Introduction
The force that holds the Universe together has been a challenging notion to discover. However, throughout time, the inquisitive nature of human beings made it possible to establish a clear concept of such a fundamental force as gravitation. From Aristotle to Einstein, various scientists and philosophers have contributed to this discovery, and what humankind has discovered can be mind-boggling when considering its immensity (Jones, 2019). Even nowadays, there are new facts about gravity that are left undiscovered in full, such as the appearance and physics behind black holes and their force of gravity (Berry, 2017). As with many other scientific discoveries, the clear and concise definition of gravity has allowed humankind to make significant technological progress and continues to play a crucial role in many fields of physics. The topic of this term paper is gravitation, its definition, the history of its discovery, how it scales within the Universe, and why it remains not yet fully understood.
History and Definition of Gravity
The definition of gravity went through different stages that made it gradually more accurate. People knew about the force that pulls the falling objects towards the Earth since the beginning of times, although the first attempt to provide a comprehensive explanation of this phenomenon was given by Aristotle (Jones, 2019). Since the Earth was viewed as the center of the Universe with three natural realms of elements above it, his definition focused on the belief that the objects were moving towards their “natural place” (Jones, 2019). This theory stood for many centuries until European scientists began to question its validity.
The next major step in defining gravity was made by Sir Isaac Newton. Newton has discovered that gravity extends well beyond the Earth, as the Moon holds a significant influence over the events of the other. Newton (as cited in “Newton’s law of universal gravitation formula,” 2019) stated that everybody in the Universe affects all others “with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.” He then created the formula that is now known as Newton’s law of universal gravitation (Figure 1). As humanity’s knowledge of the Universe continued to grow, difficulties in the application of Newtonian mechanics started to appear (Berry, 2017). This led to the creation of a more complex and advanced definition made by another great scientist.
The theory made many scientists puzzle themselves with redefining motion, and this was not the last discovery regarding the subject. Einstein, who made another major breakthrough in the definition of gravitation, began by establishing a postulate to define motion: the speed of light in a vacuum is always the same (Berry, 2017). Einstein’s general theory of relativity provides the best definition for the subject. He discovered that every object has a gravitational field that affects the movement of everything within it towards the direction of the object (Berry, 2017). This addition helped the scientists to reimagine many other concepts in physics. Along with Newton’s law of gravitation, Einstein’s field equations provide the most accurate take on this force.
Despite this seemingly well-defined vision of gravity, some issues with its nature remain. For example, Jones (2019) states that “general relativity is incompatible with the understanding of quantum physics.” As new technologies for cosmic exploration and studies continue to appear, new notions had to be introduced to deal with this issue. For example, dark energy and dark matter came into being as ideas that can fill the void of the newly discovered gravity-related concepts (Jones, 2019). Theories such as the theory of strings are the next step on the path of defining gravity in the correct way (Jones, 2019). Since there are no modern theories that have been proven with substantial evidence, the topic continues to attract the attention of the most inquisitive people.
The Scale of Gravitational Forces
People always experience this force, and a human body is well adapted for a standard Earth gravity. Berry (2017) provides an example, that “if the Sun were a watermelon in Piccadilly Circus, the Earth would be a grape pip a hundred metres away” (p. 3). Berry states that “our imagination rapidly loses its grip on such models” (p. 3). Comparisons such as these can make gravity challenging to understand, especially when considering its effect on a cosmic scale. However, as has been stated before, everybody affects all others, and even in this example, there is a connection, however insignificant it is.
Gravity can be especially difficult to understand when examining Einstein’s concept of spacetime. As has been discovered, gravitational pulls of a significant force bend the space around them, which can be observed in the light of distant stars that is bent by other stellar bodies as it travels through space (Berry, 2017). Black holes and other newly discovered space objects lead to another number of misleading notions due to their odd interaction with other stellar bodies (Berry, 2017). Overall, the scale of gravitational forces in Newton’s laws only works within a frame of reference where the absolute space exists (Berry, 2017). As long as humanity is unable to interact or observe such anomalies directly, the accurate scale of gravity will remain to be defined in full.
Conclusion
In conclusion, the force of gravity is what connects all bodies in the Universe with each other through the fields exerted by all objects. It is a complex force that can be defined within the existing frame of reference yet becomes less understood when applied to the Universe as a whole. Gravitation may seem to be easy to explain in the Earth’s environment, as everything is accustomed to its constant presence, yet it is one of the most challenging topics for researchers.
Gravity lies in the foundation of many other concepts in physics, both on paper and in real life. Berry (2017) states that “gravity is the weakest force in physics,” which is why it is often left unaccounted for in atomic and nuclear physics (p. 24). Despite this notion, it does not make gravitation meaningless, as it remains a cornerstone of humanity’s understanding of the existence of space and time.
While there are other difficulties with establishing a clear picture regarding this fundamental force due to the new discoveries regarding the physics of the Universe, gravity is one of the most well-examined topics. This is the direct result of the theorizing and experimentation by numerous scientific minds throughout the entire history of humankind. Gravity still holds many secrets which are yet to be discovered by humans as they continue their exploration of space and seek answers to the very nature of the Universe.
References
Berry, M. V. (2017). Principles of cosmology and gravitation. Routledge.
Jones, A. Z. (2019). The history of gravity. ThoughtCo. Web.
Newton’s law of universal gravitation formula. (2019). PhysicsAbout. Web.