And I thought seeing Mont Blanc from my town Le Creusot, France (a 216 km line of sight) was very long... not! Apparently it would only rank 6th from the bottom of this list!
Longest Lines of Sight on Earth
21–30 of 164 posts
Re: Longest Lines of Sight on Earth
#22Surely the longest distance would be, from the top of the highest point on Earth (top of Everest), to the horizon?
This is what I thought at first too, but as others have pointed out, there are lots of nearby mountains that block the horizon in the Himalayas.
Here's a panorama using the same tool the article uses:
http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.asp...
The furthest point from the top of Mt. Everest that you can see is 303km away, and it's tucked between two faraway mountains.
Edit: I'm sorry, but this comment is wrong. I used the tool incorrectly. In fact, longest LOS from Everest is 8th on the list, and is 455km long. I assumed that when the tool auto-completed Everest it would give me the peak, but it did not.
Re: Longest Lines of Sight on Earth
#23Surely the longest distance would be, from the top of the highest point on Earth (top of Everest), to the horizon?
Plug the height of Mount Everest, 29,029 feet into this calculator, and you get a distance to the horizon of 208.8 miles:
http://www.ringbell.co.uk/info/hdist.htm
However, the distances in the post reach ~334 miles. So it's not that simple.
You'll notice that several of the entries are between mountain peaks, which is what is really going on. If you can imagine a mountain peak that is visible beyond the horizon, the distance will be greater than the distance to the horizon.
Re: Longest Lines of Sight on Earth
#24Surely the longest distance would be, from the top of the highest point on Earth (top of Everest), to the horizon?
A mountain might be past the "natural" horizon but emerge from beyond it. Thus, two mountains at the right distance and line of sight could easily have a longer horizion distance.
And this is indeed the case for the ones at the top of the list. The longest possible distance to horizon is a little over 330 km, but almost 40 of the items on the list have longer line of site.
In fact, it looks like every item on the list is between two points that are each farther away than the other's horizon.
That raises the question of among all places on Earth where the longest line of sight is to the horizon, which has the longest line of sight?
Re: Longest Lines of Sight on Earth
#25You can actually work out roughly how far away the horizon should be surprisingly easily. Just use the fact that if R is the radius of the Earth and you are at height h, then from you to the horizon to the center of the Earth back to you is a right angled triangle with one side of length R and the hypotenuse of length R+h. Therefore the distance to the horizon is sqrt(2Rh+h^2) which is roughly sqrt(2Rh).
The Earth is roughly 6370 km which is not far from 6400, so if your eyes are 2m = 0.002 km up then the horizon is about sqrt(264000.002) = sqrt(25.8) km away, which is roughly 5 km or a bit over 3 miles.
If you apply this to a 6 km tall mountain, the horizon is about sqrt(263706) km away which is about 276.5 km. So something of the same height at the opposite end of the horizon would be 553 km away. So the top distance of 538 km is pretty close to the maximum that we would expect.
What about an airplane? An airplane flies about 11 km up. So it can see around 375 km. If you work it out, that puts the horizon about 3.37 degrees below horizontal. This isn't much, but if you take a plumb line and a right angle on an commercial flight, it is enough to actually see that the horizon is below horizontal.
Re: Longest Lines of Sight on Earth
#26Earlier quoted context omitted.
A mountain might be past the "natural" horizon but emerge from beyond it. Thus, two mountains at the right distance and line of sight could easily have a longer horizion distance.
And this is indeed the case for the ones at the top of the list. The longest possible distance to horizon is a little over 330 km, but almost 40 of the items on the list have longer line of site. In fact, it looks like every item on the list is between two points that are each farther away than the other's horizon. That raises the question of among all places on Earth where the longest line of sight is to the horizon…
Hawaii would be where I'd start looking for that.
Re: Longest Lines of Sight on Earth
#27Surely the longest distance would be, from the top of the highest point on Earth (top of Everest), to the horizon?
This is what I thought at first too, but as others have pointed out, there are lots of nearby mountains that block the horizon in the Himalayas. Here's a panorama using the same tool the article uses: http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.asp... The furthest point from the top of Mt. Everest that you can see is 303km away, and it's tucked between two faraway mountains. Edit: I'm sorry, but this com…
In case anyone else was wondering, the longest line of sight from Mt. Davidson, the tallest hill in San Francisco, is 148.9km, looking southeast over the length of the bay. Here's a panorama:
http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.asp...
Re: Longest Lines of Sight on Earth
#28You can actually work out roughly how far away the horizon should be surprisingly easily. Just use the fact that if R is the radius of the Earth and you are at height h, then from you to the horizon to the center of the Earth back to you is a right angled triangle with one side of length R and the hypotenuse of length R+h. Therefore the distance to the horizon is sqrt(2Rh+h^2) which is roughly sqrt(2Rh). The Earth is…
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Re: Longest Lines of Sight on Earth
#29K2 incorrectly listed as being in New Zealand?
Re: Longest Lines of Sight on Earth
#30Surely the longest distance would be, from the top of the highest point on Earth (top of Everest), to the horizon?
A mountain might be past the "natural" horizon but emerge from beyond it. Thus, two mountains at the right distance and line of sight could easily have a longer horizion distance.
which is probably why the site is called "Beyond Horizons"