Absorption & Emission Spectral Lines (2D)

This 2D companion view puts the physics of the 3D gas-cloud scene onto a single readable spectrum strip: pick hydrogen, helium or sodium, and the simulator computes each element's real spectral-line wavelengths — hydrogen's straight from the Rydberg formula, helium and sodium from their measured visible lines including sodium's tight D1/D2 doublet — then renders them as dark absorption gaps cut out of a continuous "white light" spectrum, or as bright emission lines glowing on black. A schematic below the strip shows light passing through the gas cloud toward a slit and prism exactly as a real spectrograph would see it, and the temperature slider drives genuine Doppler thermal broadening, widening each line by √(T/mass) just as it would in a real stellar or lab spectrum. Click any line, in the strip or the side list, to read off its exact wavelength, photon energy and transition.