In the past 10 years, oil prices have dropped significantly due to lower demand, caused by more efficient cars, the advent of renewable energy technologies, and many nations producing more oil in a competitive market, thus lowering prices.
The sun only lights one half of the Earth at a time. because the planet will always obscure some of the night sky from our view. Earth divides it into two equal halves called hemispheres. There are generally considered to be four hemispheres: Northern, Southern, Eastern, and Western.