In and Out
Sir Isaac Newton first explained how the tides are caused by gravitational effects in 1687. Of course for him to be able to explain these he needed first to have explained the phenomenon of gravity itself. There is evidence of philosophers in earlier times de cringing the effects of gravity on the oceans. For instance Seneca the Younger a Roman philosopher (4BC to 65AD) recognised that the tides were in some way linked to the Moon. He wrote, In point of fact, their growth is strictly allotted; at the appropriate day and hour they approach in greater volume or less according as they are attracted by the lunar orb, at whose sway the ocean wells up. This attraction that he speaks of is what Newton described over 1600 years later. To understand the tides we firstly need a working understanding of gravitational force. Gravity is a non-contact force. This is a force that acts between two objects that are at a distance as contrasted by a contact force such as friction. ...