# Superfluid helium-4
<!-- MICROSIMGEN:BEGIN v1.7 — generated by g08_place_microsims.py; three.js first (§15); do not hand-edit inside -->
## Microsims — three.js
### Superfluid helium-4 (three.js)
<div class="microsim-player">
<iframe src="https://wikitube-3d-microsims.netlify.app/Superfluid_helium-4.html" width="100%" height="620" frameborder="0" loading="lazy" sandbox="allow-scripts allow-same-origin" title="Superfluid helium-4 — three.js microsim"></iframe>
</div>
**Open it full-screen:** [Superfluid_helium-4.html](https://wikitube-3d-microsims.netlify.app/Superfluid_helium-4.html) · library `threejs` · route `microsim/threejs/`
### Related microsims
Live sims on neighbouring articles — 3 of them inside this article's own Wikipedia link tree:
- [[Boson]] *(in tree)*
- [[Dilution_refrigerator]] *(in tree)*
- [[Superconductivity]] *(in tree)*
- [[Zero-point_energy]]
*Sim hosted off-article; the article owns the reference, not the runtime (WIKI_RULES §10.4). Placed by `g08_place_microsims.py`.*
<!-- MICROSIMGEN:END -->
## Microsim
### Live player
<div class="microsim-player">
<iframe src="https://editor.p5js.org/sciencenibber/full/wxBSln5z5" width="100%" height="620" frameborder="0" sandbox="allow-scripts allow-same-origin"></iframe>
</div>
<div class="microsim-fallback">
<img src="Microsims/thumbs/Superfluid_helium-4.png" alt="Superfluid_helium-4 microsim poster" style="width:100%;border:1px solid #4445;border-radius:6px;">
<p><em>Live microsim (desktop) · <a href="https://editor.p5js.org/sciencenibber/sketches/wxBSln5z5">open sketch in the p5.js editor</a></em></p>
</div>
**Editor URL:** https://editor.p5js.org/sciencenibber/sketches/wxBSln5z5
**Description (100 words):**
A single-axis temperature scrubber for the He-4 lambda transition. The reader drags one slider for T in [1.0, 4.0] K and the sketch updates three coupled views in lockstep: the iconic heat-capacity curve c_p(T) plotted in cool blue below the magenta lambda guide and warm orange above it; a two-fluid composition bar that fills from a deep-blue superfluid component on the left to an orange normal component on the right per the Tisza-Landau fit; and a phase readout naming He I above 2.1768 K and He II below. The lambda point sits exactly where the curve diverges.
```js
// =====================================================================
// Superfluid_helium-4.js -- Wikitube microsim
// Article: Superfluid_helium-4 en.wikitube.io/wiki/Superfluid_helium-4
// Room: Helium Pattern: A (phase / state transition,
// cryogenic properties)
// ---------------------------------------------------------------------
// Idea: a 1-D temperature scrubber across the He-4 lambda transition
// at saturation vapor pressure. The reader drags a slider for T in
// [1.0, 4.0] K and watches three coupled views:
//
// 1. heat capacity c_p(T) -- the iconic "lambda" curve. It is from
// this curve's resemblance to the Greek letter lambda that the
// transition gets its name. c_p shows a near-logarithmic divergence
// on both sides of T_lambda = 2.1768 K.
//
// 2. two-fluid composition rho_s/rho, rho_n/rho (Tisza-Landau model).
// Below T_lambda an empirical fit
// rho_s/rho = 1 - (T/T_lambda)^5.6
// gives the superfluid mass fraction. Above T_lambda the fluid
// is pure normal He I and the bar is fully warm.
//
// 3. phase / readout: He I (warm, classical liquid) above the lambda
// point, He II (cool, superfluid component present) below it.
//
// Why this is *not* a duplicate of Cryogenics.js (which is also Pattern
// A): Cryogenics shows the full 2-D (T, P) phase plane and the four
// phases including the solid. This sketch zooms in on the *transition*
// itself -- the c_p curve from which "lambda" is named, plus the two-
// fluid composition that captures what makes He II physically novel.
//
// Helium-4 superfluidity landmarks shown on the views:
// * lambda point at saturation: T_lambda = 2.1768 K
// * empirical superfluid-fraction exponent ~ 5.6
// * Kapitsa / Allen-Misener discovery: 1937-38
//
// Visual layout (720 x 520 canvas):
// * top-left: HUD title + en.wikitube.io subtitle
// * top-right: control hints (drag slider, lambda position)
// * y = 90: full-width temperature slider, T in [1.0, 4.0] K
// * y = 120-380: heat-capacity curve c_p(T) vs T plot
// * y = 410-440: two-fluid composition bar (cold = superfluid,
// warm = normal)
// * bottom-left: T, c_p, superfluid-fraction readout
// * bottom-right: canonical equation
// rho_s/rho = 1 - (T/T_lambda)^5.6
//
// Conventions (Wikitube Betterfire Standard v0):
// * single ARTICLE constant at the top, single quotes
// * p5.disableFriendlyErrors = true to keep the editor console clean
// * non-ASCII (Greek lambda, rho, dots) lives in COMMENTS ONLY;
// every text() string literal is ASCII (the editor preview pipeline
// mangles non-ASCII inside strings)
// * Energy-room palette (P5_JS_EDITOR section 4): dark BG, HOT/COLD
// tones, STRUCT grey, TRAJ yellow accent
// * createSlider has explicit .position(x, y).size(w)
// =====================================================================
const ARTICLE = 'Superfluid_helium-4';
const TITLE = ARTICLE.replace(/_/g, ' ');
p5.disableFriendlyErrors = true;
// ----- Energy room palette (P5_JS_EDITOR section 4) ------------------
const BG = 18;
const FG = 240;
const DIM = [240, 240, 240, 140];
const HOT = [220, 110, 60]; // warm: normal-fluid component / He I
const COLD = [60, 130, 220]; // cool: He I curve segment
const COLDER = [40, 80, 180]; // deeper cool: superfluid component / He II
const STRUCT = [120, 130, 150]; // structural grey
const TRAJ = [240, 220, 80]; // reader marker (yellow accent)
const SCRATCH = [120, 120, 120, 90]; // grid / scratch lines
const ACCENT = [200, 100, 220]; // lambda point / line (magenta)
// ----- He-4 superfluid landmarks ------------------------------------
// The accepted saturation-vapor-pressure lambda point per CODATA / NIST.
const T_LAMBDA = 2.1768; // K, lambda transition at saturation
// Empirical two-fluid exponent for rho_s/rho = 1 - (T/T_lambda)^N.
// N = 5.6 is the canonical fit reported by London & Zilsel and refined
// by later neutron-scattering measurements; the actual critical
// exponent on the order parameter is closer to 0.67 but that only
// matters within a few mK of T_lambda. The 5.6 form fits well from
// 0.5 K through ~T_lambda - 10 mK.
const SF_EXPONENT = 5.6;
// ----- T-axis (data ranges; pixel ranges set in setup) --------------
const T_MIN = 1.0; // K
const T_MAX = 4.0; // K
// ----- c_p plot vertical range --------------------------------------
// c_p of He I at saturation goes roughly from 1 J/(g K) at 1 K through
// 3 J/(g K) at 4 K, with a logarithmic spike at T_lambda capping our
// display at 25 J/(g K). The actual c_p has a true logarithmic
// divergence -- we clamp for display only.
const C_MIN = 0;
const C_MAX = 25;
// ----- Plot rectangle in canvas pixels (set in setup) ---------------
let plotX, plotY, plotW, plotH;
// ----- Two-fluid composition-bar rectangle (set in setup) -----------
let barX, barY, barW, barH;
// ----- Slider -------------------------------------------------------
let tSlider;
function setup() {
createCanvas(720, 520);
pixelDensity(2);
textFont('system-ui');
// Plot area: leaves room for HUD top, slider, composition bar,
// and the bottom readout strip.
plotX = 80;
plotY = 120;
plotW = width - 100;
plotH = 260;
// Composition bar below the plot.
barX = plotX;
barY = plotY + plotH + 30;
barW = plotW;
barH = 24;
// Temperature slider sits in the gap between the HUD subtitle and
// the top of the plot. Step = 1 mK gives smooth scrubbing through
// the lambda peak without wasting slider precision.
tSlider = createSlider(T_MIN * 1000, T_MAX * 1000, T_LAMBDA * 1000, 1);
tSlider.position(plotX, plotY - 30);
tSlider.size(plotW);
}
function draw() {
background(BG);
// Read all the slider values once -- the rest of the frame uses
// these locals so the physics reads as physics, not as UI plumbing.
const T = tSlider.value() / 1000;
// Draw order: axes -> static c_p curve -> lambda-point guide
// -> current-T marker -> composition bar -> readout -> HUD.
drawAxes();
drawHeatCapacityCurve();
drawLambdaGuide();
drawTMarker(T);
drawTwoFluidBar(T);
drawReadout(T);
drawHUD();
}
// =====================================================================
// Coordinate transforms: (T [K], c [J/(g K)]) <-> (px, py) in pixels
// =====================================================================
function tToPx(T) {
return map(T, T_MIN, T_MAX, plotX, plotX + plotW);
}
function cToPy(c) {
return map(c, C_MIN, C_MAX, plotY + plotH, plotY);
}
// =====================================================================
// Physical models
// =====================================================================
// Heat capacity at saturation: c_p(T) = baseline(T) + lambda_peak(T).
//
// baseline: a smooth low-order ramp matching the textbook 1-3
// J/(g K) trend across [1, 4] K. Not from a fit, but
// calibrated so the off-peak curve sits in the right
// neighborhood. Below 1 K c_p drops sharply with the
// T^3 phonon term, which we do not need for this view.
//
// lambda peak: a clamped logarithmic singularity. The true c_p in
// He-4 has an exact logarithmic divergence on both sides
// of T_lambda (critical exponent alpha ~ -0.013, very
// nearly zero -> log). We use -ln(|t| + eps) with a
// small eps to keep the peak finite for display.
function cP(T) {
const baseline = 0.8 + 0.6 * T;
const t = Math.abs((T - T_LAMBDA) / T_LAMBDA);
const eps = 0.002;
const peak = 4.5 * Math.max(0, -Math.log(t + eps) - 0.5);
return Math.min(baseline + peak, C_MAX * 1.05);
}
// Tisza-Landau two-fluid superfluid fraction.
function superfluidFraction(T) {
if (T >= T_LAMBDA) return 0;
return 1 - Math.pow(T / T_LAMBDA, SF_EXPONENT);
}
// Phase classifier: 'He I' for T >= T_lambda, 'He II' below it.
function classifyPhase(T) {
return T < T_LAMBDA ? 'He II' : 'He I';
}
// =====================================================================
// Drawing
// =====================================================================
function drawAxes() {
push();
noFill();
stroke(SCRATCH);
strokeWeight(1);
rect(plotX, plotY, plotW, plotH);
// T-axis tick marks (every 0.5 K) + labels
noStroke();
fill(...DIM);
textSize(10);
textAlign(CENTER, TOP);
for (let T = T_MIN; T <= T_MAX + 1e-6; T += 0.5) {
const x = tToPx(T);
stroke(SCRATCH); line(x, plotY + plotH, x, plotY + plotH + 4);
noStroke(); text(nf(T, 0, 1), x, plotY + plotH + 6);
}
// c-axis tick marks (every 5 J/(g K)) + labels
textAlign(RIGHT, CENTER);
for (let c = C_MIN; c <= C_MAX; c += 5) {
const y = cToPy(c);
stroke(SCRATCH); line(plotX - 4, y, plotX, y);
noStroke(); text(c, plotX - 6, y);
}
// Axis titles
noStroke();
fill(...DIM);
textSize(12);
textAlign(CENTER, TOP);
text('T [K]', plotX + plotW / 2, plotY + plotH + 24);
push();
translate(plotX - 56, plotY + plotH / 2);
rotate(-PI / 2);
text('c_p [J/(g K)]', 0, 0);
pop();
pop();
}
// Draw the c_p(T) curve in two color segments to encode the He II /
// He I split: cold blue to the left of T_lambda, warm orange to the
// right. The visible discontinuity at the seam IS the transition.
function drawHeatCapacityCurve() {
push();
noFill();
strokeWeight(2);
// He II side (T < T_lambda) in cold blue
stroke(...COLDER);
beginShape();
for (let T = T_MIN; T <= T_LAMBDA; T += 0.005) {
const y = constrain(cToPy(cP(T)), plotY, plotY + plotH);
vertex(tToPx(T), y);
}
endShape();
// He I side (T > T_lambda) in warm orange
stroke(...HOT);
beginShape();
for (let T = T_LAMBDA; T <= T_MAX + 1e-6; T += 0.005) {
const y = constrain(cToPy(cP(T)), plotY, plotY + plotH);
vertex(tToPx(T), y);
}
endShape();
// Region labels: He II low-T side, He I high-T side
noStroke();
textSize(11);
fill(...COLDER);
textAlign(LEFT, TOP);
text('He II (superfluid present)', tToPx(T_MIN) + 8, plotY + 10);
fill(...HOT);
textAlign(RIGHT, TOP);
text('He I (normal liquid)', tToPx(T_MAX) - 8, plotY + 10);
pop();
}
// Vertical magenta guide at T_lambda, labelled.
function drawLambdaGuide() {
push();
stroke(...ACCENT);
strokeWeight(1);
drawingContext.setLineDash([4, 4]);
line(tToPx(T_LAMBDA), plotY, tToPx(T_LAMBDA), plotY + plotH);
drawingContext.setLineDash([]);
noStroke();
fill(...ACCENT);
textSize(10);
textAlign(CENTER, BOTTOM);
text('lambda point T = 2.1768 K',
tToPx(T_LAMBDA), plotY - 2);
pop();
}
// Reader's current-T marker: vertical yellow line + dot on the curve.
function drawTMarker(T) {
const x = tToPx(T);
const y = cToPy(Math.min(cP(T), C_MAX));
push();
stroke(...TRAJ);
strokeWeight(1);
line(x, plotY, x, plotY + plotH);
noStroke();
fill(...TRAJ);
circle(x, y, 9);
pop();
}
// Two-fluid composition bar: superfluid (cold) on the left, normal
// (warm) on the right. The split moves to the left as T approaches
// T_lambda from below.
function drawTwoFluidBar(T) {
const sFrac = superfluidFraction(T);
const nFrac = 1 - sFrac;
push();
// Background outline
noFill();
stroke(SCRATCH);
rect(barX, barY, barW, barH);
// Superfluid component fill (cool)
noStroke();
fill(...COLDER);
rect(barX, barY, barW * sFrac, barH);
// Normal component fill (warm)
fill(...HOT);
rect(barX + barW * sFrac, barY, barW * nFrac, barH);
// Caption above the bar
fill(...DIM);
textSize(11);
textAlign(LEFT, BOTTOM);
text('two-fluid composition (Tisza-Landau)', barX, barY - 4);
// Inside-bar labels, only when there's room
fill(FG);
textSize(12);
if (sFrac > 0.14) {
textAlign(LEFT, CENTER);
text('superfluid ' + nf(sFrac, 0, 2),
barX + 8, barY + barH / 2);
}
if (nFrac > 0.14) {
textAlign(RIGHT, CENTER);
text('normal ' + nf(nFrac, 0, 2),
barX + barW - 8, barY + barH / 2);
}
pop();
}
// Bottom-left readout: T, c_p, phase, superfluid fraction.
function drawReadout(T) {
const phase = classifyPhase(T);
const phaseLabel = phase === 'He II'
? 'liquid He II (superfluid component present)'
: 'liquid He I (normal classical liquid)';
const sFrac = superfluidFraction(T);
push();
fill(...DIM);
textAlign(LEFT, BOTTOM);
textSize(12);
text('T = ' + nf(T, 0, 3) + ' K ' +
'c_p ~ ' + nf(Math.min(cP(T), C_MAX), 0, 1) + ' J/(g K)',
14, height - 22);
fill(FG);
textSize(13);
text('phase: ' + phaseLabel + ' rho_s/rho = ' + nf(sFrac, 0, 2),
14, height - 6);
pop();
}
// =====================================================================
// HUD
// =====================================================================
function drawHUD() {
push();
// Top-left: title + Wikitube URL (Betterfire Standard rule 2)
noStroke();
fill(FG);
textAlign(LEFT, TOP);
textSize(20);
text(TITLE, 14, 12);
fill(...DIM);
textSize(12);
text('Wikitube microsim . en.wikitube.io/wiki/Superfluid_helium-4',
14, 36);
// Top-right: control hints (Betterfire Standard rule 3)
textAlign(RIGHT, TOP);
textSize(10);
text('drag the slider to set T', width - 14, 12);
text('cross 2.1768 K -> He I to He II', width - 14, 24);
text('Kapitsa, Allen, Misener 1937-38', width - 14, 36);
// Bottom-right: canonical equation (Betterfire Standard rule 4)
textAlign(RIGHT, BOTTOM);
fill(FG);
textSize(13);
text('rho_s/rho = 1 - (T/T_lambda)^5.6 [Tisza-Landau two-fluid]',
width - 14, height - 6);
pop();
}
// =====================================================================
// End of Superfluid_helium-4.js -- Wikitube microsim, Helium room,
// Pattern A (state transition + cryogenic property: c_p lambda curve
// and two-fluid composition).
// =====================================================================
```
## Links (Wikipedia order)
<!-- injected from _registry/childlinks/Superfluid_helium-4.json (2026-07-30T02:09:12Z) -->
`Absolute_zero` · `Anthony_Leggett` · `Anti-gravity` · `Antiferromagnetism` · `Antimatter` · `BCS_theory` · `Bar_(unit)` · `Binodal` · `Boiling` · [[Boiling_point]] · `Bose–Einstein_condensate` · `Bose–Einstein_statistics` · [[Boson]] · `CERN` · `Chemical_ionization` · `Chemical_potential` · `Colloid` · `Color-glass_condensate` · `Compressed_fluid` · `Condensation` · `Cooling_curve` · `Cooper_pair` · `Critical_line_(thermodynamics)` · `Critical_phenomena` · `Critical_point_(thermodynamics)` · `Crystal` · `Crystallization` · `Dark_matter` · `Degenerate_matter` · `Deposition_(phase_transition)` · `Diatomic_molecule` · [[Dilution_refrigerator]] · `Don_Misener` · [[Electron]] · [[Emerging_technologies]] · `Enthalpy_of_fusion` · `Enthalpy_of_sublimation` · `Enthalpy_of_vaporization` · `Entropic_uncertainty` · `Equation_of_state` · `Evaporation` · `Exotic_matter` · [[Fermion]] · `Fermionic_condensate` · `Ferrimagnetism` · `Ferromagnetism` · `Flash_evaporation` · `Freezing` · `Gas` · `Gravity_Probe_B` · `Gyroscope` · `Hagen_Kleinert` · `Heat_pipe` · `Heike_Kamerlingh_Onnes` · [[Helium]] · [[Helium-3]] · [[Helium-4]] · `IRAS` · `Immersion_(virtual_reality)` · `Inertia` · `Ionization` · `Isotope` · `John_F._Allen_(physicist)` · `Josephson_effect` · `Lambda_point` · `Large_Hadron_Collider` · `Lars_Onsager` · `Latent_heat` · `Latent_internal_energy` · `Leidenfrost_effect` · `Lev_Landau` · `Liquid` · `Liquid_crystal` · `List_of_emerging_technologies` · `List_of_states_of_matter` · `Logarithmic_Schrödinger_equation` · `London_moment` · `Macroscopic_quantum_phenomena` · `Melting` · `Melting_point` · `Mpemba_effect` · `Open_quantum_system` · `Phase_diagram` · [[Phase_transition]] · `Phonon` · `Photonic_molecule` · [[Plasma_(physics)]] · `Plasma_recombination` · `Post-quantum_cryptography` · `Programmable_matter` · `Pyotr_Kapitsa` · `QCD_matter` · `Quantum_Hall_effect` · `Quantum_algorithm` · `Quantum_amplifier` · `Quantum_bus` · `Quantum_cellular_automaton` · `Quantum_channel` · `Quantum_circuit` · `Quantum_complexity_theory` · [[Quantum_computing]] · `Quantum_cryptography` · `Quantum_dynamics` · `Quantum_error_correction` · `Quantum_finite_automaton` · `Quantum_hydrodynamics` · `Quantum_image_processing` · `Quantum_imaging` · `Quantum_information` · `Quantum_key_distribution` · `Quantum_logic` · `Quantum_logic_clock` · `Quantum_logic_gate` · `Quantum_machine` · `Quantum_machine_learning` · [[Quantum_mechanics]] · `Quantum_metamaterial` · `Quantum_network` · `Quantum_neural_network` · `Quantum_optics` · `Quantum_programming` · `Quantum_sensor` · `Quantum_simulator` · `Quantum_spin_liquid` · `Quantum_teleportation` · `Quantum_vortex` · `Quark–gluon_plasma` · `Regelation` · `Richard_Feynman` · `Rollin_film` · `Roton` · `Rovibronic_coupling` · `Rydberg_matter` · `Second_sound` · `Solid` · `Solid_hydrogen` · [[Spin_(physics)]] · `Spinodal` · `Spontaneous_symmetry_breaking` · `State_of_matter` · `Strange_matter` · `String-net_liquid` · `Structure_factor` · `Sublimation_(phase_transition)` · [[Superconductivity]] · `Supercooling` · `Supercritical_fluid` · `Superdiamagnetism` · `Superfluid_film` · `Superfluidity` · `Superheated_water` · `Superheating` · `Supersolid` · `Thermo-dielectric_effect` · `Thermoacoustic_heat_engine` · `Time_crystal` · `Timeline_of_states_of_matter_and_phase_transitions` · `Triple_point` · `Trouton's_rule` · `Two-fluid_model` · `Vapor` · `Vaporization` · `Vapor–liquid_equilibrium` · `Vitrification` · `Volatility_(chemistry)` · [[Wayback_Machine]]
> **Room:** [[Helium]] · **Status:** ✅ shipped
<!-- GIFPLATE:BEGIN v1.0 g16 — Commons hotlink; do not hand-edit inside -->
## Images
<figure class="wt-gifplate">
<img src="https://commons.wikimedia.org/wiki/Special:FilePath/Thermally_Agitated_Molecule.gif" alt="Quantum Flow" loading="lazy" decoding="async">
<figcaption><strong>Quantum Flow</strong> — Show quantum flow and frictionless dynamics at low temperature.<br>
<span class="wt-credit">Wikimedia Commons · <strong>licence pending verification</strong> (run <code>g17_gif_verify.py</code> on a networked lane) · <a href="https://commons.wikimedia.org/wiki/File:Thermally_Agitated_Molecule.gif">Details</a></span></figcaption>
</figure>
*Still companion to the 1 live microsim above: the sim is the instrument, the plate is the glance. §15 keeps the player first; this sits in the image slot on [[Superfluid_helium-4]].*
<!-- GIFPLATE:END -->
## Overview
**Superfluid helium-4** is the low-temperature liquid phase of the He-4 isotope below the lambda transition at T_λ = 2.1768 K (at the saturation vapour pressure), in which the fluid exhibits a collection of macroscopic quantum behaviours — zero [[Viscosity|viscosity]], anomalously high thermal conductivity, persistent superfluid currents, film creep up container walls, the fountain (thermomechanical) effect, second sound (a propagating temperature [[Wave|wave]]), and quantised vortices of circulation κ = h / m_He. The transition was discovered independently by Pyotr Kapitsa and by John F. Allen and Don Misener in 1937–38 and named for the Greek letter that the heat-capacity curve traces near 2.17 K. The phenomenology is captured by the **Tisza–Landau two-fluid model**, in which the liquid is treated as an inseparable mixture of a normal component (carrying [[Entropy|entropy]] and viscosity) and a superfluid component (carrying no entropy and obeying ρ_s / ρ ≈ 1 − (T / T_λ)^5.6); at the lambda point the superfluid fraction vanishes and the conventional liquid He I phase is recovered. Microscopically the superfluid is closely related to Bose–Einstein condensation of the bosonic He-4 atoms, though strong interatomic interactions suppress the condensate fraction far below the BEC ideal. Superfluid He-4 is the working fluid of cryogenic infrastructure operating below 2.17 K — superconducting accelerator magnets (the LHC runs at 1.9 K), space telescopes, [[Neutron|neutron]]-scattering instruments, and any laboratory requiring kilowatts of cooling at sub-2 K temperatures.
## See also
- Room hub: [[Helium]]
- p5.js Editor conventions: P5 JS EDITOR
- Wiki root: MAIN
---
*Scaffolded by `generative-microsim` from row 23 of the Helium sheet on 2026-05-11T21:16:59Z.*
<!-- CRAFT-LINK:START g12 -->
*Built to the [[WT!P5_js_Microsim_Master_Class|p5.js Master Class]].*
<!-- CRAFT-LINK:END -->
<!-- COMPENDIUMLINK:BEGIN g19 — generated from _registry/plans/THURY_COMPENDIUM_SECTIONS.md; do not hand-edit inside -->
*Linked from the [[WT!Thury_Hydrodynamics_Compendium|Thury Hydrodynamics Compendium]], section 13, Superfluidity.*
<!-- COMPENDIUMLINK:END -->
## Wikipedia : Wikitube
**Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Superfluid_helium-4) : [Wikitube](https://en.wikitube.io/wiki/Superfluid_helium-4)
## Previous hub tags
Tree parent: [[Helium]].
Legacy hubs: none.
---
*Sources: 1 legacy note. Minted wave 1, 2026-07-30 (v1.6 order).*