Template:Are You Sure/April 28

• ... that mathematician Leopold Kronecker (1823–1891) was quoted by Heinrich Martin Weber (1893) as having said, "Die ganzen Zahlen hat der liebe Gott gemacht, alles andere ist Menschenwerk" ("God made the integers, all else is the work of man")?

• ... that geometrical frustration (or simply frustration) is a phenomenon condensed matter physics where atoms tend to stick to non-trivial positions or where, on a regular crystal lattice, conflicting inter-atomic forces (each one favoring rather simple, but different structures) lead to quite complex structures, and that as a consequence of the frustration in the geometry or in the forces, a plenitude of distinct ground states may result at zero temperature, and usual thermal ordering may be suppressed at higher temperatures?