How large would a circular wall need to be to appear straight?
How large (in terms of height and radius) would an outdoor circular wall (like a city wall on a colossal scale) need to be before a casual observer would perceive the wall as "straight"? I found "What is the minimum radius of a circular corridor for the walls to appear straight?" and based on this answer:
...the tunnel must bend less than 0.01 degrees over the proposed 20 meters visual range. Therefore, the tunnel would need to be (360/0.01)*20 meters in length, or 720 kilometers. This will put the inner radius at about 115 kilometers.
some examples of distance to the horizon courtesy of Wikipedia, and some hasty back-of-the-envelope math I came up with a minimum diameter of ~53,000km which seems... high, given that the Earth itself only has a diameter of ~13,000km. Is my math just completely off, is this formula incorrect for this problem, or is a wall that big just not possible?
This post was sourced from https://worldbuilding.stackexchange.com/q/149643. It is licensed under CC BY-SA 4.0.
0 answers
0 comment threads