Physically accurate black hole you can put in your room
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…
In plain words
This browser-based application displays a physically accurate black hole visualization using real relativistic physics. Created by an astrophysicist at Harvard's Black Hole Initiative, it allows users to view the black hole on any screen or place it directly into their physical space using AR or VR technology. The simulation demonstrates relativistic effects like light bending around the black hole and Doppler boosting, which alters brightness based on viewing angle. Users can zoom out to observe fast jets where these effects are most pronounced, and see markers indicating other viewers' positions in real time.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
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 bending around the black hole, and special relativistic "Doppler boosting" changing brightness depending on the viewing angle — zoom out to see the fast jet where the latter effect is especially pronounced. Faint markers show where other viewers are standing right now. Alternatively, put the black hole in front of your camera and watch it lens your actual surroundings. Light winds around the hole, so you see both what's in front of you and what's behind you at once (when the device and browser allow both camera feeds). The closer to the black hole, the stronger the bending — and the longer the light-travel delay: wave at it and watch the changes propagate inward. (unfortunately, WebXR restrictions make AR passthrough and the camera feed mutually exclusive) No signup, basic features work on every device, no data uploaded — the camera feed never leaves your device. Source code: https://github.com/aplavin/blackhole.plav.in. Enjoy having a black hole in your room, or use it for education/outreach — any questions, feedback, or suggestions are welcome!
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