[Beowulf] Re: ECC Memory and Job Failures (Huw Lynes)
laytonjb at att.net
Sun Apr 26 05:33:19 PDT 2009
Robert G. Brown wrote:
> On Fri, 24 Apr 2009, Pfenniger Daniel wrote:
>> Since the natural level of radiation over a lifetime correponds
>> to a semi-lethal instantaneous dosis, I would think that for the
>> crew working years in airplanes the cumulated radiation coming
>> from cosmic rays may be significant.
> It is. The rule of thumb in the medical community is that it is roughly
> equivalent to a low-dose X-ray. IIRC one of the worst parts isn't the
> radiation itself, it is secondary stuff from cosmic rays hitting the
> body of the plane on the way in, creating a shower of e.g. beta
> particles or other ionizing radiation. Radiation in general causes
> oxidative damage to cells, so take your antioxidants if you plan to fly.
Ahh... remember this well. The amount of radiation is also proportional
to the altitude you fly. The Concorde flew well above normal commercial
flights so the radiation exposure was much greater. After a number of
years of service there was some discussion about tracking passengers
travel time to limit their exposure. They tracked the exposure time for
flight crews pretty carefully.
Remember the good old SST days? Same problem. When there was a
resurgence of SST discussion in the 80's and early 90's these questions
reared their ugly head as well. It was even worse when Reagan wanted
everyone to be able to travel to Tokyo in a couple of hours at Mach 25
(remember the Orient Express discussions?) You had to fly high enough
that the exposure was pretty significant.
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