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Earth-Moon-Sun tides

What you are seeing: Earth as a 3D sphere with the L=2 tidal bulge made visible. The Moon orbits in the equatorial plane and the Sun lies at +x. As the Moon moves, the bulge moves with it; when the Sun and Moon align (new or full moon) the bulge gets bigger (spring tide); at quadrature it gets smaller (neap tide)

Figure 1. Earth with the lunar + solar L=2 tidal bulge made visible; Moon (gray) at the chosen orbital phase; Sun lies at +x. Method: closed-form L=2 Legendre tidal potential h(theta) = A_lunar P_2(cos theta_M) + A_solar P_2(cos theta_S).
lunar phase (°)60
bulge scale0.08
animation speed2

WHAT TO TRY

  • Vary each control and watch the rail readouts respond.
  • Compare the diagnostic plot against the live scene.