SHUTDOWN NOTICE

Dear Readers,

I would like to thank all of you for the support that you have provided in making World of Physics - a success during its journey. I regret to inform all of you, that the blog is now disabled for further articles. I apologize to all for any inconvenience caused to anyone. I will not be able to write more articles due to time constraint as I am no more a student. Now I am an employee of a MNC. I hope that the articles were useful for you and would have helped you in understanding of physics.

For any suggestions or feedback, please feel free to write: anubhavgupta1989@yahoo.com

With Appreciation,
Anubhav Gupta

Expansion of Universe

The fact that the universe is expanding was established using the Doppler shift of light from different galaxies. Light emitted by star falls in continuous spectrum and as it passes through different stars the continuous spectrum is lost. Edwin Hubble, an American astronomer confirmed the existence of many galaxies other than Milkyway. He concluded that the galaxies are moving away from the earth and farther away the galaxy is from us, more is the speed. This can be established using a three dimensional coordinate system considering that the earth is at origin while the other coordinates represent various galaxies. Since universe is expanding, it is clear that the distance between galaxies and earth is also increasing. This increase is at a constant ratio k for a particular time t. Thus, it is clear that more the distance of the galaxy from earth more is its speed as compared to the galaxy nearby to it. This can be clearly explained by giving a simple example of inflating a football. If we mark different points on the football and inflate it with air, each point will find the other points moving away from it, and farther the point is, greater is the separation.


By: MOLLA RAMIZUR RAHMAN

Gravitational Force

          It all started when a 22 year old boy who returned home from his college discovered most of the understood fundamental of physics while dealing out with the force of attraction between the two bodies. Gravitation has been defined as the force experienced by any two bodies in the universe by virtue of their mass. The gravitational force was first experienced by the great scientist Issac Newton. When an apple fell on his head he realized that the Earth pulls everybody towards itself. Later, he concluded that everybody in the universe attracts each other which he named as gravitational force.