Radiocarbon short course in Jena, Germany

The week was very nice. Lucky us, the schedule was not very intense. However, everything  was very advance, and hard to understand. One of the first lecture was the nomenclature in radiocarbon studies, and at that time I understood that this week was going to be tricky... The first thing was that the abbreviation BP didn't mean Before present, but instead, before physics, 1950. When measuring 14C (=radiocarbon) you will have a value that mirrors the concentration in the atmosphere at the time something die. However, if you for example analyzing a soil sample, the carbon entering the soil comes from plants and will because of that lag behind compared to the atmosphere. So, the concentration of 14C in the soil mirrors the concentration in the atmosphere at the time it was fixed by the plant. And for complicating it a bit more, at 1963 there was a peak in the 14C concentration of the atmosphere because of bombs. So, unfortunately the equations for calculating the age of something using 14C is rather complicated since you must know if the sample died before or after BP (=1950, when the concentration started to increase)... So, to sum up, to analysing the age of a sample using radiocarbon is not as straight forward as I once thought. The next complicated thing is that the amount of 14C in samples is in the range of 10^-12, or in other words, very low. A sample will be contaminated very easy. Just imagine the age of a plastic bag or a plastic pot. Plastic is made of oil, and the carbon in oil is very very old, and may simply destroy your sample. You also have to compare your 14C concentration in the sample with the concentration of 13C to get an idea of the mass fraction that may occur when carbon is transported and when it reacts. So everything is just getting more and more complicated, and it seems like you can destroy your sample at so many times that I don't think I would dare to even try. 

Concentration of 14C in atmosphere, showing the bomb peak at 1963.
if you have sample with 140 ppm you may not know if it is from 1960 of 1975.. 

The facilities in Jena was very nice. A very large lab with a AMS (accelerator mass spectrometer) for measuring the 14C in a sample.

The week in Jena offered a lot of information, weissbier, potatoes and BBQ. a really nice week. As a bonus Ralph Keeling was giving a talk in Jena the very same week as we was there, Good stuff!