Algorithmically finding the longest line of sight on Earth
Details
- External ID
- 46943568
- Source
- HN
- Company
- —
- Product
- Algorithmically finding the longest line of sight on Earth
- Website domain
- alltheviews.world
- Launched
- Feb. 9, 2026
- Cohort
- —
- Upvotes
- 412
- Upvotes percentile
- 0.9892183288409704
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Description
We're Tom and Ryan and we teamed up to build an algorithm with Rust and SIMD to exhaustively search for the longest line of sight on the planet. We can confirm that a previously speculated view between Pik Dankova in Kyrgyzstan and the Hindu Kush in China is indeed the longest, at 530km.We go into all the details at https://alltheviews.worldAnd there's an interactive map with over 1 billion longest lines, covering the whole world at https://map.alltheviews.world Just click on any point and it'll load its longest line of sight.Some of you may remember Tom's post[1] from a few months ago about how to efficiently pack visibility tiles for computing the entire planet. Well now it's done. The compute run itself took 100s of AMD Turin cores, 100s of GBs of RAM, a few TBs of disk and 2 days of constant runtime on multiple machines.If you are interested in the technical details, Ryan and I have written extensively about the algorithm and pipeline that got us here:* Tom's blog post: https://tombh.co.uk/longest-line-of-sight* Ryan's technical breakdown: https://ryan.berge.rs/posts/total-viewshed-algorithmThis was a labor of love and we hope it inspires you both technically and naturally, to get you out seeing some of these vast views for yourselves!1. https://news.ycombinator.com/item?id=45485227
Enrichment
- Theme
- space and geospatial visualization tools
- Vertical
- Horizontal
- Function
- Analytics & BI
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- longest line of sight on earth
- Manually corrected
- False
Could you build this?
No Exhaustively computing the longest line of sight across global elevation datasets requires high-performance computing, advanced computational geometry, planetary geodesy (accounting for atmospheric refraction and the Earth's geoid), and bespoke SIMD-optimized Rust algorithms operating over terabytes of DEM data. This is a specialized academic/computational mathematics problem that cannot be vibe-coded.
What it would actually take: The solution requires ingesting global digital elevation models (DEMs like SRTM or Copernicus 30m) totaling tens of terabytes of elevation rasters, chunked and indexed into spatial hierarchies. The core algorithm implements ray-marching line-of-sight visibility with atmospheric refraction models (varying k-factors) and curved-earth geodetic calculations, accelerated with hand-tuned SIMD vectorization and GPU/cluster batching to evaluate trillions of potential summit-to-summit raycasts. This demands deep expertise in geospatial algorithms, high-performance computing, and numeric optimization.
Discussion
20 comments analyzed.
Competitors mentioned: QGIS, Traditional topographic maps, Standard viewshed algorithms
Concerns raised: Accuracy issues at shorter ranges due to polygon resolution vs elevation map, Heatmap visibility disparities - dark areas may hide valid views, Storage costs extremely high (200GB+ for single line of sight per point), Atmospheric haze and visibility limits not accounted for in theoretical sightlines, Observer height assumptions may not match real-world conditions
Feature requests: Evaluate refraction only at specific azimuth points rather than full grid, Improve short-range resolution and accuracy near peaks, Better handling of atmospheric refraction effects in calculations, Use absolute global values for heatmap instead of dynamic per-viewport scaling
Competitors
Other products that read as similar to this one — 53 launches clear the similarity bar, closest 8 shown.
Attention rank: #2 of 54 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 79 days after the earliest competitor.
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- What if the speed of light was 5 km/h? · hn · 2026-09-10 · 626 upvotes · similarity 0.39
- AxionOrbital Space : SOTA Foundation Models for 24/7 Earth Observation · yc · 2026-01-06 · 230 upvotes · similarity 0.38
- StratoSync · ph · 2026-09-15 · 1 upvotes · similarity 0.38
Other launches for this product
- No other launches for this product.
Same idea, different domain
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