Rabbi Michael Broyde & Rabbi Howard Jachter
The topic of electricity in halacha is unique to our generation since there are no direct precedents in the Talmud or rishonim and the halachic discussion of this topic has been ongoing for less than 100 years. It is only since the technology developed and appliances became electrically poweredthat many of these questions arose... Over time many works were printed and it has become an established part of rabbinic literature. ("Electricity," Encyclopedia Talmudit 18:642).
The advances of technology have posed practical challenge to decisors throughout the ages. One of the hallmarks of Jewish law is its ability - and desire - to assimilate technological advances into thepractices of observant Jews. The application of ancient and venerated principles of halacha to new situations has been, and remains, one of the essential tasks of modern decisors of Jewish law. In the last one hundred years, this task has become considerably more difficult due to the rapid and frequent changes in the state of technology.
This article surveys halacha's response to one of thetechnological breakthroughs of the last 150 years: the invention of electricity. In particular, it explores halacha's understanding of the use of electricity on Shabbat and Yom Tov within the rubric of prohibited work (melacha).1 The technological revolution caused by the widespread use of electrical appliances has led to great discussion and debate within halachic circles. Thousands of monographs,responsa, and books have been written by halachic authorities in the preceding decades relating to the use of electricity on Shabbat and Yom Tov.2
This article is divided into five sections. The first discusses the basis for the prohibition of turning on or off incandescent lights on Shabbat. The second addresses the use of electricity where no light and heat is produced (e.g., turning on a fan). Thethird discusses the differences between Shabbat and Yom Tov for purposes of the rules developed in sections one and two. The fourth analyzes various specific appliances in light of the rules developed, and the fifth discusses various issues relating to the use of timers to control appliances on Shabbat and Yom Tov.
I. Incandescent Lights on Shabbat
A. Turning On Incandescent Lights DuringShabbat
One of the earliest issues involving electricity found in halachic literature was the permissibility of turning on an incandescent light on Shabbat.3 The overwhelming majority of the decisors maintain (for reasons to be explained) that turning on an incandescent light on Shabbat violated a biblical prohibition.
The Mishnah (Shabbat 41a) rules:
One who heats a metal pot [literally, a boiler]may not pour cold water into it to heat it; however, one may pour water into the pot or a cup in order to temper it.
The Talmud (Shabbat 41a-b) in discussing this mishnah states:
Rav Says this mishnah is only ruling [that it is permitted to pour water into a heated pot] when the water temperature is modified, but if the metal is hardened it is prohibited [to heat the metal]. Samuel says this ispermitted even if hardening occurs. [The Talmud replied] if the primary purpose [of heating the metal] is to harden the pot, nobody permits it heating.
So, too, the Talmud (Yevamot 6b) declares:
Rabbi Sheshet rules that the cooking [burning] of a wick [of metal], just like the cooking of spices is prohibited on Shabbat [because of the biblical prohibition to cook on Shabbat].
Rambam codifiesthese rules (Shabbat 12:1) by recounting:
One who heats a metal bar in order to temper it in water has violated the biblical prohibition of lighting a flame.
Ravad immediately disagrees as to the nature of the biblical prohibition and rules that heating a metal bar until it glows is prohibited because of either cooking (as Rambam elsewhere appears to classify it (Shabbat 9:6)) or as ma'keh...