Uneven Gravity

Our planet isn’t a perfect sphere, as such Earth’s mass is distributed unevenly. Ponder how uneven mass manifests itself as uneven gravity.

There's uneven gravity

Pictured above Hudson Bay, Canada, one of Earth’s gravitational anomalies.

Science has pondered lower gravity in Hudson Bay since the 1960s. Basic laws of gravity dictate its force is proportional to mass in a given region. One theory steps 20,000 years back to the last ice age, a time when behemoth ice sheets crinkled Earth’s crust, displacing mass. Another theory credits tectonic plates, movement of magma and subduction.

We think of gravity as constant, one planet, one equal gravitational force. I wonder how many know they weigh 1% less at the equator than the poles. Rotation creates centrifugal force which varies by latitude because our planet is a oblate sphere. Centrifugal is an outward force, gravity a inward phenomenon. Earth spins fastest at the equator, outward centrifugal forces cancel gravity resulting in diminished measurable weight. The link below is a great resource –


Newton’s Law of Universal Gravitation states that every particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.


Uneven gravity isn’t fickle or complicated, uneven distribution of mass and centrifugal force account for gravitational anomalies. Everything happens for a reason.



Gravitational Time Dilation

Excessive contemplation works in mysterious ways, I didn’t wake up pondering gravitational time dilation. Placing blame squarely on GPS strikes me as a reasonable explanation. I brought it on myself – putting a monotone tyrant in charge before first coffee rubbed sleep from my eyes, obviously explains an inexplicable need to understand Einstein’s theory of relativity. With each directive – turn left, right, merge – absolute faith in GPS freed my mind to concentrate on time and space.

We think of GPS as an absolute tool, one linking position of our device with that of some imagined all seeing eye. Few of us realize GPS constantly recalculates and adjusts readings based on Einstein’s theory of special relativity. If left unchecked, navigational errors of 10 km per day would quickly topple getting from point A to B.

Einstein’s theory of relativity describes the effect of gravity on space and time. Time is relative to mass and proximity of gravitational pull – speeding up as it moves further away. Time passes at different rates according to gravitational potential. Space-time depends on proximity to forces of gravity.

GPS satellites orbit 20,000 Km above, with gravitational forces four times weaker than Earth. Science proves Einstein knew what he was talking about – satellite clocks tick 38 microseconds faster a day than clocks on our planet. I urge you to read the link below. It explains gravitational time dilution – I’m still digesting my first dip in the relativity pond.