We can understand the gezeira of limiting a individual to 2000 ama outside the city in that, perhaps, chazal wanted to prevent us from using Shabbos to take long hikes. Is this a correct assumption? Are we told what the rational for the gezeira of "tachoomim" is?
If the abovce is correct then why was an issur of "tachoomim" also established for objects?
Thank you and Shalom
Reuven
You are correct in your suggestion that there is some reasoning behind the prohibition of Techumin, both according to the opinion that maintains that the 12-Mil limit is mid'Oraisa, and according to the opinion that there is no prohibition mid'Oraisa, but the Rabanan enacted the concept of a Shabbos Techum similar to the Techum of the cities of the Levi'im (see Insights 36:1). The basis of the prohibition, as you suggested, is to ensure that a person stays in his place on Shabbos or in his city (as the verse states, "A person shall not go out of his place on Shabbos" (Shemos 16:29), see Eruvin 17b). According to the opinion that Techumin is mid'Rabanan, why did the Rabanan base their decree on the size of the cities of the Levi'im? The answer is that since the point of the decree is to ensure that one stays in his city on Shabbos, the Rabanan defined the area of one's "city" based on the existing definition in the Torah of the size of a city -- the cities of the Levi'im.
It seems that the prohibition may be part of the general prohibition against conducting business on Shabbos, since most of the people who go from one place to another is for the sake of conducting business. If so, it makes sense that the prohibition of Techumin applies also to objects; this will ensure that a person does not send merchandise with someone else to be sold or traded, or meet someone from another city, each one at the end of his Techum, and give the merchandise to him. (The Torah, though, permitted on to make an Eruv Techumin in order for him not to feel overly restricted.)