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Cosmologists have for long presented various hypotheses on the origin of the universe before the Big Bang happened. Now, research from the Harvard-Smithsonian Center for Astrophysics suggests a new method to arrive at the right theory.

The cosmic microwave background (CMB), or a glow originating from the Big Bang that penetrated each area of space, seems to be "smooth and uniform" at first, but then exhibits variations. These arose from quantum fluctuations in the beginning of the universe that have subsequently stretched with the expansion of the universe.

Even though conventional probes into the early birth of the universe tried to seek traces of gravitational waves in the CMB, the new paper gives alternative theories.

"Here we are proposing a new approach that could allow us to directly reveal the evolutionary history of the primordial universe from astrophysical signals," Xingang Chen, co-author of the study, said in a press release.

While earlier, scientists tried to identify spatial variation in the primordial universe, they could examine an element of time, which made it tough to unearth the evolutionary history of the universe.

"Imagine you took the frames of a movie and stacked them all randomly on top of each other. If those frames aren't labeled with a time, you can't put them in order," Chen said. "Did the primordial universe crunch or bang? If you don't know whether the movie is running forward or in reverse, you can't tell the difference."

The "clocks" seem to exist in the form of heavy particles that can trace the passage of time. These particles are called "primordial standard clocks," and move back and forth like a pendulum. They can act as the time labels mentioned in the "movie frame analogy", according to HNGN.

"Ticks of these primordial standard clocks would create corresponding wiggles in measurements of the cosmic microwave background, whose pattern is unique for each scenario," said Yi Wang, co-author.

Still, a lot more research is required.

The findings are expected to be published in the Journal of Cosmology and Astroparticle Physics  and the pre-print can be seen on arXiv.