Adjust wavelength. See associated color. Look at electrons, light bulb, & glow-in-the-dark toy to see which color has the highest energy. Adjust amplitude (wave height). Amplitude doesn't affect electrons, unless frequency is high enough. How do you explain this photoelectric effect?
Higher frequency has higher energy, color goes towards purple, and can knock electrons out of metal. Surprisingly, if wavelength isn't high enough, high amplitude doesn't affect electrons. Likewise, there's a threshold energy level for the glow-in-the-dark. Notice glow-in-the-dark (phosphorescence) continues for a bit even after energy is lowered. While classical electromagnetism predicted that sufficient light amplitude (intensity) would dislodge electrons, experiments instead show electrons are dislodged only with high frequency light (regardless of the light's intensity or duration). So, Einstein proposed light is not a wave, but rather discrete energy packets known ("photons"). Before Einstein figured out this riddle, all were confused. I added sound, although the photoelectric effect is a light phenomenon. For sound waves, higher frequency yields a higher pitch. When frequency doubles, the sound is an octave higher. When amplitude is higher, volume is higher. λ, Wavelength in meters F, Frequency in Hertz (Hz) C, Velocity of Light = 299,792,458 meters/second λ = C/F >600 nm, long-wavelength red light has too little energy even to knock electrons into the higher energy state required for phosphorescence. I slowed down the visual or else we'd just see a blur.
