[ExI] Captchas

[BillK]

2011/8/13 spike wrote:
<story snip>
> The one thing I noticed, which sticks with me to this day, is that even the
> most robust urine stream immediately dispersed into an arc of individual
> droplets, which was quite educational.  I realized that a urine stream would
> probably not be electrical conductor.  All those stories about hobos
> urinating upon the third rail of the subway track and having their privates
> blown off were apparently mythical urban legends.
>
> Years went by.  A fun local TV show called Mythbusters actually tested the
> notion with a urinating dummy.  They confirmed that indeed, any urine or
> water stream consists of individual droplets and is not particularly
> conductive to electricity.  Buster the anthropomorphic dummy could safely
> urinate on the third rail all he wanted.
>


Please don't try this at home!

There have been several cases reported in newspapers of electrocution
deaths with burn marks to prove the cause.

One critic of Mythbusters wrote
Subway systems use direct current. When Jamie and Adam tested this
myth, they used a generator which produced alternating current. This
in itself totally screwed up their results, since they did not test
the system using accurate data.

Secondly, they made no allowance for the return of current. In 3rd
rail systems, the third rail itself carries a positive charge, where
as the running (track) rails carry a negative charge. Once the power
is used by the traction motors in the cars, it is returned through the
track rails to the power distribution station.used a generator which
produced AC and third rail systems use DC.
--------------------------


Voltage probably matters as well.

At least one death has been reported from peeing on an unnoticed power
line that had been brought down in a storm. Power lines can carry huge
voltages.



BillK