Sunday, November 16, 2008

In Order to Justify My Title

I will preface this post by saying: This idea is half-baked, and only published upon stiff encouragement by friends. Take it with a grain of salt.

Several days ago, I happened across a book at a local Barnes and Noble written by the noted oceanographer, Robert Ballard; being a childhood hero of mine, I naturally could not resist leafing through the very spectacular (if morbid) pictures contained therein. One sight that has always struck me, and I believe a great many other people is that of the lonely bronze telemotor standing on The Titanic's destroyed bridge. Yet, beyond it being a ghostly reminder of what was, it also presents a problem for the casual viewer: why is it barely corroded, when the rest of the ship is disintegrating?

Now the simple answer is that "Bronze oxidizes more slowly than steel", which is true, to a point. Bronze is an alloy of copper and tin, both exhibit higher resistance to corrosion than iron. However, this may be just part of the answer. Copper exhibits an oligodynamic effect, or a tendency to be anti-microbial. Now, a large cause of decay on the Titanic are iron metabolising bacteria, which form structures called Rusticles, which are actually large colonies of the iron devouring bacteria.

It would seem plausible, therefore, that there is not a copper metabolising analogue simply because the surface of copper is too inhospitable for single celled organisms to effectively use. Interestingly enough, copper anologues to iron do exist in nature; the first that comes to mind is the Horseshoe Crab, whose blood, instead of containing the iron chelate hemoglobin, contains only the copper chelate hemocyanin.

This is not a complete thought, but interesting, none the less. Some questions that remain include: if copper chelates are not toxic to crabs, why can bacteria not adapt to use copper metal? Is the blood of horseshoe crabs also oligodynamic? Is the toxicity of copper truly the reason why bacteria do not metabolise it? These are questions I have yet to be able to answer, but with ample digging through journals, answers may present themselves. However, even though this idea is not complete, it does show, in some sense, my interest, and why I am trying to keep a blog: the art of history, and the sciences of chemistry, biology, and physics are deeply linked, and by pursuing history through the sciences, one may encounter secrets that otherwise would have been obscured.

1 comment:

Ray Yaegle said...

Well done Michael! I even understood it, so bully for me as well.

I think your blog is going to turn out just fine -- good luck.