💫 Supernova Standard-Candle Hubble Diagram (2D)

This 2D companion drives the same standard-candle distance formula as the 3D Supernova Standard-Candle Hubble Diagram, but turns the three fixed reference curves into a hands-on fitting exercise: a deceleration-parameter slider draws your own magenta curve through the plotted Type Ia data, a live fit score tells you numerically how well that curve matches the scatter, and a Hubble-constant slider rescales the distance axis independently of the curve's shape. Hit "Snap to best fit" and the dial settles near q₀ ≈ -0.55 — reproducing, by hand, the same conclusion the 1998 high-z supernova surveys reached: the universe's expansion is accelerating.