"二向箔" (er xiang bo) is a tool that is used to eliminate all lives in the planetary system in Liu Cixin's "Three-Body III – Dead End" of the science fiction "Three-Body".
"二向箔" (er xiang bo) is a two-dimensional space that is specially processed. It is 8.5 cm long, 5.2 cm wide and no thickness. The moment meeting with the three-dimensional space, it will make a dimension of the three-dimensional space roll up to the micro, which makes the three-dimensional space and all the things in the three-dimensional space fall into it. It will expand outwards soon, faster and faster; and never stop, to make the attack target become a two-dimensional picture.