Elise Cutts: Why are there two tides a day?

Why are there two tides a day?

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. [Directed by Rémi Cans, Atypicalist, narrated by Alexandra Panzer, music by Salil Bhayani, cAMP Studio].

Earth experiences two high tides every day, the result of a delicate dance between the Moon’s gravity and the planet’s rotation. The Moon pulls ocean water toward it, creating a bulge, while the Earth’s motion forms a second bulge on the opposite side. Ancient armies like Alexander the Great’s once faced tidal phenomena such as a tidal bore along the Indus River, centuries before Newton explained the science. The Sun’s gravity, local geography, and even the movement of distant planets all weave together to produce tides that shape our world and others.