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Zaldarriaga probes universe’s start

2 min read

How matter clumped into stars, galaxies a key question

Matias Zaldarriaga is peering back into time to find his roots – and the roots of everything else ever created.
Zaldarriaga, named professor of astronomy in July, is an expert in cosmology, which is the study of the origins and evolution of the universe.

A theoretical astrophysicist, Zaldarriaga is trying to understand the faint cosmic whispers of the big bang, that split-second explosion of inconceivable violence when all matter was hurled outward on a journey that would form the universe around us – somewhere between 10 billion and 20 billion years ago.

The period from the big bang to about 400,000 years later, when radiation called the “cosmic microwave background” was formed, is the focus of Zaldarriaga’s research.

The cosmic microwave background radiation is thought to be a very faint echo of the big bang, and researchers believe that it provides a window back into time. By studying it, astronomers are seeking to understand conditions 400,000 years after the universe was created.

“By looking at this radiation, we can actually see a picture of the universe 400,000 years after the big bang,” Zaldarriaga said.

What they see is that the cosmic microwave background radiation is nearly evenly dispersed throughout the universe. That means that astronomers examining it from Earth see very much the same thing no matter what part of the sky they look at.

But they don’t see exactly the same thing wherever they look.

Measurements in the past decade or so have detected slight variations in the cosmic microwave background that researchers believe are the first signs of the clumping of matter in the universe that eventually led to the formation of galaxies, stars, and planets.