Shalom,
Question on the previous day's daf: The Gemara permits insulating a cold flask but not to insulate a hot pot to retain its heat. How do we reconcile this with science, as we know that 'cold' is really just a variation of heat? It would seem odd to permit one and not the other, as it is doing virtually doing the same thing (reataining heat/'cool'). What is your take on this?
Thank you,
Gilad
Shalom Gilad,
The Gemara's leniency regarding insulating a cold flask has nothing to do with whether or not the flask is scientifically hot. The reason that insulation of a hot pot is prohibited because of one's mindset that he is concerned that the pot stay hot.
When someone is concerned that his pot stay hot, he might very well come to boil it up again transgressing the prohibition against cooking on Shabbos (Bishul), or stoke the coals surrounding the pot, thereby transgressing the prohibition against lighting a fire on Shabbos (Mavir). This is why Chazal forbade insulating hot dishes. However, when someone insulates a cold dish, he is showing that his mindset regarding this pot has nothing to do with cooking or creating fire. Chazal therefore saw no reason to forbid insulating a cold flask on Shabbos.
Take Care,
Yaakov Montrose