3. Describe your childhood
I had a great childhood, but in retrospect it was fairly lonely - I was definitely the only astrophysicist in the village, so to speak. The funny thing is I didn't feel lonely - I only realised it when I was in an environment with other people who were interested in what I was interested in that I had been. Mum and Dad were surprised to find they were raising a scientist, I think. Dad was a doctor who loved amateur theatre and mum, Shirley Maddock, did many things - actor, writer, and worked in radio and television. She'd left TV when we were kids but she wrote books at home. Dad was really enthusiastic about Mum's career and her success and I think that was important for us to see growing up.
4. What did your parents teach you?
In my wife's family it was all very people-focused but in my family people were talking about ideas a lot. For both of them their real passions were in the humanities. Dad is in fine fettle, but Mum died in 2001. Their love of writing and the effort they put into polishing something for publication made a huge impression on me. Writing as a scientist is a bigger deal than most people realise. And in some unexpected ways, I have followed in their footsteps. Mum worked in TV in New York in the late 50s, and when I moved to Columbia University, I visited neighbourhoods she had told me about when I was a kid.
5. What's the point of knowing about the Big Bang?
To a scientist it's like rowing across the Tasman or climbing Everest - because it's there. Will it affect our lives? In the long run it must do. Not building a better machine exactly but it changes our view of the world and our place in it. Understanding how big the universe is makes our home seem more fragile.
6. Do you believe there was ever a nothingness?
I'm not sure. Our universe is roughly 13.8 billion years old, so the Big Bang happened at a fixed point in the past.
But what was there before it is anyone's guess - maybe a nothingness, maybe another something. We're working on it. We still don't understand the Big Bang itself but we've made vast progress in the past 25 years and we need a good idea now that we don't yet have. When do good ideas happen? About once a week, maybe when you're talking to someone and you realise something's interesting. Someone said scientists don't yell "Eureka", they go "oh, that's weird".
7. When did you stop believing in God?
I never started. Same with smoking, so I can't tell a quitting story. Some cosmologists are religious, but I'm not one of them. That doesn't mean you don't have a capacity to wonder and appreciate beauty. I used to be a much more militant atheist. I'm a pretty mellow one now. Does cosmology make you more philosophical? Well the funny thing is when you are actually doing it, it's a very detailed calculation and you're trying to figure something out. Then someone asks you a question and you step back and go "wow, I'm trying to explain how the universe began!" We're engaged in this quest that has kept people awake for millennia. It's a very humbling thing to work on.
8. Are there parallel universes - and if so, what's happening there?
Almost all theories of the Big Bang seem to imply that the event we call the Big Bang happens an infinite number of times. Either sequentially or concurrently. Maybe both. So it seems very likely that there are parallel universes. As to what would be happening in them - everything!
9. What kind of father are you?
A slightly distracted one at times, it has to be said. I have two fantastic boys, and I love seeing the world through their eyes as they grow up. They have endless questions, which is great. But not always at bedtime.
10. I've read your blog about climate change deniers: has Colin Craig got your goat?
I hope not - I can't imagine what he'd do with it. A lot of politicians are more climate procrastinators than climate deniers - they know there's a problem, but they are putting off tackling it. But Colin Craig spouts the most amazing nonsense on climate, and seems to have no understanding at all of what he is talking about. It is possible he is just making a cynical play for the most gullible 5.1 per cent of the electorate, but in either case it's not pretty to watch.
11. Is New Zealand funding its science research well, in your opinion?
New Zealand scientists have a huge number of great ideas that are going to waste because they can't get the support they need to chase them. But I wouldn't want to pretend it is a simple issue. The Government puts a good deal of money into science, and unlike many other countries we are not going through a round of cuts. Yet as a percentage of GDP, science funding here is well below most industrialised countries. A big part of this gap comes from our private sector spending relatively little on research and development. The biggest discoveries are always surprises, and we need to make space for them to happen. New Zealand does a poor job of nurturing young scientists - a lot of the research money we do spend goes to "silverbacks", and because they run the system they can be slow to see that this is a problem.
12. Are there concepts that even theoretical cosmologists find difficult to grasp?
Definitely! For me, the most unsettling concept in cosmology is the "multiverse" - the idea that our universe is just one "pocket" in an infinite ensemble of universes. It sounds like science fiction, and it amazes me that you can actually do the maths. In my lifetime we've gone from knowing almost nothing about the Big Bang to going out with a big telescope and seeing halfway across the universe. We're living in a special time, between when we didn't have a clue, to knowing the answers. We're just not sure when that will be.