Some people today have trouble telling the difference between science, technology and magic. Of course there is some overlap, and the magic of yesterday is the science of today. But some of the confusion is because of the unfortunately low overall interest in science in our culture.
A few years ago, I got a call from one of my colleagues who specializes in doing investigations for insurance companies. He had a potential client who wanted him to “carbon date” a piece of galvanized steel.
Hmm, interesting! According to theAmerican Galvanizers Association,an “early” patent for galvanizing in France was taken out in 1837.
Wikipedia,carbon dating is not really useful for anything that was produced since the beginning of the industrial revolution in the 18th century.
In addition to that, there has to be CARBON in the material that is to be dated. Galvanizing is a layer of ZINC that is used to cover a piece of steel. Zinc is an element. Carbon is a different element. There is essentially no carbon in zinc. There may be an oily carbon-containing LAYER on top of the zinc-galvanizing layer, but there is no carbon IN the zinc. Whatever traces of oil are present would certainly be too new to qualify anyway.
So, it is obviously impossible to carbon date galvanizing. Maybe I am being too harsh. Maybe, since I did not actually talk to the person, he said, “something LIKE carbon dating.”
The eMuseum atMinnesota State Universityhas a very interesting series of articles on 12 different methods used to measure characteristics that can reveal the “absolute” age of some material objects. Most are used for ceramics, bones, mineral sediment, soil and trees. Some of them are only useful if the object has been heated to the melting point. This might be OK for hot-dip galvanizing, except the methods have really only been developed for mineral materials, and (WHOOPS!) if you move them before you determine their exact orientation, the method does not work.
The bottom line here is that there is no magic wand to wave over a metallic object and have the age revealed. Even looking at a piece of metal that has a layer of oxide, so that it looks used, can be confusing. Some steel surfaces rust very quickly, and clean aluminum oxidizes essentially instantaneously. There is an iron pillar in Delhi, India, that is believed to be at least 1,600 years old based on the inscription, and many archeologists/metallurgists argue that it might be about 3,000 years old. Yet, the material has essentially the same shape that it did when it was made. Look for yourselfhere.
With the experts arguing over a 1,300-year range, it is highly unlikely that any current technology can, for example, tell directly what year a standard structural steel member was made. And as for the year, month and day … forget it! That is what record keeping is for.