Shabbat Phone


A medical scenario: It is Friday night. Dr. Shabtai sits down to eat the Shabbat meal with his family, and suddenly, the phone rings! Should he run to answer the phone? Clearly, a mortal threat takes precedence over the prohibitions of Shabbat, even when there may be a doubt about the nature of the danger. But experience has shown that most phone calls are not true emergencies – one patient has forgotten where to buy medicine, another one wants to check when he has an appointment, the doctor who will replace Dr. Shabtai on call (a nonobservant Jew) wants to tell him that he will be a few minutes late, and so on. If this is really typical, shouldn't we do everything we can to decrease the Shabbat desecration?

 A security scenario: It is Shabbat afternoon. The rotation of the guard has been delayed because a military briefing is taking longer than planned. The soldiers on duty are anxious – their replacements are more than five minutes late. The obvious solution is an angry phone call to the command post. But what if the duty soldier is a Hesder student who has explicitly asked not to be contacted by phone for matters that are not directly connected with military operations? What can be done? Will it always be necessary for a nonobservant soldier to be on duty at the command post? How can the Shabbat desecration be reduced?

   The Zomet Institute has met this important challenge by developing the Shabbat Phone, which works on a new technology technique of "modified current" which is permitted on Shabbat without any limitations.

   The number keypad is a touch keypad (capacitance sensing). Touching the sensor with a finger changes the capacitive properties and the frequency of the sensor, because of the electronic properties of the human body. There is no need to open or close an electric circuit. The halachic approval for this action is based on the fact that the prohibition of using electricity on Shabbat is to open or close a circuit (this is a violation of the action of Boneh – construction – or Molid – "giving birth" to something new). But modifying a property setting (current, voltage, frequency, or capacitance) of an existing current is permitted. The change-sensor applies a voltage to electrical devices connected to it. In the Shabbat mode the 'Send' button for dialing the number and lifting or hanging up the receiver works on the principle of gramma (indirect operation). 

 For details and prices, contact The Zomet Institute.

  Shabbat Phone Instructions
Jump to page content