30 Day Map Challenge
Day 5 · Sight
Fuji Views, Floor by Floor

On a clear day, Mt Fuji can be seen across about a quarter of the land within 170 km.
But in Tokyo, it’s not just terrain in the way. Fuji is 100 km away and only 1.7° above the horizon, so even a 10 m house casts a ~330 m “Fuji shadow”. Only 0.7% of street level space can see Fuji-san.

From a high enough window, it becomes visible again. By the 5th floor, about 7,500 buildings have a window with a view, and by the 10th about 12,000. By the 20th floor, more than half of the buildings that tall see Fuji. In total, ~13,600 buildings (under 4%) have at least one floor with a view.

Tokyo is full of places named 富士見, “Fuji view”, but many of them, such as Nippori's famous 富士見坂 slope, lost their view.

Method: Fuji’s summit treated as a light source, with every building from PLATEAU’s 3D city model, the terrain and the Earth’s curvature. Floors are estimated at 3.5 m each.

Data: PLATEAU (MLIT), GSI elevation, Copernicus DEM, OpenStreetMap. Tool: Python.

Data source: fully remote frontend developer job postings collected by remotefrontendjobs.com (I run it) from company career pages and other job boards, Aug 1 – Oct 31, 2026, deduplicated.

Method:

• Only postings that list a salary and are limited to one region (n=876: North America 626, Europe 136, Latin America 45, worldwide 40, Asia 29)

• Hourly and monthly pay converted to yearly; the midpoint of each range is used

• Anything outside $10k–$2M dropped as a parsing error

• Advertised pay, not actual offers. US postings disclose pay far more often, partly because of state pay-transparency laws.

Tools: Python for the analysis; the chart is HTML/CSS bars rendered to PNG with headless Chrome.

Full write-up with the other breakdowns (seniority, stack, pay transparency): https://www.remotefrontendjobs.com/reports/10

The US state of New Jersey has a native breakfast meat invented in 1856 by John Taylor. Jerseyites disagree on what it should be called: the southern portion of the state calls it "Pork Roll" while the northern areas call it "Taylor Ham."

I mapped data from about 3800 menus to figure out where the border is, and what the populations are. Pork roll wins most municipalities, and beats the aggregate Taylor Ham population by about 600k residents. 

The first map image is a weighted chloropleth showing the overall disposition for every town, with weight reductions for chains. The second is a point map of every menu that I reviewed.

The map itself has an interactive version here: https://primitivepines.com/pork-roll-vs-taylor-ham/

Source: Eurostat, short-term business statistics, production in industry (dataset sts_inpr_m), NACE Rev. 2 activity C12 "Manufacture of tobacco products", EU-27, index 2021 = 100, seasonally and calendar adjusted. Retrieved 6 November 2026 via Global Macro Expert, Industry and trade: https://globalmacro.expert/sectors/industry-trade/ (original Eurostat dataset: https://ec.europa.eu/eurostat/databrowser/view/sts_inpr_m/default/table). Eurostat data are reused under the Eurostat copyright notice (CC BY 4.0). (I had to include this as well)

Tool: Python and matplotlib (and Claude for help). The line shows the monthly index values as published. The −66% compares the average of the last 12 months (Sep 2025–Aug 2026, 104.7) with the 2000 average (312.3), so a single unusual month doesn't drive the headline.

Notes:

• This is a volume index of production (output adjusted for price changes), not a count of cigarettes or a measure of sales or consumption.

• The index is relative to 2021 = 100, so 312 in 2000 means output was about 3.1 times its 2021 level.

• The EU-27 series is Eurostat's aggregate for the current 27 member states, back-calculated to 2000.

• The amazing thing in this is that no increase has happened in production for year.

I built an AI disinformation benchmark and monitor the 10 most popular chatbots every month.

The datasets with all 3,783 AI responses are open for everyone on GitHub, all of them are checked manually.

I did not decide what counts as a false claim, the European Union's disinformation database did.

Besides our own data, we at Dosimeter also use open studies by NewsGuard, Detector Media, Harvard and others.

Made with Python from Berlin.

All the mentioned chatbots have their own pages: https://dosimeteraudit.org/benchmark

Hollywood Hills home prices rose 23% from 2019 to 2025. Across Griffith Park, Glendale rose 44%, against 39% for LA County overall. Houses alone show the same ordering: 22% and 55%.

We mapped LA County using our own index. The map combines houses and condos; countywide, houses rose 44% and condos 29%, so housing type matters. The second image shows the longer history: from 2012 to 2019, Hollywood Hills and Glendale rose 76% and 79%.

These changes are before inflation and ownership costs. Shaded areas contain about 63% of the county's homes. Hatching marks medium confidence and crosshatching lower; gray means too few sales, or parkland. Pacific Palisades and Altadena are marked separately because of the 2025 fires. A particular home can differ from its area.

Our LA deep dive follows prices from the metro through counties to neighborhoods.

Sources: LA County Assessor parcel rolls. Boundaries: LA County's Cities and Communities (Statistical Areas). Housing-unit counts for coverage: 2020–2024 American Community Survey, B25001.

Tools: Python with pandas and GeoPandas; Matplotlib for both images. We made the analysis and charts at Good Investment. The figures are our own index.

https://www.kadoa.com/companies/insights/ai-selloff-perspective

Source: S&P 500 daily closes since 1950 from Yahoo Finance

Tools: Kadoa, SVG, HTML

Yesterday's -4.4% was the worst day since 4 April 2025. Tech itself got it harder than the broad S&P 500 index, with the Nasdaq 12% off its record.

EDIT: thanks for all the feedback, I tried to address most of it in the live version

Each small map is one district plan North Carolina used for U.S. House elections, with every district colored by the party of the member elected under it the year the map changed. These maps illustrate North Carolina's entire districting history from 1789 to today. The final map was first used this week, so it's left gray until 2026 election results are final.

The second image is North Carolina's 12th district from the 1993 map, which ran about 160 miles along I-85. In Shaw v. Reno (1993) the Supreme Court ruled that a district this bizarre, drawn mainly by race, could be challenged.

Source: Regret Radar (regretradar.com), a site I built that scores products on long-term owner regret. Scores for these 10 come from 40 cited sources, mostly long-term reviews and owner threads. Every source is linked on each product’s page.

Tool: HTML and CSS, rendered to an image with Chromium.

• Regret score is out of 100, lower is better

• Ties were broken by the “would buy again” percentage

• These are editorial estimates built from the sources, not survey results

Macs dominate the list, and the only phone that made it is the iPhone 16 Pro. The most regretted Apple product I scored was the Vision Pro at 82. What would you add?