HorizonYou are currentlybrowsing as guest. Click here to log in 

The Horizon is that imaginary line on the Earth's surface that marks the furthest point that can be seen from your vantage point. The exact distance to the horizon depends on your altitude, and increases as you get higher. That's why the lookout on a ship was always posted at the highest point on the ship.
The exact values depend, or course, on the local topography, but we usually get close enough simply by assuming the Earth is a sphere. We need to know the size of the Earth to do the sums.
Interestingly, the distance to the horizon calculation is effectively identical to the calculation of orbital velocity.
Enrichment tasks
Find a formula for the distance to the horizon from a height h on a spherical planet of radius R.
Formulate an experiment to find the minimum height from which people would perceive the horizon to be curved rather than a straight line
Last change to this page Full Page history Links to this page 
Edit this page (with sufficient authority) Change password 
Recent changes All pages Search 