The Difference Between Zero and Nothing

The Science Show, ABC Radio National | 26 July 2008

Wilson da Silva reports from the EuroScience Open Forum meeting in Barcelona.

Wilson da Silva: Climate change has been pretty important at the EuroScience Open Forum, and very relevant to Barcelona though because it was forced to import water from France this year. They've had an intense drought. They're experiencing this throughout lots of parts of the world, including Australia, where dry conditions are clashing with the growing demand from agriculture and urban development and, certainly in Spain, tourism.

And Sir David King, the former chief scientific advisor to the British government, made the point that we're really facing something that humanity has never faced before. We have a population explosion, which is a key challenge, at the same time that we have issues about food and energy security with increased terrorism to throw in there, while we're trying to deal with the effects of climate change, which are generally negative rather than positive.

He was saying that with world populations going to 9 billion by 2050 from about 6.8 billion now, that 30% increase is going to place huge pressures on demand for more water, more food, more oil, more land, at the same time that climate change is actually making those resources more scarce.

David Fisher: It's been suggested that future conflicts will be over resources like water.

Wilson da Silva: That right, the United Nations a few years ago did warn that we could see the first food and water wars. One of the predictions that David King made was intriguing, he reckons that within ten years that the price of carbon from emission trading will be as important to economies as GDP or inflation, and that businesses and government will avidly follow carbon prices.

David Fisher: And I suppose it will be part of the finance report each night.

Wilson da Silva: That's right, yes.

David Fisher: An esoteric topic was the difference between zero and nothing, but with big implications. What's going on there, Wilson?

Wilson da Silva: Yes, Gerry Gilmore, an astrophysicist at Cambridge was talking about cosmology, and he's actually a New Zealander who's been in Britain for many, many years. He's an expert on cold dark matter, which apparently makes up 25% of the universe. There's 70% dark energy which is pushing the universe apart, and only 5% is the solid stuff that you and I know, like teacups and forests and mountains.

He was saying that we think in time space units. An object is here now and then it's there later. But when an object is not there, he said it's a kind of a zero object, the object is not in front of him anymore. But there's still space there, so what he's saying is there is space, there isn't nothing. And if you take away space then truly there is nothing.

He said that cold dark matter is not nothing because it's cold (in astrophysical terms, it's not moving very fast), and it's dark, although that's a misnomer, apparently it's transparent to light, light doesn't interact with it, but it does respond to gravity, which is how it was found. So it is matter. He was at the end saying that perhaps dark energy, which is completely mysterious, perhaps it's a quantum effect to be found between zero and nothing.

David Fisher: Does this solve the mystery of dark matter and what it all is or just create further uncertainty?

Wilson da Silva: The people in the audience, some of them were nodding their heads in agreement, others were shaking their heads in bewilderment, I'm not really sure if it solved anything, but it was certainly an interesting discussion.

David Fisher: Could you tell us about the work that was reported on gender balance?

Wilson da Silva: Yes, choosing the sex of children...Tom Shakespeare from the University of Newcastle was saying that bio-ethicists generally don't see strong reasons to interfere with the choice of parents when it comes to what he called reproductive autonomy. But the unintended effects of that were mentioned by Jyotsna Gupta from the University for Humanistics in the Netherlands, and he said that pre-conception sex selection in places like India was having a devastating impact. Although abortion is legal in India, selective sex abortion is not. Before it was introduced on a wide scale, the natural birth rate in India in 2000 was about 952 girls for every 1,000 boys, which is pretty much the global average. Within five years this ratio had fallen to 814 girls per 1,000 boys, a 15% reduction. He said that in many places of the world, sex selection means the elimination of females.

David Fisher: And we've heard about some of the implications of that in China. It really screws things up, doesn't it.

Wilson da Silva: It does, and it creates a problem 15 and 20 years in the future when you have lots and lots of men and an imbalance in the genders.

David Fisher: On The Science Show we hear a lot about nanotechnology. It's fascinating and it seems to be everywhere, but there are concerns. What's going on there?

Wilson da Silva: There are concerns. I've got to tell you, David, I was surprised just how much of it is everywhere, everything from scratch resistant paint and odourless socks to fuel cells, stain resistant fabrics, and something called thermochromic glass. I thought it was science fiction; glass that switches from transparency to translucence at the flick of a button. But they're also being used in drug delivery systems and this is where the concern has been raised. While nanotechnology in medicine is leading to earlier and better diagnosis, there are also risks to health.

Herman Stamm of the European Institute for Health and Consumer Protection in Italy was saying that mostly there seems to be no new hazards for human health or the environment as far as they can tell. However, the risk arises from the unknown toxicity of engineered nano-materials once they're travelling in body tissue. These are mostly in novel pharmaceuticals. These nanoparticles may attach or translocate to organs and cause toxic effects, and nobody knows what the long-term environmental impact of nanoparticles are, although there's some interesting work with tiny particulates from car exhausts which we do know leads to high rates of coronary heart disease, so there is some concern there.

There was an interesting one that I hadn't heard of at all; nanoparticles used in covert surveillance. You get lightly dusted with a surveillance particle and then they can keep track of you. Isn't that interesting?

David Fisher: Great material for TV cop shows, I'm sure. Barcelona is a great artistic and literary city. Did this aspect of Barcelona show itself during the meeting?

Wilson da Silva: It certainly did. There was quite a strong theme of discussion about art and science, maths as art. There were some poetry readings. In fact Roald Hoffmann who won the Nobel Prize for Chemistry in 1981, he actually these days splits his time between research at the lab at Cornell where he is and writing poetry and plays. He's published 300 poems and five books of poetry and written three plays, of which he's hoping to get one played in Australia. One of his plays, Oxygen, was played in New Zealand at the Commercial Theatre, but it's never played in Australia, he says.

He was talking about how art and science dovetail each other way more than people think, but it takes quite a bit of an effort to get people to see that, and he talked about how the precision and economy required in poetry was very similar to the kind of work that he was doing in molecular chemistry. In trying to figure out how molecules connect you have to remove a lot of data in order to see the clarity, and it's kind of like poetry, he said.

David Fisher: Wilson, how does the European science festival compare with the others that we're more familiar with, the British and American association meetings?

Wilson da Silva: This is a new one, they have it every two years, and there's a diversity of languages in the sessions. All the answers are in English and all the presentations are in English but the questions are sometimes in different languages. One of the things that bothered me, though, was to see a very large representation from Singapore.

David Fisher: It bothered you?

Wilson da Silva: It bothered me because here is a country that's the size of the greater Sydney economy and yet it was making a fabulous presentation, it had a stand that was the size of six stands, it was promoting itself and its extraordinary investment in science, and it made me think that if something the size of the Sydney economy can do this much in science, why doesn't Australia even have one stand or some kind of representation.

David Fisher: Did we not have a national stand there?

Wilson da Silva: No, and we don't have them at the AAAS or at the British meetings either. It saddens me that we get so few gains in science funding and science promotion in Australia that we accept them, and yet when you see how it actually should be done, the way Singapore is doing it, you see what the impact could be if only we just committed to it.

David Fisher: So was the Singapore stand attracting people? It was big..

Wilson da Silva: It was surrounded by people whenever I was down at the exhibition stand, which just made me think that obviously they know how to promote their science, both externally outside the country and internally.

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