Light 1 Visible Spectrum. Visible Light: the wavelengths that are visible to most human eyes. ... 2 Speed of Light. ... 3 Light Can Travel Slower. ... 4 Wavelength and Frequency are Linked. ... 5 Light Travels in Straight Lines. ... 6 Wave 7 Photons. ... 8 Intensity. ... 9 Inverse Square. ... 10 Polarization. ... More items...