Situated high above the Atacama Desert of northern Chile, the Simons Observatory is poised to capture echoes of the Big Bang with unprecedented precision. Two of the smaller telescopes have been tested and are generating data as of June 2024. There are a total of four telescopes with over 60,000 sensors designed to detect and measure fluctuations in the Cosmic Microwave Background (CMB) radiation–radiation left over from the birth of the universe, a thermal signature of the Big Bang.
According to the Simons Observatory’s official website:
The Simons Observatory (SO) will provide scientists with an unprecedented platform to study the nature of the fundamental physical processes that have governed the origin and evolution of the Universe via high-precision measurements of the temperature and polarization of the Cosmic Microwave Background – the oldest light in the Universe.
The existence of the cosmic background radiation–the oldest light in the universe—is one line of evidence supporting the Big Bang theory, a theory pointing to a beginning of the universe. Fr. Spitzer presents this evidence in his books and the Faith and Science video series. Let’s do a quick review and then see what this new information from the SO will add to our current understanding of cosmic beginnings.
Initial Conditions at the “Beginning”
The earliest conditions at the beginning of the universe were much hotter and denser than they are currently. Scientists believe tiny fluctuations in energy called quantum fluctuations increased dramatically seconds after the Big Bang in a period of rapid expansion (and cooling) known as inflation. These oscillations, through a series of expansions and collapses, generated all of the known matter in the universe, from baryons to the myriad of galaxies now in existence. The Simons Observatory website explains it this way:
The fluctuations also were imprinted in the heat of the early Universe; just as some patches of the Universe were a bit denser than others, some patches were a bit hotter. And we can map these regions of higher and lower temperatures by observing what has been called “the first light,” the cosmic microwave background (CMB), the heat leftover from the hot early phase of the Universe.
Some 380,000 years later, the universe cooled sufficiently to allow protons and electrons to begin forming “neutral” atoms, mostly hydrogen and helium. (As an interesting comparison, 380,000 years compared to 13.8 billion years is about the same fraction as one day in the life of a 70-year-old person.) Freed from matter, photons–light or radiation–continued to expand with the universe. Because of this expansion, the wavelengths of the photons stretched out into the microwave range. Thus, the cosmic microwave background (CMB) radiation was born.
Predicted in 1948, the existence of the CMB was confirmed in the 1960s. The CMB seemed to “come from everywhere,” and so it was believed to be uniform throughout the universe. However, in 1992, the Cosmic Background Explorer (COBE) satellite detected fluctuations in the CMB. What did this tell us? According to NASA:
These cosmic microwave temperature fluctuations are believed to trace fluctuations in the density of matter in the early universe, as they were imprinted shortly after the Big Bang. This being the case, they reveal a great deal about the early universe and the origin of galaxies and large scale structure in the universe.
Mapping the CMB
Credit: NASA/JPL-Caltech/ESA
The first image of the CMB was released in 1992, followed by a more precise map in 2003 using data from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP). Finally, in 2013, the Planck satellite team released its own more complete map.
The Cosmic Microwave Background as seen by Planck. Credit: ESA and the Planck Collaboration
https://cdn.mos.cms.futurecdn.net/p93nfisEnJqkRkh8878JRE.jpg
As impressive as the increased details are from the Planck data, data from the SO should allow a more precise and more dramatic view of the CMB.
With up to ten times the sensitivity and five times the angular resolution of the Planck satellite, and roughly an order of magnitude increase in survey speed over other, currently operating, CMB experiments, SO will measure both temperature and polarization fluctuations in the CMB to exquisite precision at several frequencies.
These more precise measurements will allow scientists to explore the mass, energy, and interactions of primordial particles, including photons, neutrinos, electrons, and positrons. This information could shed light on the processes involved in the evolution of the Universe and on the earliest structures that were formed during that period. These are exciting times indeed!
