boric acid to try to cool it all down, is that a good idea? >> it's hard to say. i imagine their judgment is this is the only tool left in their tool kit, but it -- sea water, with all the salt it contains, can be extremely corrosive to equipment, especially at high temperatures, so i expect this is a last ditch effort to cool the core, but it will ultimately destroy most of the reactor. >> very quickly, what if that doesn't work? >> if that doesn't work, then we'll be faced with further core melting and a larger radiological release to the environment and more countermeasures will have to be applied to protect the population. >> edwin lyman thank you so much for your thoughts and brings us up to date on this nuclear crisis in japan. in general, tsunamis are among the most devastating natural forces on earth. but how exactly do they form and why are they so powerful?