Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Sparks

Yes, Brian, I quoted you wrongly. You wrote INSULATOR not concuctor.
But the rest of my statement stands. Partial vacuum at low E (when Ohm's
law is applicable) is a better insulator than dry air under normal P. I am
assuming that free charges are due to cosmic rays only. We are referring
to different conditions, low E and high E. Sparking, of course, happens at
high E.

Ludwik Kowalski wrote:

I am a little surprised that dry air is a better INSULATOR than the vacuum.
Cosmic rays produce free charges in the air but not in the vacuum.
Less pressure --> less free charges per unit volume.

Brian Whatcott wrote:

.... But air, particularly dry air is an excellent insulator - so much
better than the (soft) vacuum.