h a l f b a k e r yA riddle wrapped in a mystery inside a rich, flaky crust
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I heard that the iphone is getting a 20 megapixel display. The 20 megapixel display records a few hours of nothing, then the math DSP seeks scintillation events
It would have been reassuring or informing at Fukushima or Chernobyl
Pretty easy to test with a smoke detector n an iphone as well.
Old theme on HB (reduntant to this idea)
Walking_20Geiger_20Counter
[theircompetitor, Apr 21 2013]
Camera phone Geiger counter app
http://hackaday.com...o-a-geiger-counter/
[mitxela, Apr 21 2013]
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Annotation:
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Would moderate levels of radiation give any
significant signal above the background "dark noise"
of the camera? I suspect not. Ingenious, though. |
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Very high speed film can detect raiation but I seriously
doubt that the noise from a CMOS sensor would tell you
anything. |
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The Wiki entry for Scintillator mentions that " Polyethylene naphthalate has been found to exhibit scintillation by itself without any additives" and will probably replace plastic scintillators. Maybe even covers which light up at all the wrong times? |
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As [MB] says, unless the dark current noise of the
camera is abnormally low (usually involving a deeply
chilled camera), that will completely swamp
scintillation events. |
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Am out of my depth, but omniWiki says that dark current noise exists in all diodes, including it seems photodiodes use for existing scintillation detectors. It may very well be the case that scintillation detectors today woudn't be sensitive to moderate levels of radiation. |
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Scintillation counters use a photomultiplier. This
is incredibly more sensitive than a CCD. They also
tend to be optimized for extremely low dark
current, and don't develop thermal noise. They
also have extremely high amplification, so a single
event will produce a significant current. |
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iPhone CCDs, on the other hand are whatever they
can get cheap off the shelf, are decidedly not
optimized for either low dark current, nor for high
quantum efficiency, and have no particular
amplification. They also aren't chilled to reduce
thermal noise, which CCDs require for high
sensitivity applications. Since they tend to be
optimized
for fairly bright daylight, or at least require a
flash, the scintillation event is almost definitely
not going to be detectable. |
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Polyethylene naphthalate does fluoresce blue at some level of radiation which eludes me. As a complete aside, I wonder if a similar process is behind the coloured lights some people see just before an earthquake. |
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//coloured lights some people see just before an earthquake// Are you sure that's not the LED flashes on their smartphones as they try to film the devastation? |
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Seeing coloured lights, falling over, can by symptomatic of many things. |
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As can feeling the earth move. |
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The videos I have seen of "earthquake lights" on
Youtube all seem to show iridescent clouds and/or
sundogs, both of which are actually very common
but seldom noticed. Another video showed
(probably) a power transformer blowing up in the
distance. Yet I believe "earthquake lights" are fairly
well documented. |
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Does anyone have a link to a video of some non-
mundane "earthquake lights"? |
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I'll believe in pre-earthquake phenomena (lights,
animal behavior, whatever) once there is a
documented case of someone reporting it before
the earthquake. Oh, and no documented cases of
someone reporting the identical phenomenon
without an earthquake following. |
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Given twitter/instagram (and the fact that
earthquake reports online are now outpacing the
ground wave in many cases), it seems reasonable
that if these things actually happened, there
should be at least a few pictures of the lights on-
line. |
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The animal thing is a little harder, because pets
sometimes just behave weird. There I'm looking
for a statistically significant increase in "weird pet"
reports prior to the quake. |
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