1. what causes a hurricane? where does a hurricane get all of its energy? 2. why are coastal populations so vulnerable to excessive damage (other than the fact that they live on the coast)? 3. where in a hurricane is the atmospheric pressure lowest, and approimately how low might that be? 4. when is hurricane season (which months)? why then?

answer:

light intensity falls off inversely with square of distance

explanation:

a beam of light become fainter and fainter if we remove   it to away from a wall

let us take an example

when we shine a torch on a wall , light reflected on the wall is smaller and very sharp but when we move torch away from the wall we will notice that light reflected on the wall is larger and duller and it will reaches a point when   we will not see any thing on the wall .

similarly if we will place to a candle near to a wall or person sitting by it we will able to see his /her face brightly   or wall clearly .

as we move candle away the face, face gradually invisible and wall also appear duller. this is happening because light spread very little when we keep it close but light spread widely and become less intense as it move away. the light rays spread fewer light reach a particular point making it difficult for eye to see it.

this can be explained by

inverse square law of light intensity

the intensity of light is inversely proportional to the square of the distance from the light source. this principal used to calculate distance in astronomy

laser light travels fastest among all the form of light, one of the reason is that   it is highly focused and form very narrow core .

what i can see in this picture is a river that became dirty, all i can say is that people are keep on throwing trashes on the river and now it is dirty.