Asymptotic Safety: The Quantum Gravity Fixed Point (2D)

Every candidate "theory of everything" has to explain why quantum gravity doesn't blow up at short distances. Asymptotic safety answers this without extra dimensions or new particles: it treats Newton's constant and the cosmological constant as running couplings, exactly like the running coupling of the strong force, and asks whether their flow settles onto a finite fixed point at infinitely high energy instead of diverging. This 2D simulator draws the renormalization-group flow directly as a phase portrait — the dimensionless couplings g̃ and λ̃ on the two axes — and shows dozens of trajectories, each starting from a different low-energy condition, curve onto a single non-Gaussian fixed point as the energy scale climbs toward the Planck scale. Pick your own starting coupling g̃₀ to trace one highlighted flow by hand, adjust the quantum-correction strength and the coupling between g̃ and λ̃ to relocate the fixed point live, and watch the "spread from FP" readout collapse toward zero as every flow gets swallowed by the same attractor — the mechanism that would make gravity, on its own, into a consistent, predictive, unified quantum theory.