Why gravity's strength is actually different throughout planet Earth

On Earth, gravity's strength can be stronger or weaker depending on the altitude. 

Why gravity's strength is actually different throughout planet Earth
May 10, 2018

I’m going to admit something here. Like many people do at some point in their lives, I’m trying to lose some weight. I’ll also admit, it’s not going well. 

But there may be good news.

Instead of worrying about dieting or adjusting what I eat, there might be something else I can do to shed some weight—I can simply move to higher ground.

Gravity isn’t the same everywhere on Earth. This means, I’ll weigh less if I’m at a higher altitude. 

This might come as a surprise. You might have previously thought that gravity is uniform across our planet, having not felt anything to the contrary.

Gravity is the force by which a planet—in our case, Earth—draws objects toward its center. Gravity holds everything on the Earth, from people and animals to cars, water and even the atmosphere. Essentially, gravity holds our world together.

However, researchers at the University of Perth in Western Australia combined gravity data from satellites and topographic data to map gravity changes between 60 degrees north latitude and 60 south latitude. That’s about 80 percent of Earth’s landmass.

They found that gravity varies because the planet is not a perfect sphere. It’s also not uniformly dense.

In addition, gravity is weaker at the equator because of centrifugal forces produced by the planet’s rotation. Gravity is also a bit weaker at higher altitudes, being farther from Earth’s center, such as the summit of Mount Everest.

So what does this mean for my diet?

The study shows that I would lose about one percent of my body weight in moving from the Arctic Circle to a high mountaintop in Peru. The trouble is, my mass would not change.


Back to the diet.

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