Editing Kissing number (section)

==Generalization==
The kissing number problem can be generalized to the problem of finding the maximum number of non-overlapping [[congruence (geometry)|congruent]] copies of any [[convex body]] that touch a given copy of the body. There are different versions of the problem depending on whether the copies are only required to be congruent to the original body, [[translation (geometry)|translates]] of the original body, or translated by a lattice. For the [[regular tetrahedron]], for example, it is known that both the lattice kissing number and the translative kissing number are equal to 18, whereas the congruent kissing number is at least 56.<ref>{{Cite journal|last1=Lagarias|first1=Jeffrey C.|last2=Zong|first2=Chuanming|title=Mysteries in packing regular tetrahedra|journal=Notices of the American Mathematical Society|date=December 2012|pages=1540–1549|url=https://www.ams.org/notices/201211/rtx121101540p.pdf}}</ref>