Tides are the rising and falling of ocean levels caused by the gravitational pull of the sun and moon combined with the rotation of the earth. When the highest part of the wave reaches a specific location, it is said to be high tide, and when the lowest part of the wave reaches that same location, it is said to be low tide. Depending on the area and its proximity to the moon, tides can occur once or twice per day. A tide cycle consists of the sea level rising until high tide, then falling until low tide. The cycle then begins again.
Seleucus of Seleucia proposed the theory that tides were caused by the moon in 150 BC.
During the 1100s, when Latin translation interpreted the findings of Muslim astronomers, they formed the foundation of the understanding of tides.
Al-Bitruji, an astronomer who challenged the Ptolemaic astronomy system, proposed in the 1100s that the tides were caused by the circulation of the heavens. On the moon, he has a crater named after him.
Simon Stevin, an engineer, physicist, and mathematician, defied many of the prevalent myths about ebb and flood in 1608.
In 1609, Johannes Kepler, an astrologer, astronomer, and mathematician, proposed that tides were caused by the moon, basing his beliefs on ancient ideas.
Galileo Galilei proposed his own explanation for tides in 1632, but he was mistaken. He proposed that tides were caused by the earth’s rotation around the sun.
Isaac Newton was the first to explain tides in terms of gravity and its relationship to the sun, earth, and moon.
The gravitational force of the moon is only one tenth of that of the Earth. However, other factors, such as the earth’s spin and the resulting centrifugal force, play a role in tides.
Despite having a much lower gravitational force than the earth, the moon is the most important factor in the formation of tides on Earth. This is due to the sun’s gravitational force being even less than the moon’s (at only 46% of the moon’s force).
Tides occur as a result of the moon’s gravity pulling water up and the earth’s gravity pulling water down.
When the moon, earth, and sun are aligned, the sun’s gravitational force adds to the moon’s gravitational force, resulting in maximum tides.
Tides are usually only 1.6 feet or less apart in the deepest parts of the ocean, away from shorelines.
The world’s highest tides can be found in Canada, in the province of Nova Scotia, at the Bay of Fundy.
The gravitational force that causes tides is known as ‘tractive force.’
Most places in the oceans have two low tides and two high tides per day, but some only have one.
Spring tides (higher tides) occur during the new and full moon phases. When this occurs, the moon and the sun are on the same side of the earth.
When the moon is in its first or last quarter phase, it causes neap tides (lower tides). When this occurs, the moon is perpendicular to the Earth-Sun line.
Tide FAQs:
1. What are tides?
Tides are the regular rise and fall of the ocean’s surface. They are caused by the gravitational pull of the moon and, to a lesser extent, the sun, on the Earth’s oceans. The moon’s gravity pulls the water towards it, creating a bulge of water on the side of the Earth closest to the moon (high tide). On the opposite side of the Earth, the moon’s gravitational pull is weakest, allowing the water to bulge out in the opposite direction, creating another high tide. Between these high tides, the water level drops, creating low tides. As the Earth rotates on its axis, different locations experience high and low tides throughout the day.
2. How often do tides occur?
Most locations experience two high tides and two low tides each day, with a period of roughly 12 hours and 25 minutes between them. This is called a semi-diurnal tidal regime. However, some places have a diurnal tidal regime with only one high tide and one low tide each day. The exact timing and height of tides vary depending on the location and the relative positions of the moon and sun.
3. Why don’t tides happen exactly every 12 hours?
The moon doesn’t orbit the Earth perfectly every 24 hours. It takes the Earth about 24 hours and 54 minutes to rotate under the same high tide bulge. So, high tides occur about 54 minutes later each day.
4. What are spring tides and neap tides?
The sun also exerts a gravitational pull on the Earth’s oceans, although weaker than the moon’s. When the sun and moon are aligned (during new moon and full moon), their gravitational pulls act together, creating higher high tides and lower low tides, known as spring tides. Conversely, when the sun and moon are at right angles to each other (during first and third quarter moons), their gravitational pulls partially cancel each other out, resulting in smaller differences between high and low tides, called neap tides.
5. Where can I find tide predictions?
There are several resources available online and in tide tables that provide tide predictions for specific locations. These resources consider the gravitational forces of the moon and sun to predict the timing and height of high and low tides.
Here are some examples:
- National Oceanic and Atmospheric Administration (NOAA) Tides & Currents https://tidesandcurrents.noaa.gov/
- Tide-Time https://www.tidetime.org/north-america/united-states/
- US Harbors https://www.usharbors.com/
These resources allow you to search for specific locations and view tide predictions for upcoming days or weeks.
Facts are such an important foundation for knowledge and understanding. They provide us with a solid base upon which to build our opinions and beliefs. In today’s world, where misinformation and fake news are so prevalent, it’s more important than ever to have access to reliable and accurate facts. We must be vigilant in seeking out trustworthy sources and ensuring that the information we consume is backed up by evidence and research. Only by doing so can we make informed decisions and contribute to a more informed and just society. Thank you for highlighting the importance of facts on your blog!