Answer: An obsession is an unwanted, intrusive, and often unpleasant thought that causes an increase in anxiety.
It was possible because it helped him navigate in territories that were completely unknown to him. Thanks to it, he could determine where his ship was based on the position of the sun and the time of the day and he used this to navigate all the way to India.
The movement of materials away from place is called erosion.
Your reading above gets my article completely backwards. The research shows that women who work outside the home have LOWER rates of depression than those who do not, even when we control for other factors, like pre-existing health problems that might make some women less likely to work. Someone needs a better fact checker or copy-editor!