200 most important Astronomy topics - Sykalo Eugen 2023

The Discovery of Cosmic Microwave Background Radiation

Cosmic Microwave Background Radiation (CMB) is a form of electromagnetic radiation that fills the entire universe and is believed to be the leftover radiation from the Big Bang. This discovery, which confirmed the Big Bang theory and revolutionized our understanding of the universe, was made by two astrophysicists named Arno Penzias and Robert Wilson in 1964.

Background

The study of stars and galaxies began in the early 1900s with the work of astronomers like Edwin Hubble. By the 1930s, scientists had developed a basic understanding of the universe and believed it to be static and unchanging. However, in the late 1940s, Ralph Alpher and George Gamow proposed a new theory called the Big Bang, which suggested that the universe began as a hot, dense point and has been expanding and cooling ever since.

One prediction of the Big Bang theory was the existence of a faint glow of radiation that would be detectable throughout the universe. Alpher and Gamow suggested that this radiation would have a temperature of about 5 Kelvin (about -268 degrees Celsius) and would be uniform in all directions. However, it wasn't until the 1960s that technology had advanced enough to allow for the detection of this radiation.

The Discovery

In 1964, Penzias and Wilson were working on a radio telescope at Bell Labs in New Jersey. They were trying to detect radio waves emitted by the Milky Way, but were puzzled by a faint background noise that they couldn't explain. They initially thought it might be due to pigeon droppings on the antenna, but after cleaning it, the noise persisted.

At the same time, a team of scientists led by Robert Dicke at Princeton University were also searching for CMB. They had predicted that if CMB existed, it would show up as a faint radio signal with a temperature of about 3 Kelvin (about -270 degrees Celsius).

When Penzias and Wilson heard about Dicke's work, they realized that the background noise they had been detecting was actually CMB. They immediately published their findings, which confirmed the prediction made by Alpher and Gamow 16 years earlier.

Significance

The discovery of CMB provided strong evidence for the Big Bang theory, which states that the universe began as a hot, dense point and has been expanding and cooling ever since. The fact that CMB is uniform in all directions also supports the idea that the universe is isotropic, or the same in all directions.

CMB radiation has been studied extensively since its discovery, and has provided valuable insights into the early universe. For example, it has allowed scientists to determine the age of the universe (about 13.8 billion years) and the composition of the universe (about 5% normal matter, 27% dark matter, and 68% dark energy).

The study of CMB has also led to the development of new technologies, such as the Cosmic Background Imager (CBI) and the Wilkinson Microwave Anisotropy Probe (WMAP), which have allowed scientists to study CMB in greater detail and with higher precision.