In what appears to be a revolutionary cosmic observation, astronomers have reportedly detected a signal from the first stars of the universe. According to reports, the discovery has given researchers an unparalleled glimpse into the events that occurred right after the Big Bang.
While our current night sky is teeming with bright, twinkling stars, scientists say that this has not always been the case.
Apparently, the ancient signal that they have detected suggests that it took nearly 200 million years after the Big Bang for the earliest stars to emerge from the darkness.
This detection was discovered in the form of a radio signal by researchers from the EDGES project. It was assumed to have been triggered when lights from the earliest stars began making interactions with hydrogen gas.
Studies suggest that this gas was one of the first elements to have filled the primordial empty space of the early universe.
The detection of this signal is likely to open up a new line of inquiries and issues to be tackled by the scientific community.
“The era of cosmic dawn has been entirely uncharted territory until now,” Cynthia Chiang, a physicist from the University of KwaZulu-Natal in South Africa, was quoted as saying. “It’s extremely exciting to see a new glimpse of this slice of the universe’s history, and the EDGES detection is the initial step toward understanding the nature of the first stars in more detail.”
Timeline of how the Universe was created from the Big Bang showing when the first stars emerged | NASA
Signal From the First Stars
For hundreds of years, many myths and scientific theories have been formulated to explain the origins of the cosmos. Among these theories, the most popular and widely accepted is the Big Bang theory.
Georges Lemaître, a Belgian Catholic priest, astronomer, and professor of physics at the Catholic University of Leuven, was the first scientists to suggest that the universe is expanding.
In the late 1920s, he proposed what became known as the Big Bang theory based on his hypothesis of the primeval atom or the cosmic egg.
According to studies, the universe was conceived billions of years ago with a fixed amount of energy and matter. However, shortly after it was born, it was plunged into deep darkness. It was only until hot gases fused with masses of dark matter that the first stars were formed.
This phenomenon eventually ignited the nuclear hearts of young suns.
These early stars breathed ultraviolet light into the cosmos and their photons merged with primordial hydrogen gas. This led the photons to absorb background radiation and become translucent.
After this event, the hydrogen atoms started producing radio signals that traveled through space at a predictable frequency. This same signal was what astronomers detected through a radio antenna, the size of a tabletop, called EDGES.
“This is the first real signal that stars are starting to form, and starting to affect the medium around them,” Alan Rogers, a scientist at MIT’s Haystack Observatory, said in a statement.
“What’s happening in this period is that some of the radiation from the very first stars is starting to allow hydrogen to be seen. It’s causing hydrogen to start absorbing the background radiation, so you start seeing it in silhouette, at particular radio frequencies.”
New Findings from the Early Universe
In a studypublished by the researchers in the journal Nature, they described the signal from the first stars as “stretched” or “redshifted”. These are terms used to identify fingerprints of the earliest stars in radio waves. This is because the signal has been traveling through space for a long time now.
“The first indication of the signal emerged within weeks of turning on the instrument in 2015,” Judd Bowman, a coauthor of the study from the Arizona State University, said. “At first we assumed it was a problem with the instrument, because it was larger than anything we expected.”
The astronomers admitted that detecting the signal has been a tremendous technical challenge. Peter Kurczynski of the National Science Foundation, said:
“There is a great technical challenge to making this detection. Sources of noise can be a thousand times brighter than the signal they are looking for. It is like being in the middle of a hurricane and trying to hear the flap of a hummingbird’s wing.”
The radio signal reportedly dates back to around 180 million years after the Big Bang that occurred over 13 billion years ago.
One substantial information that the researchers found from the distant signal was that the gas in the early universe was apparently much colder than what was expected.
One explanation that they offered is that baryons, or ordinary matter, may have lost their energy when they interacted with dark matter during those early times.
It is believed that dark matter makes up a vast portion of the matter in our universe. However, it has never been directly observed.
According to Bowman, if their theory is confirmed, it would be considered as another fundamental discovery about the mysterious dark matter.
Bowman said that they welcome other researchers to confirm their detection using different radio telescopes.
In the future, he hopes that they would have new resources dedicated to the study of the signal from the first stars to gain more information.
“Now that we know this signal exists, we need to rapidly bring online new radio telescopes that will be able to mine the signal much more deeply,” he went on to say.