If an axis goes through the world, where is the spot exactly opposite Har HaBayit where the axis comes out? Is it in the middle of the Ocean? Should there be anything special expected about this point? Has anyone ever been there?
There is one opinion that if Jerusalem is the center of the world, then the halachic international dateline is 180 degrees from there.
While the Encyclopedia Talmudit (22:665-694) presents no less than thirteen opinions regarding this issue, the most widely accepted views are those of the Chazon Ish, who places the line 90 degrees east of Jerusalem (longitude of 125 degrees east); Rav Yechiel Michel Tukitchinsky, who places the line 180 degrees from Jerusalem (longitude of 145 degrees west); and Rav Zvi Pesach Frank, who rules that Halachah accepts the legal international date line, located 180 degrees from Greenwich, England.