Will the Third Beis Hamikdash Have Wi-Fi and Elevators?

In this week’s episode, the topics discussed by Rabbi Braun include:Modern technology in the third Beis HamikdashWill the third Beis Hamikdash include modern inventions, such as central air conditioning, heating, Wi-Fi, electric lights, sound systems, and elevators?Does the rule of hakol bichsav forbid any additions or changes, and does it apply to the entire Har Habayis, even underground?Is there room to permit additions that are not for the avodah itself, items that are detached from the structure, or features built in from the very start of construction?Why did some shuls in the past not allow heating systems?Rubbing the hands during netilas yadayimIs the practice recorded in Hayom Yom, rubbing the hands together with the extra water of the final pour, limited to washing for bread, or does it extend to washing for davening and other washings?Is the rubbing meant to satisfy the opinion that washing extends beyond the fingers, or is it purely for added tahara and cleanliness (“erchatz b’nikayon kapai”)?Should one also rub the hands when washing in the morning, as indicated in numerous Kisvei Arizal?Does the practice apply when washing merely for cleanliness or because of ruach raah (e.g., after leaving the bathroom)?Wrapped challos on top of the cholent pot   May one place dry challos wrapped in aluminum foil on top of a cholent crockpot on Shabbos to warm them?Does the wrapping constitute hatmanah (insulation), and does it depend on whether the purpose is to retain heat or only to keep the challos from drying out?Does the leniency of covering food to protect it (e.g., from mice) apply even when the covering is heated by the fire below and adds heat?Ladling from and covering pots on ShabbosIs ladling food out of a pot on the fire a form of meigis (stirring), and must the pot first be removed from the flame even when the food is fully cooked?What is considered “off the fire”: a pan resting on a Sterno water pan that does not touch the flame, or a pot held in the air above the fire?Is covering a pot, or adding a second cover, a form of bishul, and is it an issur de’oraisa when the food is not fully cooked?Are there reasons to be stringent not to re-cover a pot on the blech, even when it’s already fully cooked?An onen who handed arrangements over to the Chevra Kadisha  When funeral arrangements are given over entirely to the Chevra Kadisha, does the heter of nimsar lekatafim (handing the burial over to the carriers) apply, allowing the onen to daven and perform mitzvos?Does it make a difference if family members still follow the aron at the levaya or remain involved in the arrangements on some level?What halacha applies to an onen in another city whose siblings are taking care of the arrangements?What can be learned from the Rebbe’s own conduct after the passing of his mother and, in a different manner, after the passing of his brother?Waiters and photographers eating meat during the Nine Days    May the waiter, singer, and photographer hired for a seudas mitzvah (such as a bris or bar mitzvah) during the Nine Days eat meat along with the participants?What about during the actual week of Tisha B’Av, when a bris meal is limited to a bare minyan plus immediate relatives?Taste absorption in modern-day utensilsDo today’s pots and dishes actually absorb taste the way vessels did in earlier times, and can scientific experiments have any bearing on these halachos?Is this a question of “changing halacha,” or of clarifying the facts, given evidence that earlier generations also tested whether taste is actually transferred?