About Eventide 2540

What is Eventide 2540?

Eventide 2540 is a browser experience, still being built, and this companion site, about a civilization called the Vigil. It lives as computation around Vesper, a stellar black hole, and Ember, the small orange star it orbits with, 28 light-years from the Sun. The story's present is 2540, First Light: after three decades of building on starlight, the Vigil starts its first controlled feed into Vesper. The minidisk radiates 1 × 10¹⁵ W, its first petawatt of black-hole light, while Ember supplies almost all of the plant's collected power. This starts a plan to grow far larger. It is the third piece in a series, after Concordia 2045 (a rotating habitat in Earth orbit) and Titan 2100 (a city at Saturn). Each uses an explorable setting to explain the physics that shapes its design.

This one is about the limits of computation: what a thought costs, how fast it can run, how much a region can remember, and why a civilization that thinks for a living might go inward and cold instead of outward and large.

What is physics and what is invention?

The site uses these basis tags to distinguish the fictional setting, design assumptions and scientific claims:

• physics: equations, measurements and demonstrated principles, with a real source. Examples are the cost of erasing a bit and the size of a horizon.
• design: a value chosen for the Vigil, such as the radiator temperature or the power it first ran on.
• challenge: engineering that needs development well beyond what had been demonstrated by 2026, such as self-copying factories.
• fiction: the setting of 2540. The dates, the names, the people and the history are invented.
• law: real treaties and rules in force in 2026.
• illustrative: an explanatory drawing, not a depiction, such as the way a mind is drawn as a landscape of its own numbers.
• styled: a visual pushed beyond what an eye would see, so that something faint or invisible can be shown.
• frontier: physics or philosophy that is argued and not settled, such as black-hole information, holographic storage and minds as software. Where a page leans on one of these, it says so in plain words, and the folded part of the page says exactly what is argued.

The physics comes from published work, and each explainer page lists its sources at the end. Everything the site cites is gathered on further reading.

How are the calculations kept consistent?

The site's calculated quantities come from a shared generator that computes the design from inputs including the masses of the hole and its star, the power the Vigil runs on, the temperature of its radiators and a few more. It writes one data file, and every page, toy and scene reads its numbers from that file. Pages reference values in that data file through number tokens.

When an input changes and the site is rebuilt, dependent pages receive the updated values. References to values the generator does not produce fail the build.

Who and what is it built from?

Eventide 2540 is made by David Veksler, with AI tools.

• Inspiration. The setting's ideas, minds that live as software, choose their own clock rate, copy themselves and travel by light, are inspired by Greg Egan's novel Diaspora (1997). The names, places and story here are original.
• The pages are written in Markdown and built with marked, with the maths typeset by KaTeX. The type is Newsreader, Inter and JetBrains Mono, served by Google Fonts.
• Models and stills are made in Blender. The black holes in the stills are drawn by a ray tracer carried over from David's earlier M87 Descent, and the model catalog shows the models in the browser with three.js, built with Vite.
• The narrator is a synthetic voice. It is a blend of Kokoro-82M's stock voices, layered with slightly detuned copies of itself so that it sounds like a mind speaking as several. No recording of a real person is used anywhere.
• Planned, not shipped in 2026: the browser experience itself, and sound effects and a score from local generative models.
• Physics sources are credited in the further reading, including work by Landauer, Bennett, Bekenstein and Hawking.