Thursday, March 8, 2007

Pills of... misunderstanding

Sometimes it is quite frustrating to meet a new wonderful person, and find out that we do not speak the same language. It is really a shame! Just think about all the important facts we are not able to share because of a language gap!
This is the way that sometimes scientists feel when what they say is misunderstood: frustrated. It is nobody's fault but the tradition of using words to mean something different according to the context. To illustrate this point, I will give a short list of terms which are commonly used by scientists in a completely different meaning than the ordinary language:

Organic: we've seen this before. For a chemist, organic simply means that something contains the chemical elements carbon and hydrogen, with some oxygen, a little sulphur, some phosphate and of course nitrogen. Methane gas is best known for its use for heating and for cooking. It is hard to think of the methane gas as organic, but strictly speaking, methane is the prototype of the family of alkanes. But nowadays it is possible to buy organic produce, and eggs, and even organic meat! For the vast majority of people, "organically grown" means that something has been produced without the help of man-made fertilizers and pesticides, using manure as fertilizer. For a chemist, regular meat and produce are just as organic as "organic" ones, since they contain all the above mentioned elements. I wouldn't like to eat feldspar*, no thanks!

Chemicals: this is one of my favourite misunderstandings. In chemistry, we define a chemical compound whenever we have an homogeneous substance of which we can define the exact chemical characteristics, such as melting point, composition, if we're lucky the structure. In the collective mind, a chemical usually sits in a purified form on a shelf in a laboratory. So it is hard to see why vanillin, extracted from the cured vanilla pod, is considered a chemical compound** by a chemist. According to definition, though, vanillin's chemical characteristics are well defined, including its structure. Vanillin can also be easily synthesized in a lab (and it is absolutely identical to the one synthesized by the plant). Another very common chemical is glycine, the simplest aminoacid, synthesized by virtually all plants and animals and present in almost all the proteins. Its chemical properties are very well defined, but normally people do not think of stuff made by plants and animals as being chemical, because when people hear about chemicals they immediately think of man-made substances, usually toxic. Not so, not so...

Nuclear: for people who studied Latin at school, this is trivial. Nucleus comes from a Latin word meaning "core", therefore the nucleus (adj: nuclear) is basically the core of something, whether it is a cell or an atom. So scientists were quite confused when people were scared of taking a nuclear magnetic resonance (NMR); in the end, they changed the name to the friendlier definition of "magnetic resonance imaging" (MRI). This technique has nothing to do with radiation, but with the magnetic properties of the atomic nucleus. Radioactivity is nuclear, in a sense, because it is generated in the nucleus. The bad reputation probably comes from the "nuclear bomb", which uses the power harnessed in the atomic nuclei to wreck havoc. So when a journalist asked a geneticist to change "nuclear" with "of the nucleus", we all were a bit annoyed.

Aromatic: this is really funny! For many people, aromatic means that something has a very good smell... Aromatic herbs, aromatic gardens... But in chemistry, there is a whole category of compounds which are called aromatic and frankly, they stink! Have you ever tried to solve a moth invasion using naphthalene? I have (I had an invasion of carpet beetles) and my house stank for days and days... Aromatic compounds have very special characteristics and their chemistry takes many chapters in an organic chemistry textbook; the best way to describe them is by imagining very flat molecules (they are planar) with a very strong stability***.

* no carbon in feldspar; it is a rock that contains mostly silicon and aluminium. Yummy!
** it is an aromatic compound, but this one actually smells good!
*** for the most curious people, wikipedia has a very good article on aromaticity.

1 comment:

Kate said...

Nice post! Informative and entertaining; my favourite kind. :-)