We have already learned in the Mishna that transferring an object from a public domain to a private domain is one of the forbidden activities on. It is clear that carrying within a private domain is permitted. What if an object remains in a private domain and merely travels through a public domain? That question is dealt with on today’s daf. The Gemara teaches:
One who throws an object from the private domain to the other private domain and there is the public domain in the middle, Rabbi Akiva deems him liable for carrying out into the public domain, and the Rabbis deem him exempt because the object merely passed through the public domain and did not come to rest in it.
In explanation of Rabbi Akiva’s position, the Gemara introduces the idea of kelutah me-mi she-hunhah damiah – that an object in airspace is considered at rest.
It is possible to identify two fundamental approaches in clarifying the essence of the principle that an object in airspace is considered at rest. According to Rashi and R Hananel, an object passing through airspace of a certain domain is considered as if it were placed on the ground of that domain. In the Jerusalem Talmud, on the other hand, this phrase was understood to mean that all the airspace in a certain domain is considered as if it were solid matter upon which the objects rest. The principle was formulated: The air within the partitions is like its substance, i.e., it is viewed as being like the ground beneath it.
According to Rabbi Akiva’s opinion, an object that passed, even briefly, through the airspace of the public domain is considered as if it came to rest in that domain. Therefore, one who threw the object has, for all intents and purposes, lifted the object from the private domain and placed it in the public domain, and he is liable.