Editing Angular momentum (section)

== Angular momentum in nature and the cosmos ==

[[Tropical cyclones]] and other related weather phenomena involve conservation of angular momentum in order to explain the dynamics.  Winds revolve slowly around low pressure systems, mainly due to the [[Coriolis force#Meteorology|coriolis]] effect.  If the low pressure intensifies and the slowly circulating air is drawn toward the center, the molecules must speed up in order to conserve angular momentum.  By the time they reach the center, the speeds become destructive.<ref name="Tropical Cyclone Structure"/>

[[Johannes Kepler]] determined the laws of planetary motion without knowledge of conservation of momentum.  However, not long after his discovery their derivation was determined from conservation of angular momentum.  Planets move more slowly the further they are out in their elliptical orbits, which is explained intuitively by the fact that orbital angular momentum is proportional to the radius of the orbit.  Since the mass does not change and the angular momentum is conserved, the velocity drops.

[[Tidal acceleration]] is an effect of the tidal forces between an orbiting natural satellite (e.g. the [[Moon]]) and the primary planet that it orbits (e.g. Earth).  The gravitational torque between the Moon and the tidal bulge of Earth causes the Moon to be constantly promoted to a slightly higher orbit (~3.8&nbsp;cm per year) and Earth to be [[ΔT (timekeeping)#Values prior to 1955|decelerated]] (by −25.858 ± 0.003″/cy²) in its rotation (the [[ΔT (timekeeping)#Universal time|length of the day increases]] by ~1.7 ms per century, +2.3 ms from tidal effect and −0.6 ms from post-glacial rebound).  The Earth loses angular momentum which is transferred to the Moon such that the overall angular momentum is conserved.