Cosmic microwave background radiation (CMB) is a type of electromagnetic radiation that permeates the entire universe. It is the oldest light in the universe and is a remnant of the Big Bang, the event that is believed to have started the universe's expansion.
The CMB was first discovered in 1964 by radio astronomers Arno Penzias and Robert Wilson. They were conducting experiments with a large radio telescope and noticed a faint, uniform background noise that was present regardless of where they pointed the telescope. This noise turned out to be the cosmic microwave background radiation.
The CMB provides important clues about the early universe and the formation of galaxies. It also supports the Big Bang theory and helps us understand the age, composition, and expansion of the universe.
The CMB is measured using specialized instruments, such as satellite-based telescopes and ground-based radio telescopes. These instruments detect and measure the faint microwave radiation emitted by the CMB and create images of the CMB across the entire sky.
No, we cannot see the CMB with our eyes because it is a type of electromagnetic radiation that is outside of the visible light spectrum. It has a wavelength of about 1 millimeter, which is much longer than the wavelengths of visible light. However, it can be detected and measured using specialized instruments.