Time Dilation by Latitude

Time Dilation by Latitude refers to Albert Einstein's prediction that clocks would tick slower at the equator than at the poles.

From The Fascinating Life and Theory of Albert Einstein:

Precision clocks were not yet advanced enough to measure the effect at the time, but since the invention and and advancement of atomic clocks there have been efforts to use these new technologies to measure and demonstrate this effect.

University of Maryland
https://umdgrb.umd.edu/~goodman/review/ThemeGroup2_Exp.ppt

In 2005 the University of Maryland found that there was no difference in clock time with Atomic Clocks:



Clock Transport to Thule
A University of Maryland at College Park slideshow shows the following:



University of Adelaide
The equivalence principle as a stepping stone from special to general relativity: A Socratic dialog S. P. Drake School of Chemistry and Physics

Full Text Link (Archive)

Professor Drake at the University of Adelaide explains that there is no time dilation between different latitudes. Professor Drake then proceeds to provide an explanation for the lack of time dilation. The paper is written in the form of Socratic dialog.

Explanation
In order to explain the lack of this effect on a rotating Earth, Professor Drake goes on to explain that clocks tick the same rate by virtue of Einstein's Equivalence Principle:

Luboš Motl
Theoretical physicist Luboš Motl (bio) also uses the Equivalence Principle to cancel out the effect. From his blog:

https://motls.blogspot.com/2014/07/is-time-going-slowly-near-equator.html?m=1 (Archive)

Addendum
The above authors use the Equivalence Principle to explain why clocks tick at the same rate across the surface of the Earth. The Equivalence Principle says that effects on Earth are indistinguishable from an Earth (or compartment) which is accelerating upwards.

https://slideplayer.com/slide/8138482/



The approach of using an upwardly accelerating Earth as an explanation for why clocks at sea level all tick at the same rate is one which we can only express agreement with. Curiously, this principle not only applies to gravity, but to the rotational motion of the Earth as well. Time dilates at different altitudes in agreement with an upwardly accelerating Earth, but not at different latitudes as might be suggested by a rotating Round Earth.

It has been argued that the Equivalence Principle is only a local effect, yet we find university explanations which utilize it as a worldwide effect to explain why time dilation does not occur at different latitudes due to the different longitudinal speeds of the Earth. Dr. Motl even goes as far as to say that it is only possible to cancel out the effect by using the Equivalence Principle and that any other argument is assuredly incorrect. Once again it dawns upon the thinking man that our Earth is not the globe of popular credulity, but an upwardly accelerating plane.