A shaky polyhedron is a non-rigid concave polyhedron which is only infinitesimally movable. Jessen's orthogonal icosahedron is a shaky polyhedron (Wells 1991).
Shaky Polyhedron
See also
Flexible Polyhedron, Jessen's Orthogonal Icosahedron, Multistable Polyhedron, Rigid Polyhedron, Rigidity TheoremExplore with Wolfram|Alpha
References
Blaschke, W. "Wackelige Achtflache." Math. Z. 6, 85-93, 1920.Cromwell, P. R. Polyhedra. New York: Cambridge University Press, p. 222, 1997.Gluck, H. Almost All Simply Connected Closed Surfaces are Rigid. Heidelberg, Germany: Springer-Verlag, pp. 225-239, 1975.Goldberg, M. "Unstable Polyhedral Structures." Math. Mag. 51, 165-170, 1978.Jessen, B. "Orthogonal Icosahedron." Nordisk Mat. Tidskr. 15, 90-96, 1967.Wells, D. The Penguin Dictionary of Curious and Interesting Geometry. London: Penguin, p. 161, 1991.Referenced on Wolfram|Alpha
Shaky PolyhedronCite this as:
Weisstein, Eric W. "Shaky Polyhedron." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ShakyPolyhedron.html