Re: cherenkov radiation

["Tom Savin" <lexicon@hotbot.com>]

 Hi Jim,  so are you saying that the blue color is because the radiation is moving faster than the speed of light (in that medium)?  Does this mean that their is a "blue shift'  "as in stars coming at us" that we pick up.  In astronomy red shifts are more commonly known for objects that are moving away from us.  I think a novel experiment would be to have a video camera and see whether or not it picks up the blue shift/light.  Ideally, we should also include two people - one with eyes closed and another with eyes wide shut.  That will certainly clear up this debate.  We would have to interview the people ASAP before they were not able speak.  Best Regards,  Tom
--

On Wed, 8 Nov 2000 17:18:23    Dukelow, James S Jr wrote:
>
>Jaro Franta wrote:
>-----Original Message-----
>
>	<snip>
>
>I refer specifically to the "blue glow" phenomenon.
>Kevin Roark of LANL says much the same thing in his article posted at URL
>http://www.lanl.gov/worldview/news/releases/archive/00-099.html
>>It is my understanding, reinforced by a brief Internet search, that Jaro's
>understanding of Cherenkov radiation is not correct.
>
>Cherenkov radiation occurs when charged particles move through some medium
>faster than the speed of light in that medium.  If the medium is transparent,
>then we can see the Cherenkov radiation. There is nothing special or privileged
>about water, although that is the context that most of us are familiar with.
>Cherenkov "glow" can occur in air, even dry air, where it is the basis for an
>"instrument", the STACEE (Solar Tower Atmospheric Cherenkov Effect Experiment),
>that uses a heliostat array and a photomultiplier to detect the atmospheric
>trace of particle "showers" caused by extremely high-energy gamma rays arriving
>from active galactic nuclei.  There is another instrument based on detecting
>Cherenkov radiation in an aerogel material.
>
>The Tokaimura blue flash was probably in the air near the vessel, but was
>certainly not caused by gamma rays and neutrons in the eyeballs, since neither
>of those are charged particles.  Secondary charged particles might have resulted
>in some Cherenkov in the eyeball, but it wouldn't be perceived as a blue flash
>localized near the criticality.
>
>Best regards.
>
>Jim Dukelow
>Pacific Northwest National Laboratory
>Richland, WA
>jim.dukelow@pnl.gov
>
>These comments are mine and have not been reviewed and/or approved by my
>management or by the U.S. Department of Energy.
>
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