Using a little knowledge of angles, one can approximate the radius of the earth. The experiment involves looking at either the sunset twice. This is while lying down and when standing. There is a lapse in time that the sun takes to disappear from the eyes of the experimenter. This is the time it takes to in the experimenter, to transfer his angular displacement.
About earth’s mass, it is measurable upon understanding of the attraction forces that exist between two bodies, and the relationship between the stars, and their radius is obtainable experimentally (Universe today 2010).
The experiment team first found an unblocked sunset. While lying down facing the sunset, a partner measured the height of my eyes from the ground. The moment the top of the sun disappeared from the horizon, the stopwatch was started. At the same time, one partner stood up. As expected, the sun was visible again. A partner again measured the height below my eyes while standing. As soon as the sun disappeared again, the stopwatch was stopped.
The difference in height of the eyes while lying down and standing up represents the displacement height. The difference in the time between the sun’s appearance and disappearances is a representation of the angle of displacement of the sun. Taking the cosine of angular displacement and multiplying it with the height displacement gives an approximate value of the radius of the sun. This is to be 6871 (Physicsclassroom nd).
Upon obtaining the value of earth’s radius, Newton’s rule is applicable since radius is a component of the mass equation. The value of G is already obtained through experiments based Cavendish’s experiment.
However, this value is not accurate due to the lapse in time between starting and stopping the stopwatch. There was also a probable error in using the meter rule to take height measurements.
Using the knowledge of angular displacement, the radius of the earth is found to be 6871 KM. The objective of the experiment was achieved. This was an 8% error compared to the theoretical value of 6378 Km. The error was due to the problems in timing.
The earth’s mass amounted to, m = 5.546 × 1024 kg with a discrepancy from the standard of m = 5.96 × 1024 kg resulting from the error in computation. The difference arises due to a standard error that is inherent in the determination of the value of g. It is imperative to note that the force between two bodies that a human being can measure is relatively small; this makes accurate determination of g a challenge (Glenn 2002).
The experiment also found out that the radius of the stars is a key component in obtaining their masses and by application of the knowledge of relative density, the weight of earth and its distance from a star would assist in computation.