Posted by: Kash Farooq | October 28, 2011

Interview with Brian Schmidt: 2011 Nobel Prize in Physics Joint Winner

“We will look out to a Universe on which you cannot do cosmology because there is nothing to see. It will be a very empty Universe.”

Brian Schmidt - 2011 Nobel Prize in Physics, Joint Winner

Brian Schmidt - 2011 Nobel Prize in Physics, Joint Winner (image by Belinda Pratten)

Brian Schmidt of the Australian National University in Canberra was recently named as a joint winner of the 2011 Nobel Prize in Physics. The formal citation reads:

“For the discovery of the accelerating expansion of the Universe through observations of distant supernovae”.

Brian and his team’s work on the expansion of the Universe fundamentally changed astrophysics – it opened up a whole new area of science and introduced the world to the concept of Dark Energy.

Brian kindly agreed for me to call him to chat about the award and the science behind it. An edited 10 minute version of the interview is available on episode 107 of The Pod Delusion. The full 20 minute version is available on this page too.

Kash Farooq: Let’s start at beginning. You moved from the US to Australia in 1994 and made the discovery in 1998. Can you briefly explain what you and your team discovered, and how you discovered it?

Brian Schmidt: I finished my PhD at Harvard in 1993 and I started a post doctorate fellowship at the Harvard-Smithsonian Centre for Astrophysics; I was part of the Smithsonian side rather than the Harvard side. I was looking for something to do and in 1994 Mario Humuy from Chile came up and showed us his new data on supernovae, which showed that you could use them to measure distances very precisely. At the same time Saul Perlmutter who had been trying to discover supernovae for about 6 years and then suddenly found 7 of them.

So, I was going down to observe in Chile in 1994. I had a chat with the group down there and I hatched a plan that we would take on Saul Perlmutter’s team in measuring how fast the Universe was slowing down over time. This was just before I moved to Australia.

I figured that although Saul’s team had been working on this a long time, our team had been working on it from the other side – from the supernovae side. And so it seemed to me to be a reasonable thing to go out and try this experiment.

When I moved to Australia it was really about trying to measure what the Universe did back in time by looking at really distant objects. I really put my heart and soul into it when I got to Australia for three and a half years.

Kash: One of the interesting stories neatly demonstrates how science can work. You were actually expecting the complete opposite of what you found, and this opened up a whole new area of physics. Can you tell me more about that?

Brian: I always like to work on big questions. When I came to Australia I decided I may as well try to answer a big question; the question I was looking to answer was how fast does the Universe slow down, and therefore gauge the future of the Universe.  If the expansion is slowing down a lot then the Universe will reach a maximum size and then gravity will take over and run the Universe in reverse. Just like a ball you throw up in the air, it will crash down and we get the Big Bang in reverse, which we like to call the Gnab Gib!

So that was the big question we were trying to answer.

After about 3 years, the data were coming in. I was talking to Adam Reiss who was spearheading this work (we handed out each part of the project to young people, Adam was one of the young people on the team). He was doing a huge amount of work. The data showed that the expansion of the Universe was not slowing down at all but was speeding up. That was a real crazy thing to be confronted with. It didn’t make a lot of sense. It seemed just impossible. It was a pretty scary time when we first saw that result.

Kash: How many times did you double check, triple check your results before you decided to make the announcement?

Brian: Initially you just start looking for problems, checking and rechecking everything but after a while you’ve done everything you can and nothing is obviously wrong. We opened it up to the team and said “OK guys, we’ve got this crazy result. Any test you want us to do, we’ll test. We think we’ve done everything.”

The group came up with all sorts of things to think about so we went through and worked more. But at some point it slowly sunk in that the universal acceleration we were seeing just wasn’t going to go away.

It took a few months but we’d done everything we could several times, and several people did it and everyone just got the same answer.

Kash: When you made the announcement, just like the recent faster than light neutrinos announcement, what was the reaction around the world? Were scientists skeptical?

Brian: I was expecting a reaction very similar to the faster than light neutrinos announcement, where they’ve gone out as a good team, they’ve gone out and said “Hey we see this” and most of the world says “It’s got to be wrong”.

In our case I was expecting to say this is just wrong and we’ll figure out the problem. Some people were skeptical, and I don’t blame them for being skeptical – I would have been skeptical as well. I was skeptical when we released it – I just could not make the result go away.

There were some problems in cosmology back in 1998 where things did not quite work properly. The accelerating Universe only worked if the Universe was full of energy that was previously unaccounted for, the stuff we call dark energy – what Einstein called the Cosmological Constant.

Now it turns out that this dark energy fixed most of the outstanding problems in cosmology. It wasn’t that this dark energy had been disproved; it was just crazy that somehow we had missed 75% of the Universe. And this 75% of the Universe caused gravity to work in reverse. It just seemed too crazy to believe.

I think for the guys that are measuring the faster than speed of light neutrinos, I commend them for coming out. I have to admit that I suspect there will be something found wrong – but I could be wrong. Maybe the Universe really is crazy and for some reason these neutrinos, which are at very high energy, just travel faster than the other neutrinos that we have measured from supernovae, for example.

Kash: Where did the term “dark energy” come from? Was it just an obvious choice as the term “dark matter was already in use?

Brian: I believe the term dark energy was invented right here in Canberra, Australia, in ‘98 or ’99 by Mike Turner, a very well known cosmologist, who we invited here to give a cosmology talk right after the acceleration announcement. We had a big conference here. He invented the term for his talk called “Dark Energy”.

It’s “energy” because it is tied to space. It’s “dark” because we can’t see it. When astronomers discover something they can’t see, we just call it “dark x”; in this case x was energy.

It was a term that sounded good and made sense as it fit in with dark matter and describes what’s going on.

Kash: What does the acceleration mean for the distant future of the Universe?

Brian: Right now, when light travels through the cosmos to us it has to compete with the expansion of the Universe to get to us. Light takes a long time to get to us, but it gets to us.

In the future because the Universe is speeding up, it is expanding faster and faster over time, at some point galaxies we can see now, the Universe will be stretched so much between us and those galaxies that the light will never reach us.

If you take this to further and further in the future it turns out that the entire Universe that is not gravitationally bound to us right now will eventually be stretched beyond our ability to see it. We will look out to a Universe on which you cannot do cosmology because there is nothing to see. It will be a very empty Universe.

The part of the Universe we are part of will all collapse down into a giant super galaxy and the stars in the super galaxy will slowly use up their nuclear fuel and turn into little stellar embers that just fade into oblivion.

It will be a very cold lonely Universe in the future.

Kash: What does the award mean for Australian science? How has the public and media reacted?

Brian: It’s been really positive. Australia hasn’t had a Nobel Prize in Physics since 1915 for Bragg Scattering – a very important discovery. It’s been a long time between drinks.

Australia spends a lot of effort on science and has a really good university system here. But I think the excitement of a Nobel Prize really has captured everyone. I’ve got to meet with members of both parties; the prime minister; the finance minister. Everyone is really excited. Even what I would describe as the “shock jocks” on radio, have been universally really excited it.

It has really been incredibly positive and I think it has caused the country, as best as I can tell, to reflect on why science is important. And that’s what is really important to me. I want people to understand that the county’s future prosperity fully depends on educating people and getting scientists to go and be able to do things that invents new technologies and that’s where the prosperity is going to come from.

Kash: Do you think the award will help funding?

Brian: Australia is in an interesting situation right now. There is quite a healthy economy; politicians like to say that we are in a dire situation, but the reality is that we are in a very good situation.

We could certainly do better on our funding. Our research grant programme is underfunded a lot by international standards, even by British standards, which I know have taken a huge hit over the last few years.

There are a lot of things we do fund well. We fund our major infrastructure very well. Australia is keen to bring the Square Kilometre Array to Australia; we think we have a superb place to do this next generation radio telescope and the government is spending lots of money on that.

There is also a giant new telescope that I am helping with in the optical regime called the Giant Magellan Telescope.

So the funding situation is a little hit and miss, but I think it’s pretty good.

What I’m hoping I can bring is to emphasise the importance of continuity. One problem we have in Australia is that each government has a set of new ideas and the whole landscape changes with the changing government. As a scientist working on a 5 to 10 year horizon that changing landscape makes it very hard to plan.

We don’t have to spend that much more money but we just need to spend it really smartly. If we do that then science in this country will flourish.

Kash: How do answer the typical question from a politician – how will your research make money?

Brian: We had a science awards dinner the other night where I gave a speech. The Australian Scientist of the Year was the person who invented the techniques with polymers that Australia uses to make our money. I pointed out to everyone “Gosh, I try to worry about how to make money with my discoveries and this man truly took the most direct route for making money with his discovery!” You never know how your discovery is going to work out.

One of my colleagues, John O’Sullivan, was a radio astronomer who in the 1970s was looking for evaporating Black Holes, as predicted by Stephen Hawking. He never found them but what he did realise was that he was having to correct the way radio waves travel in many different directions to the Earth through space – what he called multipath propagation. He realised that this was the same problem we were having doing high speed radio communication – basically he invented Wi-Fi. He was responsible for the protocol 802.11. This has made Australia billions of dollars and it is worth hundreds of billions of dollars internationally.

Basic research in astronomy turned into billions of dollars worth of stuff.

Research is funny. If you just invent what you know, you asymptotically approach no change. Basic research provides revolutions.

Society has emerged out of the dark ages because of that basic science and education transferring into the knowledge chain that eventually gives us technology. I try to explain that chain to the government and I think the government gets it. I’m not sure if they believe it, but I think they get it.

Kash: Where do you go from here? What are you currently working on?

Brian: I am in the final stages of putting a new telescope onto the sky called SkyMapper. This is a telescope which is, from Australia, going to survey every square inch of the southern sky to a level 10 million times fainter than you can see with the human eye, 36 times.

SkyMapper

SkyMapper is a state-of-the-art automated wide field survey telescope located at Siding Spring Observatory near Coonabarabran, central New South Wales, Australia. (Image - Wikimedia Commons)

This map of the sky will catalogue billions and billions of objects. It’s really useful to find very rare objects in the sky that can help us to decipher how things work. For example, it will be able to find if there any Pluto-like objects that have not been discovered in the southern sky – the southern sky has not been looked at very carefully.

It will help us find the most distant objects in the Universe. It will help us find stars that have been thrown out of the central super massive black hole region of the Milky Way. It will help us find stellar fossils left over from just after the Big Bang.

It is going to produce a treasure map that we can use the biggest telescopes that we have now and in the future to go through and do detail studies.

It’s a huge project that is just getting started right now. It will take more than a petabyte of data (1000 terabytes, each terabyte is a 1000 gigabytes).

Kash: I’m going to have to ask you the question that I’m sure everyone has: did you think the phone call was a wind up?

Brian: I have a couple of mischievous graduate students and it occurred to me that it could be a practical joke. But I was incredibly impressed by how good they got the Swedish accent. After a couple of seconds it became pretty clear to me that this was more than just a prank.

Kash: Finally, astrophysics is not your only passion – you are also a winemaker. Judging by the “we have sold out” message on your website, winning a Nobel Prize is good for wine sales!

Brian: When I moved to Australia I decided that I one of the things I could do that I could not do anywhere else was do something crazy and run a vineyard.

We have 1.1 hectare Pinot Noir vineyard. It is my therapy to make sure that astronomy doesn’t take over my life.

Maipenrai Vineyard and Winery

Maipenrai Vineyard and Winery

Things we slow at first but about a year ago I started getting it right and have been selling well. I was down to four cases when the Nobel Prize announcement went out. Those four cases sold literally within 60 seconds after the announcement.

It’s certainly a great marketing tool, which I’ve been recommending to all my fellow winemakers!

Kash: Which is easier? Astrophysics or winemaking?

Brian: They are very different and they are similar.

With astrophysics, I try to do everything perfectly. I don’t like making mistakes Winemaking is all about making mistakes. Where I try to be pretty much perfect all the time in my astronomy, in my winemaking I know I’ll never be perfect. So in some sense I think, as you can never achieve perfection in wine making, therefore it’s the harder thing to do but it does require a slightly different set of skills.

Related links

My Telegraph article – Dark energy: the universe is destined to become a very cold and lonely place.

My 21st Floor article – Ben Still Interview: Faster than Light Neutrinos.


Responses

  1. […] Kash Farooq interviews 2011 Nobel Laureate Brian Schmidt about his research and the discovery of dar…; the audio of the interview is also available as a podcast. (For more on dark energy, here’s my Nobel post and an explanation of how dark energy drives cosmic acceleration.) […]

  2. […] Interview with Brian Schmidt: 2011 Nobel Prize in Physics Joint Winner (thethoughtstash.wordpress.com) […]


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