How far is the horizon from 1000 metres?
There isn’t a fixed answer because your perception of the horizon can be affected by conditions such as weather, time, your location, the view in front of you, and how high you are above sea level. The horizon will be further away if you are standing on top of a cliff as opposed to sitting on a beach.
A general calculation is to multiply your height in metres above sea level by 13, and calculate the square root. You will then be left with a number, which is the distance to the horizon in kilometres. There are more precise means of calculation but I’m sure you don’t want to go near explaining trigonometry, the curvature of the earth, and light refraction to your child.
Short answer: If you are of average height – say 1.75 metres – and at sea level facing the ocean, the horizon is 4.77 kilometres away.
