ELECTRIC CHARGE : WHY '+' ? WHY '-' ?

We all know that there are two types of electric charge. We label them as '+' and '-'. One may wonder why these charges have been labelled so? Historical evidences give no solid reason for this naming practice.

A long time ago people found that certain materials when rubbed with cloth or fur were able to pick up (attract) small objects(like a piece of paper). A piece of ebonite was said to be charged when rubbed with fur. Similarly, a glass was said to be charged when rubbed with silk. But the charge on ebonite was not similar to the charge on glass, i.e. there were two kinds of 'charge' and so for the convenience of description and identification they were labelled '-' and '+',respectively by someone or by a group of some people. '-' and '+' have no mathematical significance nor any magical reason for being labelled like that. Had they named '+' charge as '-' and '-' charge as '+', that would not have had any significant impact on the description of phenomena of electricity. Thus, electron is negatively charged because it has the same electrical properties as a piece of ebonite when rubbed with fur and proton is positively charged because of its electrical behaviour similar to the glass rubbed with silk. So let us recollect Shakespeare : What's in a name ? An electron would behave electrically similarly if it were named 'proton'!!!

DUST BOWL

American state of Oklahoma suffered severe drought situation in 1930s. there was no crop due to lack of rain and the fields had dried to the extent that the soil blew away as dust and created what was called a 'DUST BOWL' region. People had to leave that area for further survival. A similar drought situation development took place in the state of Illinois in July 1988 when the then President Ronald Reagan during his visit to the state told farmers :"This is the worst natural disaster since the Dust Bowl of 1930s."

A NASA scientist in his report to a committee of the US Congress had told that "DUST BOWL DROUGHT" was 99 per cent certain to be caused by pollution of air and that it was an early sign of a dangerous climatic change, a change which leads to a general warming of the global atmosphere. This, in turn, affects the rainfall, as well as having other side effects. He said this atmospheric pollution was the "GREENHOUSE EFFECT". Thus 'DUST BOWL' was blamed on the Greenhouse Effect.