Our planet isn’t a perfect sphere, as such Earth’s mass is distributed unevenly. Ponder how uneven mass manifests itself as 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 –
http://wtamu.edu/~cbaird/sq/2014/01/07/do-i-weigh-less-on-the-equator-than-at-the-north-pole/
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.
https://simple.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation
Uneven gravity isn’t fickle or complicated, uneven distribution of mass and centrifugal force account for gravitational anomalies. Everything happens for a reason.
notestoponder 
Great post – gravity at particular points is measurably lumpy because of added mass concentrations, which is both cool and kind of odd all at the same time. Though I’d check your figures – the difference between pole and equator is about 1 percent, of which the effects of centripetal force at the equator (0.034 m/s squared) makes up about a third.
Thanks for the fact check, my bad, I knew that but goofed. Correction made. 🙂
There’s that place in Oregon where the ‘vertical’ is displaced. Oregon Bend, is it?
Not sure, I’m off to research 🙂
Einstein came to the stunning conclusion that gravity is the same as acceleration, like an accelerating car. We knew that from a formulaic perspective but he proved that it was he same. So when you are in an elevator, you literally feel your weight increase or decrease. Thanks to him we can imagine the earth’s gravitational field as the skin of an almost round potato with with bumps and dimples.i
Once you see that, it would be unthinkable that the earth’s gravity would be a smooth sphere with contant gravity. The variations make the earth real.
PS, only our weight varies – which is an indication of force. Our mass stays the same, unless we eat too much.
I just wish more people bothered to ponder gravity. Sigh
Can’t really blame people for that. Studying gravity makes one grave, and that leads to the grave and that’s a grave issue.
Hey…I thought the earth was flat😜
Hey Mary, you’ve watched too many Bugs Bunny cartoons…
My personal equator is actually around one percent heavier than my extremities (poles) …
But be assured I am working to correct this.
Thus, I too will soon reflect less gravity and more gravitas.