Can You Detect the Earth's Curvature from a Lighthouse?

In summary, if you had an accurate transit and were standing on a lighthouse high above, you could theoretically detect the curvature of the earth. However, this would not be practical in practice due to precision and accuracy issues.
  • #1
zuz
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If you stood on a lighthouse high above with a very accurate transit, would you be able to detect the curvature of the earth?
 
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  • #2
You mean, by measuring the angle between the horizon and (ironically) the horizontal? Yes, in principle. To see if it's possible in practice depends on looking up the precision and accuracy of your instrument and a fairly straightforward exercise in trigonometry.
 
  • #3
There is an old tale that lighthouse keepers with telescopes would watch for expected sailing ships then warn merchants below with appropriate flags for different vessels. First they saw the tips of the tallest masts on the horizon, then the sails, then the body of the approaching ship; thereby confirming the curvature of the ocean surface.
 
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  • #4
Klystron said:
There is an old tale that lighthouse keepers with telescopes would watch for expected sailing ships then warn merchants below with appropriate flags for different vessels. First they saw the tips of the tallest masts on the horizon, then the sails, then the body of the approaching ship; thereby confirming the curvature of the ocean surface.
Or from the other direction, it is a standard thing in ship navigation to have handy a table of height vs horizon distance in order to predict when (how far away) you should see navigation aids.
 
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  • #5
No flat earther has ever been able to measure the curvature of the earth.
 
  • #6
profbuxton said:
No flat earther has ever been able to measure the curvature of the earth.
I doubt one can be a flat earther put an honest effort into it. It really isn't hard. The method described here requires only a nice day on the beach with a pair of binoculars, watching ships (with access to google and/or a ship tracking app).
 
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  • #7
zuz said:
If you stood on a lighthouse high above with a very accurate transit, would you be able to detect the curvature of the earth?
Theoretically, it is easy. Practically not so.
Regarding precision one may face problems due to refractive index of atmosphere, and the change in the dip of horizon from case to case. Read old article considering these issues:
http://www.fer3.com/arc/imgx/Dip-of-the-horizon-Freiesleb.pdf
 
  • #8
zoki85 said:
Theoretically, it is easy. Practically not so.
Regarding precision one may face problems due to refractive index of atmosphere, and the change in the dip of horizon from case to case. Read old article considering these issues:
http://www.fer3.com/arc/imgx/Dip-of-the-horizon-Freiesleb.pdf
"Detect", not "measure".

Note, atmospheric refraction at the horizon is partially a function of Earth's curvature too.
 
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  • #9
russ_watters said:
"Detect", not "measure".
A mere detection can be issue in extreme cases. Fata Morgana mirages
 

Related to Can You Detect the Earth's Curvature from a Lighthouse?

What is the curvature of the Earth?

The curvature of the Earth refers to the gradual slope or bend of the Earth's surface. It is the result of the Earth's spherical shape and is measured in degrees.

How is the curvature of the Earth calculated?

The curvature of the Earth is calculated using the formula for the circumference of a circle. This formula takes into account the radius of the Earth and the distance between two points on its surface.

At what distance can the curvature of the Earth be seen?

The curvature of the Earth becomes visible at a distance of approximately 3 miles (4.8 kilometers) from the observer. This is due to the Earth's large size and the fact that it is a relatively smooth sphere.

Does the curvature of the Earth affect everyday life?

While the curvature of the Earth may not have a direct impact on our daily lives, it does play a crucial role in navigation and the design of structures such as bridges and roads. It also affects the way we perceive distances and the shape of the horizon.

How does the curvature of the Earth differ on different parts of the globe?

The curvature of the Earth remains relatively consistent across the globe, but it may appear more pronounced in areas with higher elevations or steep terrain. Additionally, the Earth's curvature is slightly greater at the poles compared to the equator due to the Earth's oblate spheroid shape.

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