Re: Electrosensitivity and potential charge of a cat

["Bjorn Cedervall" <bcradsafers@HOTMAIL.COM>]

>>I think the capacitance is more like 10-20 pF (pico-farads, not 

>>nano-farads).

---

>I will call the prof. again and check. I am definitely not the person to 

>ask and may be the cause due to bad memory - a factor of 1/1000 - must get 

>that one right.

------------------------------------------------------



OK - I had a second talk with my Swedish physics friend (Hans Wiksell - he 

approved to me mentioning his name). Asked him about the capacitance - he 

gave it about 1 nF - and assumes as a first approximation that the 

resistance in the cat is zero (which Hans points out that it is not).



I then asked more about that and he commented by saying that electric 

properties of materials belong to his area of expertise - but adding that of 

course actual measurements would be the appropriate action. As some of this 

so far is more of theoretical considerations rather than actual data 

measurements it seems wise at this moment to focus on the character of the 

calculations rather than assuming data speculations as truths. Here is an 

abbreviated translation of what Hans also, as a clarification, emailed me.



Energy during the discharge (voltage = 10 kV): 1/2UUC = 0.05 Ws = 0.05 J



The frequency at which the discharge occurs is very dependent of C and the 

inductance L (Henry). Assuming L = 500 microhenry (which may be too high) 

one gets 0.22 MHz. ( f = 1/(2 pi SQR(LC)))



This corresponds to a discharge time of about 1/MHz or 0.000 005 s. Divide 

the energy by the time => 11 kW as peak power (but only during a very short 

time).



Hans says that in an actual situation, there will be a damped (attenuating) 

oscillatory discharge that exists for a much longer time - the peak power 

will therefore be lower but certainly still quite high. That discharge at 

0.22 MHz should easily be picked up by a nearby AM radio receiver.



Hans suggests a simulation with 0.9 % NaCl (saline) in a metal container 

placed on a cat fur (Hans' cats do not want to participate in any 

experiments he explains) a capacitor that can take at least 30 kV and a few 

other gadgets. Hans points out that if you hold the cat in a paw you cannot 

charge it.



Please comment with whatever additional experiences, considerations or 

corrections that you may have.



My personal comments only,



Bjorn Cedervall   bcradsafers@hotmail.com





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