Tides
The moon's gravitational force pulls on water in the oceans so that there are "bulges" in the ocean on both sides of the planet. The moon pulls water toward it, and this causes the bulge toward the moon. The bulge on the side of the Earth opposite the moon is caused by the moon "pulling the Earth away" from the water on that side. The Moon affects tides on Earth through gravity.
The Sun also affects Earth's tides, but not as much due to its greater distance from the Earth. It's not the simple force of attraction that makes the tides, but the difference in the attractive force on the opposite sides of the Earth. Since gravity lowers by the square of the distance between two objects, some math will show you how the effect works. The 8000 mile diameter of the Earth is more notable when compared to the 250,000 mile distance to the moon than it is to the 93,000,000 miles to the sun.
If you are on the coast and the moon is directly overhead, you should experience a high tide. If the moon is directly overhead on the opposite side of the planet, you should also experience a high tide.
During the day, the Earth rotates 180 degrees in 12 hours. The moon, meanwhile, rotates 6 degrees around the earth in 12 hours. The twin bulges and the moon's rotation mean that any given coastal city experiences a high tide every 12 hours and 25 minutes or so.
A spring tide is the exceptionally high and low tides that occur at the time of the new moon or the full moon when the sun, moon, and earth are approximately aligned. A neap tide is a tide that occurs when the difference between high and low tide is least; the lowest level of high tide. Neap tide comes twice a month, in the first and third quarters of the moon.
The Sun also affects Earth's tides, but not as much due to its greater distance from the Earth. It's not the simple force of attraction that makes the tides, but the difference in the attractive force on the opposite sides of the Earth. Since gravity lowers by the square of the distance between two objects, some math will show you how the effect works. The 8000 mile diameter of the Earth is more notable when compared to the 250,000 mile distance to the moon than it is to the 93,000,000 miles to the sun.
If you are on the coast and the moon is directly overhead, you should experience a high tide. If the moon is directly overhead on the opposite side of the planet, you should also experience a high tide.
During the day, the Earth rotates 180 degrees in 12 hours. The moon, meanwhile, rotates 6 degrees around the earth in 12 hours. The twin bulges and the moon's rotation mean that any given coastal city experiences a high tide every 12 hours and 25 minutes or so.
A spring tide is the exceptionally high and low tides that occur at the time of the new moon or the full moon when the sun, moon, and earth are approximately aligned. A neap tide is a tide that occurs when the difference between high and low tide is least; the lowest level of high tide. Neap tide comes twice a month, in the first and third quarters of the moon.