The general idea that has been taught to people is that there is an imaginary axis that crosses the earth from the north pole to the south pole (or vice versa).And that is the axis of rotation.
But I have always thought that idea is not so accurate and that there are other poles that are the true and the geographics don't coincide with the true poles.
If I am correct with that idea, I can affirm that there is also a true equatorial line that doesn't coincide with the geographical equatorial line.
Am I right?
I asked that question because I live in Ecuador and here there is a commemorative monument of the French geodesic mission (between 1736 and 1744) and besides being a tourist center in which visitors are shown experiments as a container full of water with a siphon in which no swirl occurs because they are in exactly the equatorial line, in addition to other tricks.
Here you can see a video of different experiments:
I have reasoned and I think that the effects caused by being on the equatorial line would happen if the axis of the earth did not have wobbles and according to what it says here:
"Precise location The precise location of the Equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's spin axis, which drifts about 9 metres (30 ft) during a year. This effect must be accounted for in detailed geophysical measurements"
Then the true equatorial line would change in a range of +/- 9 meters each year and the effects shown to tourists on the equatorial line may have been for the following reasons:
They are false tricks since the effects of the equatorial line move throughout the year in an area of approximately 9 meters and for such "experiments" to happen they should move the devices to find the effects of the equatorial line constantly throughout the year.
The tricks are true, but they do not happen exactly on the geographical equatorial line, but within a range of 9 meters.