Why are there two tides a day? - Elise Cutts
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In the 17th century, Isaac Newton offered the first gravitational explanation of tides. As he correctly identified, tides are choreographed by the motions of celestial objects, and Earth’s tides in particular are mostly driven by the Moon. But the precise nature of this relationship is actually quite nuanced. Elise Cutts explains how the Sun and Moon are responsible for the tides.
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Tidal bores occur all over the world, and impact not just ancient battles but life and agriculture in the present day. The classic example occurs in Zhejiang province in China on the Qiantang River. The tides reach their greatest height between the fifteenth and eighteenth day of the eighth lunar month, and reach about 29 feet tall, earning the river the local nickname of the "Silver Dragon."
Newton was one of the philosophers to work on the problem of gravity, but he and Descartes, Kepler, and Einstein all followed in the footsteps of ancient philosophers like Pytheas and the Venerable Bede of Jarrow Abbey, who made observations about the tides relationship with the moon in their own day.
The tides are impacted by both the moon and the sun, and the highest and strongest tides are created by a new moon or a full moon, also known as perigee, when the sun, moon and Earth are in alignment. When the sun and moon are at right angles to each other, the solar tide lessens the lunar tide's effect and produces what are called neap tides.
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Meet The Creators
- Educator
- Elise Cutts
- Director
- Rémi Cans, Atypicalist
- Narrator
- Alexandra Panzer
- Storyboard Artist
- Marie Zivec, Haimeric Pays
- Animator
- Marie Zivec, Haimeric Pays
