Hacker News: tppiotrowski

New comment by tppiotrowski in "LA Metro has some of the slowest escalators on Earth"

tppiotrowski — Sun, 27 Sep 2026 01:17:51 +0000

I remember the same in Tiblisi, Georgia!

New comment by tppiotrowski in "Worst-case glacial lake flood scenarios in a transboundary Himalayan basin 2022"

tppiotrowski — Thu, 27 Aug 2026 01:38:17 +0000

Syabru Besi is downriver of the border and the starting point for the Langtang valley trek which is probably the third most popular trekking location in Nepal (behind Everest basecamp and Annapurna circuit). I think the tourist data they have is from tourists that are traveling with guides but from my experience many tourists also bypass the official requirements and trek solo so the number could be much higher if the Langtang is affected.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Thu, 13 Aug 2026 00:37:14 +0000

The cloud effect is really nice!

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Thu, 13 Aug 2026 00:35:34 +0000

Building data comes from OvertureMaps data which is a superset of OSM. I update the building data set each month so if you make changes in OSM they should show up on ShadeMap at latest 30 days later.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 23:18:03 +0000

Nice. I'm really proud of how fast the annual sunlight calculation is for a location but it def needs better UX.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 20:06:17 +0000

"Top of canopy" - view from above like looking down from an airplane window. You won't see any shadows looking down on a forest because you only see sunlight landing on the top of the canopy. Most accurate.

"Below canopy" - what shadows would look like on the ground. If you're in a dense forest everything is in shadow because the trees obscure the sun. I guesstimate how big and where the below canopy shadows land. Any vegetation that's more than 2 meters tall, I place a shaded area beneath it. Not super accurate because it treats trees like cylinders instead of a sphere/triangle on top of a cylinder.

"No trees" - only building and terrain shadows are shown on the map.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 18:51:57 +0000

The map likely geolocated you somewhere without buildings (or maybe in the ocean) and where it is the middle of the night (so everything is in shadow).

Try this link which shows the shadows at the Space Needle in Seattle WA today at 5pm:

https://shademap.app/@47.61991,-122.34913,15.43536z,17865792...

Or look at the shadows of the Alps at sunrise:

https://shademap.app/@45.46158,6.45036,7.47555z,178633748245...

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 17:48:09 +0000

Agreed. From current data it's not possible to know the type of tree, only their locations so the model is simplified.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 17:22:48 +0000

Sorry about that. The current tree estimate is done via computer vision but I am working on migrating to LiDAR backed data which should eliminate false positives.

Just waiting for the TBs and TBs of data to download and then this Macbook M4 is going to make some heat...

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 17:12:29 +0000

Thanks for the reply. Do you have a tree or bush outside your window? I estimate where tree shadows fall but it's not super accurate. In the settings dialog you can toggle, "below canopy", "above canopy" or disable tree shadows altogether.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 16:54:30 +0000

Site maintainer here. There is a polygon drawing tool in the upper right corner of the map. You can use it to draw polygons on the map and assign them a height. The shadows will update instantly. You can use it to add buildings that are missing from the map, simulate a tree placement or even simulate cutting down a tree if you set the height to 0.

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 16:52:40 +0000

Website creator/maintainer here. Happy to try and diagnose the error if you elaborate on what the discrepancy is (tree, building, hill, etc)...

New comment by tppiotrowski in "Shade Map"

tppiotrowski — Wed, 12 Aug 2026 16:48:06 +0000

Not specifically for eclipses but has been useful in finding places where the sun will be visible during the current eclipse since the eclipse will occur when the sun is quite low on the horizon.

New comment by tppiotrowski in "Shademap: Global Sun Simulation"

tppiotrowski — Tue, 02 Jun 2026 14:06:15 +0000

Happy to field any questions about the project.

New comment by tppiotrowski in "I let AI build a tool to help me figure out what was waking me up at night"

tppiotrowski — Mon, 11 May 2026 21:48:51 +0000

Related project I did in 2014 tried to do this. I was a web developer so used the web audio APIs to trigger a recording when the decibel level exceeded a certain value. I was living in a big tent in my friends back yard in Sydney at the time and was convinced it was airplanes coming into SYD that were waking me up at 4am but never really captured conclusive evidence because my laptop battery couldn't make it through the night :)

New comment by tppiotrowski in "Entities enabling scientific fraud at scale (2025)"

tppiotrowski — Wed, 11 Mar 2026 15:10:09 +0000

Maybe we need a journal completely dedicated to replication studies? It would attract a lot of attention I think.

New comment by tppiotrowski in "Map of all the buildings in the world"

tppiotrowski — Wed, 10 Dec 2025 16:55:09 +0000

> This is a huge leap from the previous global dataset, which contained about 1.7 billion buildings

I use the monthly release of Overture Maps building dataset and the last one had around 2.3 billion buildings iirc

[1] https://docs.overturemaps.org/blog/2025/11/19/release-notes/

New comment by tppiotrowski in "The last-ever penny will be minted today in Philadelphia"

tppiotrowski — Thu, 13 Nov 2025 01:46:02 +0000

I remember thinking there's a small arbitrage opportunity in countries that don't have pennies and nickels. In NZ I believe stores round to the nearest decimal (.02, .01 => .00 and .03, .04 => .05). They lose on some sales but gain on others. However, they don't round if you use a CC.

Here's one for the FIRE folks: if it rounds up, use a CC and if it rounds down use cash. Use all those pennies you save using your CC to retire 3 minutes early.

New comment by tppiotrowski in "Vibe Code Warning – A personal casestudy"

tppiotrowski — Tue, 11 Nov 2025 02:43:15 +0000

I think what Claude generated code is still missing is the feeling of "I learned something from reading this code. Reading this code made me a better programmer". We're not there yet. That's why we have forgiveness for the scripts/tests/etc Claude writes - those are purely for utility. However, reading Claude code must make us feel like we're getting smarter, not dumber.

New comment by tppiotrowski in "I analyzed 180M jobs to see what jobs AI is replacing today"

tppiotrowski — Mon, 03 Nov 2025 15:03:28 +0000

My experience using Claude code is that it's excellent at React/React Native and because apps are mostly a View layer the consequences of bad "vibes" are less far reaching.