A physicist facing Chemistry

Uff! When I, a physicist, write about Chemistry, I remember the deep and wide abyss that separates two specialization areas...! Today I finished one of these texts, about a new electroanalytical detector – the kind of thing that you find inside, say, a commercial sensor of glucose in the blood – built by Brazilian researchers in Campinas. I must say that a page from the Electrochemical Encyclopedia with some basic information was very helpful to me. Maybe it is for you too, if you are interested in such matters. If you are really interested, try the original article. Well, I had fun!

Patagonian nature!

I travelled to the south of Argentina and Chile this year – Tierra del Fuego and Torres del Paine, at the extreme South. Mário Sérgio Teixeira de Freitas, a physicist and astronmer that was with me, put many photos about nature in his site. It has explanations about atmospheric phenomena, biology and so on. Unhappily, he is having problems with the software and at this moment some images don’t appear (but some do in the Portuguese version). Patagonia (the name of the whole region) has an amazing nature. You can also see his very interesting images and comments about other trips.

Science writing in the web

Some sites about science writing. The International Science Writers Association (ISWA) is the oldest one (1967). It is behind the World Federation of Science Journalists (WFSJ), instituted in a meeting in Brazil in 2002, that has online courses, a list of member associations around the whole world, links to publications like Science in Africa and so on. In Brazil, we have the Associação Brasileira de Jornalismo Científico (ABJC); see also Comtexto’s portal. The Science and Development Network (Scidev) has sections about science communications dedicated to each part of the world. Good wading!

Nuclear weapons without 90%-enriched uranium

A correction. Some days ago I said that one needs to enrich uranium to at least 90% to build a bomb. However, the nuclear engeneer Sérgio Guerreiro Ribeiro remembered in "O Globo" (in Portuguese) that it is not necessarily so. It is also possible to make it with plutonium-239 (Pu-239), that is produced as “waste” in common nuclear power plants. And a bomb needs about 8 kg of Pu-239, against 25 kg of uranium-235. Plutonium produced normally in power plants have 60% of Pu-239 and a weapon needs 93%, but there are techniques to reach this proportion. Useful numbers to assess scenarios...

Science in Africa

Wading through the web, I found an interesting set of texts about African science, collected by Scidev. According to one of them (in PDF), by three Thomson Reuters experts, the countries with the largest numbers of scientific papers in that continent are South Africa, Egypt, Algeria, Kenya and Nigeria. Now prepare yourself for some surprises. Namibia ranks third in... space science researches. Just as Uganda in immunology and Ethiopia in... economics & business. The last two are normally associated only with poverty, famine and war. I’m glad to say, reality is just more complex than that.

Nanomemory

Writing about nanowires that exhibit memory effects. When light containing information hits it, this nanowire can, in some cases, absorb the light and keep part of the information in the energetic levels (excitations) of its atoms for some time – and then reemit the light back. In other cases, it has no memory effects. Having or not having memory can be controlled with the incident light – and this is the major achievement of a research made in Brazilian and Cuban universities and published last year. Slowly we see the pieces of nanoscale artifacts being thought, built and put together!

An old samba

Ludic interlude. Here is a song that cites who is considered the greatest Brazilian physicist, Cesar Lattes (1924-2005): “Ciência e Arte” (“Science and Art”), by Cartola and Carlos Cachaça, released in 1979. It mentions also the great architet Pedro Américo – one scientist and one artist. One can listen Gilberto Gil’s version in his CD “Quanta”, that has some other songs about “science and art”, in a very poetic way – and also a letter from Lattes himself (in Portuguese) that finishes quoting another architet, João Batista Artigas: “When Science clams up, Art talks”. Good listening!

Understanding mistrust in science and science itself

“The Universal Ethical Code for Scientists and the ‘Crisis of Trust in Science’” (PDF), by S. John and T. Lewens, is a somewhat long text, but it may be interesting to take a look on it or on the resumè at the beginning. It is part of a broader study of the Department for Business Innovation & Skills of UK government. It discusses the complexities of the origins of mistrust in science and scientists. I found it also useful to disassemble common oversimplifications and idealizations about the nature of scientific research, that sometimes makes people react with mistrust when exposed to reality.

Zeferino Vaz (may/27/1908 - feb/19/1981)

At exactly 92 year ago the physician Zeferino Vaz, one of the main founders of the State University of Campinas (Unicamp), was born in São Paulo. He spend 12 years as its leader in its first times (1966-1978), when 10 of the institutes and faculties of the university were built. He was really a kind of “faculty-maker”: he was directly responsible for the creation of six other faculties in the state of São Paulo, four of them of Medicine. And he managed to avoid military interventions at Unicamp, that happened in several other universities in the dictatorship of 1964-85. It was not an easy task.

Venter's natural artificial life

Let’s call an apple an apple. I don’t think what Craig Venter did may be called “artificial life” or even “artificial cell”. He sinthetized the DNA of a bacteria, put it in a cell and the cell started to reproduce normally. That is a truly important and amazing advancement, but the pre-existing living cell was a natural living bacteria. So we cannot call the result an “artificial cell” (see also this Science Now text). However, many newspapers and scientists around the world used that expression. Venter’s Institute itself talked about “sinthetic cell” in its press release. It does not seem so.

Physics at Unicamp: being different

These days I have been writing about the History of the Institute of Physics (IFGW) at Unicamp, one of the main Brazilian centers of research on this area. It had an odd beginning: while in Third World countries theoretical investigation predominates, IFGW turned its emphasis to experimental applied studies three years after it was created. That lead to important results soon, like the Brazilian auto-sufficiency in optical fibers production – although the Institute is relatively new (1967). It is very interesting to decipher why and how that shift happened. This is what I am working on now!

Numbers about bombs, Iran and so on

I have seen journalists saying that Iran will have a nuclear bomb soon because he is enriching uranium at 20%. Well, we have to take care with numbers. A nuclear weapon needs enrichment of 90%. Nuclear power plants use 5%. Reactors for research, 20%. In Nature, it appears at 0,71%. These numbers are the proportion of uranium-235 in the mixture of U-235 and U-238, the two main kinds ("isotopes") of U. According to Global Security, a set of 850 to 1000 ultracentrifuges spends 1 year to produce U enriched at 90% enough to produce a bomb (20-25 kg). Just numbers, but useful to assess scenarios.

The unknown great scientists

So what makes a good scientist? The preferred parameters in academy are the number of publications and of patents registered. General public maybe tends to emphasize revolutionary discoveries. But Helton Escobar at his blog (in Portuguese) notes that the advancement of science depends on many others qualities: the ability to admnistrate large projects, to teach and educate, to write about science to non-specialists, to be good curators of science museums, expositions and collections. Virtuosity may be found in all of these skills. His answer: We need all of kinds of scientists. Bingo.

Following atoms with x-ray

At this moment, writing about the researches about x-ray crystalography done at Unicamp, Brazil. Yes, x-ray is useful not only to medical imagery, but also to study structure of matter at atomic level. One interesting subject is ultrafast pulsed x-ray (about 10^-14 seconds each pulse!), with which one may follow the movements of individual atoms in real time and see directly what they do when, as an example, hard steel is forged (“martensitic transitions”). How atoms "orchestrate" themselves to behave collectivelly in such transformations - something that is not yet fully understood. Cool.