We had a big aftershock today. It went on for a minute. Side by side movements to begin with, then vertical. It's the first time in a long time we've all run outside. Japanese keitai (cell phones) sound a warning when an earthquake begins so everyone was outside checking the details on their phones (for some reason my smartphone doesn't have this facility). Time: 2:36 pm (too like 11 March, 2:46 pm for comfort), Magnitude 6.8, weak Force 5 here in Koriyama. A tsunami warning went out, only 50 cm and it was withdrawn after half an hour, still, nerve-wracking for people on the coast. I phoned our Sendai office to suggest one of our staff go home early but he happened to be taking today off so that was good. On television tonight a spokesman from the Met Office has just said that it will 'take years' for things to get back to normal and we need to take care for another six months to a year.
The weather has suddenly cooled down though the heat is set to return next week. Yesterday I saw a woman walking in 'the outfit' - hat, mask, long sleeves, gloves. No one walks round like that anymore. She must be either paranoid or an outsider. Levels are generally under 1.0 microsievert/hour in Koriyama these days, a third the levels in March. Life goes on as usual. But I really must get to grips with this question of radiation and work out if I'm OK and whether I need to change my lifestyle.
I've been reading up on the subject. First, a book called Radiation and Reason: The Impact of Science on a Culture of Fear written in 2009 by Wade Allison, a nuclear and medical physicist at the University of Oxford. His thesis is that the perception of radiation - an unseen enemy, the science of which is difficult to understand - encourages 'alarm and unrestrained flights of imagination'. He sets out to explain the science and analyses data: from victims of Hiroshima, from radiotherapy, and from studies of 'dial-painters' who painted radioactive luminous paint on clock faces (licking the tip of the paintbrush to acheive fine detail) and so long as their lifetime dose was under 10 gray didn't get bone cancer. His conclusion is that, on balance, the benefits of nuclear energy to combat global warming and save the planet are worth the dangers, which he thinks are over-rated.
Next, I've been following a blog by Professor Takeda of Chubu University. He's a nuclear expert but has taken it on himself to address people's fears and answer their questions. It's in Japanese but the language is straightforward and to the point. His current rant is against the safety level for food which at 20 mSv/year he thinks is too high.
And then there's the work I've mentioned before by David MacKay which appeals to us to think seriously about climate change, weigh up the pros and cons, and decide what mix of energy sources we would find acceptable to supply the energy that we need. Here are links to the video and the book.
So that's the bibliography. Now I have to do the calculations and see if I can work out how much radiation I've been exposed to. Not an easy task for someone who gave up physics at age 14. Watch this space.
So goodnight from a much cooler Koriyama. Currently 21'C. Same as London!