SciBlogs

Archive December 2009

What’s ahead in 2010? Shaun Hendy Dec 29

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2010 is shaping up to be a defining year for New Zealand’s RS&T system. We will be hearing how the Government will set its RS&T priorities and what these priorities will be. The CRI task force will be reporting back, and we will find out how the Government is going to encourage R&D in the business sector. As I discussed in a post last month, the money spent by the business sector on R&D is strongly correlated with patenting.

What will I be blogging about in 2010? I have devoted quite a bit of time this year discussing data that we have extracted from the OECD patent database. There is still a lot of information to be mined from this database and I will be continuing to discuss this in the New Year. For instance, I will have more to say about inventor networks and how their structure changes with network size. I also want to look at some specific networks in more detail, comparing their size and structure between countries.

I will also follow up on some of my earlier posts on bibliometrics. It took me a while to get permission from Thompson Reuters to start publishing citation data, but this has now come through, so I will be looking at how the impact factors of New Zealand institutions have changed over the last 20 years. I also want to follow up with more detail on the surprisingly large co-author networks that exist within the New Zealand science community.

Of course, from time to time, I will blog on other matters that interest me throughout the year. I have been following the progress of some new types of collaborative research: mathematicians have been learning how to use the mass collaboration that blogging allows to prove theorems and solve original research problems. This is, after all, the reason that the web was created in the first place.

Collaboration, whether through blogs or other means, may be the key to New Zealand taking its own R&D to scale.

In the meantime, I hope you are all enjoying your holidays!

The nanoscience of ice hockey Shaun Hendy Dec 21

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n1009628089_30065983_4015During my PhD studies in Canada, I devoted a considerable amount of time and effort to becoming a mediocre ice hockey player. I have a scar and a grainy photograph to prove it.

You can imagine, then, what a difficult decision it was to come back to New Zealand to start a post-doctoral fellowship in a city without an ice rink. And despite the promises of our plucky mayor, my skates still hang unused in the closet.

While we wait for the rink to be built, it’s worth discussing what makes ice skating possible in the first place. One explanation commonly offered is that as water is denser than ice, the pressure of a skate blade will melt the ice underneath, creating a lubricating layer of water on which the skater glides.

However, this doesn’t explain why ice is slippery to walk on, whether or not skates are worn. And sure enough, it turns out that the pressure generated by a skate blade (a few hundred atmospheres) is only enough to lower the freezing point by about 3 degrees C – how do people skate at 4 degrees below zero?

In fact, ice is slippery because it is covered by a thin layer of water even at atmospheric pressure. The first person to suggest that this might be the case was the hugely influential English scientist Michael Faraday in the 1850s. He was intrigued by the fact that ice cubes tend to stick together when brought into contact and guessed (correctly) that this was because the cubes were covered by a layer of water too thin to see, but which freezes when the ice cubes touch.

These days we can measure this thin liquid layer using a variety of modern techniques: at one degree below zero, it turns out that the thickness of this layer on ice is about 100 nanometres, or one ten millionth of a metre, enough to make ice very slippery.

We have also discovered that this behaviour is not unique to water – at temperatures close to their melting points, most solids will be covered by a thin layer of their melt. Bridget Ingham, a colleague of mine at Industrial Research Ltd, recently returned from the Australian Synchrotron with x-ray measurements of the thickness of the liquid layer that forms on indium nanoparticles close to their melting points.

The presence of this molten layer below the melting point also explains why it is impossible to superheat most solids. As the temperature of a solid approaches the melting point, this liquid layer simply grows and grows, until eventually the whole solid disappears at the melting point.

This is in contrast to liquids, which can often be supercooled well below their freezing point. Freezing rain is another phenomenon that Canadians are more familiar with than Wellingtonians – this occurs when supercooled droplets of rain freeze on impact with the ground.

Despite the lack of facilities in Wellington for the study of ice skating, we do have a small company here called Beaglehole Instruments, which makes devices that can measure the thickness of these liquid films. This company was spun off from Victoria University in the 1990s after several physicists there became interested in thin premolten liquid layers. These physicists made some of the first measurements of the thin liquid layer that forms on a metal close to its melting point.

Nanostructures have an annoying habit of melting well below their normal melting temperature, so in nanoscience today, we are very interested in substances that don’t premelt. You can imagine that it is pretty difficult to keep a 10 nanometre ice crystal stable when ice usually forms a 100 nanometre liquid layer at –1 C. And it is the same with metallic nanocrystals, which obviously can’t be used in a nanoelectronic device if they are going to melt when the device heats up after it is switched on.

Hence the interest of another colleague of mine, Nicola Gaston, in very small gallium particles that for some reason are able to remain solid hundreds of degrees above the melting temperature of normal gallium. It seems that there is still quite a bit to be understood about surface melting.

p.s. The first lucky reader to guess which player is me in the photo, or alternatively, upon which part of my anatomy my ice hockey scar resides, gets a free skating lesson when the Wellington ice rink gets built.

The productivity of inventors in cities Shaun Hendy Dec 16

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In previous posts I have looked at data that showed that bigger cities produce more patents per capita. For instance, over the 30-years that the OECD database covers, Auckland has produced one PCT patent for every 750 people, whereas Sydney has produced one for every 550 people. Why is this?

We have seen that inventors that participate in large collaborative networks tend to be more productive. It could be that the opportunities to collaborate, which will presumably be greater in a larger city, increase the productivity of inventors in bigger cities. For instance, if you are putting together a research team that needs specialist skills, it is more likely that you’ll find people with the right skill set in a larger city.

Inventor productivity We can test this by looking at the dependence of inventor productivity on city size. On the left I have plotted the inventor productivity (that is, the number of patents per inventor) versus city size for cities in Australia. This can be less than 1 as typically there is more than one inventor per patent application. As you can see, inventor productivity does not have a dependence on city size in this data. We have found similar results in all the countries we have looked at, including New Zealand.

The corollary is that the number of inventors per capita increases with city size in a similar way to the number of patents. Bigger cities have more patents and more inventors per capita. This seems to rule out collaborative network effects as the cause of the higher number of patents per capita in bigger cities.

What else could be going on? Economists talk about knowledge spillovers where innovations that take place in one business, spur innovation in neighbouring businesses. In this scenario, we would expect to see inventors clustered together, while not necessarily being more productive. This idea is at least consistent with the data above. We’ll explore this in later posts.

2009 RS&T Scorecard released Shaun Hendy Dec 09

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The 2009 RS&T scorecard is now available here. Unfortunately I wasn’t able to obtain a pre-release copy from MoRST so I have not had time to fully digest it.

However, I will draw your attention to the interesting plot on page 4 which charts the number of patents per billion dollars GDP (2009 PPP). This measure presumably says something about the R&D intensity of economies. I find it extremely interesting that the scaled data for New Zealand and Australia are so similar.

Readers will recall that in a previous post I observed how the patent gap between New Zealand and Australia seems to be related to the differences sizes of our cities. Does this then mean that the GDP gap between the two countries is also related to the differences in city size? I suspect so, and sure enough there do seem to be some economists (such as Phil McCann now at the University of Groningen) who have similar suspicions.

As a country we have little control over many of the circumstances that dictate our economic geography.  So is it actually possible for us to close this GDP gap with Australia? Lowering tax rates doesn’t seem to me to be the answer – what do we do when Australia lowers their rates? Instead, along with many others, I think we need to move from a commodity-driven to an innovation-led economy, something that may in fact be more easily accomplished in a smaller country, and something that the Scandinavian countries have managed. Can we follow suit?

The first blog? Shaun Hendy Dec 05

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In 1993 a physicist called John Baez started posting This Week’s Finds in Mathematical Physics to several usenet newsgroups. The style and regularity of John’s posts very much anticipated the modern blog, even if the web wasn’t yet world-wide, and he is, if we can apply the term retrospectively, still blogging.

Readers of soc.culture.new-zealand in the mid-90s will remember other early efforts along these lines from Russell Brown (still blogging at Public Address) and Brian Harmer. These guys kept many expats up to date on New Zealand news, sport and politics in the days before web browsers could.

My own contribution to early internet culture is that I may have sent John Baez his first piece of spam. I was reading John Baez’s posts on sci.physics early in 1993 when I was a summer student at Industrial Research Ltd, and starting to think about where I would go to do a PhD. These were the days that you applied for graduate studies by writing to Universities via snail mail. Yes, actual hand writing was involved!

I decided to speed things up – I pulled a list of 30-40 email addresses from likely sounding Universities in the USA and Canada from sci.physics, and proceeded to spam them with PhD applications. I was surprised by how many replies I received – in the early 1990s, it was probably still a novelty to get a form email from a prospective graduate student.

One person who replied was John Baez, giving me with all sorts of advice about careers in physics. In the end I did my PhD at the University of Alberta in Canada. The person who I had emailed there (who actually turned out to be a grad student) had replied with a small essay on the virtues of the physics department at the U of A. It turned out to be  good advice.

In fact, a well directed and personalised email can still be a good way to make contact with a potential PhD supervisor. However there are also now plenty of PhD spammers who email out form letters like I did – these days they probably largely get ignored.