Talk:Static electricity

Figure caption - charged by contact?

This is supposed to be a non-technical article. I had written that the girl on the playground slide had been "charged by friction", which in my opinion as a physicist is not false. Now User:DJIndica changed this to "charged by contact". In my opinion such a phrase is likely to be misunderstood as "charged by contact to an electrical conductor at high voltage".
Also, it is preferable not to specify the sizes of thumbnails. Users that are logged in can specify the size matching their computer screens under "my preferences" -> "files". /Pieter Kuiper (talk) 15:53, 21 January 2008 (UTC)

As far as the thumbnail size is concerned that's a good point, I just thought it would look good larger. Is there a way to specify it as a percentage of the screen width?

I'm pretty sure the statement "charged by friction" is incorrect. The important point is that a region of the surface of one object is brought into contact with a region of the surface of another and then separated. Rubbing the two objects together ensures this happens many times, increasing the effect. However, the coefficient of kinetic friction does not play a role (unless there is a pyroelectric effect due to heating, but that's unlikely to be significant). Even if the surfaces were entirely frictionless, there would still be charge exchange, provided the two materials are at different points on the triboelectric series.

I see that "charged by contact" could be confusing, although "Contact induced charge separation" is listed (and explained) as one of the causes of static electricity. Perhaps "charged due to contact with the slide" would be better.

Thoughts/suggestions? --DJIndica (talk) 18:59, 21 January 2008 (UTC)

As you say, friction is making contact and separating many times. The separation step may separate charges, and this leads to charging. Such an explanation is too detailed for a caption, and just saying "charged by friction" is adequate. /Pieter Kuiper (talk) 19:50, 23 January 2008 (UTC)

I say that making contact and separating many times leads to charge separation but that is not the same as friction. There may be friction or there may not, but either way it is the fact of making contact and not friction that is the origin of the charge separation. Do you feel that the current caption: "Charged by contact with the slide" addresses your concern about misinterpretation of the word "contact"? --DJIndica (talk) 20:58, 23 January 2008 (UTC)