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Name: Ian T.
Status: other
Grade: other
Location: N/A
Country: N/A
Date: 8/17/2005


Question:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

The site above tells me that "Electric current is the rate of charge flow past a given point in an electric circuit".

So is the Solar Wind a current, even though it largely consists of positive and negative charges moving in the SAME direction?


Replies:
Yes and No!! The definition you give of "electric current" is meant to be applied to electric circuits. When you consider a different set of circumstances, different phenomena, frequently definitions then need to be changed or modified to fit the new circumstances. That is the case here. In the case of solar winds the charges are not confined to a wire (obviously) so one modification that would have to be made is to consider a solid angle of space and it is likely that the definition would also be modified to take into account positive vs. negative charges. The point is that the conventional definition is no longer convenient, or is a "stretch" to apply, so new terms need to be defined that are applicable to the new set of circumstances. The phenomena dictate the definitions we use, not the other way around. Do not "force" the phenomenon to fit a definition.

Vince Calder



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