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Garrett’s Blog: The Earth Actually Isn’t Round

There are actually some people still around that think the Earth is flat. Some of them are celebrities, most of them have social media. There’s actually a...
geoid

There are actually some people still around that think the Earth is flat. Some of them are celebrities, most of them have social media.

There’s actually a ‘Flat Earth Society’ which (like most conspiracy theorists) allege it’s all a conspiracy by NASA and the government.

These folks have way more faith in the government than I do; after all, government can’t balance a budget, have a civil conversation, or even keep a sex act a secret but somehow they’re fooling billions of people into thinking the Earth is round and our air and water are being poisoned to control our minds.

Although if you live in Flint, Michigan; your water is actually poisoned because of government.

It’s too bad there’s not a guy just orbiting the Earth with a Twitter account so we could independently verify their claims.

Wait, there is… Astronaut Mark Kelly is floating around up there. According to his Twitter the Earth is very much round. Or is it?

Turns out the Earth is actually an “oblate spheroid”. It’s not a perfect sphere.

In Geographic Information Systems we refer to it as a “Geoid”; the Earth is very much imperfect and defined by the irregularities in the gravitational field.

geoid

The actual shape is something like the image above. Not really like the desk globe you got in high school, is it?

But there’s more, because of the Earth’s rotation and it’s liquid molten center, the properties of the fluid and the rotational velocity also affect the shape.

As the Earth rotates, a bulge is created along the equator. In fact, the distance to the center of the Earth from the equator is actually around 15 miles greater than it is at the north and south poles.Think of it more like an egg turned sideways.

equator

The circumference of the Earth at the equator is also a greater distance than the circumference at the poles due to gravitational and rotational effects. (Image: ScienceVibe.com)

As the crust of the Earth is shaped and formed over millions of years, the uneven mass tries to reach equilibrium by swelling at the equator.

The Earth is dynamic and always changing (it’s never really stopped changing). Over time this results in a process called Polar Wandering. If you look at the magnetic field over millions of years you can see how the gravitational shifts and changes occurred and are recorded in the rock record.

From outer space the world looks very much round and like most things in life you can only see the imperfections if you look closely.

However, the fact that the Earth isn’t a perfect sphere does affect science. Not so much in cartography (map making) as it does in Geodesy which is modeling the Earth and solving complex problems with exact coordinates. To account for the errors GIS (geographic information systems) use different datums & projections as well as true reference points that approximate geographical positions for analysis.

So no, the Earth isn’t flat… but it’s not perfectly round either!

-Garrett

 

 

 

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