What is the difference between the direction of geomantic omen and that of modern science?

the modern direction is only eight directions, namely east, south, west, north, southeast, southwest, northeast and northwest, or 36 degrees, but it is not easy to measure.

The direction of geomantic omen is twenty-four mountains, that is,

[Kangua] represents three mountains (due north);

[gen gua] represents [ugly gen yin] three mountains (northeast);

[the divination] represents [Jia Mao B] three mountains (due east);

[Xun Gua] stands for [Chen Xun Si] three mountains (southeast);

[Li Gua] stands for [Bing Wuding] three mountains (due south);

[Kun gua] stands for [Wei Kun Shen] three mountains (southwest);

[Dui Gua] stands for [Geng Youxin] three mountains (due west);

[dry divination] stands for [guarding dry sea] three mountains (northwest);