Gravity

Gravity, the enemy of mankind, the undefeatable force the keeps us from flying and drops apple upon our heads. As everyone 2nd grade and up up should gravity is pulling force that all objects, particularly big ones, exert on each other. So, lets jump into some questions and answers what is it, why is it, and how it is used.

Gravity can be imagined as two metal balls that are laid on a circular spandex sheet. The first ball is slightly larger than the second, when it is placed anywhere on the sheet it will “gravitate” to the center. When the second ball is placed it will started to fall down till it next to the first larger ball. If you then placed another ball larger than the other two, it would replace the first and come to rest in the center of the sheet. On earth the gravity is 9.81m/s which terminal velocity the fastest an object can free fall. But on smaller objects than earth gravity is much lower. For example on the moon terminal velocity on the moon is only 1.625 m/s. Along with falling gravity also cause weight. Interestingly enough weight all depends all depends on gravity, if you took a scale and weighed a 25 pound barbell it would weigh 25 pounds but on a dwarf planet it might only weigh eight pounds.

So now that “the what” is covered, lets go over the why. Why gravity exist has not yet been discovered by scientists, however it is common knowledge that it does exist. If you don’t believe it exists perform this simple task, take a penny hold it three feet above ground, then release the penny if it falls then gravity exists. One theory that could explain gravity, is the theory of relativity. The theory of relativity states that gravity is more than a force, it’s a curvature in the space time continuum. This would look a lot like the ball a sheet example, where the sheet is the time space continuum and the ball is an object in space. One way we could see curvature in space is by looking at a phenomenon called gravitational lensing. In large objects in space, such as galaxy clusters, a straight beam of light will hit it and seem to bend around it.

Although gravity does keep humans from flying it has played a big role in our existence for millenia. The first hunting traps humans set where mainly falling rock drops or snares. Both of the traps depend on gravity to work. Along with hunting gravity powered many of the machines humans used to build and create goods. For example mills, the machine that built the early American economy. Mills rely on falling water to turn a wheel and gears which means to an extent it is powered by gravity. Another machine that gravity powers is the inclined plane, the first simple machine. Because of these and many other reasons gravity is one of the most important forces of nature.