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The theory that tides were caused by the moon was introduced in 150 BC by Seleucus of Seleucia.
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Muslim astronomers formed the basis of the understanding of tides in Medieval times, during the 1100s when Latin translation interpreted their findings.
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In the 1100s a theory that the circulation of the heavens caused the tides was introduced by al-Bitruji, an astronomer that defied the Ptolemaic astronomy system. There is a crater on the moon named after him.
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In 1608 Simon Stevin, an engineer, physicist, and mathematician defied many of the then-current misconceptions about ebb and flood.
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Johannes Kepler, an astrologer, astronomer, and mathematician, suggested that the moon was responsible for tides, in 1609, basing his beliefs on ancient ideas.
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In 1632 Galileo Galilei provided his own explanation for tides but he was incorrect. He suggested that the tides were caused by the earth moving around the sun.
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Isaac Newton was the first to explain tides with gravity related to the sun, earth, and moon.
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The moon's gravitational force is only one tenth-million of the earth's gravitational force. But other factors such as the earth's spin and resulting centrifugal force, contribute to tides.
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Despite the moon's gravitational force being so much less than the earth's gravitational force, it is the most important factor in the creation of tides on earth. This is because the sun's gravitational force is even less than the moon's gravitational force (at only 46% of the moon's force).
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Tides are caused because the moon's gravity is pulling the water up, while the earth's gravity is pulling the water down.
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Maximal tides are caused when the moon, earth, and sun are aligned as the sun's gravitational force adds to the moon's gravitational force at these times.
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In the deepest parts of the ocean, away from shorelines, tides are usually only different by 1.6 feet or less.
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The world's highest tides can be found in Canada at the Bay of Fundy in the province of Nova Scotia.
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Gravitational force responsible for tides is referred to as 'tractive force'.
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In most places in the oceans there are two low tides and two high tides each day, but some places only have one.
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Spring tides (larger tides) happen when the new moon and full moon phase is occurring. When this happens the moon is on the same side of the earth as the sun.
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Neap tides (weaker tides) happen when the moon is in its first quarter or last quarter phase. When this happens the moon is at a right angle to the earth-sun line.
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