Hiranya Peiris

So Stephen and Roger Penrose had contrasting ideas about the physics of the very early universe, and they were debating each other.

And I was transfixed by this lecture.

And then afterwards, I built up my courage.

I was a very, very shy young girl.

But I went up to Stephen and asked for his thumbprint.

And lo and behold, they actually had an ink pad, because other people probably do also ask for his thumbprint.

And so I actually still have that somewhere.

I visited there to see whether that's where I wanted to go.

And a young professor called David Spergel came late in the evening to pick me up from the train station and take me to a very welcoming group of graduate students.

And again, it was this feeling of belonging.

It felt like I had come to another family.

And David later was my PhD advisor as well.

But I had this gut reaction that that was the place where I belonged.

One of the crucial points that makes my field possible is that light has a speed limit, which means that when you look into the distant universe, you see things as they were in the past.

That's absolutely right.

So the oldest light we can see in the universe is the cosmic microwave background.

So the analysis involved comparing the patterns of the very early light that we can see in the cosmic microwave background with theoretical models.

And different cosmological models make different predictions for the pattern.

It's like a fingerprint.

It identifies the theory.