Category: Chemistry

This “Personal Reactions” interview with Eric Scerri originally appeared in my column in The Alchemist webzine, 1998-04-03.

Biography:
Professor Eric Scerri, born 30th August 1953, Malta. Nominated for the Dexter Award in the History of Chemistry. Interested in the philosophy of chemistry, especially philosophical aspects of the periodic system and of quantum chemistry.

Position:
Assistant Professor, Bradley University, Illinois.

Major life events:
Gaining a PhD in History and Philosophy of Science at King’s College, London on the Relationship of Chemistry to Quantum Mechanics. Being invited to the home of philosopher of science Sir Karl Popper for a discussion on quantum mechanics, chemistry, philosophy, life and the universe. Going to the US as a postdoctoral fellow in History and Philosophy of Science at Caltech. Becoming editor of Foundations of Chemistry.

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How did you get your current job?
Job advert in Chemical and Engineering News.

What do you enjoy about your work?
Lecturing to students and generally interacting with people. Being paid to do what I enjoy the most, chemistry.

What do you hate about your industry?
The presence of large numbers of people who do no research, do not keep up with recent developments and pontificate endlessly about how “professional” they are.

What was your first experiment?
My first experiment while teaching was the fountain experiment.

Did it work?
No it did not. As anyone who has tried it will tell you, it’s tricky. I made sure I got it to work the second time.

What was your chemistry teacher at school like?
Excellent, warm and inspiring. Both women: Mrs Davis and Mrs Walden at Walpole Grammar, Ealing, London. The school has now been demolished to make space for a housing estate.

Meeting Popper must have been a formative experience?
You bet! First, he got very angry with me because I had sent him an article in which I was criticising his views on the discovery of hafnium. According to him and many others Bohr predicted that hafnium should be a transition metal and not a rare earth and that led directly to the discovery of hafnium by Coster and von Hevesey. The full story is far more complicated as I and others have emphasised.

Popper in fact accepted my specific criticisms on the hafnium case. I think his initial anger was a sort of knee-jerk reaction, which he had to all critics. After about five minutes, he became a perfectly charming host and answered all my questions and made me feel like an equal even in purely philosophical matters.

What is your greatest strength?
Presentation of ideas in lectures. Being able to criticise arguments.

Weakness?
Sometimes over-critical.

What advice would you give a younger scientist?
Concentrate on mastering mathematical techniques. If the student ever wants to go into theory she will have to be a master of mathematical techniques. Chemical theory is very, very interesting.

What would you rather be if not a scientist?
A jazz and blues musician.

In whose band?
In my own band! I have been playing since I was 16 or so.

Which scientist from history would you like to meet?
Linus Pauling

What would you ask him?
About the genesis of quantum chemistry and about the people he came into contact with during his postdoctoral stay in Germany. I think he had the deepest respect for them but was personally more interested in applications to chemistry than reaching a deep understanding of quantum physics. His own approach may have appeared a little too cavalier to the European purists. By his own admission Pauling was working with Bohr’s old quantum theory when he first went to Europe only to be informed by Wolfgang Pauli that more sophisticated versions of quantum mechanics had been developed. Pauling immediately made the switch.

How has the Internet influenced what you do?
Enormously. First of all on a practical level I can find addresses, e-mails, phone numbers of anyone I care to with a little bit of searching. If I read an interesting article I can track down the author and ask them a question a few moments after first reading their ideas.

I should also point out that the Internet brings problems. A student recently wrote a paper for me on the history of the periodic table. He referred exclusively to material on the Internet. Most of the paper was filled with inaccuracies, complete mistakes etc. It was not the student’s fault. The problem is that anyone can set up a beautifully illustrated web page without bothering about the academic content and cast it out on to the Web for unsuspecting students to find. There is of course no [peer] review process for what goes on to the Web.

Wasn’t the student a bit naive to assume total credibility of unqualified sources?
Okay, you are right. He was not a brilliant student and he was lazy. Let’s just say it is tempting for students to sit in their own rooms and surf the Web instead of getting their butts into the library.

Why do you think the public fears science?
Lack of knowledge of course and the hard-edged and clinical image portrayed by many scientists.

What are the ultimate goals for chemists?
I am a philosopher of chemistry and chemical educator. I cannot really answer this question which seems to be directed towards “real chemists”. But do you really mean “ultimate goals”? If I were a theoretical chemist I would say to be able to calculate everything from first principles so that we would never need to do experiments and could pack up and go home. If I were a real chemist reaching such “ultimate goals” would not be much fun.

What will chemistry do in the next ten years?
Nor am I a fortune-teller.

You could speculate though…
Well, I really think computational chemistry and modelling will go on expanding as quickly as do developments in the computer industry. Chemists are going to have to get used to the idea that more and more “experiments” will be done on the computer. This should not imply however that quantum chemistry could explain everything in chemistry – that chemistry has been reduced. Far from it. It just means that computational chemistry can be used as a useful tool along with the various spectroscopic techniques, which have already revolutionised chemistry.

What invention would you like to wipe from history?
Chemical weaponry

It is the dead of night, one summer just after the turn of the next century. Despite the darkness, a Midwestern farmer is surveying his acres of crops. From several clumps of plants scattered randomly throughout his fields there emanates an eerie blue glow. The farmer worries: The plants are obviously under stress.

If scientists in the United Kingdom are right, this scene might be played out all over the world. Glowing blue plants may someday provide an early-warning system that will alert farmers to infection and herbivore attack in time for defensive action.

At the Institute of Cell and Molecular Biology at the University of Edinburgh, a team led by plant biochemist Anthony Trewavas has been developing a genetic-engineering program to meet this goal. They are working with a protein that causes certain marine creatures, such as the jellyfish Aequorea victoria to give off light when they are attacked by predators. In response to touch, jellyfish cells fill rapidly with calcium ions, which act as a cellular alarm signal during the organism’s response to stress. The calcium ions bind to various molecules, including the protein aequorin. In binding to calcium aequorin gains an influx of energy, which it dissipates by giving off photons. In other words, it glows.

Plant cells also have an electrical response to stresses such as infection, touch and cold shock. Calcium ions pour in, again playing a signaling role in mobilizing the organism’s defenses. Trewavas and his team wanted to effectively amplify the calcium signal so that the farmer could lend a helping hand to a stressed plant. He reported the team’s latest results at the annual Science Festival of the British Association for the Advancement of Science in Newcastle-upon-Tyne in September.

A motivation for the research is the widespread use of blanket spraying of pesticides. Farmers practice blanket spraying in anticipation of infection or infestation because they would lose crops if they waited for visible signs of attack on leaf surfaces–if you wait, it is often too late to rescue the harvest. Farmers equipped with an early-warning system might be able to spray in time to prevent losses, and to spray only areas affected.

In the early stages of their work, the Edinburgh team transferred the genes that code for the fluorescent calcium-binding protein aequorin from the jellyfish into tobacco plants and mosses. They succeeded in their first goal: When wounded or infected or otherwise stressed, test plants responded quickly by giving off a very faint blue glow, detectable by ultrasensitive camera equipment.

“At the moment,” says Trewavas, “the light is not visible to the naked eye, but that is because this is a jellyfish gene, not a plant gene.” The jellyfish gene includes a number of DNA sections (codons) that plants use rarely, if ever, and this difference in how the genetic information is arranged limits plants’ ability to “read” the gene. “That means we need to resynthesize the gene to optimize it for plants,” he said.

The team hopes to increase expression of the protein, using appropriate promoters, so that the glow is visible in darkness. The choice of promoters could also make the signal more specific, so that, for instance, it would indicate a response to infection rather than to cold shock. Even if one seed in a thousand produced a plant capable of glowing, the warning would be more effective than that achieved in experiments using microinjected fluorescent dyes. Dyes that respond to accelerated calcium flow have been used to monitor plant stress, but these techniques are limited to single or small groups of cells.

Trewavas is optimistic that his technology will be available to farmers by 2000. “If the jellyfish can do it,” he says, “then so can we.” Neal Stewart, Jr., assistant professor of biology at the University of North Carolina at Chapel Hill, shares Trewavas’s bullish outlook and is beginning his own research. “I think that perhaps the year of commercialization may be optimistic–maybe not–but new and improved fluorescent proteins should be on line soon.”

The reference for my original article on this topic is American Scientist, Volume 84, Issue 1, p.25-26