Some 13.8 billion years ago, the universe began in a big bang – or, at least, that is what we think happened. Astrophysicist Jo Dunkley is at the forefront of efforts to work out exactly what took place in the immediate aftermath of that moment of cosmic creation. And a new telescope might just help her answer this question once and for all.
The issue with the big bang is that we can’t see it directly. The best we can do is look at the cosmic microwave background (CMB), often called the afterglow of the big bang. Faintly daubed across the whole sky, this radiation is all that is left of the first light that could travel in the universe. Subtle patterns in this light fit with the well-established idea that the big bang was followed by a period known as inflation, when the universe expanded at a rip-roaring pace. But it has never been proven.
Dunkley, who is based at Princeton University, thinks that observing the CMB in finer detail than ever before will clinch the deal, specifically by helping us see patterns imprinted by gravitational waves from the dawn of time. To glimpse these, she plans to use the Simons Observatory, a purpose-built telescope in Chile that is on the cusp of switching on.

As she prepares for this opportunity, Dunkley spoke to New Scientist about her…