A bolometer is a sensitive instrument used to measure the power of incident electromagnetic radiation, particularly in the infrared range. It works by detecting changes in temperature caused by the absorption of radiation, which is then converted into an electrical signal. Bolometers are commonly used in astronomy, thermal imaging, and various scientific research applications. The basic design of a bolometer includes a material that changes resistance with temperature, often made from materials like vanadium oxide or silicon. These devices can detect very small amounts of energy, making them valuable for studying faint astronomical objects and for applications in night vision technology.