INTERACTIVE EXPLANATIONS

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Move a parameter and see what the model predicts. Every tool includes its equation, units or dimensionless convention, assumptions and a route into the research.

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These tools calculate idealized model predictions. They do not display experimental data or establish that a model applies to every physical implementation.

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MODEL 01

Penrose’s proposed lifetime

Hypothesis explorer. E_G is an entered gravitational self-energy of a mass-density difference. This is not a complete collapse model or a verified universal law.

τ ≈ ℏ / E_G
MODEL 02

A freely spreading quantum packet

One-dimensional free particle, initial unchirped minimum-uncertainty Gaussian. Dimensionless units: ℏ = m = 1. The plotted position density broadens under unitary evolution.

σₓ(t) = √[σ₀² + t²/(4σ₀²)]
MODEL 03

Squeezing an uncertainty ellipse

Ideal pure one-mode Gaussian squeezing with ℏ = 1. The ellipse represents one-standard-deviation widths, not a particle trajectory. Loss and technical noise are omitted.

σₓ = e⁻ʳ/√2; σₚ = eʳ/√2; σₓσₚ = 1/2
MODEL 04

Combine two coherent inputs

Ideal lossless balanced combiner with a chosen phase convention. Curves show input field amplitudes and their sum; the readouts give normalized power fractions in the two output ports.

P₊ = [1 + r² + 2r cos φ] / [2(1 + r²)]
MODEL 05

Watch a vibration lose mechanical energy

Underdamped viscous oscillator: m = k = 1, x(0) = 1, v(0) = 0. Energy is calculated from displacement and velocity; it is transferred to the omitted environment.

ẍ + 2βẋ + x = 0
MODEL 06

Small-particle Rayleigh scattering

Unpolarized light, a fixed isolated particle much smaller than every selected wavelength, and fixed optical properties. The curves show relative differential cross section in the Rayleigh…

Cross-section scaling ∝ λ⁻⁴; angular shape ∝ 1 + cos²θ
MODEL 07

A structured beam carries a phase winding

Transverse p = 0 Laguerre–Gaussian-like mode in dimensionless waist coordinates. Opacity encodes normalized intensity; cyclic color encodes phase. Paraxial pure modes have orbital angular…

u ∝ r^|ℓ| e⁻ʳ² eⁱℓφ
MODEL 08

Reflection at an impedance boundary

Lossless acoustic plane waves at normal incidence between two positive real impedances. The coefficients are energy fractions; pressure-amplitude transmission can exceed one without…

R = [(Z₂ − Z₁)/(Z₂ + Z₁)]²; T = 1 − R
MODEL 09

The noise cost of phase-insensitive gain

Ideal quantum-limited phase-insensitive linear amplifier, coherent input, vacuum idler, quadrature vacuum variance 1/2. G is power gain. The pump supplies output energy.

V_out = (2G − 1)/2; N_added = (1 − 1/G)/2
MODEL 10

Phase noise washes out fringes

Equal path populations and independent zero-mean Gaussian phase fluctuations averaged over many runs. This models the observed reduced fringe contrast; it does not identify the underlying…

V = exp(−σφ²/2); P = [1 + V cos φ]/2
MODEL 11

Cross a waveguide cutoff

Ideal uniform vacuum rectangular guide, TE₁₀ mode, perfectly conducting walls and no loss. Below cutoff, β is imaginary and the depicted field is evanescent. Finite barrier transmission…

β/k_c = √[(f/f_c)² − 1]
MODEL 12

Rotate a quantum measurement basis

Born-rule predictions for a normalized real two-level pure state and an ideal projective measurement. Displayed bars are calculated probabilities, not experimental counts or a…

P₀ = cos²(θ − α); P₁ = sin²(θ − α)
MODEL 13

Account for a one-dimensional collision

Body 1 has mass 1 and initial velocity 1; body 2 starts at rest. An isolated one-dimensional encounter uses restitution 0 ≤ e ≤ 1. Lost translational kinetic energy becomes internal modes,…

v₁′ = (1 − em₂)/(1 + m₂); v₂′ = (1 + e)/(1 + m₂)
MODEL 14

Sweep a damped resonance

Steady-state linear oscillator with drive ratio r = ω/ω₀ and damping ratio ζ. Amplitude is normalized to the static displacement F₀/k. The finite-damping displacement peak need not occur…

A = 1 / √[(1 − r²)² + (2ζr)²]
MODEL 15

Read a constant-rate decay law

Memoryless exponential survival model; time and lifetime use the same arbitrary unit. Expected survivors are calculated for an initial population of 1,000. Real quantum survival can depart…

S(t) = exp(−t/τ); t½ = τ ln 2
MODEL 16

Find the phase-locking threshold

Adler phase model with fixed detuning Δ and coupling K, integrated from φ(0) = 0.2 rad using fourth-order Runge–Kutta. Time uses a chosen unit; Δ and K have inverse-time units. This is a…

dφ/dt = Δ − K sin φ
MODEL 17

A brief push leaves a ringing response

Unit-mass, unit-frequency oscillator initially at rest, driven by one rectangular force pulse with fixed external impulse J = 1. Restoring forces act during the pulse, so residual energy…

F = J/Δt during the pulse; J = 1
MODEL 18

Exchange energy between two coupled modes

Lossless reciprocal coupling between two equal-frequency modes, with constant coupling κ and detuning Δ. Normalized length units are used; κ and Δ have inverse-length units. P₁ + P₂ = 1.…

P₂ = [κ²/Ω²] sin²(ΩL); Ω² = κ² + (Δ/2)²