Mayo man John Regan recounts his path to becoming an astrophysicist

INTERVIEW: by Dr. Richard Martin

The Regans from Maryland, Castlebar, are family friends.

Paul Regan and my younger brother Liam were close childhood friends – and still are.

I remember them both knocking around the tennis club on Pavilion Road as young bucks. Now they’re both adults - married with kids.

They’re both physicians – both graduates of the Galway Medical School. Life is a fast moving train.

Seamus Regan is well known throughout the town and county as a building contractor and is also a good friend of my father. I bumped into John Regan (Paul's older brother) on a beautiful morning in the Mall. We stood talking for a few minutes and exchanged numbers.

He’s a fascinating man. He is an astrophysicist in the Department of Theoretical Physics in Maynooth. He obtained his PhD in astrophysics from Cambridge University in the mid noughties, which is obviously a unique and extraordinary achievement.

The Cambridge Maths Department in science terms is akin to Real Madrid. Only the very best are considered for admission. And only the fittest survive in that environment.

I’m open to correction but I only know of two others from Castlebar who’ve studied in Cambridge. Damien Coady (son of Matt Coady) studied mathematics as an undergraduate in Cambridge in the mid-1990s and later graduated from the Harvard Business School. The well-known local historian and lawyer Dr. Michael M. O’Connor also studied law in Cambridge in the 1980s.

The three men were all secondary students in St. Gerald’s College.

According to John Regan’s faculty page, his day job entails ‘using powerful supercomputers to model the formation and evolution of black holes in the early universe which can then be used to understand how these objects form and grow over cosmic time’.

I wanted to find out more about his life journey and share it with the wider Castlebar populace. We arranged to meet in Palestine House, Castle Street, Castlebar, a few weeks back on a damp wet Saturday evening.

Here is the conversation.

RM: You left St. Gerald's when I started in 1999. Did you have Sean Kearns and Christy Tynan for Maths and Applied Maths?

JR: I was very lucky, I had both of them for those subjects.

Sean was a fantastic teacher. Christy was, I felt, really, really passionate about his subject. I had Christy for Physics and Applied Maths.

He had a really interesting teaching philosophy. You’d just come in and work through the problems. It was a real problem-solving class.

And he taught me physics as well, and he was just brilliant. He's a chemist, though. That's his passion.

RM: That's the amazing thing. He's not really a physicist or an applied mathematician.

Do you think that meeting those teachers sparked an interest in science?

JR: I don't think it sparked my interest. I think that would be the wrong and unfair way of saying it. It developed my interest. I already had the spark.

But I had excellent teachers in maths, physics, science, applied maths. And I think that developed my interest.

Because let's say you could have had the spark, but then you didn't have a teacher to bring it on. I had the spark and the teachers to bring it on.

I think you were probably the same?

RM: Yeah. I think it's a lot like kind of horse racing.

I mean, you need the three, you need the jockey, you need the horse, you need the trainer. And if one thing is missing.

JR: Yeah, if you miss one of those cogs, I think that's a big loss. I think if I had been in St. Gerald's and that calibre of teacher wasn't available. .

Obviously, people can adapt, but the teachers were available, which I think was a massive bonus. You know, I think that's key. I thought St. Gerald's was a very, very well run school.

RM: It still is. I was there last year. It's never lost the academic ethos. Some of the Leaving Cert students were exceptional.

JR: I think it definitely had the academic ethos, but it was a school that functioned very well. It seemed to be a very fair school. It was strict, but not overly strict, I think.

Good sports facilities, just a well-run school.

RM: Good culture.

JR: Good culture. Maybe that's it.

RM: After your Leaving Cert, you then went on to Trinity. Why did you pick theoretical physics over maths?

JR: I was always quite interested in the physics side of things and probably to some extent astrophysics as well. Maths was too abstract for me.

RM: Am I right in saying that you won an award as an undergraduate?

JR: That's right.

RM: What did you win?

JR: I think it's called the Arthur Lester Award. It was for mathematics in my third year.

RM: After your undergraduate degree you did an MSc in High Performance Computing in Trinity and then went to Cambridge to do a PhD in Astrophysics. Tell us about Cambridge. It's such an intimidating place, how did you cope there?

JR: It's funny, I have a lot of very good friends who I did my PhD work with and I remember talking to them every day and we found it very, very hard going. Very hard.

You were just thrown in and the level of supervision you were given was minimal. They weren't coming to your desk asking how you were or helping you out with the problems.

They were like: bring me results.

RM: I can totally relate to that because it was the same when I went to Oxford.

JR: Because they're very busy people and they're working on a lot of different things and they probably have a tonnes of students and they're like, look, if you're sinking, that's fine.

They're not going to come and help you out or get you over the line. You have to do that yourself. So it's a really tough environment.

RM: But did you find that it made you better then?

JR: Oh yeah, yeah.

RM: Why is that?

JR: It makes you more independent, more adaptable, more resourceful, more resilient, all of those things. And you really learn to work and work through problems and persevere.

RM: Do you think it's a bit cruel though or is it just the way it is?

JR: Yes, it definitely is. I think it is a bit cruel. But it's just the way it kind of has to be.

I think if you make it too soft, I don't think you're doing anybody any favours. It has to be a bit hard.

It is a tough environment. But what you gain is exceptional then because the contacts and the networks you have after either doing a PhD in Cambridge or a postdoc in Cambridge is, you have this network then of people who you are very comfortable with, who know you, who can relate to you. And you can always go back and use those networks and leverage those networks.

That's been a huge advantage for me. It's unbelievable.

RM: Your own research is in astrophysics. So what is a black hole?

JR: So a black hole is a region of space-time that light cannot escape from.

You cannot get out of the black hole. That's what a black hole is.

RM: But it's not just light, is it?

JR: It's just everything.

Anything that goes into a black hole, it's in the black hole forever. It's trapped in there. Black holes form from the end point of stars.

The amount of mass that is in a star, once it stops burning, is so dense and so heavy that gravity cannot hold it up anymore. That's where a black hole comes from. So you get black holes forming from the end point of stars.

That's what a black hole is.

What I work on a lot actually is trying to understand how the first black holes in the universe formed. So how did we get the first very massive black holes forming.

I mean ones that are a million times the mass of the sun.

RM: I have to ask you this question.

In our galaxy, the Milky Way, there are 10 billion stars, and the universe is potentially infinite with an infinite amount of galaxies.

Do you think it's likely or unlikely that there's life out there?

JR: There is definitely life out there, right?

RM: Why?!!

JR: Because nature doesn't do things in black and white. And black and white would mean that we're the only one, right? Nature doesn't do that. Nature does continuums, right? Everything we see in nature is always a continuum.

We see a continuum in black holes in terms of the mass. We see small black holes and we see massive black holes. We see small planets and massive planets.

We see small stars and massive stars. We always see a continuum. And we see all different kinds of planets. We never, ever see black and white in nature.

So there's a few things that will happen over the next decade or maybe two, but I think it'll be the next decade. We'll find Earth 2.0. So you'll find a planet that is identical, basically, to the Earth in terms of its orbital distance from the sun, it'll be power from its star and it'll have the same composition.

And then we'll start to peer at its atmosphere and we'll see what it looks like. Probably what you'll find is that a lot of these things is they're just full of vegetation, right? And then the question becomes, well, how frequent does intelligent life evolve? That, of course, we don't know. My understanding is that we'll start to create life in the lab in the next 10 years as well.

RM: So this seems like something you've thought about a lot.

JR: It is, yeah. And also, I'm in a privileged position because I go to a lot of talks on exoplanets, so I kind of know the field as well a little bit.

RM: So this is something that people are actually thinking about and talking about.

JR: Oh, absolutely.

RM: How do you contact other life forms?

JR: Well, I think there's a few things to think about there as well. One is there's no reason to believe that we're particularly intelligent. So you'd probably have more intelligent species out there.

Again, it's going to be a continuum. Less intelligent and more intelligent, right? We'd be somewhere, I don't know where we'd be on that spectrum. But there's no reason to believe we'd be at the top of it.

......

Like I said I’ve know the Regans for well over two decades, but I’d never actually had the opportunity to sit down with John Regan and have a proper chat.

Reflecting on the experience I was struck by a few things.

Firstly, his humility. He’s still just a local lad from the town. Easy going and self-deprecating, keen to acknowledge the great mentors he has met on his journey.

Secondly, his obvious passion for his research in astrophysics and the search for a deeper understanding of our universe is inspiring.

Why are we here? Is there life out there?

In my experience scientists are very spiritual people. The laws of the universe are encoded in beautiful mathematics. Paul Dirac famously stated: “God is a mathematician of a very high order.”

In the back of my mind putting this piece together, I hope that younger people around the town read this article and are inspired by his journey and achievements and have the ambition to emulate his career path in their chosen fields.

As a teacher, I always try and impress on students that it’s criminal not to achieve your full potential – whatever that is.

John Regan certainly has.