In a model describing these systems, if the kinetic energy term is neglected, one can use the Thomas-Fermi approximation. A linear relation of these systems that includes the sound velocity as a coefficient can be derived from the dispersion law of the Bogoliubov excitation spectrum. The Zeeman (“ZAY-mahn”) effect is used when creating these substances using a magneto-optical (-5[1])trap, or MOT. A nonlinear Schrödinger equation describes the wavefunction of a single particle in a model of these substances named for (*) Gross and Pitaevskii (“pee-TIE-ihf-skee”). Wolfgang Ketterle (“VOELF-gahng KEHT-ter-luh”) produced these substances from a gas of sodium atoms, (-5[1])while Eric Cornell and Carl Wieman produced them by laser cooling rubidium atoms to (10[2])170 nanokelvins. For 10 points, name these substances composed of ultra-cooled spin-one particles, the so-called “fifth state of matter.” ■END■ (10[2])