Mysteries of our time
Why is gold gold-coloured? What's it like at the centre of Jupiter? And what can we do about belching cows? An award-winning New Zealand scientist has the answers to at least some of the world's most pressing questions. By Adam Dudding.
AT 12, Peter Schwerdtfeger was given a chemistry set. He proved to be so good at blowing stuff up that his parents received a stern visit from the Stuttgart police.
These days Professor Schwerdtfeger's chemistry experiments are rather more sophisticated – and mainly take place inside a supercomputer rather than the real world – but the thrill of seeing what happens when one atom meets another is unchanged. "Science," says this cuddly-looking bearded German who has a taste for AC/DC, Beethoven and Estonian minimalist composer Arvo Part, "is fun".
Schwerdtfeger is based at the Auckland campus of Massey University and has been in New Zealand since the late 1980s, but he was last month awarded a 60,000 ($105,000) prize by Germany's Alexander von Humboldt Foundation, in recognition of three decades of work at the cutting edge of theoretical physics and chemistry.
Schwerdtfeger, 55, supervises six post-doctoral researchers and a PhD student and is an unabashed champion of pure research, believing the current pressure on science departments to create high-tech startup companies rather than focus on basic research "does some real damage to the academic world".
Yet his pointy-headed studies in the polysyllabic jungle of "heterogeneous catalytic processes" and "electroweak interactions" still have connections to an extraordinary range of potential future technologies, from methods for finding new Alzheimer drugs to reducing the global warming effect of New Zealand's burping cows, or even – one day – to ways to filter the methane out of gassy coal mines, reducing the chance of tragedies such as the Pike River Coal mine disaster.
Underpinning all of these is Schwerdtfeger's investigations in the fuzzy area between physics and chemistry. He is expert at running extremely precise computer models of chemical reactions at the level of individual atoms, enlisting not only the quantum equations that describe the weird indeterminacy of the subatomic world, but also Einstein's relativistic equations that describe the weirdness of objects moving at high velocities.
Those high-speed relativistic effects are often disregarded by chemists, because the outermost electrons that cause atoms to cling together move pretty slowly. But, in fact, even small relativistic effects can be significant, says Schwerdtfeger, and taking them into account has let him solve mysteries that some of us probably hadn't even realised were mysteries.
Such as the goldness of gold. Apparently, if you plug gold into the formulae that describe light hitting a sheet of metal, but ignore relativity, you predict a greyish metallic shine just like that of silver. Schwerdtfeger has shown that the distinctive yellowness of the precious metal is predicted only if relativity is folded into the calculations.
That's a cute fact, if unlikely to amaze the average jeweller. But there's more to gold than that, says Schwerdtfeger. In the past 15 years the metal has been shown to have very unusual catalytic functions – helping certain chemical reactions to take place more efficiently – if tiny clusters of gold are arranged in specific shapes or "nano-clusters".
"We are now starting to understand why," says Schwerdtfeger, "and that is due to relativistic effects."
This could be useful: for decades chemists have been looking for a non-toxic replacement for the environmentally calamitous use of cyanide to extract gold from low-grade ore. Where experimentalists have failed, says Schwerdtfeger, computational chemists like himself may eventually succeed by modelling reactions on a computer. "If we were to find something like that, it would be fantastic."
NON-COMMERCIAL breakthroughs are no less exciting: in 1993 Schwerdtfeger predicted a new molecule, "gold fluoride", and described it at a conference in Belgium. The next year a German mass specroscopist who'd been at the conference "went back to Berlin, put it in his machine, got the gold fluoride, and published it".
One profound mystery that Schwerdtfeger and his collaborators have turned their attention to is the curious fact that life on earth knows its left hand from its right hand. Many molecules can exist in two almost identical, but mirror-image, forms. But oddly, in nature almost all sugars are "right-handed" while amino acids, the building blocks for our boldies, are built "left-handed".
This preference in nature for one molecule but not its reflection is called "chirality". The spiral shape of DNA is just one of chirality's consequences, and there is much at stake behind understanding it. Some creationists say chirality is proof of God's design, while evolutionists just hope it will help reveal how life sprang up four billion years ago.
Pharmaceutical manufacturers, too, need to understand chirality, if only to avoid disasters such as the morning sickness drug thalidomide which caused an epidemic of birth defects when taken by tens of thousands of mothers in the 1950s. It turned out that the drug was converted into two mirror-image chemicals within the body, one harmless and one that led to deformities. Drug makers are already throwing vast sums into building and programming supercomputers that can model the interactions of new drug molecules within the human body.
Schwerdtfeger's contribution to chirality research has been to calculate the vanishingly small (indeed as-yet unobserved) differences between the energy states of a given molecule and its mirror image. A research group in Paris is now running an elaborate multimillion-dollar experiment off the back of those calculations.
"They are taking the molecules that we predicted, putting them into the gas phase and trying to measure for the first time the difference between the right-hand and left-hand molecules."
So far, of the 50-odd theories for why nature chose one molecule over its mirror image, "we have killed two hypotheses", says Schwerdtfeger. He laughs. "This is our contribution – killing two hypotheses."
The scientific journals in Schwerdtfeger's cosy office on Massey's Albany campus are calling – as part of the professorial elite of the university's Institute for Advanced Study, he is "constantly reading and learning; if you know a lot then you get new ideas". But he has time to mention one other area of study, high pressure physics.
He and his colleagues have squashed the gases neon and argon to unimaginable pressures, and have been delighted at how well their predictions turned out. As usual, this might be useful one day, but really it's knowledge for knowledge's sake.
There are new materials, perhaps even new superconductors to be found using high-pressure research, says Schwerdtfeger, but in the meantime "you might also understand the physics of planets in a better way", such as whether the hot, pressurised core of Jupiter indeed consists of metallic hydrogen.
Schwerdtfeger's projects have been helped along over the years with six Marsden grants worth $4 million, but he is concerned that the size of the pure research grant pot means many applicants miss out. It worries him, too, that at many universities in New Zealand "what counts most is how much money you bring into the system, rather than if you have a paper published in Nature".
The question is this, says Schwerdtfeger: "Are we really just here to commercialise, or are we here to educate our kids and learn from fundamental science, so we can teach our kids what is going on in nature?"
WHY FUNDAMENTAL RESEARCH MATTERS
When asked about the usefulness of pure science, Peter Schwerdtfeger likes to quote the line attributed to American inventor Ben Franklin: "What's the use of a newborn baby?"
Here are a few of the scientific babies Schwerdtfeger has been helping nurture.
High pressure physics: Could lead to development of room-temperature superconductors. "There are billions of dollars to be saved in the transport of electricity over long distances, where currently much of it is lost as heat."
Modelling of gold "nano-structures": Could lead to catalysts to make chemical reactions more efficient, and lead to replacements for cyanide in gold mining.
Modelling of mirror-image molecules: Could ultimately lead to better drugs for diseases such as Alzheimers (with the side benefit of explaining the origins of life on earth).
Modelling "graphene": One of Scherdtfeger's colleagues is looking at how the newly discovered form of carbon might be used to create "molecular sieves" for separating mixed gases. Such sieves may one day be able to separate a gas such as methane from air swiftly and efficiently, leading to improved safety in gassy mines, and tackling greenhouse emissions from belching livestock.
Sunday Star Times