pattern speedの例文

• As it turns out, it is very hard to measure the galactic pattern speed, since the pattern as whole evolves independently of the motions of individual stars in the same way that ripples run across the surface of a lake much faster then the motions of individual water molecules.
• The rotation speed of the arms is defined to be \ Omega _ { gp }, the "'global pattern speed "'. ( Thus, within a certain non-inertial reference frame, which is rotating at \ Omega _ { gp }, the spiral arms appear to be at rest ).