Thanks for the replies!
Thank you very much, Simon! I have used your post in a debate in another forum: http://forums.spacebattles.com/threads/iron-giant-vs-supcom-aeon-gc.332686/page-2.
I appreciate your help.
Regards,
Lonious
I'm quite aware of how to compute how FAR you are from the horizon, but my question is, how WIDE is the observable horizon at sea level (like, from left to right, how many kilometers is this):
http://www.jeicentral.com/wp-content/uploads/2014/10/far_sunset_in_te_ocean_horizon-wide.jpg
Thanks!