Somewhere between 50 to 1 billion years after the Big Bang, our universe experienced something known as Cosmic Dawn.

This was the time period in which the very first stars, black holes, and galaxies began to form, bringing light and complexity to a universe that was – prior to Cosmic Dawn, in a period known as the Cosmic Dark Ages – mostly made up of hydrogen and helium.

And as the name suggests, thanks to the lack of light, it was infinitely dark.

Though the early period of formation in the Cosmic Dawn is fascinating, it is uniquely difficult to fully understand, thanks to it being so far away that even our most powerful telescopes can’t see those early stars being formed.

However, thanks to researchers at the University of Cambridge, UK, we could be closer than ever to a solution.

That’s due to a project known as REACH (the Radio Experiment for the Analysis of Cosmic Hydrogen), led by the Cambridge’s Institute of Astronomy’s Professor Anastasia Fialkov.

Using telescopic radio antennae, the project looks deep into the universe not using visual signals, but radio signals, enabling researchers to gather ground-breaking astronomical data, as Fialkov explains in a statement:

“This is a unique opportunity to learn how the universe’s first light emerged from the darkness. The transition from a cold, dark universe to one filled with stars is a story we’re only beginning to understand.”

How does a radio antenna help to decode the early universe?

Well, there is a specific radio signal – known as the 21-centimeter signal – that is produced by hydrogen atoms as they filled the gaps between the early stars.

And according to the team’s most recent paper, published in the journal Nature Astronomy, this technique will clearly evidence the transition from a hydrogen-filled universe to one brimming with galactic and cosmic activity.

What’s more is that the project takes into account x-ray emissions, which are produced as stars collapse and die, helping them to understand not only how the earliest stars formed, but how they died too – and what came after.

It is worth noting that REACH is still being tested and calibrated, but the team are confident in the models that they have produced, as Fialkov continued:

“We are the first group to consistently model the dependence of the 21-centimeter signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die. These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang. It takes a bit of imagination to connect radio data to the story of the first stars, but the implications are profound.”

So thanks to the REACH project, and other radio antennae projects currently in production, we may soon be able to sense our way back to the very beginnings of the universe.

And for those aiming to understand where life and the universe came from, that prospect is very exciting indeed.

If you thought that was interesting, you might like to read about a quantum computer simulation that has “reversed time” and physics may never be the same.