Bend light. Slow time. Ride a black hole.
An interactive spacetime laboratory. Drag events across a Minkowski diagram, fly at 0.99 c through a Doppler-shifted starfield, and watch light from an accretion disk curl around a spinning Kerr black hole — every pixel ray-traced through the real geometry of general relativity.
14-day free trial with a 14d.space account, then Pro €39 or Premium €79 (one-time). A year of updates included.
EHT M87*: 42 ± 3 µas ring
Special relativity you can drag, general relativity you can fly through.
Every view shows the equations it uses, the units and the source of every constant. Lengths around black holes are in M = GM/c² with SI conversions alongside; everything else is SI.
Minkowski diagram
Drag events and boost a second frame: Lorentz transformations, light cones, invariant hyperbolae and the relativity of simultaneity — with intervals classified timelike or spacelike.
Time dilation & length contraction
γ(β), light clocks at rest and in motion, and measured cases: cosmic-ray muons, the LHC, the ISS, GPS and the Parker Solar Probe.
Twin paradox
Instant or 1 g turnarounds with hyperbolic motion, proper-time clocks on both worldlines and yearly light signals that resolve the paradox by Doppler counting.
Velocity addition
Why 0.9 c ⊕ 0.9 c = 0.9945 c: collinear and transverse addition, and rapidities that simply add.
Relativistic starfield
Look around at up to β = 1 − 10⁻⁸: aberration crowds the stars ahead, the Doppler factor recolours them (Planck + CIE 1931) and the searchlight effect brightens them — until the cosmic microwave background glows visibly.
Four-momentum & E = mc²
The mass shell E² = (pc)² + (mc²)² for real particles (PDG 2024), kinetic energy versus ½mv², and the energy in any mass.
Collisions & decays
Two-body decays boosted into the lab (π⁺ → μ⁺ν, Z → e⁺e⁻, H → γγ) and production thresholds — why the antiproton needed 5.6 GeV and why colliders win.
Schwarzschild black hole
Exact null geodesics: photon sphere at 1.5 r_s, a shadow of 3√3 GM/c², the Einstein ring, and a thin disk from the ISCO coloured by gravitational and Doppler shifts. Sgr A*, M87* and Cygnus X-1 presets.
Kerr black hole
Spin a from −0.998 to 0.998: frame dragging, the ergosphere, the ISCO from 9 M down to 1.24 M, prograde and retrograde photon orbits and the D-shaped shadow, checked against Bardeen's analytic outline.
Orbits & embedding diagram
Geodesic orbits drawn on Flamm's paraboloid with the effective potential: rosettes, zoom-whirls and plunges, and a periapsis advance that matches the exact elliptic-integral result and Mercury's 43″ per century.
GPS & gravitational clocks
+45.8 µs/day from weaker gravity, −7.2 µs/day from orbital speed: the net +38.6 µs/day that GPS corrects every day (Ashby 2003), for any orbit, and Pound–Rebka on a tower.
Gravitational lensing
Drag a background galaxy behind a point mass: arcs, two images, an Einstein ring, magnifications and time delays, with distances from the Planck 2018 cosmology.
Gravitational waves
The quadrupole chirp of an inspiralling binary: frequency sweep, strain h(t) and the chirp mass — 28.1 M☉ for GW150914 — inferred from f and ḟ alone.
Cosmology lab
Friedmann expansion a(t), Hubble's law, comoving, luminosity and angular-diameter distances and lookback times; Planck 2018 ΛCDM gives an age of 13.79 Gyr.
Alcubierre warp bubble
York time, energy density and the shape function of Alcubierre's metric, with the total negative energy it would need. Clearly labelled: exotic matter required.
Traversable wormhole
Ray-traced view through a Morris–Thorne (Ellis) throat into another sky, its embedding diagram and the null-energy-condition violation that holds it open.
Calculator, notebook & Nova
Fourteen unit-aware formulas, a Markdown lab notebook, CSV and PNG export (Premium) and questions to Andromeda Nova about what is on screen (Premium).
Real equations, checked against measurements.
Black holes are rendered by integrating the geodesic equations for every pixel on the GPU — d²u/dφ² + u = 3GMu²/c² for Schwarzschild, Hamilton's equations in Boyer–Lindquist coordinates for Kerr. A blackbody seen with frequency ratio g is again a blackbody at g·T, so disk colours come straight from Planck's law. The app runs a self-test at start-up and the same numbers are asserted in its unit tests.
We label what is known — and what is not.
Special relativity, the Schwarzschild and Kerr solutions, light bending, gravitational time dilation, gravitational waves and FLRW cosmology are established and tested by experiment or observation; the app says where it simplifies (thin disks, point lenses, inspiral without merger). The Alcubierre warp bubble and traversable wormholes are exact solutions of Einstein's equations that require exotic matter with negative energy density. They are shown as theoretical geometry, never as engineering — every such view carries a "theoretical · exotic matter required" banner.
Pay once. Keep it forever.
Start with a 14-day free trial with a 14d.space account, then Pro €39 or Premium €79 (one-time) — everything unlocked during the trial, no card needed. Every licence is perpetual and includes a year of updates. Andromeda Relativity runs with your 14d.space account in the browser and on the desktop; there is one trial per account, separate from other Andromeda products.
14-day trial
For a first look at every instrument.
- Everything in Premium, unlocked for 14 days
- One trial per 14d.space account, shared by the desktop and browser versions
- Free account, no card required
- Afterwards: Pro €39 or Premium €79, one-time
Pro Most popular
For students, teachers and the curious.
- Minkowski diagrams, time dilation, velocity addition
- Twin paradox, relativistic starfield, four-momentum
- Ray-traced Schwarzschild black hole, orbits on Flamm's paraboloid
- GPS clocks, gravitational lensing, cosmology lab
- Calculator and lab notebook
Premium
For researchers, lecturers and science communicators.
- Everything in Pro
- Ray-traced Kerr (spinning) black hole
- Gravitational waves and relativistic collisions
- Alcubierre warp bubble and traversable wormhole (theoretical)
- AI assistant (Andromeda Nova)
- CSV / PNG / notebook export, priority updates
Your Andromeda Relativity order
Find your purchases and original keys in your account. Sign in with the email used at checkout.
Checking payment and licence delivery…
Open Andromeda Relativity (desktop or in your browser) and sign in with the 14d.space account for the email you used at checkout — your licence is applied automatically. To use it with another account, choose Activate licence key and paste the key once; a key belongs to one 14d.space account. Keep a copy of the key and your Stripe receipt.
Prices in EUR. Any applicable tax is shown at checkout.
| 14-day trial | Pro | Premium | |
|---|---|---|---|
| Minkowski diagram, time dilation, velocity addition, calculator, notebook | ✓ | ✓ | ✓ |
| Twin paradox, relativistic starfield, four-momentum | ✓ | ✓ | ✓ |
| Schwarzschild black hole, orbits & embedding diagram, GPS clocks | ✓ | ✓ | ✓ |
| Gravitational lensing, cosmology lab | ✓ | ✓ | ✓ |
| Unlimited use after 14 days | – | ✓ | ✓ |
| Kerr black hole, gravitational waves, collisions & decays | 14 days | – | ✓ |
| Alcubierre warp bubble, traversable wormhole (theoretical) | 14 days | – | ✓ |
| AI assistant, CSV / PNG / notebook export, priority updates | 14 days | – | ✓ |
Install Andromeda Relativity
One installer for every edition. Sign in with your 14d.space account: a new account starts its 14-day trial, a purchase made with your account email unlocks Pro or Premium. The ray-traced views need a graphics card or integrated GPU with up-to-date drivers (a resolution setting keeps them smooth on older hardware); the browser version runs anywhere WebGL 2 does.
Checking for the latest tested release…
Windows
Windows 10 or 11 · x64 · .exe installer
Windows download unavailableRun the setup file. It adds Andromeda Relativity to the Start menu and desktop. Uninstalling keeps your settings, notebook and licence.
Linux
x86_64 · .deb package or AppImage
Linux download unavailableInstall the .deb with your package manager, or make the AppImage executable and run it.
Browser
Any modern browser with WebGL 2 · nothing to install
Open Relativity in your browserThe same laboratory, served from 14d.space. Sign in with your 14d.space account; your notebook stays in your browser.
Download SHA256 checksums · Verify the file before running it.
Before you install
Are the black holes real calculations or artwork?
Real calculations. Every pixel is a light ray traced backwards through the exact Schwarzschild or Kerr geometry with a fourth-order Runge–Kutta integrator on your GPU. The shadow edge, photon ring and lensed far side of the disk come out of the equations; the app overlays the analytic critical curve so you can check. The accretion disk is a thin Shakura–Sunyaev disk with blackbody emission; an optional turbulence texture only modulates brightness and is labelled as a visual aid.
Where do the constants and data come from?
CODATA 2018 constants, IAU 2015 nominal solar and Earth values, PDG 2024 particle masses, Ashby (2003) for GPS, LIGO/Virgo for GW150914, Planck 2018 for ΛCDM, the Event Horizon Telescope for the M87* and Sgr A* rings. The Model & sources view lists them and runs the physics self-test.
Is the warp drive science?
The Alcubierre metric is a correct solution of Einstein's equations, but it needs matter with negative energy density in amounts no known physics provides, and later work found further obstacles. The app shows it as theoretical geometry with that warning on screen, together with the energy it would require. The same applies to traversable wormholes.
What does the browser version need?
A browser with WebGL 2 and a 14d.space account. It is the same application, served from 14d.space. The desktop version adds native file export and automatic updates.
Do I need a 14d.space account?
Yes. Andromeda Relativity runs only with a signed-in 14d.space account, in the browser and on the desktop. Each account gets one 14-day trial with everything unlocked, shared by both versions; afterwards Relativity asks for Pro (€39) or Premium (€79). Purchases made with your account email are applied automatically, and you can activate a licence key on your account once. Manage your signed-in computers at your account.
Does the desktop app work offline?
Yes. After you sign in, the desktop app works offline for 7 days at a time and renews its sign-in automatically whenever it is online.
Does the AI assistant cost extra?
No. The Premium assistant is answered by Andromeda Nova, and Andromeda never bills you separately for it. Without a connection the assistant answers simple questions from the app's own physics.
How do updates work?
Andromeda Relativity checks 14d.space for a newer verified release shortly after it starts and every four hours, and installs it when you close the app (Windows) or the next time you open it (Linux). Only packages signed by 14d.space are accepted. The browser version is always current.
What happens after the update year?
Your licence keeps working forever with every release from your update year. Nothing stops, nothing expires.