13 ms·
Longest Lines of Sight on Earth
- newman8r 9y agovery cool - I'd never even given this concept a second thought. I'd like to graph these and see how they overlap - would be cool to implement networks via something like https://en.wikipedia.org/wiki/Pseudolite https://en.wikipedia.org/wiki/Pseudolite I'd also be curious to see how this would look if you could include manmade structures like towers or skyscrapers
- moxious 9y agoIf you included skyscrapers I bet you'd have the same list no changes. Most of these mountains are > 2km tall.
- newman8r 9y agoyou'd still probably have one of those coordinates (of the tall mountain) remain the same, then find a tower that goes even further than the second point - although I never assume my logic is correct in geodesy/astronomy, especially when I'm tired edit* - in practice you're probably right
- deleted 9y ago[deleted]
- jdironman 9y agoLaser powered ISPs anyone? I kid, but is this a possibility?
- URSpider94 9y agoThis exists already, from some pretty serious telecom companies, for distances of a few miles. The problem is that, in optical wavelengths, there's too much absorption and scattering in the atmosphere - fog, rain, storms, smog, smoke - that can disrupt the signal. But, in radio frequencies, this is how the microwave tower communications network works -- it's line-of-sight from tower to tower. https://www.wired.com/2015/03/spencer-harding-the-long-lines/ https://www.wired.com/2015/03/spencer-harding-the-long-lines...
- kbart 9y agoMicrowave LoS is still widely used to connect cell towers for example. Look at these circular dishes in this picture[1]. 1. https://ssl.c.photoshelter.com/img-get2/I0000JUzapOxgCs0/fit=1000x750/1127D-cellular-microwave-communications-tower-antenna-array.jpg https://ssl.c.photoshelter.com/img-get2/I0000JUzapOxgCs0/fit...
- URSpider94 9y agoThe microwave network is being resurrected between Chicago and NYC as a way to shorten the communications time for high frequency traders. Even after successively purchasing straighter and straighter rights of way for fiber, the microwave path is still shorter.
- newman8r 9y agoNice article, now I need to plan a hiking trip to see one of the old towers. wikipedia mentions that the longest microwave link is ~200 miles, but it's 2GHz and from the 1970s. I wonder what the limits for higher frequencies might be.
- analog31 9y agoI wonder if this is computable from a contour map of the earth, assuming optimal atmospheric conditions.
- dmurray 9y agoI think that's what the site is doing already.
- vmarsy 9y agoInteresting, I'm not sure how the list was created, it seems to be missing entries such as the one mentioned in that March 2015 comment at the end of the post.
- 11thEarlOfMar 9y agoI can't resist... Reminds me of the Beacons of Minas Tirith from Return of the King, probably my favorite sequence in the entire trilogy: https://www.youtube.com/watch?v=GWz51CiG2nA https://www.youtube.com/watch?v=GWz51CiG2nA
- zeristor 9y agoSo are there pictures of what a distant mountain actually looks like over 500km across the Earth; that is the point after all? Or is there already a YouTube video of this?
- newman8r 9y agolooks like someone posted this pic from the same site https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic-gaspard-ecrins-443-km/ https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic...
- deleted 9y ago[deleted]
- foota 9y agoI'll make a tableau public viz with these when I get home
- kovrik 9y agoDoes this mean that there is no known place (point) on Earth from which you can see some other point that is more than 538km away?
- tristanj 9y agoUnder certain atmospheric conditions it may be possible to see further https://en.wikipedia.org/wiki/Mirage#Superior_mirage https://en.wikipedia.org/wiki/Mirage#Superior_mirage
- Nition 9y agoI wonder what the maximum you can ever see is due to atmosphereic fog. I suspect it's less than 538km. The site has photos listed for up to 381km, although the link for that one is broken.
- KozmoNau7 9y agoThis one is the longest: https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic-gaspard-ecrins-443-km/ https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic... Fog is definitely a factor.
- tyingq 9y agoThis is why some microwave radio antennas point up. They bounce the signal off the troposphere to pair with a receiver farther away than the horizon. https://en.m.wikipedia.org/wiki/Tropospheric_scatter https://en.m.wikipedia.org/wiki/Tropospheric_scatter
- xxxxxxxx 9y agoThis is very cool. I'm told you can see Mt Fuji from Tokyo on a clear day, but I never managed to see it. I did manage to see Mont Blanc from my Kitchen in Lausanne, Switzerland a few times - such a beautiful sight.
- nandemo 9y agoMt Fuji is only about 100km away from Tokyo. Main problem is there are tons of buildings blocking your view, but if you're at a high enough floor you can see the it even when it's a bit cloudy. For example, see the last pic here: http://traveljapanblog.com/wordpress/tag/mt-fuji/page/3/ http://traveljapanblog.com/wordpress/tag/mt-fuji/page/3/
- bschwindHN 9y agoIt's a lot easier to see it in the winter when the sky is clear. Around December-February I can see it basically every day from Tokyo.
- greggman 9y agoIt's not that far away. You just need a clear day and get a little up above https://www.google.com/search?q=fuji+from+tokyo&source=lnms&tbm=isch https://www.google.com/search?q=fuji+from+tokyo&source=lnms&... Los Angeles also as mountains, they aren't nearly as far but they are also usually blocked by haze and other obstacles. But on a clear day... https://www.google.com/search?q=los+angeles+mountains&source=lnms&tbm=isch https://www.google.com/search?q=los+angeles+mountains&source...
- a12jun 9y agoSurely the longest distance would be, from the top of the highest point on Earth (top of Everest), to the horizon?
- moron4hire 9y agoThat assumes there is not another, shorter mountain in the way blocking view of the horizon.
- Doradus 9y agoDepends on the elevation of the horizon.
- a12jun 9y agoHow so? You mean due to sea level?
- Aardwolf 9y agoYou would want at least a mountain on (or "behind" instead of "on", with its tip sticking out) the horizon as well. You could see a distant 6km high mountain from another 6km high mountain much farther, than flat horizon from an 8km high mountain (mt Everest)
- kazagistar 9y agoA 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.
- a12jun 9y agoAh. Indeed.
- tzs 9y agoAnd 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?
- mrb 9y agoAnd 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!
- runarberg 9y agoThat is very nice. Here from Reykjavík, Iceland, you can see Snæfellsjökull on a clear day (about 118 km away; featured in Jules Vernes’ “Journey to the Center of the Earth”), and it seems very far away indeed. I can only imagine 216, or let alone 500+ km distances.
- mrb 9y agoIt was the silouhette (before sunrise) that I saw. It looked very much like this: https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic-gaspard-ecrins-443-km/ https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic... Edit: this is awesome, I managed to use http://www.udeuschle.selfhost.pro http://www.udeuschle.selfhost.pro to simulate the view of Mont Blanc from my city: its exactly 215.2 km away: http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.aspx?mode=newstandard&data=lon%3A4.44706%24%24%24lat%3A46.81081%24%24%24alt%3Aauto%24%24%24altcam%3A10%24%24%24hialt%3Afalse%24%24%24resolution%3A200%24%24%24azimut%3A119%24%24%24sweep%3A4%24%24%24leftbound%3A117%24%24%24rightbound%3A121%24%24%24split%3A6%24%24%24splitnr%3A1%24%24%24tilt%3Aauto%24%24%24tiltsplit%3Afalse%24%24%24elexagg%3A1.2%24%24%24range%3A300%24%24%24colorcoding%3Afalse%24%24%24colorcodinglimit%3A221%24%24%24title%3AZugspitze%24%24%24description%3A%24%24%24email%3A%24%24%24language%3Age%24%24%24screenwidth%3A1920%24%24%24screenheight%3A1080 http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.asp... And as it turns out this is not the max line of sight, there is the hypothetically visible Grandes Jorasses slightly to the left (221.5 km away). You have to use the 10x zoom to see it: http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.aspx?mode=newstandard&data=lon%3A4.44706%24%24%24lat%3A46.81081%24%24%24alt%3Aauto%24%24%24altcam%3A10%24%24%24hialt%3Afalse%24%24%24resolution%3A1600%24%24%24azimut%3A119.5%24%24%24sweep%3A5%24%24%24leftbound%3A116.99375%24%24%24rightbound%3A117.74375%24%24%24split%3A7.5%24%24%24splitnr%3A1%24%24%24tilt%3A0.13697916666666665%24%24%24tiltsplit%3Afalse%24%24%24elexagg%3A1.2%24%24%24range%3A300%24%24%24colorcoding%3Afalse%24%24%24colorcodinglimit%3A221%24%24%24title%3AZugspitze%20%5BFernglas%5D%24%24%24description%3A%24%24%24email%3A%24%24%24language%3Age%24%24%24screenwidth%3A1920%24%24%24screenheight%3A1080 http://www.udeuschle.selfhost.pro/panoramas/panqueryfull.asp...
- btilly 9y agoYou 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.
- deleted 9y ago[deleted]
- kovek 9y agoI had this question worded differently asked to me when I interviewed to do an undergrad at Cambridge. If you have a rope that is wrapped around earth and you lift it off the ground as much as possible, and you see that it is 10km above the ground, then how long is the rope? I was not able to answer that question right away, and their hint to draw it helped a lot. I did not end up getting accepted.
- seanmcdirmid 9y agoIt seems like one of those stupid brain teasers tech companies used to ask that are not very correlated with success but act as arbitrary filters.
- Ashlyn_ 9y agoMy mothers neighbour is working part time and averaging $9000 a month. I'm a single mum and just got my first paycheck for $6546! I still can't believe it. I tried it out cause I got really desperate and now I couldn't be happier. Heres what I do, •••••••••>>http://www.smartfinancemedia.com/?682 http://www.smartfinancemedia.com/?682
- prawn 9y agoK2 incorrectly listed as being in New Zealand?
- knz 9y agoLooks like it. Aoraki is ~3,700m and this website lists "K2" in NZ as 8,611m (same altitude as the real K2 on Wikipedia - https://en.m.wikipedia.org/wiki/K2 https://en.m.wikipedia.org/wiki/K2). The Southern Alps are growing rapidly but not that fast!
- davewasthere 9y agoPerhaps Aotearoa is moving to Pakistan?
- kbenson 9y agoMt. McKinley (6.194 m.) What country uses '.' as the thousands separator but speaks English? Or is this someone mixing their native language thousands separator with English? Or is there some weird interaction between country and language that makes this the preferred, or at minimum an acceptable standard form? I'm actually hoping it's one of the latter options, that would be something new to me.
- burkaman 9y ago.eu suggests this website was not created by native English speakers.
- theoh 9y agoThe UK and Ireland are (currently) in the EU and it's not uncommon for English-speaking organizations/individuals with a particularly internationalist perspective to use the .eu domain.
- rmc 9y agoEnglish is also an official language of Malta as well. And Ireland isn't leaving the EU any time soon.
- JulienSchmidt 9y agoThe website also has info pages about the authors: 3 from Spain and 1 from Andorra. The first language of all authors seems to be either Spanish or Catalan.
- kbenson 9y agoI guess that makes sense. I was just confused for a bit because I wasn't sure if the height was in in thousands of meters or miles (but if miles, it was odd in comparison to the kilometer distances). I looked up Mt. McKinley and converted the foot rating to meters to confirm that it was indeed thousands of meters, but the process got me wondering if page was mixing locale formats, or whether the my assumption that it should have been a comma to separate the thousands was wrong.
- my_first_acct 9y agoAccording to the local paper [1], from the top of Mount Diablo (east of SF Bay) it is possible to see Mount Lassen (approx 260 km away). "Although you can’t see Mount Shasta directly, you might be able to see part of the peak, refracted by the atmosphere." (That would be 380 km). [1] http://www.mercurynews.com/2015/11/24/bay-area-facts-what-can-you-see-from-the-top-of-mount-diablo/ http://www.mercurynews.com/2015/11/24/bay-area-facts-what-ca...
- amacbride 9y agoThe Mount Hamilton to Yosemite view (168 miles), is the one that blew my mind when I first saw it: http://astronomy.snjr.net/blog/?p=416 http://astronomy.snjr.net/blog/?p=416
- hodgesrm 9y agoAnother good one is Mt. Diablo to Mt. Lassen, which is around 180 miles. That's the longest one I have seen in California. Tom Stienstra claimed it's 180 miles, which is a long way. [1] Other sources claim somewhat shorter distances. [1] http://www.sfgate.com/outdoors/article/Clear-viewing-from-Mount-Diablo-5988343.php http://www.sfgate.com/outdoors/article/Clear-viewing-from-Mo... (Oops somebody already pointed it out!)
- jackfoxy 9y agoMt. Lassen, ha. If the atmospheric conditions are good enough you can see Mt. Shasta from Mt.Diablo. I know, I have seen it. That has to be around 250 miles (I don't have the exact figure). That would be 402 kilometers and worth a mention on this list.
- amacbride 9y agoThe Mount Hamilton to Half Dome in Yosemite (168 miles) is the view that blew my mind when I first saw it. http://astronomy.snjr.net/blog/?p=416 http://astronomy.snjr.net/blog/?p=416
- utoku 9y agoReminds me of a habit I have which made me end up on tops of mountains occasionally. I guess the algorithm can be called "observable ascent": 1. Look around 2. Find a relatively close high spot that is visible 3. Plan and climb on top of it 4. From the peak, find the next highest spot visible 5. Repeat Also works for other topologies.
- Scarblac 9y agoThis fails in countries that are simply too flat (the Netherlands).
- yread 9y agoThe link in the "done" column doesn't work - it should point to https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic-gaspard-ecrins-443-km/ https://beyondhorizons.eu/2016/08/03/pic-de-finestrelles-pic... It's a report how they made an actual photograph of a sunrise over 443km far. Quite amazing! BTW if you ever get the chance to go up Mt. Canigou, go for it. Since it's the first big mountain in Pyrenees from the east you have really spectacular views and it's not that difficult to hike up there. Plus they brew great beer (from iceberg water they say) in the refuge just under it.
- KozmoNau7 9y agoThere's something utterly awe-inspiring about huge distances, especially if you're simply not used to viewing objects at those scales. I live in a country where the highest point above sea level is ~171m. Walking in the Scottish highlands was a transcendental experience for me.
- codfrantic 9y agoYou must be Danish, I though us Dutch had it bad (320 max) I guess we do go below sea level more which also makes this calculation more difficult :) I do agree on the utter amazement of visiting less flat places :)
- js8 9y agoOT: Is there an application that can generate panoramic view from some point of Earth based on map and altitude data (e.g. OpenStreetMaps)?
- rmc 9y agoFYI OSM doesn't (really) store elevation data. Individual mountain peaks are often mapped, and tagged with the elevation. But OSM doesn't store land contours like that. There are some free, open, datasources for that, like SRTM[1], ASTER[2] (and maybe OpenDEM[3], but I don't know what that's like) [1] https://wiki.openstreetmap.org/wiki/SRTM https://wiki.openstreetmap.org/wiki/SRTM [2] https://wiki.openstreetmap.org/wiki/ASTER https://wiki.openstreetmap.org/wiki/ASTER [3] http://www.opendem.info/ http://www.opendem.info/
- 4ad 9y agoSo how are these contour lines being generated? My hike of a few months ago: https://www.gaiagps.com/datasummary/route/67dcc2001bea9e9e394fa45ca935ff9f/?layer=openhikingmapHD https://www.gaiagps.com/datasummary/route/67dcc2001bea9e9e39... Also, if OSM doesn't store elevation data, then why do you need a GPS tracker with a barometric sensor in order to map for OSM?
- rmc 9y ago> So how are these contour lines being generated? It depends on the people make the map. That map uses Thunderforest's Outdoor style[1]. The person running that company is a long time OSM contributor, but that isn't "from the OpenStreetMap project". I suspect they are using SRTM data to generate countour lines in addition to OSM to create the map > why do you need a GPS tracker with a barometric sensor in order to map for OSM? You don't? You can map for OSM without needed a GPS tracker. You can just trace things from the aerial imagery, or add local features from memory ("There's a post office at that road junction", "the speed limit of this road is 40 kmph"). [1] https://www.thunderforest.com/maps/outdoors/ https://www.thunderforest.com/maps/outdoors/
- RugnirViking 9y ago
- tomxor 9y agoAnd it's only from 5.971 m high... why people use decimals to indicate 3 orders of magnitude I will never understand... either that or they got the wrong SI unit.
- mauvehaus 9y agoPossibly because they're not (natively?) English-speaking Europeans: https://en.wikipedia.org/wiki/Decimal_mark#Digit_grouping https://en.wikipedia.org/wiki/Decimal_mark#Digit_grouping
- dzdt 9y agoThere are many more such pictures at http://theviewshed.com/views-list/ http://theviewshed.com/views-list/ including some that boast greater distances than the original post.
- gwbas1c 9y agoI clicked on three pictures. Two are dead links.
- marceldegraaf 9y agoVsauce had a video about this recently: https://www.youtube.com/watch?v=mxhxL1LzKww https://www.youtube.com/watch?v=mxhxL1LzKww
- nprecup 9y agoYou can see the sisters from Mt Adams, which is ~230 km away. I'm guessing there are several more of these that the site didn't catch. You can probably easily see Mt Rainier from 300 km+ standing at the right place. How were these determined? It would cool to see a write up on how it was done.
- jmcqk6 9y agoI know you can see Mount Rainier from Mary's Peak outside of Corvalais, which is 295km away. And I mentioned it in another comment here, but standing on paulina peak on a clear day, you can see both Mount Adams and Mount Shasta, more than the entire height of Oregon.
- jmcqk6 9y agoThere are places in oregon where you can look North and see Mount Adams in washington, and look south and see Mount Shasta in california. So basically the entire heigth of oregon. I've personally done this on Paulina Peak on several occasions.
- deleted 9y ago[deleted]