'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 variations that naturally occur in the level between successive high tide and low tide are referred to as the range of tide. At most shores throughout the world, two high tides and two low tides occur every lunar day, the average length of a lunar day being 24 hours, 50 minutes, and 28 seconds. One of these high tides is caused by the direct-tide dome and the other by the opposite-tide dome.