Thursday, April 7, 2011

4/7/11 "Cloud Shine" measurements

Today was slightly cooler and more overcast, so I took some outside readings to see if I could pick up any evidence of radioactive "cloud shine". No conclusions can be drawn yet, more data will be required to establish baselines. ( Because of the geometry of the sensor, there is a directional bias)

Reading #1 (unit inside its case, sensor pointed skyward)
79 minutes total
2979 counts total
Average= 0.01077 mR/hr

Reading #2 (unit inside its case, sensor pointed at southern horizon)
71 minutes total
2200 counts total
Average = 0.00885 mR/hr


  1. I saw your comparison with no rain and rain on the paper towel off your car and the different readings, but what does it mean? How bad is that reading?

  2. Elizabeth,
    Qualitatively it was not good, but to quantify how bad it was for me personally, without knowing exactly what the fallout was, is very hard to do.

    If someone did know, the answer would likely be x number of people of x hundreds of thousands would come down with cancer over their life times.

    If the fallout I measured blew in from Fukushima, it probably was immediately dangerously radioactive to people when it was over Hawaii and California. (a much quicker and more substantial risk of cancer)

    The other danger is if this stuff continues coming down for months. People would be getting cumulative exposures. And if the half life were longer, there would be lots of environmental build up.

  3. AVERAGE yearly radiation from natural and manmade sources equals around 500 millirems (we'll use your terminology though sieverts is the standard these days).

    That means your test shows only a spike of 5x average normal dosage per hour. Who knows where that rainwater came from? Not that it matters... Just taking a flight on a jet will get you DOUBLE that (or 10 times) amount of radiation just from the added exposure to cosmic radiation the higher you go.

    Since radiation falls directly in relation to the square of distance from the source, and they are getting 0.1 msv per hour (10 mrems) in Tokyo 100km away... You do the math and tell me if the test has anything at all to do with Fukishima.

  4. kanati,

    The fallout in the rain video was roughly 19X background radiation.

    And you do realize that there is a difference between radiation from background versus eating and drinking the source of that radiation? It is the diffrenance between getting an X-ray and eating the X-ray machine.

    In that regard, I have to ask -what's the square of the distance from the source when you eat or breath the source?