Electricity on Shabbat
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- 1 Electricity on Shabbat
- 2 Using Electric Appliances
- 2.1 Phones
- 2.2 Recorders
- 2.3 Electric Blanket
- 2.4 Automatic Doors, Doorbells, and Door Chimes
- 2.5 Shabbos Elevators
- 2.6 Refrigerators
- 2.7 Security Cameras
- 2.8 Motion Sensor Toilets
- 2.9 Motion Sensor Lights
- 2.10 Hearing Aids and Microphones
- 2.11 Medical Monitoring
- 2.12 GPS
- 2.13 Dishwashers
- 2.14 Watches
- 3 Setting Timers before Shabbat
- 4 Sending Email on Friday
- 5 Reading by candle light versus light bulb
- 6 Using a light bulb for Shabbat Candles and Havdala
- 7 Static Electricity
- 8 Yom Tov
- 9 Using a Smart Phone on Shabbos
- 10 The Shabbos App
- 11 Electric Sensors
- 12 Credits
- 13 Sources
Electricity on Shabbat
- It is forbidden to turn on any electric device whether it is plugged into the wall or runs on batteries. 
- According to many poskim it is Biblically forbidden to turn on an incandescent and fluorescent light bulb. However, if one needs to turn on a light for someone who is mortally sick (see Medicine on Shabbat) one should turn on a fluorescent instead of an incandescent light bulb. 
Changing an Existing Current
- In a theoretical discussion, according to those poskim who hold that closing a circuit is a Biblical violation of Boneh or Makeh Bpatish, changing a current could be a Biblical violation of Shabbat and is certainly forbidden.
- However, according to Rav Shmelkes and Rav Shlomo Zalman Auerbach, who believe that the issue with closing a circuit is a rabbinic one of introducing a new feature into the wire, there is no technical issue with changing the amount of energy in a circuit. Yet, some argue that even according to Rav Shmelkes's approach changing a current should be forbidden.
Using Electric Appliances
- According to many poskim it is Biblically forbidden to turn on an oven or warming plate. 
- In Israel, the widespread minhag is to leave electric appliances running on Shabbat even though the electric companies are run by Jews who violate Shabbat. 
- It is forbidden to turn off or dim an electric light. 
- It is forbidden to turn off any electric appliance. 
- It is forbidden to pick up a phone off the receiver, speak on a phone, or return the phone to the receiver on Shabbat. 
- Some say it is a good practice to unplug the phone before Shabbat so that if someone calls on Shabbat one won't hear it ring. 
- It is forbidden to speak into a tape recorder even if the recorder was turned on before Shabbat. 
- It is permitted to use an electric blanket on shabbat, provided one does not move the knob that adjusts it. It is proper to place scotch tape on top of the knob in order to prevent oneself from accidentally adjusting the blanket on shabbat. 
Automatic Doors, Doorbells, and Door Chimes
- It is forbidden to enter an automatic electric door which opens with a motion sensor unless there is a need to enter a hospital with an electric door for the needs of a patient who is in a life threatening situation. 
- It is forbidden to press an electric doorbell on Shabbat. 
- Some say that it is forbidden to open a door that will cause an electric chime or bell to go off.
- It is forbidden to use a regular elevator on Shabbat. Some allow using a 'Shabbat elevator' which stops at every floor, while others forbid, and some say one may go up in the Shabbat elevator but not down. It is forbidden to touch the elevator doors when they are closing. 
- Some poskim write that only elderly and sick people should use shabbat elevators 
- Some poskim permit opening a refrigerator door only when the motor already is running, while many poskim hold that one may open the door even if the motor is off.  If one forgot to disable the light he is permitted to ask a gentile to open or close the refrigerator for him. 
- Many poskim permit walking in an area where there surveillance cameras will capture a person’s image as long as he does not intend to be recorded. 
- Walking in the Kotel Plaza according to a minority opinion is forbidden on Shabbat but many poskim are still lenient.
Motion Sensor Toilets
- Many poskim permit using an electrical automatic toilet if no other toilet is available. 
- If someone has a grama system (for example Zomet's grama alarm) set up so that when the door is closed a mechanism will close an alarm system after some time, according to some poskim it is permitted to use it for a significant need.
Many poskim would permit closing a door that sets up an alarm system that only go off after some time as it is considered grama.
Motion Sensor Lights
- Some poskim permit walking in an area where a motion sensor will turn on a light provided that one does not intend to turn on the light if there’s no other way to walk. 
- If one is already in the room that has a motion sensor and the lights are on and as long as one is inside the lights stay on one may stay in the room.
Hearing Aids and Microphones
- Someone who's hard of hearing may use a hearing aid which was turned on before Shabbat. It's proper to attached a piece of scotch tape on the button so one doesn't come to turn it off on Shabbat. 
- It is permitted to use a hearing aid on Shabbat even if it automatically adjusts the volume depending on the loudness of the environment.
- It is forbidden to use a microphone on Shabbat.
- A patient hooked up to a monitor that measures his heartbeat and the like doesn't have to be concerned for its functioning on Shabbat.
- A person who needs to wear an oxygen mask with monitors to sleep may do so on Shabbat.
- Someone with Alzheimer's or an Autistic child who needs to wear an electronic GPS device to track his location and even alert a responsible party in cases of danger may do so on Shabbat.
- It is forbidden to set a timer before shabbat to automatically operate a dishwasher on shabbat. 
- Most poskim are lenient to allow wearing an automatically winding watch if it is still running.
- According to many poskim the same is true of an electric automatic watch that it may be worn on Shabbat. However, some hold that it is forbidden to wear an electric automatic watch or solar powered watch on Shabbat.
- Winding a watch that stopped on Shabbat is forbidden. 
- However, if it is still running some poskim hold that it is permitted to wind it on Shabbat, however, others hold it is forbidden.
- Wearing a smartwatch or fitbit on Shabbat is forbidden.
Setting Timers before Shabbat
- It is permitted before Shabbat to set a timer for lights or other electric appliances to go on or off on Shabbat.
- One may set an alarm clock before Shabbat even though it will make noise on Shabbat.  See Making music on Shabbat.
- Some forbid leaving a digital photo frame which presents a slideshow of pictures set from before Shabbat to continue during Shabbat. 
Sending Email on Friday
- Strictly speaking it is permissible to send an email on Friday afternoon from America to Israel when it is already Shabbat in Israel or on Saturday night from New York to California where it still is Shabbat but it's praiseworthy to avoid it. However, one may not send it to a non-observant Jew who may look at it on Shabbat. 
Reading by candle light versus light bulb
- One isn’t allowed to read by a candle (wick in oil) on Shabbat because there is Gezerah that one will come to tilt the wick. 
- There is a dispute whether the Gezerah applies to a kerosene lamp. Thus, if one wants to read by a kerosene lamp on Shabbat, one should make a recognizable sign that says “Today is Shabbat” to remind oneself no to fix the lamp on Shabbat in order to satisfy all opinions. 
- One is permitted to read by wax candles 
- One is permitted to read by electric lights.  This is true even if there is a dimmer on the light which controls the amount of light. 
Using a light bulb for Shabbat Candles and Havdala
- Common consensus among the halachic authorities is to consider electricity as fire for the purpose of Shabbat observance. Just as lighting a fire is a Biblical violation of Shabbat, so too is the flipping of a switch which turns on a light. As such, many families are particular to place a covering over the light switches in the home in order to ensure that they are not switched on or off accidentally over the course of Shabbat.
- This concept has broad halachic ramifications and applications. For example, if a woman is without candles on a Friday afternoon, she may be permitted to simply turn on the electric lighting that normally lights up the home and even recite the usual blessing over this "lighting". This is because the light bulbs essentially accomplish the role that the traditional Shabbat candles are intended to serve. The electric lights actually become the Shabbat candles and one will discharge one's Shabbat candle lighting obligations with them. While such an approach should never be relied upon in normal circumstances, it is permissible in extenuating ones. Some authorities suggest that when making use of electric lights for one's Shabbat candles the accompanying blessing should be omitted.
- If one is forced to use the electric lights in one's home as the Shabbat candles they should be shut off momentarily and then turned back on in order for them to now be designated as the Shabbat "candles". Indeed, every week before the lady of the house lights her Shabbat candles, she should momentarily turn off the household lights and then turn on them back on. When she makes her blessing over the candles she should have in mind that her blessing include the electric lights as well which will also be providing light over the course of Shabbat. Those who are forced to use the electric lights instead of candles should endeavor to turn on even those lights which are not normally used in order for there to be some distinction that the electric lights are in honor of Shabbat. Even a desktop light could be used for this purpose. Some say that this only includes incandescent bulbs and not fluorescent.
- The issues are essentially the same with regards to Havdala and one may use an electric light in place of a Havdala candle in a time of need. In fact, it is reported that Rabbi Chaim Ozer Grodzinsky would always use an electric bulb for Havdala in order to demonstrate how strongly he felt that electricity is to be treated exactly like fire from the perspective of halacha. Nevertheless, there are those authorities who discourage the use of an electric light for Havdala. Among their opposition to it is the fact that the blessing recited upon the Havdala candle includes the word "fire" which seems to imply the need for actual fire, not merely light. As such a light bulb would not be acceptable according to this view. Even among the authorities who permit the use of electric lighting when needed many would disqualify the use of fluorescent bulbs as they work differently than standard light bulbs.
- According to most poskim, the unintentional creation of static electricity from clothes is not a halachic problem. 
- Most poskim agree that turning on or off an incandescent light on Yom Tov is forbidden rabbinically. Although in the past some poskim permitted turning on lights on Yom Tov, it was based on an incorrect assumption. Thus, the accepted minhag is to follow the poskim who say that it's forbidden. 
Using a Smart Phone on Shabbos
- Battery: The battery can get extremely hot from use - this can be a potential issur derabanon of making a fire (Mavir).
- Writing: Text that is typed and erased remains on the phones hard drive. This text potentially involves an issue of writing (Koseiv), erasing (Mochek) and improving the functionality of the phone (Metaken).
- Sounds: Sounds are made when a user notifies or is notified of new messages, etc. This is a potential issur derabanon of making noise (Hashma'as Kol) which is assur.
- Screen: Turning the screen on and off is similar to turning a regular light on and off - this can be an issur derabanon of making a fire (Mavir) according to some Poiskim. 
- Charging: When you plug the wall charger into or out of the phone constitutes a violation of creating or breaking a circuit which is forbidden.
The Shabbos App
This piece is in the process of being written since many details about the app are undisclosed. Also, see the discussion page.
- Rabbinic Approval: Firstly, let us point out that they don't present any rabbinic approbations. Saying it is muter before actually getting any approval is a big chutzpa to Orthodox Judaism which takes the rabbinic opinions very seriously. The rebellious elder who is unfit to legislate isn't considered "zaken mamreh" since he has no credibility, yet his audacity and disrespect to the rabbis is greater than the person who is fit to legislate and rebels.
- Grama: Having the app respond randomly in a delayed fashion is not permitted because of grama: 1) The grama is completely illusionary - immediately upon touching it sends signals to the phone and randomly it'll decide to respond, that's not grama at all. Internally, the input receivers and programming callbacks are triggered when the "soft keys" are pressed. Immediately, those signals and processes go into motion even though you might not see any visible result. 2) The entire idea of defining grama as a delay is very questionable. Rav Soloveitchik holds that grama is only when something is completely disconnected physically and temporally from the initial action. However, if a delayed result is the product of a series of a chain reaction or a process, that is all considered your original action. Accordingly, this would be forbidden. 3) Even if it is actually considered grama, grama is forbidden according to the Rama 334:22.
- Eino Kayama: Having the data erased hourly is not a reason to permit writing on smartphone. 1) Writing in a non-permanent fashion is still asur m'derabbanan. 2) It is not temporary - anything which lasts as long as you need it to last even if it is erased afterwards isn't temporary. 3) The quality of the writing is permanent. Even though when you write it you know that you'll erase it soon or you set up a system which will erase it soon, the writing in it of itself is permanent if not erased afterwards.
- Zilzul Shabbat: The Gemara Sanhedrin 46a describes a case in which the supreme court in Yerushalayim condemned a person who rode a horse on Shabbat. Even though technically, riding a horse on Shabbat is only a rabbinic prohibition, it is considered a serious infraction upon the sanctity of Shabbat. According to Rav Moshe and many gedolim this would be considered zilzul Shabbat. The burden of proof is upon the one trying to deviate from the standard practice to show that this isn't zilzul.
- Bottom line - a person should not use this app on Shabbat. If someone wants to become non-Orthodox (and keep half-shabbos) they're don't need to ask anyone's permission or pervert halacha to do so, but please don't pretend that this is actually Orthodox. 
- It is forbidden to speak to "Siri" or Alexa or another other voice activated electronic device on Shabbat.
- It is forbidden to walk in front of an motion sensor to open an electric door to cause it to open. If one needs to enter a door that is activated by a motion sensor he can walk immediately behind a non-Jew who is entering for his own benefit.
- Many poskim hold that it is permitted to walk in front of a motion sensor that will turn on a light in a lit place if one doesn't try to turn it on and doesn't care about it.
- It is forbidden to use an electric card key to open a lock on Shabbat.
- It is permitted to sleep with an electric blanket that is turned on before Shabbat and has any buttons or adjustable knobs covered.
- Special thanks to Rabbi Ari Enkin author of the Amot Shel Halacha series for his contribution to this article. If you would like to purchase his books please click here.
- A few halachot on this page are derived from the Halachipedia Article Issue 25 - Electronics on Shabbat.
- Menuchat Ahava 24:2 holds that the prohibition involved is that by completing the circuit one creates an electric current in the wire like there is a prohibition to create a fire (Molid) on Shabbat.
- There's is a lengthy discussion about which melacha is involved when using electricity. One suggestion is that it is a violation of Mavir (Lighting a fire). See a very interesting comparison of Rav Henkin (Edut LeYisrael p. 151) who seems to compare an electric current to movement of electrons when a person starts to walk or hits a piece of metal and says that’s not called a fire unless the fire is visible. Rabbi Yitzchak Schmelkes Beit Yitzchak Hashmatot to YD 2:31, says that completing a circuit constitutes a rabbinic violation of molid. In Beitza 23a the gemara prohibits one from adding scent to a garment because of molid. Similarly, the Beit Yitzchak argues, introducing electricity into a device is molid.
- Rav Shlomo Zalman Auerbach Minchat Shlomo 1:9 says that the two are different because adding a scent to a garment is adding something to it, that it never had before. Electricity on the other hand was put into this device to be activated and deactivated often. Rav Shlomo Zalman concludes that even without light, the halachic precedent has been established to be concerned for a rabbinic prohibition with the activation of electric device. The Chazon Ish OC 50:9, rules that completing a circuit constitutes a violation of the melacha of boneh, building and deactivating a device by opening the circuit would constitute a violation of soter, destroying. Another possibility raised by Heichal Yitzchak 43 is the prohibition of makeh bepatish, delivering the final blow, completing any item in a way that now renders it beneficial.
- Menuchat Ahava 24:3-4. Incandescent bulbs and halogen bulbs contain filaments that can get extremely hot. The Gemara Shabbat 42a, discusses the concept of gachelet shel matechet, a glowing hot piece of metal. The Avnei Nezer OC 229 based on the gemara in shabbat 42a says that according to most Rishonim, heating a piece of metal to the point that it is glowing hot is a biblical violation of havarah, kindling. Rav Shlomo Zalman Auerbach in Minchat Shlomo 1:12, says that since turning on an incandescent bulb ignites a glowing hot metal filament, it would be in violation of havarah from the torah.
- Kedushat Hashabbat pp. 22-23 quotes Rav Elyashiv as explaining that according to the Chazon Ish it would still be a Biblical violation of Shabbat to change the current since the change creates something new. He explained that it isn't a physical building and an addition to the building that we're discussing, rather it is an abstract type of building that is created when a useful circuit is closed and the same is created when the current is changed. Rav Asher Weiss in Minchat Asher 1:32 who agrees with the Chazon Ish that it is considered Makeh Bpatish to close a circuit is concerned for the prohibition of Makeh Bpatish when changing the current.
- Minchat Shlomo 1:9. One precedent for such an approach is found in the Maharil (Etrog no. 15). He explained that if a person has an Etrog that he took out of a wool cloth on Yom Tov he can return it back to the wool even though it’ll become scented on Yom Tov because of its contact with the Etrog since the wool was already scented beforehand. It is only molid to introduce a smell but not to increase more of what is already existent. This is quoted by the Magen Avraham 511:11 and clarified further by the Shulchan Aruch Harav 511:7.
- Kedushat Hashabbat pp. 22-23 quotes Rav Elyashiv as explaining that changing a current is forbidden even according to the Beit Yitzchak. Introducing electricity in a wire isn't comparable with scent in a clothing since an increase of scent is an addition of quantity but more electricity is a qualitative addition and forbidden because of molid.
- Menuchat Ahava 24:3
- Menuchat Ahava 24:1
- While Melamed Lehoil OC 49, Kuntres Gorem HaMalot 185, Maharsham 2:146, Minchat Shlomo pages 85-88 and pages 107-109, Shemirat Shabbat Kehilchatah 13:1 all say this prohibition is rabbinic and this is the conclusion by Rabbi Jachter and Rabbi Broyde, Machaze Avarham OC 41 and Beit Yitzchak Hashmatot YD 2:31:8 say it is a violation from the torah and this possibility is also raised by Rav Shlomo Zalman.
- Menuchat Ahava 24:5
- Menuchat Ahava 24:6,8,9.
- Lifting the Phone: In addition to the problems of circuits or the problem of a light flashing when lifting the phone, Rabbi Levi Yitzchak Halperin in Maaseh Choshev 1:60 argues that starting the dial tone violates the rabbinic prohibition of making a noise, or hashma'at kol.
- Dialing: In addition to the problem of circuits being built by dialing a phone, Rabbi Benzion Meir Chai Uziel Mishpatei Uziel 1:13 writes one violates makeh bipatish, delivering the final blow but Chacham Ovadia Yosef in Sh"t Yabia Omer 1:20 disagrees because the phone is a functional object even before one dials. Rabbi Yitzchak Schmelkes Beit Yitzchak Hashmatot YD 2:31 and Rabbi Chaim Ozer Grodzinski Achiezer 4:6 say that one violates the rabbinic prohibition of making a noise, hashmaat kol, in the place where the phone rings. Rav Shlomo Zalman Auerbach Minchat Shlomo pages 75 and 76 argues that maybe since this is indirect and rabbinic one may be lenient. In the Sinai 5705 journal page 152 he argues that since the noise is made in another's house it is possible that the rabbinic prohibition doesn't apply at all because you would never come to fix the object in someone else's house.
- Talking into the Phone: Rabbi Yitzchak Schmelkes Beit Yitzchak Hashmatot YD 2:31 asserts that talking into the phone is also a problem of making a noise, or hashmaat kol. Rabbi Shlomo Zalman Auerbach Minchat Shlomo page 67 and Rabbi Eliezer Waldenberg Tzitz Eliezer 1:20:10 both disagree based on the Rama 338:1 where he rules that the prohibition of making a noise doesn't apply when this is done through a human voice. Since talking into the phone increases the electrical current being used, Rabbi Yitzchak Yaakov Weiss Minchat Yitzchak 3:38 and 3:60 prohibits based on that. Rav Shlomo Zalman Auerbach (Minchat Shlomo page 110) writes that the increase in current is not a problem in appliances where heat is not created.
- Menuchat Ahava 24:10
- Menuchat Ahava 24:13, Yechave Da'at 2:57. Igrot Moshe OC 3:55 forbade recording a shiur on Shabbat or the like since speaking into it might cause the voltage to increase in the circuit and also it might be considered molid to have something new introduced into the memory of the recorder.
- Igrot Moshe 3.50, Menuchat Ahava 1.24.37, Yechave Da'at 2.49
- Shemirat Shabbat Khilchata 40:19
- Menuchat Ahava 24:14
- Chelkat Yakov 1:78 writes that it is forbidden to enter a door that will cause an electric chime to go off. He explains that even though it is a Shinuy, Melacha Sheino Tzaricha Lgufa, and a Pesik Reisha Dlo Nicha Leh since the concern is a Biblical one of Maavir it is prohibited. He was discussing a device that created sparks when the circuit was closed and he considered those to be a Biblical violation of Shabbat. He also points out that perhaps this isn't considered a Shinuy since that is how the system is set up to be used. However, regarding Yom Tov he is lenient since Molid Esh is only derabbanan. Shemirat Shabbat Khilchata 23:57 agrees that it is forbidden to enter a door with an electric chime or bell.
- Shemirat Shabbat KeHilchata 23:49 (in the new edition 23:58) permits uses a Shabbat elevator on Shabbat. Sefer Maliyot BeShabbat (chapters 1 and 7) holds that one may go up in the elevator but not down. Menuchat Ahava 24:15-6 concludes that one shouldn't use the Shabbat elevator to go up or down unless there is a great need in which case he is lenient to allow going up in the Shabbat elevator. Rav Yosef Henkin (Edut LeYisrael p. 121) rules that for someone who's weak to do a mitzvah such as daven with a minyan, one can be lenient to use an elevator on Shabbat as long as the non-jew is the one who presses the button and not a Jew. He then says one doesn't need to protest someone who is lenient if the non-Jew is pressing the button, but a pious person (baal nefesh) would be strict.
- Or Letzion 2.47.36
- Rav Shlomo Zalman Auerbach (Minchat Shlomo 1:10) permits opening the refrigerator at any time because completing the circuit to run a motor may not involve any melacha at all, and even if it is, it is permitted because it is grama. He says that he’s not sure that it should be considered a psik reisha d’lo nicha lei as one doesn’t want the hot air to cause the motor to run sooner, because one also does want the motor to run so that the food doesn’t spoil. Tzitz Eliezer 8:12:4, 12:92, Rav Moshe Feinstein (quoted by The Shabbos Home vol 2, p. 482; see, however, Igrot Moshe 2:68), Rabbi Mordechai Willig (“Halacha Engages Modernity Part 8,” min 18-22), Rav Benzion Meir Chai Uziel in Piskei Uziel 15, and Rav Joseph B. Soloveitchik quoted by Rav Aharon Lichtenstein agree. Rav Willig commented that the minhag in America is to be lenient. Rabbi Simcha Zellig Rieger in Hapardes (1934 volume 3 p. 6) is one of the earliest rulings on this issue and was lenient to allow opening the refrigerator based on the opinion of the Aruch that pesik reish dilo nicha leih is permitted.
- In defining grama, Rav Hershel Schachter (“Electricity on Shabbos,” min 73-6) explains that according to many achronim who understand grama as a delay in time, it isn’t even a psik reisha to open a refrigerator if the motor will turn on at a later time, while according to Rav Soloveitchik, who defined grama as a total disconnect in action, if it was certain that opening the door would cause the motor to go on any earlier, perhaps it would be forbidden to open the door when the motor wasn’t running based on koach achar m’urev bo. (See B’Ikvei HaTzon siman 7).
- On the other hand, Rav Ovadia Yosef (Yabia Omer 1:21) assumes like Rav Shlomo Zalman that it is grama, but thinks that completing a circuit may involve an issur deoraitta of hav’ara. He also is uncertain if this should be considered a psik reisha d’lo nicha lei and concludes that it is permitted, but it nevertheless is proper not to open the door unless the motor is running. Har Tzvi 1:151, Menuchat Ahava 24:19, and Rav Henkin (Edut LeYisrael p. 122) agree that although it is permitted, it’s proper to be strict.
- Lastly, Chelkat Yaakov O”C 76 argues that while it may be a psik reisha, perhaps it is not considered grama since this is the intended normal way it is used. Therefore, he rules that one may only open the door when the motor already is running. Minchat Yitzchak 2:16 and 3:24, Az Nidberu 2:36, Sh"t Igrot Moshe 2:68, 4:74, and Mishnat Rabbi Aharon 1:4 agree.
- Shemirat Shabbat KeHilchata 10:12, Orchot Shabbat (vol 3 p. 62), and The Shabbos Home (p. 482) quote the two approaches but do not give a final ruling. Shemirat Shabbat Kehilchata (10:12) recommends setting the refrigerator to a timer.
- Rabbi Willig (min 33-35) says that using a water fountain on Shabbat depends on how long it takes for the motor to turn on. He mentions that one shouldn't use a water fountain which clearly will have the motor go on with a single regular use. However, he did not say this as a definitive ruling but in passing.
- See Zomet.org or star-k.org for details on other problems with refrigerators.
- Yalkut Yosef Chelek 4 Shabbat 5 page 229, Iggerot Moshe OC 2:68, and Shemirat Shabbat Kehilchatah 3:31. The aforementioned poskim all reject the opinion of the Aruch either because psik reishe dilo nicha leih is not permitted and they also argue that it is nicha leih because had it not been shabbat one would certainly want the light to help him see (see minchat shlomo page 91), and say that one should get a gentile to do it for him. Rabbi Broyde and Rabbi Jachter permit even asking a Jew who doesn't know that the light will turn on as this would fall under the category of mitasek. Iggerot Moshe OC 2:68 and Shemirat Shabbat Kehilchitah 31:1 also permit hinting to the gentile to disable the light so that the refrigerator could be used for the remainder of shabbat, but not telling him directly.
- Rabbi Mordechai Willig (“Halacha Engages Modernity Part 8,” min 48-49) agrees that it is permitted to walk in an area where there is a surveillance camera because unlike the light motion sensors, a person doesn’t benefit from the being videoed by the surveillance camera and thus qualifies as a psik reisha d’lo nicha lei which is permitted for a d’rabanan prohibition. Rav Shlomo Zalman Auerbach, (cited by Rav Zalman Nechemya Goldberg in Ateret Shlomo vol 6, p. 57), Yabia Omer 9:35, and The Shabbos Home (p. 489) agree.
- Rabbi Hershel Schachter (“Electricity on Shabbos,” min 62-8) explains that if one is doing an action that is physically disconnected from where the melacha is occurring, it isn’t considered a psik reisha. Thus, Rav Schachter says that there’s what to rely on to permit walking in an area where there is a surveillance camera or a motion sensor which will turn on a light as long as one doesn’t have intent to be videoed or turn on the light.
- Sh"t Besel Chachma 6:65 suggests that walking in a place where there are surveillance cameras isn't considered Koteiv whatsoever and is no different than looking in a mirror on Shabbat.
- See the lenient opinions in the previous footnote. However, Rav Elyashiv (Or HaShabbat v. 25 p. 157) held that walking in the Kotel Plaza on Shabbat is forbidden since one does benefit from the added security with the surveillance cameras and as such it isn't considered an unintentional action.
- Rabbi Josh Flug (Sukkot To Go 5770, p. 27) writes that it is certainly permissible to use a toilet with an automatic flusher if no other restroom is available because most assume that using electricity is prohibited only d’rabanan and therefore is permitted for kavod habriyot. He says that perhaps it is even permitted if going to the non-automated toilets is inconvenient, since it may be a psik reisha d’o nicha lei on a issur d’rabanan.
- Practical Laws of Shabbat (Rabbi Rafael Soae, p. 335) quotes Kedushat HaShabbat (Rabbi Moshe Harari p. 79) who says that if there’s no other bathroom available other than one which has toilets that automatically flush when one moves away, one may use the toilet because of Kavod HaBriyot.
- Rabbi Yisrael Belsky in Shulchan HaLevi 7:7 permits using this type of bathroom if there is no other bathroom available, but if there’s another option, he forbids using the electrical toilet. Rabbi Aryeh Lebowitz (“Using Automatic Bathrooms on Shabbos”) quotes Rav Belsky as saying that kavod habriyot would not be a leniency in order to wash one’s hands with an automatic sink.
- Minchat Shlomo 2:60:20
- Sheivet HaLevi 9:69 permits walking in an area where there is a motion sensor that will activate a light, such as those attached to the outside of buildings. He explains that davar she’eino mitkaven refers only to when one does an action that may cause an unintended melacha. If, however, one is walking normally and makes no motion in order for a melacha to occur, it is not even a psik reisha as long as one’s intent isn’t to turn on the light. Orchot Shabbat (p. 79) quotes Rav Elyashiv and Rav Nissim Karlitz who say that since one doesn’t have a direct connection to the melacha and doesn’t care about the light, it’s not called melechet machshevet. The Shabbos Home (p. 489) agrees.
- Rabbi Mordechai Willig (“Halacha Engages Modernity Part 8,” min 50-60) challenges this line of reasoning because it should be considered a psik reisha d’nicha lei and turning on a light might be deoraitta. Furthermore, The 39 Melachos (p. 1215) says that if one can’t avoid walking in a place that will turn on a light because of a motion sensor and the streets are dark so that one will benefit from the light turning on, one shouldn’t leave his house! He does permit one to walk past such a motion sensor if he closes his eyes at the time when the light will turn on because in such a case then it is not considered niche lei, even if one will open one's eyes right afterwards.
- On the other hand, Rabbi Hershel Schachter (“Electricity on Shabbos,” min 62-8) explains that if one is doing an action that is physically disconnected from where the melacha is occurring, it isn’t considered a psik reisha. Thus, Rav Schachter says that there’s what to rely on to permit walking in an area where there is a surveillance camera or a motion sensor which will turn on a light as long as one doesn’t have intent to be videoed or turn on the light.
- Minchat Asher 1:31:5
- Menuchat Ahava 24:11, Sh"t Yabia Omer 1:19(19), Minchat Yitzchak 2:17-8, 3:41, Minchat Shlomo 1:9, Tzitz Eliezer 6:6, Shemirat Shabbat Kihilchita 34:28. Rav Shlomo Zalman in his teshuva Minchat Shlomo 1:9 is dealing with microphones and concludes that a change in a voltage of a current isn't molid but still using a microphone is forbidden since it is audible and is a violation of Avsha Milta, degrading Shabbat. However, regarding hearing aids the Shaarim Metzuyim Bhalacha cites a letter from Rav Shlomo Zalman Auerbach that it is permitted to turn up a hearing aid on Shabbat and as there's no issue of muktzeh with a hearing aid that is already on. Chelkat Yakov 119 forbids using a hearing aid on Shabbat because he holds that connecting the circuit is Biblical as it created sparks (according to the science of that time which is no longer the case) and he leaves it unresolved if it is permitted to use if was already functioning before Shabbat.
- Rav Asher Weiss in Minchat Asher 1:31:1 writes that using hearing aids which automatically adjust depending on your surrounding. In a quiet place it amplifies noise and in a loud place it lowers the amplification. He explains that it is permitted to use them and move around while wearing them since either that isn't considered your action that the device changed its functionality or that it is but it is permitted since the accomplishments of the change in voltage in the circuit are insignificant and don't violate makeh bpatish, boneh, or molid. The automatic mode of hearing aids is described here: https://www.boystownhospital.org/knowledgeCenter/articles/hearing/Pages/PutYourHearingAidsOnAutomatic.aspx.
- Rav Shlomo Zalman Auerbach in Minchat Shlomo 1:9 s.v. ach writes that even if one solves all melacha issues with speaking into a microphone on Shabbat nonetheless it is forbidden since it creates an audible noise which is a violation of Avsha Milta (Shabbat 18a, Rama 252:5), which is Zilzul Shabbat. One of his precedents is the Nodeh Byehuda OC 30 regarding umbrellas where there is a concern of Zilzul Shabbat even if it was open before Shabbat.
- Minchat Asher 1:31:2
- Minchat Asher 1:31:4
- Minchat Asher 1:31:3
- Shemirat Shabbat Kehilchata 12:37, Menuchat Ahava 1.24.31. The Shemirat Shabbat Kehilchata's proof is that when you close the door even though it is totally off it is considered a grama when the melacha will occur later like we find in Mishna Brurah 253:100. Rav Hershel Schachter (Electricity on Shabbat min 35) explained that it was forbidden to use a dishwasher on Shabbat even if it is going to turn on at a later time since closing the door is considered a grama for when the timer will turn on. Since the dishwasher doesn't function if it isn't closed it may not be used. It is also forbidden to illegally get a mechanic who will break the dishwasher so that it starts even if the door isn't closed.
- Yabia Omer OC 6:35 writes that according to his opinion that as long as the watch is still running then it is certainly permitted to wear a watch that self-winds while it is still running. He adds that even those who hold that it is forbidden should agree with the automatic watch since it is a pesik reisha dlo nicha leh on a derabbanan. Additionally, it could be a shinuy and also derech levisha (Rav Poalim 1:26). Chelkat Yakov 1:75, Tzitz Eliezer 9:20, Shemirat Shabbat Khilchata ch. 28 fnt. 57, and Rabbi Mansour agree that an automatic watch is permitted. Shemirat Shabbat Kehilchata quotes Rav Shlomo Zalman who was lenient since fundamentally when the watch is still running it isn't fixing to wind it especially in that it is "fixed" with the simple action of just swinging one's hand. Tzitz Eliezer's reason is that many permit winding the watch while it is still running and here it is a dvar sheino mitchaven and a shinuy. Az Nidbaru 2:39 says it is forbidden.
- The reasons for the mechanical self-winding watch seem to apply to the electric recharging watch as well. See above. Rabbi Daniel Mann on eretzhemdah.org holds that it is permissible to wear the kinetic watch on Shabbat since the transfer of mechanic energy to electrical energy in a battery back into mechanical energy doesn’t create any circuit and is permitted. Additionally, it is similar to some of the arguments made about the automatic watch (that it is a pesik reisha, shinuy, derech levisha). Rabbi Pfeffer on dinonline.org, Rabbi Yisrael Rozen, and Rabbi Li’or on yeshiva.co agree.
- Orchot Shabbat v. 3 26:50 concludes that it is forbidden since one's movements cause the electric charge to cause the watch to function. He also forbids a solar watch. Rabbi Moncharsh on revach.net holds that it is forbidden to wear an electric automatic watch on Shabbat.
- Chayei Adam 114:19 writes that it is Biblically forbidden to wind a watch on Shabbat since it is metaken like Eruvin 103a which says if harp string snaps it is a melacha to fix it. The Tiferet Yisrael in Kalkelet Hashabbat no. 38 argues that it isn’t a Biblical prohibition since tying a string on the harp is assembling parts of a instrument but when winding a watch there are no parts being attached. Chazon Ish also asks this but answers that the opinion of the Chayei Adam was that creating a functional unit is considered Boneh even if it isn’t the assemblance of units in a permanent way. In conclusion some hold that winding a stopped watch is a Biblical prohibition and others hold it is only rabbinic but either way it is forbidden. That is the conclusion of the Mishna Brurah 338:15 and Yabia Omer OC 6:35.
- Yabia Omer 6:35 explains that it is permitted since the whole issue with winding the watch is that it is equal to fixing it but if it didn’t stop that isn’t considered fixing it to prevent it from stopping. Even though the Mishna Brurah 338:15 is strict unless there is a need for someone sick unless you can find a non-Jew. Piskei Teshuvot 338:9 cites the Daat Torah 338, Minchat Shabbat 80:240, and Darkei Chaim VShalom 419 as lenient. Teshuvot Vhanahagot 1:202 quotes that Rav Chaim Ozer was lenient. In his discussion, Yabia Omer has some interesting comparisons to discuss this halacha. He writes that it is comparable to the Nodeh Beyehuda YD 201:35 who says that you can put boards into the mikveh and that’s not a problem of having a mikveh formed with something that’s mekabel tumah since it didn’t start like that even if those boards are preventing the mikveh from becoming invalid. Similarly, the Trumat Hadeshen writes that you can preemptively fix the letters of a mezuzah so that they don’t fade too much and it isn’t considered an issue of not writing the mezuzah in order. Lastly, it is like the Eliya Rabba who says that you can soak meat that was out for three days since you’re keeping status quo and just preventing its status from becoming forbidden and that isn’t considered fixing (tikun).
- Rabbi Rozen on zomet.org explains that even if all the observable noises and notifications that the watch makes are turned off simply wearing it is forbidden since it isn't appropriate for Shabbat.
- Sh"t Maharam Shik 157, Chazon Ish 38:2, Shemirat Shabbat KeHilchata 13:26, Menuchat Ahava 24:30, Sh"t Yabia Omer 3:17.
- Ben Yehuda (responsa 151) writes that it is rabbinically forbidden to use a timer that turns on a light on Shabbat. He writes that there's no Biblical melacha to set a timer since it was all put in place before Shabbat as per the Nemukei Yosef b"k 10a. However, he writes that it is rabbinically forbidden based on the opinion of Rabba in Shabbat 18a who says that it is a disgrace to Shabbat to leave grain in a water-grinder that will become ground on Shabbat. Rav Yosef in the gemara argues that it is permitted and only forbidden according to Bet Shamai. The Shulchan Aruch 252:5 rules like Rav Yosef but the Rama is stringent unless it will result in a loss. He says that based on the Rama it is forbidden to set a timer before Shabbat and even though everyone knows that it is set before Shabbat that logic isn't applicable if the melacha in question is Biblically forbidden. The Kaf Hachaim 252:73 cites this opinion. Ish Matzliach (v. 3 p. 17) writes that his father wouldn’t use timers even for the lights.
- The Shabbos Home (Rabbi Simcha Cohen, vol 2, pg 537) and Sh"t Maharshag YD 1:7(2) permit. However, Sh"t Igrot Moshe 4:70(4) only permits if it is not heard outside his personal room. See Shemirat Shabbat KeHilchata 28:29 (and 28:30 in new edition) who permits before Shabbat for mitzvah purposes setting a mechanical alarm clock that involves removing a pin (see there).
- Rav Hershel Schachter (OU Kosher Webcast, 2011, min 16-8)
- Rav Hershel Schachter (OU Kosher Webcast, 2011, min 9-13) ruled that strictly speaking it's permissible but it's praiseworthy to avoid it.
- Practical Laws of Shabbat (Rabbi Rafael Soae, vol 1, pg 170-1) writes that it's permissible unless one is sending the email to a non-observant Jew who may look at it on Shabbat in which case it's forbidden because one will be encouraging violation of Shabbat.
- Mishna Shabbat 11a says that it’s forbidden to read by the light of a candle because one will come to tilt the wick. Rashi explains that if one tilts to wick (which is flickering) towards the oil so that it lights well, one will be violating Mavir (lighting a flame on Shabbat, which includes adding fuel to a flame). S”A 275:1 quotes this as halacha. Kitzur Shulchan Aruch 80:1 agrees.
- Bet Yosef 275:12 quotes a dispute between the Rif, Rosh, Tosfot and Rabbenu Chananel who permit checking cups by a kerosene candle because it produces a lot of light and there’s no concern one will tilt the wick against the Rambam 5:16 who forbids a kerosene candle based on a difference in versions of Shabbat 12b. S”A 275:12 rules stringently like the Rambam. However, Ramban (Shabbat 12b) explains that even those who permit a kerosene candle because it produces a lot of light are only lenient by checking cups for cleanliness, but to read by the light even the Rif and Rosh will forbid. Lechem HaPanim (Kitzur S”A 80:16), Misgeret Zahav (Kitzur S”A 80:1), and Sh”t Mekor Chaim O”C 6 write that a kerosene lamp is permitted because the flame doesn’t decrease and one can set it to give off as much light as one wants before Shabbat and so there’s no concern one will tilt the wick. Mishna Brurah (Buir Halach s.v. VeEin) writes that this leniency isn’t so clear, but one can rely on it to learn Torah, especially in a Bet Midrash. Mishna Brurah permits if one hangs a sign by the lamp that says “Today is Shabbat and it’s forbidden to light a fire” for a few reasons. Kaf HaChaim 275:13 argues that because one can increase the flame when necessary, it’s forbidden to read by a kerosene lamp. [Sh”t Ani Chomah O”C 19 asks on the Kaf HaChaim that the clearly when the Lechem HaPanim and Mekor Chaim permitted they knew that one could increase the flame but still permitted because one doesn’t usually increase the flame.] Yalkut Yosef (Kitzur S”A 275:2) rules like the Mishna Brurah.
- Bach in name of Maharshal, Taz, and Magen Avraham (in cases of need) permit reading by a wax candle because there’s no Gezerah of tilting the wick. However, S”A 275:1 forbids reading by a wax candle because one will come to trim the wick and maybe extinguish it. Eliyah Rabba and Buir HaGra concur. The Mishna Brurah 275:4, however, permits reading by wax candles because nowadays the wax produces a clear flame and there is no issue that one will tilt or trim the wick. Similarly, Yalkut Yosef (Kitzur S”A 275:3) is lenient based on Rav Ovadyah’s later writing in Halichot Olam 3 (unlike his stringent ruling in Sh”t Yabia Omer 1:16:6-9 and Yalkut Yosef (first edition Shabbat vol 1 pg 317)). Kitzur Shulchan Aruch 80:1 writes that the minhag is to permit reading by a wax candle, however, one should put up a sign to remind oneself to trim the wick.
- Sh"t Yechave Daat 3:20, Sh"t Rivivot Ephraim 1:222:27.
- Sh”t Yacheve Daat 6:20 holds that even those who are strict by a kerosene lamp will allow an electric light because it produces a clear flame and gives off a lot of light [the leniency of a kerosene lamp, which produces a lot of light and the leniency of a wax candle, which produces a clear flame.] Additionally, he adds that we shouldn’t extend Chazal’s Gezerah of a oil and wick to electric lights because we aren’t allowed to make new Gezerah’s or add to preexisting ones (Magen Avraham 301:58). Thus, Sas Anochi (Kuntres Rach VeTov pg 78c) and Sh”t Yashkil LeAvdi O”C 2:9 who are strict by a kerosene lamp if it’s made of multiple candles, allow electric lights. Sh”t Yachave Daat also argues that electric lights are permitted because Chazal only forbad tilting a wick already in oil but permitted adding more oil [the same distinction is found in Sh”t Igrot Moshe O”C 93 concerning leaving food from before Shabbat on a gas flame.] On the other hand, Sh”t Shoel VeNishal 1:76 forbids reading even by electric lights based on a Hagahot Asheri (Shabbat 12b) who is uncertain about a wax candle even though there is no issue of tilting the wick and so too any lighting should be forbidden even though there is no issue of tilting (because of Lo Palug Rabanan, the Rabbis didn’t differentiate in their Gezerah’s). However Sh”t Yacheve Daat (in the footnote) argues that we shouldn’t forbid because of the Hagahot Asheri’s uncertainty as this is a matter of Derabanan (see there as there are some Achronim who say Safek Derabanan LeKula doesn’t apply to a Safek that we don’t know the halacha. Additionally Bnei Tzion 265:3 explains that the Hagahot Asheri was uncertain when a Gezerah doesn’t have any reason to apply whether it should be permissible or forbidden as the Rabbi’s extend their Gezerah to any case as in the case of a mirror that’s not sharp enough to cut hair (Shabbat 149a) as Rabbenu Moshe (quoted in Ran) rules. However, since in the case of Shabbat 149a, Rif, Rambam, and Rosh, S”A 302:13 permit mirrors that can’t cut, then, so too wax candles aren’t forbidden(Getting Dressed).
- Sh"t Yechave Daat 6:20
- Beit Yitzchak Y.D. 1:120, Achiezer 3:60, Melamed L’Hoil O.C. 49, Tzitz Eliezer 3:17, Chelkat Yaakov 1:52, Yesodei Yeshurun 5:147. Chazon Ish Orach Chaim 50:9 says that the problem is the melacha of cooking. On the other hand, Maharsham 2:246, Chasdei Avot pp. 43-75; Yam Gadol OC 26, Levush Mordechai OC page 47-51 all say that turning on a lit switch is only forbidden on a rabbinic level. Rav Shlomo Zalman Auerbach Minchat Shlomo page 103-105 addresses this opinion at length and concludes that they are in error.
- Shemirat Shabbat Kehilchata 13:32
- Shemirat Shabbat Kehilchata 43:4. Rav Moshe Soloveitchik (quoted in Nefesh Harav pg. 155), Rav Mordechai Willig (“The Positive Mitzvos of Shabbos,” min 49-51), Yabia Omer O.C. 2:17, and Rav Henkin (Eidut LeYisrael p. 122) agree.
- Rav Ovadyah Yosef (Yalkut Yosef Shabbat vol 1 pg 188, Yabia Omer OC 2:17) agrees that one can make a bracha on it but emphasizes that it's a last option and that preferably one should have a designation that the bulb is for Shabbat candles.
- Rav Shlomo Zalman (Shemirat Shabbat Kehilchata (ch. 43 fnt. 22) held that using an electric bulb plugged into the wall is questionable since the fuel to keep it lit on Shabbat wasn't present at the time of the lighting. Rav Moshe Feinstein (quoted by Rabbi Tendler in Moreshet Moshe v. 2 p. 51) agreed with this concern.
- Tosfot Shabbat 25b
- There are two reasons why we light Shabbat candles. The first is for “Oneg Shabbat” which requires that the home be illuminated Friday night in order that people not stumble in the dark. The second reason is for “Kavod Shabbat” which calls for plentiful lighting in honor of Shabbat, as was the custom upon receiving a distinguished guest.
- Shraga Hameir 5:11. see also The Radiance of Shabbos (p. 12) who quotes Rav Moshe Feinstein as saying that one should not recite a bracha on an electric light.
- Teshuvot V’hanhagot 2:157
- Az Nidberu 1:79, Shemirat Shabbat Kehilchata 43:N171
- Tzitz Eliezer 1:20
- Rav Hershel Schachter (“Lighting Shabbos Candles,” min 36-7) holds that while one may light an incandescent bulb with a bracha, one may not light a fluorescent or neon bulb with a bracha. This opinion is repeated in this shiur on yutorah.org.
- Shaarim Metzuyanim Behalachah 96:6, Az Nidberu 8:2, Rivevot Ephraim 3:599
- Shaarim Metzuyanim Behalachah 96:6. Nefesh Harav pg. 156
- Har Tzvi 2:114
- Hachashmal L’or Hahalacha 3:88
- Shemirat Shabbat Kihilchita 15:72 quoting Rav Shlomo Zalman Auerbach. Tzitz Eliezer 7:10 writes that there is no problem because the static makes no real impact in that small amount of time, there is no precedent for this type of electricity in the times of the mishkan, and this type of electricity cannot start a fire at all. Sh"t Yabia Omer 5:27 and Sh"t Yechave Daat 2:46 says it is permitted because one does not intend for them, and doesn't care for them. (psik reishe dilo nicha leh.) Chazon Ish OC 50:5 rules stringently in this however.
- It is permissible on Yom Tov to add to or transfer an already existing flame and even lighting a new flame is only a rabbinic prohibition. Shulchan Aruch 502:1 and Beiur Halacha "Ein Motziin." See Sh"t Yabia Omer OC 1:19 and poskim cited there. The poskim who permit it include Rav Yechiel Michel Epstein (The Aruch Hashulchan) in a letter published in Kovetz Vaad Chachamim 1 (Shevat 5663), Even Yekara 3:168, Ohr Chadash page 64, Rabbi Tzvi Pesach Frank in Kol Torah 5694, Mishpetei Uziel OC 19, Hilchot Rabata LeShabbata 1:7, as well as more poskim quoted in Chashmal Behalacha 2:5. However, Rabbi Broyde and Rabbi Jachter explain that this is based on a faulty understanding of electricity that completing a circuit only transfers an existing flame, which isn't correct. Thus, they reject these arguments and conclude that since this is not the view of the majority of the poskim it is prohibited. The poskim who forbid turning on a light on Yom Tov include Rav Ovadia Yosef in Sh"t Yabia Omer 1:19, Rav Moshe Feinstein in Iggerot Moshe OC 1:115, Chelkat Yaakov 1:51, Yaskil Avdi 2:10 and 4:27:3, and Shemirat Shabbat Kehilchatah 13:2.
- The Rambam (Shabbat 12:1) holds that heating a metal in order to temper it is a Biblical violation of lighting a fire (Mavir).
- Rama 245
- See Rabbi Shmuel Eliyahu in a shiur on yutorah.org about using tablets on Shabbat for the Magen Dovid Adom and doctors in hospitals. He takes for granted that writing on tablets is forbidden for regular use but discusses its use for doctors.
- See above.
- As of 10/3/14 the Shabbat App site does not have any rabbinic approvals.
- See Rabbi Hershel Schachter's letter regarding women wearing Tefillin
- Rabbi Michael Siev and Rabbi Yitzchak Rosen from tzomet present this argument against the Shabbos App; the process is set in motion immediately even if the response is delayed. See details about touchscreen technology on wikipedia.
- cited by Rav Schachter in Bikvei HaTzoan Siman 7
- See Rabbi Yitzchak Adlerstein's argument against the Shabbos App which is similar to this approach in not defining grama as a delayed reaction.
- Mishna (Shabbat 104b), Rambam (Shabbat 11:15), Shulchan Aruch 340:4
- Rav Hershel Schachter (Gemara Shabbat Shiur #28 (min 32-3)) explained that every writing in the world is temporary. Rather the Mishna considers anything that doesn't last as long as a person would normally need it for to be temporary. However, a camera system which is deleted after some time is considered permanent since it serves the intended purpose by being recorded and kept for as long as it is was necessary. He added that this is reasonable since this is how the industry makes such camera's and doesn't consider the recording to be flawed in that it doesn't last forever.
- Avnei Nezer OC 180
- Rambam (Sanhedrin 24:4) codifies this.
- Igrot Moshe OC 4:60
- Mishna (Bava Kama 76a)
- The Jewish Week cites Rabbi Moshe Elefant (from the OU) as considering the Shabbos App to be "very distasteful and not permissible on Shabbos.” Rabbi Michael Siev from Yeshivat Lev HaTorah explained how that the App is halachically problematic. Besides the issues above, he adds that the display changing is an issue.
- Rav Hershel Schachter (shiur on yutorah 10/3/14) merely mentioned the Shabbos App as a "chiddush" of our generation in a joking manner. He didn't go into any detail as he explained the he didn't know of its details.
- Igrot Moshe YD 1:173 writes that it is forbidden to activate an electronic device with your voice on Shabbat.
- Shevet Halevi 9:68 writes that it is forbidden to intentionally cause a motion sensor to cause an electric door to open on Shabbat.
- Shevet Halevi 9:68, Ubyom HaShabbat 32:18
- Shevet Halevi 9:68 writes that since one doesn't care about turning on the light it isn't even considered a pesik reisha on a derabbanan and is permitted. He repeats this in 1:47, 3:41, 3:97, and 9:69.
- Shevet Halevi 9:68
- Igrot Moshe OC 3:50 writes that the blanket isn't muktzeh since it is a kli for heter and isur and more significantly heter. In terms of a concern that one is going to adjust it one needs to cover the buttons before Shabbat. See there for more details.