Belshazzar's Clock, luminous paint night clock
There should have been a video here but your browser does not seem to support it. Over a number of years, I’ve experimented with various projects which use luminous paint and ultra violet LEDs to make raster or vector displays. You can see an indifferent video of the very first one here:
Belshazzar's Clock, luminous paint night clock launched on January 8, 2025 with 73 votes, #422 of 6,142 launches that month and more than 95% of that year's launches. The site was still online in September 2026, 1 year on.
In plain words
Belshazzar's Clock is a night clock featuring luminous paint that glows in the dark. Designed for use in bedrooms or other low-light environments, it allows users to tell time without turning on lights. The clock is built for anyone who needs to check the time during nighttime hours while maintaining dark conditions for sleep. Its luminous display is the key feature that distinguishes it from standard timepieces.
written from the facts on this page · September 2026
From the sources
Over a number of years, I’ve experimented with various projects which use luminous paint and ultra violet LEDs to make raster or vector displays. You can see an indifferent video of the very first one here: As these displays were mainly intended as installations at Maker Faires and EMF Camp, they tended to be on the big side, around 2 metres long and 500 mm to 1.5 metres high. Accordingly, they never found permanent homes, and because of the general pressures of installation work, there are only a couple of rough videos to record their existence. Here’s another one of Belshazzar 2, which was a vector display with a low power UV laser: Belshazzar’s feast, or the story of…from blog.karliner.net
Does a similar job
all alternatives →
Luminous Objects Clock2021 · luminousobjects.com · ▲8260 LED arrays power an all new kind of time keeper
- NANebula – Alarm clock where you grow stars while you sleep2017 · alextumanov.com · ▲345
Virtual Sun2020 · innerscene.com · ▲101We built CircadianLab, a free in-browser tool for lighting design. It uses webGPU shaders to calculate melanopic equivalent daylight illuminance (mel-EDI, formerly EML, relevant for circadian rhythm and WELL v2 compliance), photopic illuminance, UGR glare per CIE 117, and actual daylight through windows and skylights. It has a database of 400,000+ IES files from 81 lighting manufacturers and supports easy sharing of scenes/configs with other people. Daylight uses the NREL Solar Position Algorithm and a Perez clear / intermediate / overcast sky model, mixed into the same…
More life & fun this month
the category →
A free city-building game in your browser. You are the mayor. You know what the city needs. Now get it past the zoning board, the neighbors, the appeals court and the next election.
Life & fun · 1d ago · permit.petercai.com
- IV
Life & fun · 13d ago · tanzaniaeducationproject.org
Turn a phone, tablet or TV into a sign. Type a message and it fills the screen: welcome signs, timers, Wi-Fi passwords and more. No app, no account, free.
Life & fun · 14d ago · bigwords.page
Play a free virtual guitar online with your keyboard or by touch. Slow songs down and see every chord, string and strum. Acoustic, classic, electric and bass.
Life & fun · 8d ago · guitoro.com
Carrier settings from iPhone, Pixel and Galaxy firmware, decoded and compared: APNs, VoLTE, 5G and Wi-Fi Calling per carrier, and what each build changed.
Life & fun · 12d ago · carrierexplode.com
Life & fun · 22d ago · space.bl2.net
Source: Show HN post ↗
Launched alongside, January 2025
the whole month →
Hello! I'm Byran. I spent the past ~6 months engineering a laptop from scratch. It's fully open-source on GH at: https://github.com/Hello9999901/laptop
Dev tools · 2025 · byran.ee
- TITetris in a PDF▲1,289
I realized that the PDF engines of modern desktop browsers (PDFium and PDF.js) support JavaScript with enough I/O primitives to make a basic game like Tetris. It was a bit tricky to find a union of features that work in both engines, but in the end it turns out that showing/hiding annotation "fields" works well to make monochrome pixels, and keyboard input can be achieved by typing in a text input box. All in all it's quite janky but a nice reminder of how general purpose PDF scripting can be. The linked PDF is all ASCII so you can just open it in a text editor, or have a look at…
Life & fun · 2025 · th0mas.nl
21st.dev▲1,211I originally built this app to organize and reuse interesting React + Tailwind components I came across on Twitter, inspired by the shadcn/ui approach. Later, a friend started contributing their own components, and it got me thinking—this could grow into something bigger, like an NPM for design engineers to share and use components. Would love to hear your thoughts!
Dev tools · 2025 · 21st.dev
Create lifelike, personalized AI avatars from text prompts
AI · 2025 · jogg.ai
CSS library based on Counter Strike 1.6 UI.
Life & fun · 2025 · cs16.samke.me