What Causes Tides?

Gravity is one major force that creates tides. In 1687, Sir Isaac Newton explained that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth (Sumich, J.L., 1996).Tidal forces are based on the gravitational attractive force. With regard to tidal forces on the Earth, the distance between two objects usually is more critical than their masses. Tidal generating forces vary inversely as the cube of the distance from the tide generating object. Gravitational attractive forces only vary inversely to the square of the distance between the objects (Thurman, H.V., 1994). The effect of distance on tidal forces is seen in the relationship between the sun, the moon, and the Earths waters.

High tide is when the moon pulls the water up further onto the beach creating less sand space.Low tide is when the moon pulls the sea out further creating more sand space.

What causes the seasons?

The seasons are caused by the tilt of the Earth's rotational axis away or toward the sun as it travels through its year-long path around the sun.

The Earth has a tilt of 23.5 degrees relative to the "ecliptic plane" (the imaginary surface formed by it's almost-cicular path around the sun). The tilt toward the sun is maximized during Northern Hemisphere summer in late June (the "summer solstice"). At this time, the amount of sunlight reaching the Northern Hemisphere is at a maximum.

In thespring, seeds take root and vegetation begins to grow. The weather is warmer, and often wetter. Animals wake or return from warmer climates, often with newborns. Melting snow from the previous season, along with increased rainfall, can cause flooding along waterways. [Related:6 Signs Spring Has Sprung]In thesummer, temperatures may increase to their hottest of the year. If they spike too high, heat waves or droughts may cause trouble for people, animals, and plants. Rainfall may increase in some areas. Others may receive less water, and forest fires may become more frequent. [Gallery: Stunning Summer Solstice Photos]In theautumn, or fall, temperatures cool again. Plants may begin to grow dormant. Animals might prepare themselves for the upcoming cold weather, storing food or traveling to warmer regions. Various cultures have celebrated bountiful harvests with annual festivals. [Gallery: A Rainbow of Fall Leaves]Winteroften brings a chill. Some areas may experience snow or ice, while others see only cold rain. Animals find ways to warm themselves, and may have changed their appearance to adapt. [Gallery: Images of Stunning Snowy Landscapes]Location, location, locationThe timing and characteristics of the seasons depends upon the location on Earth. Regions near the equator experience fairly constanttemperaturesthroughout the year, with balmy winters barely discernable from warm summers.But for areas to the north and south, the seasons can change more significantly. People closer to the poles might experience icier, more frigid winters, while those closer to the equator might suffer hotter summers. Other factors can also affect the weather and temperature over the seasons; some areas experience dry summers as temperatures spike, while others might call summer their "wet season," experiencing higher than average rainfall. Mountainous regions might experience more snowfall than plains within the same latitude, while oceanfront property could see an increase in violent tropical storms as the weather shifts.The time of year a region experiences a season depends on whether it is in the northern or southern hemisphere. The Southern Hemisphere experiences winter while its northern neighbors chart summer; the north sees the slow blossom of spring while the south brings in the autumn harvest.