In a News story (Nature 466, 302–303; 2010), you discuss Seung-Hun Lee's analysis of the official South Korean report on the sinking of the warship Cheonan on 26 March (S.-H. Lee and P. Yang, preprint at http://arxiv.org/abs/1006.0680; 2010). In my opinion (I am independent and not politically connected), neither this work nor the report from South Korea's Joint Investigation Group (JIG) seems sufficiently technically convincing to explain the event fully (see also http://go.nature.com/aS7Eoz; http://go.nature.com/JQLzcU and http://go.nature.com/7bpWYL; in Korean).

It is reasonable to assume that all navies now use some form of aluminized explosive for their torpedoes. Good simulation experiments are only feasible if they use the same aluminized explosive as the torpedo in question; however, it is unlikely that the explosive's producers will identify themselves in this case, let alone make it available. Assuming it was not an accident, only the party responsible for sinking the Cheonan can carry out the proper simulation experiments.

Having related knowledge and experience of the subject, I find that the critical weakness of Lee's simulation experiment is that it didn't use explosive; also, I believe that Panseok Yang's analytical (electron-dispersive spectroscopy) data were not properly corrected so should not be compared with the JIG's uncorrected data. As for the JIG experiment, it does not reproduce the actual conditions of an explosion. It used 15 grams of sealed explosive in sea water (compare with the 200–300 kilograms in the suspected torpedo), producing an explosive pressure of less than 1,000 atmospheres; however, the temperature and pressure inside a torpedo just before it explodes are likely to reach up to 5,000 °C and 200,000 atmospheres, which will oxidize almost all of the aluminium in the explosive.

Even without simulation experiments, it should still be possible to determine whether the deposits from two different sources (the ship and the torpedo) are the same material, and whether they contain the forms of aluminium used in explosives.

My concern is whether the currently available data from the deposits have been correctly sampled and interpreted. A more comprehensive chemical and physical analysis should provide more accurate and useful information.