Tuesday, March 15, 2011

Japanese Nuclear Panic - Panic!!!

Run around waving your arms in the air; test all the food coming in from Japan; cower in fear at the thought that the Fukushima nuclear plant will explode and spread radiation over China or across the Western seaboard of the USA; tremble at the thought that the plant will go into meltdown and burrow it's way through the Earth until it pops up off the New York seaboard.

Or you know don't. The highest radiation figure released at a distance of 43 miles is 3,560 nanosieverts before dropping rapidly. What the hell's a Sievert? To put it simply it's a measure of how radiation affects biology.Is this figure high or low? For ease of comparison I'll convert it to millisieverts (mSv) that's 0.00356 mSv; from Wikipedia we're exposed to 0.24 mSv/year from cosmic radiation 0.28 mSv/year from ground radiation.

Ah but doesn't radiation follow an inverse square rule that means at half the distance it's twice as much? So just one mile away it will be 43x43 as large or...wait for it... 6.58244 mSv about as much as a mild chest CT-scan. Except that rule only applies to a point source that is an object pumping out radiation and that's not happening here. It's a one-off dosage that's airborne. To put it another way - someone's lit a fire; put it out and the hot air is dispersing across the area with no more hot air coming in to replace it.

But hey don't take my word for it why not try Fox News instead; yep I'm just about to link to an interview conducted by Hannity. Fox News home of We're all going to die and it's all the Democrats fault with a report on how all this fuss and worry is pretty much unfounded.

In this instance if Fox News can produce this sort of thing what the hell is all our media panicking about?

2 comments:

Neil said...

http://www.facebook.com/l.php?u=http%3A%2F%2Fxkcd.com%2Fradiation%2F&h=f026a

to answer your seivert question. and this is most interesting reading if you've not seen it.

FlipC said...

I hadn't seen it, thanks. It's a neat graphical representation of the dosage scales.