Frosty Wren Labs

See what can’t be seen

Black holes, pulsars, and the sky at nearly the speed of light: things nobody can see directly, brought to life by simulations that calculate the physics live in your browser. Turn them around, change the settings, switch each effect on and off to see what it does, and read how it all works.

The simulations run live on your graphics card; best on a laptop or desktop.

A ray-traced black hole with its accretion disk bent over the shadow by gravity

Black Hole

What a black hole would really look like: its glowing disk bent up and over the top by gravity.

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A neutron star with its magnetic field lines and the light cylinder around it

Pulsar

Watch a city-sized neutron star spinning up to hundreds of times a second, its magnetic field sweeping around it, and see the pulses of light a telescope would pick up.

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An Einstein ring: a distant star lensed into a ring around the star in front of it

Microlensing

Finding planets nobody can see: a star’s gravity splits a distant star’s light, and a planet leaves its mark.

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A die moving past at 90% of light speed: it looks turned, showing its back face

Fly-By

What an object near light speed really looks like. It doesn’t look squashed, it looks turned so that you can see its back.

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The sky ahead from a ship at 99% of light speed: the stars crowded into a glowing patch

Starflight

The real night sky from a ship near light speed. Stars crowd ahead, the sky glows.

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How these are made Every picture on this page comes from our simulation engines. Each one is calculated from the underlying physics, tested against independent reference code, and comes with its method, its limits and its references. About the Labs ↓

About the Labs

How these are made

Most pictures of black holes, pulsars and fast-moving objects are drawn. These are calculated: every pixel comes from the equations, running on your computer’s graphics card as you watch. Each exhibit lets you switch the physics on and off piece by piece, so you can see what each effect does.

Each simulation is checked against a separate program written to test it, and every number quoted on its page comes from those tests or from a cited source. The limits of each model are stated on the page.

Images made with our simulations are free to use for any purpose, with credit to Frosty Wren Studios and a link to the exhibit. Built with Claude Opus 5.5. Corrections are welcome at info@frostywren.com.

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Plain-language guides