An aether is absolutely necessary to account for such a change by direct contact with matter.

Subject: Angular Momentum kills General Relativity Theory. Dear Professor, Since 2016, there has been an increase of the speed of rotation of the Earth on itself andthe length of the days is decreasing. The decrease expected for 2021 is 0.07 milliseconds per day. The duration of the days normally increases! These changes in the speed of rotation of the Earth on itself involve a change in the Angular Momentum of the Earth. As shown by the video Aether against relativity  the explanation by tides does not comply with the angular momentum conservation. The Moon attraction may only move the water of Ocean up and down. The frictions in the water and on the bottom of the Ocean generated by the tides are symmetrical. Their moment cancel one another. Gravitation cannot act perpendicularly to its direction. An aether is absolutely necessary to account for such a change by direct contact with matter. This is what Newton said and he recognized he had no answer: “So then Gravity may put the Planets into Motion, but without the divine Power it could never put them into such a circulating Motion as they have about the Sun”. The General Relativity theory as well as Newton gravitation theory has no means for making or changing an Angular Momentum.  The final 2021 issue of the Worldwide list of alternative theories and critics is now available in Googlebooks. Best regards! Jeande Climont