This weekend, I watched a dreadful submarine film, K-19: The Widowmaker’. It had an all-star cast, including Joss Ackland, Harrison Ford and Liam Neeson, but it annoyed me for its historical and technical inaccuracies. As ever, the writer of the screenplay distorted the science of nuclear physics to suggest that a reactor meltdown could somehow become a bomb capable of starting WW3 by accident. It is such a popular myth I suppose it can be forgiven. However, the true stor