Christ the King

Watching a YouTube video on astronomy recently, I learned the Mercury is in retrograde.  Who knew?   And what does that even mean?  Here is what I found out.  If you were able to track Mercury’s motion every sunrise for a few weeks, it would appear to change direction.  This illusion is created by the fact that both Earth and Mercury are moving around the sun, but at different speeds.  Mercury is faster and laps Earth every four months.  When that happens, it appears to us earthlings that Mercury changes directions.  (For a better explanation and graphics, go to YouTube and search for Mercury retrograde explained without astrology!)

Early astronomers were baffled by this illusion because they assumed that Earth was the center of the universe.  Claudius Ptolemy developed a complicated system of loops to predict the various plants’ orbits.  It is a lovely design—but completely wrong.  Once Nicolaus Copernicus put astronomers (and the church) straight on the fact that planets, including Earth, move around the sun, it became obvi9us that no planet was suddenly changing directions mid-orbit.

I appreciate the lesson the YouTube video’s narrator gleaned from this paradigm shift:  “We may be vulnerable to illusions whenever we think everything revolves around us;” a handy lesson to remember.