Regardless if they are flat-earthers or not some denies that the Earth moves.  The argument is we would feel it.  The problem with this argument is we don’t feel movement in and of itself.  What we feel are changes in the movement’s speed and direction.  Such changes in the Earth’s motions are far too even for us to notice them.

Now there are other consequences of the Earth moving.  One example is airplanes flying eastward or westward.  The one flying eastward automatically flies higher than the one flying westward.  At least if they don’t fly on autopilot which make them follow the same air pressure.  This is called the Eötvös effect after Loránd Eötvös who discovered it.  Projectiles shoot over longer distances are also affected by this.

Another consequence is the Coriolis effect discovered by Gaspard Gustave de Coriolis.  It makes winds and ocean currents turn from their original direction.  North of the Equator they turn to the left.  South of the Equator they instead turn to the right.  This not only affect ocean currents and winds.  In the same way as the Eötvös effect this affect projectiles too.  In contrast, it does not matter much for which way water swirls when draining though a hole.  Other forces matter much more in this context.

Both the Eötvös and the Coriolis effect varies by latitude.  However, they vary in the opposite ways.  The Eötvös effect is the greatest at the Equator and the least at the poles.  The Coriolis effect is the greatest at the poles and gradually decrease towards the Equator.  Within about 50 kilometres (31 miles) of the Equator the Coriolis effect is negligible.  So individuals demonstrating were the Equator is by pouring down water are faking it for this reason too.

One way of showing the Coriolis effect goes by the name of Foucault’s pendulum.  It is named for Léon Foucault who first set up one.  It has to be hung up in a ball joint so it can move freely.  (Ball joints don’t favour any particular motion.)  It moves back and forth like all pendulums.  In contrast, the pendulum turns so that the directions it points gradually forms a circle.  The turning goes slower and slower the closer to the Equator it is set up.  I think the turning becomes negligible if it is within 50 kilometres or 31 miles of the Equator.  Anyway, a two-story house was built on the South Pole in 1999 – 2008.  They then took the chance to set up a Foucault’s pendulum in the stairway.  The pendulum’s direction formed a circle in petty exactly 24 hours.

The Earth’s motion around the Sun is noticeable in the movements of the celestial bodies.  Not only is there a difference in what stars one can see at different times of the year.  The planets seem to move back and forth against the background stars.  What is actually happening is that both the Earth and the other planet moves.  But they move at different speeds so that one gets ahead of the other.  This creates an illusion of the planets turning back.  Something they actually never does.

Some claim the stars don’t show any parallax.  This is because it is too small to be seen to the naked eye.  The fact is it was not observed until the 1830ies.  The distances to even the closest stars turned out to be so much longer than they had imagined.  Things can in fact be counter-intuitive and hard to find out.  Some seem to have trouble accepting this.

Uploaded on the 27th of October 2023.