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Products that do what I was playing with fundamental constants and 13.8 b years popped out does
I was playing around with fundamental constants and out popped 13.8 billion light years. What is going on? the wavelength of an electron mass photon / (2pi) * the charge radius of a proton / the black hole radius of a proton = 13.8 billion light years ((h / (m_e * c * 2pi)) * (h / (m_p * c * pi/2)) / (2G * m_p / c^2)) = 13.8 billion light years…
- 1LN
I was reviewing Dirac's Large Numbers Hypothesis (https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis) and decided to give it a second go, now with measurements of fundamental constants more precise than 100 years ago. And I stumbled upon a value for Hubble's constant that's uncannily close. Here are the full calculations. https://colab.research.google.com/drive/1K1qoUFvqZp1fWbpcKJWq63nflgwS0ZHh?usp=sharing Meaningless, or meaningful coincidence?
2021
- 2DH
2021 · colab.research.google.com
- 3PA
We have a black hole at home — with actual relativistic physics, live in your browser. I'm Sasha (Alexander) Plavin, an astrophysicist at Harvard's Black Hole Initiative studying quasars and black hole environments. I work with raytracing/radiative transfer simulations professionally, and wanted to make one anyone can play with — so I built this app. Put the black hole onto your screen (any browser), or directly into your room with AR or VR (requires WebXR, for example Chrome on Android, or any VR headset). When looking around, pay attention to unintuitive relativistic effects: rays…
Jul 2026 · blackhole.plav.in
- 4HB
2015 · atom.io
- 5AP
We ported pbrt-v4 to Julia and built it into a Makie backend. Any Makie plot can now be rendered with physically-based path tracing. Julia compiles user-defined physics directly into GPU kernels, so anyone can extend the ray tracer with new materials and media - a black hole with gravitational lensing is ~200 lines of Julia. Runs on AMD, NVIDIA, and CPU via KernelAbstractions.jl, with Metal coming soon. Demo scenes: github.com/SimonDanisch/RayDemo
Feb 2026 · makie.org
- 6IR
2021 · htwins.net
- 7IB
I built this because measuring my age in years felt boring—I wanted to see the kilometers. The first version only used Earth's orbital speed (~30km/s), but the number moved too slowly. To get the "existential dread" feeling, I switched to using the Milky Way's velocity relative to the CMB (~600km/s). The math takes some liberties (using scalar sum instead of vector) to make the speed feel "fast," but it gets the point across. Under the hood, it's a single HTML file with zero dependencies. No React, no build step. The main challenge was the canvas starfield—I had to pre-allocate the…
Jan 2026 · cosmic-odometer.vercel.app
- 8S2
Had some fun with shared array buffers over many months of free time. Skip to the end to play around with the final app. Open to ideas on how to simulate more whilst staying in js land.
2024 · dgerrells.com
- 9RA
2021 · ramp-book.com
- 10

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- 12DI
Full Paper (Zenodo): https://zenodo.org/records/18027729 Help Needed: I am looking for feedback on the experimental setup. The main engineering challenge is maintaining GHZ coherence long enough to isolate the effect from environmental noise. If you have Hi HN. Standard General Relativity posits that time dilation is caused solely by mass-energy. But what happens when information entropy reaches a critical density? I have released Version 2.0 of my paper, proposing the Information-Induced Time Dilation (ITD) hypothesis. The Hypothesis: I propose that local information…
Dec 2025
- 13IB
Mar 2026 · structuredlabs.github.io
- 14BH
2015 · github.com
- 15

- 16IW
Input a SMILES string (or pick one molecule from the examples) and it returns up to 100k molecules closest in 3-D shape or electrostatic similarity – from 10+ billion scale databases — typically in under 5-10 s. *Why it might interest HN* * Entire index lives on disk — no GPU at query-time, less than ~10 GB RAM total. * Built from scratch (no FAISS index / Milvus / Pinecone). * Index-build cost: one Nvidia T4 (~ 300USD) for one 5.5B database. * Open to anyone, predict ADMET, export results as CSV/SDF. Full write-up & benchmarks (DUD-E, LIT-PCBA, SVS) in the pre-print:…
2025 · cheese-new.deepmedchem.com
- 17GA
A fork of Solar System Live that generates animated videos showing planetary orbits over any date range. Tracks orbital statistics (how many times Earth was lapped by Mercury/Venus, or lapped outer planets) and overlays dates/ages on each frame. Example: Einstein's lifetime (1879-1955) showing 76 years of solar system evolution. Built with Python + Pillow + ffmpeg, runs locally with Lighttpd. https://github.com/simondorfman/solar_system_live
Jan 2026 · github.com
- 18SP
Context: I'm looking at Norman Wildberger's rational trigonometry[1], and here I was wondering how useful it is in physics. So I thought about testing it with the famous simple pendulum exercise. It's not obvious we get any FPS gain, but still I find it cool to even be able to get the same result differently. 1. https://en.wikipedia.org/wiki/Rational_trigonometry
2016 · grondilu.github.io
- 19PC
JavaScript implementation of the famous `10 print chr$(205.5+rnd(1)) goto 10` one line of BASIC code. data:text/html,a=()=>{document.write(Math.random(){a();window.requestAnimationFrame(update)};update() Copy and paste the above "link" in your browser.
2021
- 20BA
2020 · andrewsun.com
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- 22TA
Hi HN! I’ve spent the summer of the past 2 years building The Atlas, a procedural universe simulator that generates 1 sextillion galaxies (10²¹) from a single mathematical seed. Think No Man’s Sky meets theoretical physics, but running entirely in your browser. Everything is purely deterministic, the universe is calculated from SHA-256 hashed seeds using the golden ratio as primordial constant. There’s no database, no pre-saved data, just pure math. Time itself is treated as a coordinate, so the universe exists as a 4D structure where any moment can be computed on demand. Shut it down for…
Sep 2025 · github.com
- 23IA
Somewhat inspired by a recent post here, I also made a three-body simulation on a whim, meaning to try out macroquad[0] (verdict: really nice!). Thanks to the engine I could trivially target wasm as well, so others can get mesmerized too. The source is available here: https://github.com/sulami/three-bodies [0]: https://docs.rs/macroquad/latest/macroquad
2024 · three-bodies.sulami.xyz
- 24IR
This weekend's coding session was dedicated to recreating Jeffery Ventrella's "Particle Life". As you can imagine, I had a lot of fun with it. I recently saw this here on Hacker News and found it strange that I’d never come across it before. Source code: https://github.com/vnglst/particle-life The color palette is by Alex Cristache. https://twitter.com/AlexCristache/status/1791122643816431930
2024 · particle-life.koenvangilst.nl
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