Understanding the 5km Horizon: How Far Can We See at the Beach?

  • Thread starter Thread starter jfoldbar
  • Start date Start date
  • Tags Tags
    Horizon
Click For Summary
The discussion centers on the visibility of distant objects at the beach, particularly boats and islands, which seems to contradict mathematical calculations of horizon distance. While the horizon for a typical human is about 5 kilometers, factors such as the height of the observer and the object can extend visibility, allowing for the sighting of masts while hulls remain hidden. Atmospheric conditions, including temperature gradients and light refraction, can also enhance visibility beyond the expected horizon. Observations from Jeju Island reveal that islands up to 50 kilometers away were visible, suggesting that environmental factors play a significant role in what can be seen. The conversation highlights the complexities of horizon calculations and the influence of atmospheric conditions on visibility.
  • #31
sophiecentaur said:
And how high are your eyes above sea level?
Total distance of 51km.

Water tower is about 80 feet tall. (at least it was. It seems to be missing now.)

On a good day I can see it from the Islington bridge, which is maybe 40 feet high.
On a very good day, I see see it from the shoreline (15 feet).

For a long time I toyed with the idea of going out every few days for a year to the exact same spot and taking a pic of the horizon with some referencible landmarks in view - just to show a montage of the horizon in varying temperatures and seasons. (I may have waited too long.)
 
Physics news on Phys.org
  • #32
A.T. said:
This is what happens when the job is given to an artist, who misses the entire point. Most of the ship, especially the chimney for which the light path is shown, are not beyond the horizon anyway.
It gets the point across.

It would be very difficult - and not very informative - to try to render this to-scale.

And, I confess, there is an extreme paucity of such diagrams out there. This is the best I could find.
 

Similar threads

B Strange Phenomena when the Sun is low on the horizon?
  • · Replies 7 ·
Replies
7
Views
2K
B Can we see 2 black holes orbiting each other?
  • · Replies 57 ·
2
Replies
57
Views
4K
B Can we see matter crossing the Event Horizon with a powerful telescope?
  • · Replies 21 ·
Replies
21
Views
3K
B How do Black Holes Grow? A Far-Away Observer's Perspective
  • · Replies 67 ·
3
Replies
67
Views
5K
B Crashing into an event horizon
  • · Replies 20 ·
Replies
20
Views
2K
I How far into the Universe can we theoretically reach?
  • · Replies 34 ·
2
Replies
34
Views
4K
I 3 questions about a paper on density fluctuations in the Universe
  • · Replies 1 ·
Replies
1
Views
2K
I Crossing an Event Horizon: My Experience
  • · Replies 15 ·
Replies
15
Views
2K
Event horizon ad the age of our universe
  • · Replies 9 ·
Replies
9
Views
2K
How Far Can A Person See?
  • · Replies 2 ·
Replies
2
Views
2K