Why Does Rubber Create Sparks When Rubbed Against the Floor?

[eRa]

Rubber is an insulator, so why does it make a spark upon friction with the floor?
What would be a good material for shoe soles to avoid this problem?!

 

[derek e]

Are you sure you were not seeing the spark from a piece of rock or metal embedded in the sole of someone's shoe?

 

[eRa]

yes I am.
I did not see it. It was a part of an answer to a phy question in my solution manual!

 

[derek e]

If you have never seen it, why is it a problem with shoes?

 

[eRa]

does it really matter to you if it involves shoes!?
& believe it or not the question was about shoes!

 

[derek e]

There is no such thing as a perfect insulator. Your question doesn't have any sense of magnitude to it. This is important for determining when things matter and when they don't. People use rubber soled shoes, right? What does that tell you?

 

[Dadface]

It is because of a build up of static electricity caused by friction,electrons are scraped off one insulator and dumped on another.In air an electric field strength of about three million volts per metre can cause discharge and a spark.The most dramatic demonstration of sparking is with lightning strikes but even small sparks can be dangerous eg in environments where there are flammable materials.