Life & fun · alternatives · 2026
24 alternatives to I was playing with fundamental constants and 13.8 b years popped out
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…
This is an exploration of a mathematical coincidence discovered by combining fundamental physical constants—the Compton wavelength of an electron, the charge radius of a proton, and the Schwarzschild radius of a… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 1 we have checked on their own sites, 1 of them free or with a free tier. I was playing with fundamental constants and 13.8 b years popped out launched in 2021; newer entries below may have overtaken it.
- 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 · its alternatives →
- 2WI
Special relativity simulator in which light crawls along at a human speed, so Lorentz contraction, aberration and Doppler shift happen at walking pace.
Sep 2026 · rivendell.dmitrybrant.com · its alternatives →
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2021 · colab.research.google.com · its alternatives →
- 4RA
A short and sweet textbook on Einstein’s theory of relativity
2021 · ramp-book.com · its alternatives →
- 5PA
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 · its alternatives →
- 6
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 · its alternatives →
- 7IR
2021 · htwins.net · its alternatives →
- 8
100th anniversary of The Theory of Relativity
2015 · its alternatives →
- 9IB
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 · its alternatives →
- 10
Watch time unfold and witness 40 years of planetary change
2021 · earth.google.com · its alternatives →
- 11
Spatium▲182Hi there, humans! I'm excited to announce Spatium! I'm a big fan of any topic related to our universe. I'm also a developer, so I've put these things together and I built this new tab Chrome Extension for space lovers, astronomy fans, and science geeks like me. If you enjoyed it, please spread some love <3 FEATURES • Space images • Every day, get a fascinating image of our universe. Enjoy pictures of stars, planets, moons, galaxies, nebulae, comets and more right on your browser tab. • Sun Widget • Find out when the sunrise, sunset, first and last light times will be precisely at your…
2021 · spatium.earth · its alternatives →
- 12
Renders black hole gravitational lensing effects in an image canvas using WebGL, glfx.js, and numeric.js - cliffcrosland/black-hole.js
2015 · github.com · its alternatives →
- 13
After five weeks of nearly non-stop computation, a new record for the computation of the value has been set: 500 billion digits of precision computed with Alexander Yee’s y-cruncher. This is the Gamma function, which when evaluated with the input , results in Motivation There isn’t a pra
2020 · andrewsun.com · its alternatives →
- 14AS
I really like the look of the famous album art for Unknown Pleasures [1]. It was originally created by Harold Craft at the Arecibo Observatory from the signals of the first discovered radio pulsar [2]. I made a spectrogram that produces a similar look. It runs FFT in Rust and visualizes it with WebGL. [1]: https://en.wikipedia.org/wiki/File:UnknownPleasuresVinyl.jpg [2]: https://en.wikipedia.org/wiki/PSR_B1919%2B21
2024 · aestuans.github.io · its alternatives →
- 15
- 16
An interactive visualization of the universe
2019 · neal.fun · its alternatives →
- 17
PixelSpace▲68A tediously accurate scale model of the solar system
2014 · joshworth.com · its alternatives →
- 185C
A living gallery of unusual, creative, and beautiful ways to display the current time.
6d ago · tkgally.github.io · its alternatives →
- 19DI
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 · its alternatives →
- 20
- 21IB
Mar 2026 · structuredlabs.github.io · its alternatives →
- 22
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 · its alternatives →
- 23
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 · its alternatives →
- 24TW
Web-based quantum physics visualizer for wavefunctions and the Schrödinger Equation
2016 · ridiculousfish.com · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →