Gravitational Time Dilation

Gravitational time dilation is a phenomenon in which the difference of elapsed time manifests between two events as measured by observers situated at varying distances from the Earth. Time is seen to dilate in accord with the Equivalence Principle, which predicts that all physical effects which would occur in an upwardly accelerating rocket ship should also happen in a gravitational field. Since the time dilation of clocks would occur at different elevations inside of an upwardly accelerating rocket, it must occur at different elevations in the Earth's gravitational field as well. Supposedly only a 'local' effect, the Equivalence Principle and its uniform nature has been confirmed over various elevations.

Description
From p.8 of Cosmological Physics (Archive) by John A. Peacock, PhD. (bio) we read the following:

GRAVITATIONAL TIME DILATION



Small Scale Experiments
Ultra-precise atomic clocks have confirmed that time dilates at different elevations on a personal scale.

NIST Pair of Aluminum Atomic Clocks Reveal Einstein's Relativity at a Personal Scale (Archive)

Paper: Optical Clocks and Relativity (Archive)

Mt. Lemmon
Atomic clocks were compared between locations at the bottom and the top of a mountain, confirming the dilation of time.

Project GREAT 2016a -- Hawking, Einstein, and Time Dilation on Mt Lemmon (Archive)



Similar Experiments
A similar experiment showing time dilation on a mountain was conducted in 1977 by Briatore and Leschiutta to about 11,500 feet on Plateau Rosa, afferming that the effect meets the principle of equivalence.

Ballistic Rocket
According to the mainstream narrative it is claimed that in 1976 the Smithsonian Astrophysical Observatory and the National Aeronautics and Space Administration engaged in a joint project to test the Equivalence Principle by comparing the difference of time dilation at high altitudes and the surface of the earth. A ballistic (sub-orbital) rocket was sent to an altitude of 10,000 km (6,200 mi) on an elliptical trajectory over the Atlantic Ocean before falling back down to earth. At a great height an atomic clock on board the rocket was compared to an atomic clock on the surface of the earth, confirming that time dilates in accordance with the uniform nature of the Equivalence Principle.

http://research.omicsgroup.org/index.php/Gravity_Probe_A (Archive)

Gravity Probe A

Uniform Gravitational Field
Additional reference to the 'uniform gravitational field' of the Equivalence Principle can be seen on p.8 of How The Universe Works: Introduction To Modern Cosmology (Archive):

Elliptical Trajectory
Aeronautics and Space Report of the President - 1976 Activities (Archive) contains reference to the device's elliptical flight over the Atlantic Ocean:

June 18 - Gravity Probe A (Red Shift Experiment) - sub-orbital - Scout

Physics Classroom
In the above we saw that a clock on Earth was compared to a clock raised to an elevation of 10,000 km, concluding that the time dilation experienced confirmed the time dilation effect that would happen in a 'uniform gravitational field', per the Equivalence Principle.

According to a Physics Classroom article on gravitational theory, gravity diminishes significantly in that range. With the Earth's supposed radius (R) of 6,371 km, at 2R from the center of the Earth, at a position of 6,371 km above the earth's surface, the value of gravity is much different.

https://www.physicsclassroom.com/class/circles/Lesson-3/The-Value-of-g (Archive)



A table also appears in the article, containing the following paraphrased data:

Addendum
The experimental claims of mainstream science demonstrate that there is difficulty with finding violations of the Equivalence Principle. Experiments with very sensitive equipment show that the uniform nature of the EP is verified to various elevations. If it is claimed that there are variations in gravity, one should be able to directly reference the empirical experiments which show these variations, rather than merely claim or assert that they exist based on rumor or theory.

The few referenced experiments from science history which do claim slight variations of gravity are seen to be conducted in uncontrolled settings (See: Weight Variation by Latitude). Weight is also affected by factors outside of 'gravity'. It is also related to a buoyancy related to pressure, humidity, air viscosity, temperature, etc, which exist differently in different locations, and which may contribute in complex ways to the readings of the scale. Such experiments must necessarily be controlled from all other known factors which affects the scale, ideally conducted in a vacuum chamber. Experimental evidence otherwise shows resounding agreement with the concept that our Earth is accelerating upwards.