A wormhole — a tunnel joining two different universes. The dark circle is its mouth, and the stars you see inside it are not our stars. They are the sky of the other side, seen straight through the tunnel. Everything else in frame is our own sky, bent as it passes nearby.
Nothing here is painted or faked. Every pixel is a light ray traced backwards through curved space until it lands on one sky or the other. Drag to look around.
This is the part almost every wormhole picture leaves out. In 2008, González, Guzmán and Sarbach proved that every wormhole of this kind is unstable. Not "probably unstable" — proved, with exactly one way to break it.
Their method turns the problem into a quantum-mechanics question: does a certain particle-in-a-well problem have a bound state? It has exactly one, and that one state is the wormhole's death. Push the throat even slightly and the push grows exponentially, doubling again and again until the tunnel either blows open or pinches shut.
The time it takes is set by the throat itself: τ = 0.846 ρ / c. For a throat a kilometre across, that is under three millionths of a second. This sim runs it in slow motion by the factor you choose.
The Exotic supply slider is the price tag made playable. Einstein's equation, run backwards on this exact geometry, demands matter with negative energy in precise amounts [Lobo 2007's formalism for the Morris–Thorne metric]:
Why nature refuses: quantum fields do produce negative energy (the Casimir effect is real), but quantum energy inequalities [Kontou & Sanders 2020] bound how much can sit where for how long — roughly ħc/L⁴ over a region of size L. Setting that against the throat's requirement caps quantum-permitted wormholes near the Planck length, ~10⁻³⁵ m. Your kilometre-wide throat overdraws the quantum budget by a factor of about 10³⁷.
Honest approximation: when you cut the supply below 100%, the game drives the González–Guzmán–Sarbach unstable mode in proportion to the deficit. The instability itself and its clock are theorems; the "deficit → drive strength" link is our readable stand-in for the full non-equilibrium evolution, which no closed formula gives.
Geometry — the three tunnel lengths James et al. render in their Fig. 7 (2a = 0.01, 1 and 10 throat radii): from a thin-membrane hop to a long pipe that stacks nested images. Vantage — the approach, the mouth, inside the pipe, and the far side, each just a starting position for the same free flight.
Cross the tunnel and look ahead: a faint dark bead sits among the far universe's stars. Fly to it. It is a black hole — one solar-mass class, with a 1 km Schwarzschild radius, the same scale as the wormhole's throat. Unlike the wormhole, nothing about it needs exotic matter: black holes are the equations' preferred outcome, and we photograph real ones.
The fabric map in the panel is the same honesty drawn sideways: every bend in this universe on one sheet — the wormhole's funnel, and the black hole's pit, which unlike the funnel has no bottom.
Fly left of the black hole and you will cross a river of stars. It is built as Meingast 1, the real stream flowing through our own solar neighbourhood: about 120 Myr old, 400 pc long by 50 pc across, roughly 2000 M☉ of stars moving together with a velocity spread of only ~1–2 km/s [Ratzenböck, Meingast & Alves 2020, arXiv:2002.05728]. Its colours are not painted: every star draws a mass from a normal IMF, and its colour is the blackbody colour of its main-sequence temperature — a crowd of faint red M-dwarfs, a handful of brilliant blue B-stars, and the odd white dwarf left where a heavier star already died. That is a Pleiades-like HR diagram, which is exactly what the paper measured.
Streams form by tidal disruption: stars leak out of a cluster through its two Lagrange points — inner debris orbits faster and leads, outer debris trails — so the river traces its parent's orbit [Introduction to Tidal Streams; Odenkirchen+ 2001 for Pal 5]. The Stream age tuner stretches the tails (spread ≈ 2σvt — a readable stand-in, since σv is the paper's 1–2 km/s); Disruption moves stars from the progenitor knot into the tails.
Fly right up to any star in the river and it resolves from a point into a photosphere. The disc dims toward its edge by the measured law — the Stagger 3D atmosphere grid gives I(0.2)/I(1) = 0.4–0.6 across 4500–7000 K, so cooler stars darken more at the limb and the limb also reddens, because it shows the higher, cooler layers [Magic+ 2015; the gray-atmosphere solution sits inside that band]. Cool stars boil: granulation mottles the surface at the intrinsic 14.4% contrast — telescopes see only ~7% because their optics blur it, but a window does not [Danilovic+ 2008, Hinode vs MHD]; the cells live 5–10 minutes, time-lapsed here [Nordlund, Stein & Asplund 2009]. Stars hotter than ~7400 K have radiative envelopes — their discs are smooth, and that is why the blue B-stars show no boiling. Disc sizes are staged ~10⁵× so a close pass resolves them; the laws are not staged.
The fire. A cool star's edge is not a clean line — it burns. The limb wears a fringe of spicules: plasma jets 5,000–10,000 km tall (drawn at true proportion, 0.7–1.4% of the radius) that live 2–12 minutes and glow Hα pink — astronomers call the sight the burning prairie [Tsiropoula+ 2012]. Above them stand prominences: arcs of cool 8,000–9,000 K plasma reaching ~26,000 km, sometimes 100,000 [Labrosse+ 2010]. The surface itself rolls with supergranulation — convective waves of heat ~36 Mm across (20–75 Mm), about 24× the granule scale [Rieutord & Rincon, LRSP]. And around it all glows the corona, whose brightness follows the Baumbach–Allen law B(r) = 0.0532r⁻²·⁵ + 1.425r⁻⁷ + 2.565r⁻¹⁷ — in units of millionths of the disc: the real corona hides until an eclipse, so here it is staged ~10⁵× visible, and that staging is the only liberty taken. Hot stars show none of this fire — no convective envelope, no burning prairie. The young suns inside the cloud cores burn hardest: T Tauri stars, whose violent magnetism raises taller spicules, bigger prominences, and giant cool starspots across their faces — and whose light reddens through the dust in front of them. One honesty note: the surface pattern is contrast-stretched ~3× for the screen, the same flat-field stretch every published solar close-up uses — the pattern is the physics, the stretch is the print.
Beyond the river, to the right, hang the clouds — star-forming filaments with dense cores strung along them like beads on a string [André+ 2010; Tafalla & Hacar 2015 find the cores' separation excess below ~0.5 pc]. Each filament's cross-section is the measured Plummer p=2 profile, ρ(r) = ρc/[1+(r/Rflat)²], with FWHM ≈ 3Rflat [Arzoumanian+ 2011, Eq. 1]. The width is contested: Arzoumanian measures a near-universal 0.10 ± 0.03 pc (close to the sonic scale); Panopoulou+ 2022 find measured widths scale with distance as ~4–5× the telescope beam and call the universal value into question. So the width is a slider, not a constant — both papers are right about what they measured.
The mottling is supersonic turbulence: gas density follows a log-normal whose width obeys σs² = ln(1+b²𝑀²) exactly [Federrath+ 2010]. The Mach tuner is 𝑀; the Forcing tuner sweeps b from 1/3 (solenoidal stirring) to 1 (compressive) — compressive forcing roughly triples the density contrast, which is why that slider transforms the cloud. Colours use the two real mechanisms and never mix them: ionised gas glows in emission lines (Hα 656 nm red, [O III] 501 nm teal, Hβ 486 nm) around the embedded hot star, while dust merely scatters starlight (albedo is flat across the optical — 0.66–0.68 from g to z for RV=3.1 — so what makes scattered light blue is not the albedo but the extinction, Ag/Ai=1.80, and the forward-throwing asymmetry falling ⟨cosθ⟩ 0.56→0.40) and reddens whatever shines through it (AB:AV:AR = 1.32:1.00:0.82 for RV=3.1 dust) [Draine 2003; narrowband line work: Garner+ 2022].
Why NASA's pictures look even wilder: the famous Hubble images (the Pillars of Creation) are narrowband re-mappings — [S II] → red, Hα → green, [O III] → blue — because sulfur and hydrogen both glow deep red and the palette pulls them apart [STScI]. The Nebula camera toggle shows both truths: Eye renders the physical line colours; Hubble SHO applies NASA's mapping, with [S II] modelled where it really lives — the slow outer rims. Depth comes from self-shadowed scattering: cloud faces turned to the embedded stars glow, buried gas darkens and reddens.
Scale, honestly: these objects are parsecs and hundreds of parsecs across — 10¹⁷–10²¹ times the wormhole's kilometre. To make them flyable, each is staged: in the river 1 ρ stands for ~0.12 pc, in the clouds ~0.01 pc. The shapes, profiles, populations, and formulas are the papers'; only the metres are staged — the same honest trade as the black hole's pull.
Fall past the horizon and the ride continues, rendered from Riazuelo's interior solution [arXiv:1511.06025, Eqs. 59–66]: the darkness ahead spans exactly 84.2° at the crossing (cos δ = 23/31 — the paper's checkpoint, asserted by this game's validation) and swells toward 180°; at its rim burns the last sight — a thin blueshifted ring holding the whole outside universe (g = 1/(1 − cosδ√(rs/r))), red-dimmed sky behind you. Proper time from horizon to singularity: τ = ⅔(r/rs)3/2rs/c = 2.2 µs here, time-lapsed to 16 s with the honest clock on the HUD. Inside, the singularity is not a place ahead but a moment ahead.
Solid: the geometry, every light path, the Einstein ring, and the collapse rate. Those are theorems and quadratures, checked two independent ways.
Not solid: that a wormhole could exist at all. Holding one open requires matter with negative energy — that is forced by the equations, not assumed — and no such matter has ever been observed.
Where the game stops claiming: the growth law above is a linear result, valid while the change is small. Past about 30% the bar turns amber, and the game says so instead of pretending. The end state — blown open, or collapsed to a black hole — comes from the authors' follow-up paper. The black hole's mass is not determined by this analysis, so this game does not invent one.