'I am NOT an alcoholic': Gerard Butler reveals the real reason behind his stretch in rehab. Actor Gerard Butler has revealed his rehab agony and set the record straight over rumours of his alcoholism. The 42-year-old Scot checked into the Betty Ford Centre in February for three weeks after being injured in a surfing accident. He said: 'Maybe a stronger person wouldn't have needed to go. But I'm glad I did it.
Gravity is one major force that creates tides. In 1687, Sir Isaac Newton explained that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth (Sumich, J.L., 1996).
The earth and moon are constantly in motion around the sun, and all have their own gravitational pull. So, when the alignment between the three bodies changes, it changes the strength of the overall gravitational pull and therefore the size of the tides.