New Mexicans for Science and Reason

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Simple, Inexpensive Experiment Proves Earth is Round!

by Dave Thomas

Flat Earthers like to say that "Water finds its own level." For a few dollars, anyone can get some equipment that Proves the earth is round. You'll have to take it up to the mountains for best effect.

Theory: Use a Spirit Level as shown, to find True Level.

Here's how the above would look like to a viewer on the Flat Earth:

But, here's how the above would look like to a viewer on the Round Earth:

You'll want Maths! Here they are. R is the radius of the Earth (3960 miles), h is the altitude of the viewpoint (also in miles), and d is the distance to the effective horizon on a Round Planet. θ is the angle between True Level (straight ahead) and the Horizon (the visible edge of the Earth). Saying that the Horizon is Level is the same as saying θ = 0. But, θ is NOT Zero!! And the Horizon is below True Level.

Here's this experiment actually works out at Sea Level. Sea Level is just a hair below True Level.

Here's this experiment actually works out in the Mountains. At an altitude of almost two miles above sea level, the horizon is OVER a DEGREE below True Level.

New Online Calculator!! Enter the number of feet in the cell, then tab or click outside to see the dip angle and distance!

English           Metric

Height above surface h = feet
Radius of the planet R = 3960 miles

Height above surface, h = miles

Dip Angle, θ = degrees

Distance to Horizon d = miles

Distance to Horizon d = km

           

Height above surface h = meters
Radius of the planet R = 6371 km

Height above surface, h = km

Dip Angle, θ = degrees

Distance to Horizon d = km

Distance to Horizon d = miles

Kudos to madmelon101. This photo was my original inspiration.

Think this is CGI? Get a plastic tube, go to the mountains, and see for yourself!

Flat Earth: 0           Globe: 3

As you can see, up in the mountains, the visible horizon is below True Level. Send in your pics, I will post them here!

Last Update: Dec. 21st, 2017

Try these other NMSR Pages on Flat Earth:

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