Earth’s Rotation vs Revolution
Rotation of the earth describes the spinning of the earth around its axis, resulting in the 24 hour phenomenon of day and night over the earth. Revolution on the other hand describes the movement of the earth around the sun over a period of one year, causing seasons to occur.
Rotation of the earth causes difference in time over countries and continents. The parts of the earth that are in front of the sun experience day, while the part of the earth away from the sun has night. During the course of revolution depending upon which hemisphere of the earth is closer to the sun, and which one is farther, we have summer and winter respectively. When both the hemispheres are equidistant from the sun there is spring or autumn or fall.
The rotation of the earth around its axis follows the west to east path. The path of the earth around the sun during revolution is an ellipse rather than a circle and this is the reason why the earth is closer to the sun sometimes and farther from it other times, thus causing seasonal fluctuations in weather known as seasons.
The impact of rotation on earth goes far beyond causing day and night. It in fact impacts upon the shape of the earth, which is an oblate spheroid, ocean depth and tectonic plate movement. The earth rotates around its axis at approximately 15 angular degrees per hour. For one complete revolution the earth takes 365.25 days in a slightly elliptical orbit, which has the sun at one focal point of the ellipse.
Rotation and revolution are terms often erroneously used interchangeably because they mean the same thing in a literal and literary sense. However in geography and astronomy the two terms have entirely different meanings and connotations. From a practical point of view the implications of the two phenomena are enormous. Getting a fix on the earth’s various time zones, the study of tides and seismic activity: all of these are interlined with the earth’s rotation. The climatic seasons on the other hand depend entirely on revolution and this helps us anticipate and prepare for the changes.
From a school child’s perspective, it is fascinating to discover that because of rotation one can have night in India and daytime in the US at the same instant. They would also find it incredible that while it is the peak of winter in London in the month of December, there would be summer in Cape Town in the same month. In fact most cultural, demographic and ecological differences that abound upon this beautiful planet of ours are directly linked to these two celestial phenomena.
While we go about our daily lives do we ever for an instant imagine that we are hurtling through space perched on a rock that spins around itself, while tracing a path around its sun, which itself is part of vast galaxy of stars, one among millions and millions of other galaxies found in the universe. Truly the mind boggles.
Summary:
1.Rotation of earth takes place on its axis while revolution is its motion around sun.
2.Rotation is completed in 24 hrs while revolution takes 365 days for completion.
3.Due to rotation, there is a difference in the times across nations in the world.