# Is it possible to see the curvature of the earth with the naked eye?

The disappearance of a ship behind the horizon is one of the ways to see the naked eye that the earth has been curved. It is also evident during a lunar eclipse: the Earth works a round shadow on the moon.

You can look at that moment about 25km far, otherwise it cannot because the earth is crooked.

(Formula to create the distance how far you can look looks like this;

[Matha ^ 2 + b ^ 2 = c ^ 2 = default ABC formula [/math

• [MATHB = [/maththe distance from the observer to the horizon;
• [MATHB ^ 2 + R ^ 2 = (R + x) ^ 2; [/math
• [mathR = radius of the earth = 6371 km; [/math
• [MATHB = 芒 藛 拧 [(R + x) ^ 2-R ^ 2. [ /math )

The curvature of the earth is very difficult to see with the naked eye.

This is because the earth is so large that it looks flat, on the ground, with the naked eye.

Even at sea, seeing a sinking ship disappearing behind the horizon, it is easy to see with the naked eye, but as soon as you grab a binoculars, you will see the whole ship again.That also has to do with breaking the light. Because of the heat layers above the water, the light, as it were, bends along with the Earth’s surface.

With the naked eye you simply do not see sharp enough at that distance.What also makes it difficult is that your eyes tend to look at the horizon, and not level forward.

What you can do yourself relatively easily is the following: Go to sea, to a high point, the higher the better.Now grab a good (and long) level.

Aim the spirit level to the sea (level of course), put 2 matchboxes close to the ends.Now when you look past the matchstick you will see that the higher you come (so from the Dunes, lighthouse, upstairs on apartment block,..), the lower the horizon will be visible below the level.

This cannot happen on an uncurved earth.And with a non-curved earth, light refraction will also not lower the horizon.

Another good example could be seen in the mountains.Mountains that should be visible on a flat earth above a lower lying mountain is not visible (Perspective for Dummies: Globe-Denier Education Edition is a good explanation of this)

Incidentally, I find the video of Theofficialfacebook (How Much of the earth can you see at Once? ) about what you can see from the earth very informative and fun made.

If you are tall enough though.

On the salt flats of Bonneville, Utah, you can see the curvature of the earth with the naked eye.

The problem is that you can not look behind the curvature, because the curvature itself is in the way.You’ll see this if the curvature reproduces a lot higher, so you can also observe it over long distances.

Here’s a nice example of this:

Soundly Proving the Curvature of the Earth at Lake Pontchartrain

Yes of course you can see that, because the earth is also around.

Now I think the flat Earth will be seriously evil.

You can see it on a cloud deck.On a tall tower or mountain, etc., you can literally see the arch. At the shadow on the moon you can see that the earth is spherical. When a ship sails away and behind the horizon “disappears”, you know that the Earth is round.

Or maybe not