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Interviewer: Shamini Bundell
Welcome to this week’s Nature Podcast. In the show we’re taking a look at how to write software for quantum computers.
Interviewer: Adam Levy
Plus, the uncertain future of Asia’s mountain glaciers. This is the Nature Podcast for September the 14th2017. I’m Adam Levy.
Interviewer: Shamini Bundell
And I’m Shamini Bundell
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Interviewer: Shamini Bundell
A computer is a pretty handy device but the processor itself would be useless without software: sets of instructions and information that tell a computer how to operate. For the first computers that meant physically moving dials and cables. But now software consists of software computer programs, written in code, which allow us to do everything from analysing black hole data to posting on Facebook. But computer hardware is developing too. Physicists are starting to build working versions of a completely new kind of processor that’s based on quantum physics. And this means we’ll need a completely new kind of software. Reporter Lizzie Gibney spoke to William Zeng from quantum computing firm, Rigetti Computing, about how to make useful software for the first quantum machines. He started by explaining what quantum computers are and why researchers are so keen to build them.
Interviewee: William Zeng
Yeah so the basic idea is that all the computers we’ve been working with for the last 80 years or so are all based on electronics and actually the world is more complicated than that. There’s physics underneath it that we’ve known about for a hundred years called quantum mechanics. The idea is we’re going to try and build technology; we’re going to try and build computers that use this new kind of physics.
Interviewer: Lizzie Gibney
And what kind of things might that be useful for then? What kind of calculations would we want that computer to do?
Interviewee: William Zeng
There are two major areas of application for the world’s first quantum computers. One is molecular modelling and simulation. So, in this, you use the quantum computer to help simulate and design molecules that you might care about. The second is machine learning and this comes from the fact that the correlations that occur in quantum systems are very, very subtle and those are also the kinds of correlations you might want to have in very good machine learning models, or optimisation models.
Interviewer: Lizzie Gibney
The general idea then is that they are both kinds of calculations which would just be impossible on a regular, classical computer, or would take an exorbitant amount of time.
Interviewee: William Zeng
Yeah, absolutely. Millions of years is the kind of run time that you look at when you try and do it on a regular machine.
Interviewer: Lizzie Gibney
And so we’ve talked a few times on the podcast about the hardware that lies beneath a quantum computer and I know there are several different ways of doing that and it’s progressing quite rapidly, but in your Comment piece this week, you argued that there’s also a need to get the quantum programming, or quantum software right or we’ll end up with having these computers that, actually, nobody can even use. First of all, what do you really mean by software and programming in the quantum context?
Interviewee: William Zeng
Broadly we mean how you’re going to make use of the device. So there’s low level control that still relates a little bit to the physics, and then there’s higher level control which are programming languages that people who don’t know that it’s a physics device of a particular kind and just know that it’s a computer they can programme, work with. And it’s the software and the applications that are going to make the difference between having some very interesting experiments; you know for people with physics backgrounds like me, and world-changing technology.
Interviewer: Lizzie Gibney
And so the dream is, just in the way that whilst I probably wouldn’t be able to rewire my computer, I can deftly produce something on Microsoft Word. In the future you might be able to have scientists that are using quantum computers without actually having to have this very, very in depth knowledge of quantum computing itself?
Interviewee: William Zeng
That’s right, that’s where we want to get to and we want to integrate it with their workflows and to get there we’re in this first stage where we’re trying to develop a kind of a developer community and figure out what the building blocks are. But yeah, once you get to those eventual building blocks we want it to be something that you don’t have to know it’s a quantum computer – you just know it’s faster. We’ve also realised that it’s about how do I integrate quantum computers with regular computers and quantum classical hybrid programming is that. So, a quantum classical hybrid algorithm – there’s two kinds of quantum classical interaction that happen in one of these programmes and the first is you break up the problem so that you use the quantum computer for just the part of the problem that it’s very good at and you don’t waste that precious quantum computing resource on stuff that a classical computer could just do fine. So that splitting of a problem is the first key part of hybridisation, but there’s a second bit and the second bit is that when you’re running the part of the algorithm that’s very good on the quantum computer, you actually use the classical processor to tune or calibrate the execution of the QPU, of the quantum processor.
Interviewer: Lizzie Gibney
You said you’re a quantum programmer and you’re clearly keen for there to be more quantum programmers. Where are they going to come from? Do many exist at the moment or is it a very new kind of field?
Interviewee: William Zeng
It’s definitely new, but the chance to work at the beginning of a field again where there’s not a defined world-leading programming language yet. We’re still working on instruction sets. You have the chance to be the person that invents the quantum version of C and that’s really attractive to people who care about programming and then the potential on the application side is really attractive to the people who care about the applications. One of the really, really fun things for me, and I’ve been talking about quantum computing to people for a very long time, is that when they come and ask me well how are you going to use a quantum computer? What is a quantum computer actually? And my answer for a really long time had to be go read these books or go learn this thing and now I can say, go to this website and download this Python package. Go to Forest, install our client libraries. You yourself can see how quantum programming works and play with it and that’s extremely exciting and it’s made it much easier to see the field grow and, I think, makes me extremely hopeful for what’s to come.
Interviewer: Shamini Bundell
That was William Zeng talking to Lizzie Gibney. You can find William’s Comment piece online at nature.com/news and that’s part of a special issue on quantum software if you want to know more about the subject.
Interviewer: Adam Levy
Stay tuned for the news where we’re looking at a move to boost representation in American Universities. But now it’s time for two snappy science summaries in this week’s Research Highlights.
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Interviewer: Adam Levy
Uneaten fish food could be adding to the rising tide of drug-resistant microbes. Testing the microbes in food that’s fed to fish in marine farms revealed around 130 genes that caused antibiotic resistance. Not all the fish meal gets munched by the fish; some sinks to the ocean floor. Gene swapping between bacteria on the seabed means the genes could get into the food chain through contaminated sea food. This could pass drug resistance to bacteria that cause human diseases. Screening fish food for antibiotic resistance genes could help keep people safe. Read more in Environmental Science and Technology.
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Interviewer: Shamini Bundell
Our galaxy is drifting around with a heavy heart. A super massive black hole could be lurking near the centre of the Milky Way. For ages astrophysicists have suspected that many galaxies harbour super massive black holes at their cause. Now a powerful telescope array in Chile has honed in on a suspicious cloud of gas in our own galaxy. It revealed radio waves coming from a point-like source in the middle of the cloud. This suggested a black hole a hundred thousand times heavier than the sun. The team think it may have formed when the Milky Way gobbled up an unsuspecting dwarf galaxy. Turn your own telescopes to Nature Astronomyfor more.
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Interviewer: Adam Levy
When we talk about ice melting due to global warming, we tend to think about the Arctic or the Antarctic. But there’s also huge amounts of ice at the top of mountains. In Asia, trillions of tonnes of ice sits on mountains. The annual melt of these glaciers provides a reliable source of water for people downstream, and a lot of people live downstream. Around one 1 out of every 5 people in the world live in the river basins near Asia’s high mountain glaciers. As the world warms, these glaciers will melt faster than they can be replenished and geoscientist Philip Kraaijenbrink explains that they are already starting to shrink.
Interviewee: Philip Kraaijenbrink
There are some photos dating back from 1920 or so and you see for instance the Khumbu Glacier which is next to Mount Everest… That was 150, 200 metres thicker than it is at the moment so that’s a considerable decrease.
Interviewer: Adam Levy
And this decrease in ice will only continue as the world continues to warm. Philip has been working out what these glaciers may look like in the future. I asked him how.
Interviewee: Philip Kraaijenbrink
What we did is we modelled a lot of glaciers in the area and it was of course very difficult because there are very few observations over there. But what we did was we used the climate models. So we used 110 climate models and we developed our own glacier model which we applied to every glacier that is larger than 0.4 square kilometres. And we modelled every glacier individually, forcing it with all of the climate data so if the temperature rises then there will be more glacier melt and some of the glacier will retreat and get smaller.
Interviewer: Adam Levy
Now, a big thing we don’t know will happen in the future is just how much the world is going to warm. In Paris the world agreed to try to limit global warming to one and half degrees Celsius. What did you find the impact of this limit would be on the glaciers?
Interviewee: Philip Kraaijenbrink
So, yeah, we modelled with a lot of climate models and for only 6 of the 110 were within 0.1 degrees of the 1.5 target, but we found if we can limit the world’s temperature rise to 1.5 degrees, we lose about 36% of ice still.
Interviewer: Adam Levy
So that still seems like quite a lot of ice to lose, even with this limit.
Interviewee: Philip Kraaijenbrink
Yeah, but even if we also did a model run where we just keep the temperature stable at the current level and even then we would lose 15% of the glacier area and 14% of the ice volume.
Interviewer: Adam Levy
How likely actually is it that we’ll manage to keep the world’s warming to 1.5%?
Interviewee: Philip Kraaijenbrink
Well I’d say that’s not very likely. It’s hard to pinpoint exactly what kind of temperature rise we may expect because there are so many factors involved: politics and how we behave as a general society. But I’d say it’s highly unlikely that we’ll get to the 1.5 degrees and maybe even the 2 degrees target, I’d say already that’s a very optimistic target.
Interviewer: Adam Levy
So if we don’t manage to keep the world’s warming under 1.5 degrees or even under 2 degrees, then what’s going to happen to the glaciers?
Interviewee: Philip Kraaijenbrink
Well a lot more ice will be lost – that’s just it. We have calculated for the most extreme scenarios and our most extreme scenario which is a more business-as-usual scenario which will cause a temperature rise in high mountain Asia of about 6 degrees which is considerably more than the 1.5 degrees globally and then we would have a glacier mass loss of about 65%.
Interviewer: Adam Levy
So in one scenario it’s about 65% of the ice is kept and in the other it’s about 65% of the ice is lost.
Interviewee: Philip Kraaijenbrink
Yes, exactly. I can imagine that might be a very big difference to the amount of water in the rivers and to the mountain communities and to all kinds of other effects that may occur when this ice has gone.
Interviewer: Adam Levy
You’ve seen these glaciers; how does it feel to imagine, I guess, 65% of that amount of mass not being there anymore?
Interviewee: Philip Kraaijenbrink
Yeah that would be quite a difference and they’re just big features of the landscape and when they’re not there they will leave these holes which will be filled largely by lakes and stuff but it will be primarily an impact on the local people because if the glacier changes there are a lot of changes to the local climate as well because the energy fluxes change. It will just impact the people in the mountains the most.
Interviewer: Adam Levy
And there’s actually millions of people who would be directly affected in the mountains and further downstream. What kinds of impacts would this loss of glaciers have?
Interviewee: Philip Kraaijenbrink
Of course these changes will be most important near the mountains because there, the contribution of the mouth waters to the rivers and the irrigation water to the farmers is the largest because the further you go down stream in the rivers the more precipitation is also of influence. But people’s lives will definitely be impacted near the mountains and for all kinds of reasons: for irrigation, drinking water. A lot of these countries still use the river for their sanitation. Hydropower: all these things are quite important to them and they can change a lot if all the glaciers disappear.
Interviewer: Adam Levy
That was Philip Kraaijenbrink who’s based at Utrecht University in the Netherlands. Give his paper a read over at nature.com/nature.
Interviewer: Shamini Bundell
Whether you’re a long term Nature Podcastlistener, or brand new to the show, we’d love to hear your thoughts. Svetlana Tamitegama got in touch to tell us know she listens to the show while taking a jog through the local nature, which seems appropriate.
Interviewer: Adam Levy
To get in touch, send us an email to podcast@nature.com, or a Tweet @Nature Podcast. And if you’d like us to reach even more science-interested ears, a review or a rating on your favourite podcast provider really does make a huge difference.
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Interviewer: Adam Levy
Time now for this week’s News Chat and on the line all the way from San Francisco is NatureReporter Amy Maxmen. Hello Amy.
Interviewee: Amy Maxmen
Hi.
Interviewer: Adam Levy
Now, this week in Naturewe’ve been looking at water in Jordan. Now, Jordan is a very dry country. Just how little water is there?
Interviewee: Amy Maxmen
The average amount of water per person in Jordan per year is less than 150 cubic metres and that’s, for comparison… American’s have about 9,000 cubic metres. So Jordan has a sixtieth of the amount that’s available to a person in the United States.
Interviewer: Adam Levy
So that’s the situation now… is that likely to get worse with climate change.
Interviewee: Amy Maxmen
It’s likely to get worse with climate change and there are a number of other issues that the country has. They’ve taken a lot of refugees so their population tends to get larger and larger and they also have a lot of old infrastructure: leaky pipes. So there’s kind of a convergence of a lot of factors to make it an increasingly dangerous situation.
Interviewer: Adam Levy
When we describe it as an increasingly dangerous situation – what could it actually lead to, these water shortages?
Interviewee: Amy Maxmen
There have been warnings. The most recent one I found was there was a report from US intelligence agencies that predicts that when you have water scarcity, and if it’s coupled with poverty, social tensions – say, between ethnic groups – and weak political institutions, that can lead to conflict.
Interviewer: Adam Levy
So of course we’d like to combat this water scarcity. What kind of approaches are being tried out in Jordan?
Interviewee: Amy Maxmen
So there are a number of different approaches and a lot of them are supported, not only by the Jordanian government but also the US government, the UK government, Netherlands, various places have projects. In Jordan, for example, in this last article I wrote about MIT engineers working with engineers in Jordan on this low pressure drip irrigation system. Drip irrigation secretes just a small amount of water to crops versus, say, sprinklers or something so it uses a lot less water – only that requires more energy normally so they’re working on drip irrigation systems that use low pressure so they require half as much energy and could potentially be powered by solar and those are kind of the new systems. Something I was really interested in is there’s another project in the north of Jordan, it’s really close to Syria in a place called Umm el-Jimal. This area has been occupied for a really long time, so staring around 90AD, the Arabs that were there built these reservoirs with canals so during the winter when there are rains, particularly when there was rain in Syria which is right across the border, the water would move through the canals and fill up these reservoirs and so now there’s a big project in that area to actually revive those old systems. In 2015, Umm el-Jimal had started this project. They repaired the largest of the reservoirs in the summer of 2015. It would hold as much water as 4 Olympic sized swimming pools and the mayor was so excited he just sort of recalled the night that it was pouring rain in November for the first time. He stayed up all night just watching the canals fill with water and move into the reservoir.
Interviewer: Adam Levy
And when you were reporting on this story, did you actually get to see this reservoir for yourself?
Interviewee: Amy Maxmen
Yeah so I saw the reservoir and for the archaeologist, who was leading the effort, his point is also just sort of symbolic, saying like, this was a system that wasn’t – you know – this isn’t a cute project we have. There’s a reason why this was maintained for 800 years. So, that system – there was the Roman occupation, there was the Byzantium era, there was the Islamic era, and throughout all of those time periods, people maintain this system and continue to use it. So his point is this is a symbol showing, this isn’t a silly backwards system, this is a system to use, run off, that we can now resurrect and rely on instead of just relying on deep wells that might be in danger soon.
Interviewer: Adam Levy
Now, the idea of all this old and new infrastructure isn’t just to boost the water supply in Jordan. It could be relevant to other countries as well, right?
Interviewee: Amy Maxmen
Yes exactly, so I talked to an official from the US agency for International Development and his point was, yes, you know, this is a matter of security but also a lot of the technologies that are being tested and developed and piloted in Jordan can help us back here in the States, say , in Arizona where it’s really dry. Jordan provides a really nice test bed because they have so many issues that I mentioned before: they are dealing with a really arid state, they’re dealing with poor infrastructure, they’re dealing with a lot of problems that occur elsewhere. So if something works there, the idea is that it could be applied elsewhere later.
Interviewer: Adam Levy
Let’s move onto your second story which is also an example of something which was developed in one country and now being applied elsewhere. There was a British gender equality programme set up called Athena SWAN. Before we get to where it’s spreading – what was actually the goal of Athena SWAN?
Interviewee: Amy Maxmen
Well the goal of Athena SWAN was to increase gender equality in science and it began in 2005 in the UK and it’s been spreading. I think at this point now there’s 140 UK institutions that are involved with it.
Interviewer: Adam Levy
And there have been similar programmes now set up in Australia and Ireland. But now also the US is looking at adopting some version of this programme itself?
Interviewee: Amy Maxmen
Yeah, the US is interested in this programme and they’re also hoping to kind of add on to it, a similar sort of assessment that also doesn’t just look at gender but also looks at inclusiveness with regards to race, ethnicity, sexual orientation, disability, socio-economic class and other indicators from marginalised groups.
Interviewer: Adam Levy
It seems like in the UK it’s been lauded as quite a successful programme. Do we have a sense for why it was able to achieve quite good success in increasing equality in the UK?
Interviewee: Amy Maxmen
So one reason for the success in the UK could be that it’s been linked with grants. So, universities have to have at least a silver award from SWAN in order to get one particular pot of biomedical funding?
Interviewer: Adam Levy
What are some examples of the positive influence Athena SWAN has had on certain institutions?
Interviewee: Amy Maxmen
So at the University of Liverpool between 2013 and 2016, the proportion of women that have been promoted to professor posts has increased from 28% to 50% and likewise there awards through SWAN went from a bronze award to a silver award.
Interviewer: Adam Levy
What would be the challenges of introducing this to America and hopefully seeing similar kinds of results?
Interviewee: Amy Maxmen
Well as far as I know right now, that funding incentive doesn’t exist. So it’s not clear to me that in order to get grants you have to show that you’ve done well with this stamped equity achievement. Another challenge is going to be how to sort of assess these indicators of diversity. For example, is a university really the best judge of its own climate for diversity?
Interviewer: Adam Levy
Amy, thanks a lot for joining us. For more on those two news stories and all the latest science news, head over to nature.com/news.
Interviewer: Shamini Bundell
That’s all for this week but for more Nature multimedia, make sure to subscribe to the Nature Video Channel. That’s at youtube.com/NatureVideoChannel. Our latest video is all about adorable bats bumping into things. Until next time, I’m Shamini Bundell.
Interviewer: Adam Levy
And I’m Adam Levy.
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