Fantastic venture and poetic that the collaboration started here on lobste.rs. Did you account for the irregular curvature of the earth when calculating view sheds or was that built into the data somehow?
Yeah, it was on Lobsters "What Are You Doing This Week?" thread!
Well scientifically the globe is apparently an oblate spheroid. But we've only assumed it to be a perfect sphere. Considering this is just a first run and that the vast majority of ordinary lines of sight are not of the same order as the longest, we've just assumed that the oblateness is not a significant factor. But we'd love to research the effects more.
One of the top ten line of sites is Antarctica, which would have an advantage when considering the poles are flatter than the equator, but I don't understand how that separates from ordinary vs longest.
For a 100km line of sight the oblateness doesn't matter much, which is a majority of the world's lines of sight which Tom is calling "ordinary". If we were to factor this in for every line of sight on the planet it wouldn't change the output much, and why we didn't do the work to model it initially.
Only when it gets up into the very long lines of sight does it become more interesting of a question. Being off by 2% would be 10km for some of the longest, so it matters more that you have your model tuned.
That's where we're interested in getting into the weeds for modeling oblateness along with many other things to see how much it matters.
Thanks for posting, I was really looking forward to this! I clicked on my (very flat) hometown and it pointed to some distant hills I don't remember ever spotting on the horizon, so next time I'm there I'll have to see if conditions are good enough to see them. :)
Really cool! Love exploring familiar areas through that, looking forward trying this out during a hike one day.
What's also pretty cool is for example checking out line of sight between the Greek island Crete and Gavdos, as a kid we'd travel across the island and were always surprised on the many different points one could still see Gavdos - I guess this would allow you to play that game even further and explore the most furthest away places.
Impressive work and truly wonderful to see the positive impact of lobste.rs on "What Are You Doing This Week" postings. Whilst it's to quite hard understand all of the write-up on a casual afternoon read, it's still great inspiration. Good job both of you on the entire project, including the impressive write-ups and illustrations.
In regards of the longest distance, here is a blog posting that shows an image of how that look like if one tries to take a picture that far (almost invisible).
Aww thanks for the supportive comment. I know that both Ryan and I also enjoy geeky deep dives into niche topics, so it's wonderful to be able to give some of that pleasure back.
Also I like how the Southern coast of Gavdos seems to be in "shadow", which is really the heatmap saying that it suddenly can't see Crete.
OMG, I remember our comments about the mirrors! Ryan and I have mentioned it couple of times. It has a Travelling Salesman vibes to it. Which actually connects to one of the actual legitimate uses of this whole thing: optimisation telecommunications towers, Wifi mesh networks, etc. So it's certainly on our radar.
That's the third total submission by @tombh, second on the topic with lots of credit to another person collaborating, each with a 4 Months difference. This is generally well accepted within lobste.rs, I personally vouch for that this is certainly welcome and not spam - in contrary, this appears to be a well integrated attempt to participate the community.
briankung | a month ago
Fantastic venture and poetic that the collaboration started here on lobste.rs. Did you account for the irregular curvature of the earth when calculating view sheds or was that built into the data somehow?
[OP] tombh | a month ago
Yeah, it was on Lobsters "What Are You Doing This Week?" thread!
Well scientifically the globe is apparently an oblate spheroid. But we've only assumed it to be a perfect sphere. Considering this is just a first run and that the vast majority of ordinary lines of sight are not of the same order as the longest, we've just assumed that the oblateness is not a significant factor. But we'd love to research the effects more.
ClashTheBunny | a month ago
I don't get the second part of the consideration.
One of the top ten line of sites is Antarctica, which would have an advantage when considering the poles are flatter than the equator, but I don't understand how that separates from ordinary vs longest.
rberger | a month ago
Ryan from Tom and Ryan here.
For a 100km line of sight the oblateness doesn't matter much, which is a majority of the world's lines of sight which Tom is calling "ordinary". If we were to factor this in for every line of sight on the planet it wouldn't change the output much, and why we didn't do the work to model it initially.
Only when it gets up into the very long lines of sight does it become more interesting of a question. Being off by 2% would be 10km for some of the longest, so it matters more that you have your model tuned.
That's where we're interested in getting into the weeds for modeling oblateness along with many other things to see how much it matters.
tsion | a month ago
Thanks for posting, I was really looking forward to this! I clicked on my (very flat) hometown and it pointed to some distant hills I don't remember ever spotting on the horizon, so next time I'm there I'll have to see if conditions are good enough to see them. :)
pl | a month ago
Really cool! Love exploring familiar areas through that, looking forward trying this out during a hike one day.
What's also pretty cool is for example checking out line of sight between the Greek island Crete and Gavdos, as a kid we'd travel across the island and were always surprised on the many different points one could still see Gavdos - I guess this would allow you to play that game even further and explore the most furthest away places.
Impressive work and truly wonderful to see the positive impact of lobste.rs on "What Are You Doing This Week" postings. Whilst it's to quite hard understand all of the write-up on a casual afternoon read, it's still great inspiration. Good job both of you on the entire project, including the impressive write-ups and illustrations.
In regards of the longest distance, here is a blog posting that shows an image of how that look like if one tries to take a picture that far (almost invisible).
Do you have an answer on the mirror problem yet?
[OP] tombh | a month ago
Aww thanks for the supportive comment. I know that both Ryan and I also enjoy geeky deep dives into niche topics, so it's wonderful to be able to give some of that pleasure back.
So if I zoom in on Gavdos then click on the "In current viewport" line in the Trophy toggle on the right of the map, I get this longest line for the summit of the island https://map.alltheviews.world/longest/24.072783619995192_34.836099668851816
Also I like how the Southern coast of Gavdos seems to be in "shadow", which is really the heatmap saying that it suddenly can't see Crete.
OMG, I remember our comments about the mirrors! Ryan and I have mentioned it couple of times. It has a Travelling Salesman vibes to it. Which actually connects to one of the actual legitimate uses of this whole thing: optimisation telecommunications towers, Wifi mesh networks, etc. So it's certainly on our radar.
nadim | a month ago
Wow, nice! Has anyone ever taken a photo from up there? All I see in your links is maps.
[OP] tombh | a month ago
Our #3 longest line has been photographed https://www.guinnessworldrecords.com/world-records/66661-longest-line-of-sight-on-earth
rggr | a month ago
That's especially interesting for ham radio enthusiasts.
[OP] tombh | a month ago
Because of how the algorithm could be used to model radio waves?
patryk | a month ago
pl | a month ago
That's the third total submission by @tombh, second on the topic with lots of credit to another person collaborating, each with a 4 Months difference. This is generally well accepted within lobste.rs, I personally vouch for that this is certainly welcome and not spam - in contrary, this appears to be a well integrated attempt to participate the community.
Here a lengthy previous conversation on the topic: https://lobste.rs/s/7mx8tx/is_it_appropriate_keep_submitting
[OP] tombh | a month ago
Thanks for letting me know.