A History

The Torah says: "You shall not burn fire in all your dwellings on the day of Shabbat." The Mishnah of Tractate Shabbat, in the context of laws prohibiting cooking, states: "One who heats a metal pot may not pour cold water into it to heat [the water], but he may pour water into the pot or a cup in order to temper [the vessel]."[8] In the Gemara, Rav says it is permitted to add water to cool it, but forbidden to add water to mold the metal. Shmuel says it is also permitted to add enough water to mold the metal as long as that is not his intent, but if he intends to mold the metal it is forbidden. In a different context, Rav Sheshet says that "cooking" a metal filament is forbidden by analogy to cooking spices.
Thus, heating a metal filament might violate cooking, igniting a fire, or both. Rambam classifies heating metal as a subcategory of igniting a fire, but only if the intent is for metalwork.[11] Raavad disagrees with the first category but does classify it as cooking or as completing a product (Hebrew: מכה בפטיש, makkeh bapatish: literally, "striking the final hammer blow"). The majority of later authorities accept that heating a metal filament is forbidden as igniting a fire, and also agree that turning on an incandescent light bulb falls within the definition of this prohibition.

Nobel Prize-winning physicist Richard Feynman recounts that he was approached by young rabbis in a seminary who asked him "is electricity fire?". He replied, "no", but asked why they wanted to know, and was shocked that they weren't interested in science at all, but just wanted to interpret the Talmud. Feynman said that electricity was not a chemical process, as fire is, and pointed out that there is electricity in atoms and thus every phenomenon that occurs in the world. Feynman proposed a simple way to eliminate the spark: '"If that's what's bothering you, you can put a condenser across the switch, so the electricity will go on and off without any spark whatsoever—anywhere.' But for some reason, they didn't like that idea either"

Yeshiva Boys