Chaos Lab

Continuous flow · dim 3

Lorenz '63

Edward Lorenz's 1963 truncation of atmospheric convection. The first explicitly studied strange attractor: bounded, sensitive to initial conditions, with a fractal dimension ≈ 2.06. Origin of 'the butterfly effect'.

Lorenz '63 attractor at σ = 10, ρ = 28, β = 8/3.

Equations

dx/dt = σ(y − x)
dy/dt = x(ρ − z) − y
dz/dt = xy − β z

At a glance

Parametersσ = 10, ρ = 28, β = 8/3 (classical)
Chaotic forρ > 24.74 (Hopf bifurcation), classical at ρ = 28
Lyapunov exponentλ₁ ≈ 0.906 (classical)
HistoryLorenz, 'Deterministic Nonperiodic Flow', J. Atmos. Sci. (1963).

Try it

Open the interactive playground at /tools/lorenz.

See also

Quick quiz

Test yourself on lorenz

8 multiple-choice questions. Pick an answer for each, then submit to see explanations.

  1. Q1.Lorenz '63 came from truncating which physical system?

  2. Q2.Lorenz at classical (10, 28, 8/3) has Kaplan-Yorke dimension approximately:

  3. Q3.Hopf bifurcation in Lorenz occurs near:

  4. Q4.Smale solved the problem of whether the Lorenz attractor is truly strange:

  5. Q5.The two-wing structure comes from:

  6. Q6.Lorenz observed chaos by accident in:

  7. Q7.The Lorenz attractor exhibits which kind of symmetry?

  8. Q8.What's the largest ρ before transient chaos disappears in Lorenz?

0 of 8 answered