Why Are There No Perfect Electrical Insulators?

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SUMMARY

Perfect electrical insulators do not exist due to the inherent properties of materials and the behavior of valence electrons under high voltage conditions. While materials like plastic and wood are considered insulators, they can still allow electric charge to flow when subjected to sufficient voltage, leading to phenomena such as electrical breakdown. This discussion highlights the concept that even good insulators can become conductive under specific circumstances, such as ionization in air during events like lightning.

PREREQUISITES
  • Understanding of electrical insulators and conductors
  • Knowledge of valence electrons and their role in conductivity
  • Familiarity with electrical breakdown phenomena
  • Basic principles of voltage and electric fields
NEXT STEPS
  • Research the mechanisms of electrical breakdown in materials
  • Explore the properties of common insulating materials like plastic and wood
  • Learn about ionization processes in gases and their implications for electrical safety
  • Investigate the effects of high voltage on insulative materials
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Students of physics, electrical engineers, material scientists, and anyone interested in the principles of electrical insulation and conductivity.

RobinSky
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I just some how fell into a wiki article about http://en.wikipedia.org/wiki/Insulator_%28electrical%29" and then read the following statement:

A true insulator is a material that does not respond to an electric field and completely resists the flow of electric charge. In practice, however, perfect insulators do not exist.

The question is, why is it that there are no perfect insulators? I thought things like plast, wood, didn't allow electricity to flow through at all, but of course physics does it again, turns your head completely upside down! :rolleyes:

Could anyone explain this? I tried to google it but didn't find anything relevant.
 
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For one thing valence electrons eventually break loose at high enough voltages...that is, the medium becomes a conductor.

A simple example is how a spark plug or lightning ionizes air which is a pretty good insulator (it must be since I don't get shocked sitting here at my computer with 120 volt ac nearby!)

Check here for some interesting background:

http://en.wikipedia.org/wiki/Electrical_breakdown

Some interesting photographs...
 
Ahha! I had no idea, thanks for the reply! :)
 

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