Humans experience only a narrow slice of the physical world. Our eyes detect roughly 380 to 700 nanometers of electromagnetic radiation, while our ears detect approximately 20 Hz to 20 kHz. Everything outside these ranges remains invisible or inaudible to us. Many animals have sensory abilities that extend beyond ours. Bees and some other insects can detect ultraviolet light, allowing them to see patterns on flowers that humans cannot see. Some birds can also detect ultraviolet wavelengths. Other animals detect forms of radiation we cannot sense directly. Pit vipers have specialized heat sensing organs that detect infrared radiation from warm objects, helping them locate prey even in darkness. Some nocturnal animals are extraordinarily sensitive to faint light. Owls, for example, have eyes adapted for low light and can detect movement under conditions where human vision becomes extremely limited. For these animals, even very faint natural light can remain useful. The Universe is fi...