Bounce the beam into the receiver.
Drag the source and optical pieces. Select a piece, then drag its dotted rotation arc or use the 15° buttons. Direct enough light of the required color into every receiver.
Targets: hold enough light on a receiver for three seconds. The ring fills, then stays charged. An incomplete charge fades when the beam misses. Power switches: the lightning symbol stays on only while illuminated; its gate closes when the light stops.
Spectrum and heat: select a source to enable bands and set power per band. X-ray (0.1 nm), UV (300 nm), and thermal IR (10 μm) use false colors. All absorbed radiation heats materials; equal absorbed power produces equal heat. Heat is shown in relative units, with cooling over time.
Material transmission is simplified for these representative bands: ordinary glass absorbs much of UV and thermal IR, thin masonry partly transmits hard X-rays, and lead strongly attenuates them. Coefficients are tuned for play. Gravity bends every wavelength equally; it does not sort colors like a prism. Multiple black holes use an approximate combined field.
Press Space to pause motion, heat, and charging. Light and matter · Black holes