Eruvin are weird
Strange things found in Shulchan Aruch Orach Chayim Siman 362 with the commentary of the Mishnah Berura (eruv here is used in the Yiddish sense to refer to the enclosure, rather than the rabbinic Hebrew sense to refer to the food)
362:5 An eruv may be made of human beings standing within 3 handsbreaths, or 1/2 cubit of each other, as long as the humans do not know they are an eruv. They can walk around as an eruv (unclear if this creates a mobile zone of carrying or if they may merely circulate, perhaps for exercise). Beyur Halacha: The Bach asks: "Humans are a cubit wide. If they stood within any less than a cubit of each other, this should work" Others respond that perhaps their feet are seperate because they are walking, but if they stood still, they would be a cubit wide. However, add still others: Their feet would be seperated half a cubit while walking, but their chests would be further apart than that..
I imagine this as a group of soldiers, as who else would stand in such a formation for an extended period without knowledge that they constitute a boundary?
The eruv must have more standing than not. However, some non-standing things count as standing. For example, any hole smaller than 1/2 cubit is assumed not to exist and actually counts towards the standing. Also, a door frame (or similarly shaped object) counts as entirely standing. This last point is most of what allows for modern eruvin. However, sometimes holes swallow standing parts or vice-versa. For example:
-- ---- ---- --
1 1 2 7 2 1 1
No that isn't Morse code. It looks more empty than filled in doesn't it? And if you add it up, the holes are 1+7+1=9 while the solid are 1+2+2+1=6. So the holes are greater. Except that the solid on either side swallow the 1 that is a hole on its side. So then there are 4+4 in solid that is greater than the 7 in the center.
362:5 An eruv may be made of human beings standing within 3 handsbreaths, or 1/2 cubit of each other, as long as the humans do not know they are an eruv. They can walk around as an eruv (unclear if this creates a mobile zone of carrying or if they may merely circulate, perhaps for exercise). Beyur Halacha: The Bach asks: "Humans are a cubit wide. If they stood within any less than a cubit of each other, this should work" Others respond that perhaps their feet are seperate because they are walking, but if they stood still, they would be a cubit wide. However, add still others: Their feet would be seperated half a cubit while walking, but their chests would be further apart than that..
I imagine this as a group of soldiers, as who else would stand in such a formation for an extended period without knowledge that they constitute a boundary?
The eruv must have more standing than not. However, some non-standing things count as standing. For example, any hole smaller than 1/2 cubit is assumed not to exist and actually counts towards the standing. Also, a door frame (or similarly shaped object) counts as entirely standing. This last point is most of what allows for modern eruvin. However, sometimes holes swallow standing parts or vice-versa. For example:
-- ---- ---- --
1 1 2 7 2 1 1
No that isn't Morse code. It looks more empty than filled in doesn't it? And if you add it up, the holes are 1+7+1=9 while the solid are 1+2+2+1=6. So the holes are greater. Except that the solid on either side swallow the 1 that is a hole on its side. So then there are 4+4 in solid that is greater than the 7 in the center.