The Theory of General Relativity

The Theory of General Relativity

"The Newtonian Disability"

"General Relativity"

Whenever a person in this universe says that word, the history of modern physics prevails itself. From the starting of the era where human mind wondered the aspects of this elegant universe, few intriguing questions came along. Newton discovered gravity and called it to be a force. for more than two centuries the equations given by him proved to be true. But when our minds started to imagine even higher some difficulties with the Newtonian mechanics came along. These questions were answered by Einstein himself. And when he did, Everything changed!

The problem with Newtonian Theory

 Newton stated gravity to be a force of attraction that acts at a distance. Through his understanding of gravitational force he successfully explained the motion of the moon around the earth and the motion of other planets around the solar system. He said that moon like any free falling body falls towards the earth, but it does not crashes on earth to create a planetary catastrophe because it also moves along the direction of its velocity in the space. Consequently, it moves 38 miles forward and 16 feet towards the earth. 

    

Newtonian Laws explained that light is not affected by the gravity of any mass M. He also stated that the change in Massive M is felt through out the cosmos instantly because of the denudation of that objects gravitational pull. But through SR we know that the speed of light (c) is the cosmic speed limit so no physical entity can exceed this limit. We can imagine this as we are supposed to cross a very fragile and old wood bridge that can diminish instantly. If we cross the bridge cautiously, the bridge will survive but if we cross the bridge at a robust speed the bridge tends to fall. And so does the spacetime. Through SR we know at speed of light the Mass of the object increases beyond our imagination and so does the energy it releases. This results in spacetime Distortion. 

    

      So, how can the change of loosing that mass M can be felt instantly. For example, light from the sun takes 8 minutes to reach us so, how can impact of loosing the sun can be felt instantly. This mystery was solved by Einstein through his theory of General Relativity. 

  

Introduction to theory in next post!

Relativity

Relativity

Part-2  

Generation of New Frame of reference

     A reference Frame can be defined as an observational perspective that is used to study any event or happening in physical world, every theory that relates with motion or kinematics and even electromagnetism may compulsorily require the reference frame. And so does theory of special relativity. The difference which one can comprehend in this particular theory is the removal of Galilean reference frames or the inertial reference frames that are used in Newtonian physics by non-inertial reference frames. 

Aether

      This was sort of a problem,the problem arose when physicist studied the principle of relativity which states that their is nothing as preferred inertial frame but we know that the concept of 'Aether'

was developed after the discovery of electromagnetic waves in the early late 19th century. This concept stated that the space is filled with an unknown material that is called aether which acts as medium for propagation of electromagnetic waves, but the properties of the aether were considered absurd and the concept fell due to results of Michelson- Morley experiment.

       With the decline, the concept of absolute reference frame that supported every thing that scientist had discovered about electromagnetic propagation also fell. At last Einstein was the one that provided the true solution to this problem by dissolving the concept of absoluteness and aether by relativity.

These are the new frames where the non-primed frame is at rest and the
 primed one is moving relative to that of the rest one

  Einstein used non-inertial relative reference frames and solved the problem, the concepts of Lorentz transformation were also used to connect the two reference frames relative to each other. Acceleration, velocity distance and time were hence proved relative in the two relative frames of reference.  

                 

            

Relativity

Relativity 

Part - 1 

The theory of relativity was given by Albert Einstein which comprises of two theories The Theory of Special Relativity and The Theory of General Relativity in this specific post I will discuss about Special Relativity

The Theory Of Special Relativity

The theory Of Special Relativity deals with the space time structure, laws of propagation of light and other aspects that are considered the foundations of modern physics the theory  states that-

• The laws of physics are same for the observers in uniform motion relative to one another.
• The speed of light in vacuum is same for all observers.
• Relative mass theory
• Time dilatation
•  Length contraction
•  Mass energy Equivalence
• Finite of speed of light 
• Relativity of simultaneity

 Special Principle of Relativity- If a system of coordinates K is chosen so that laws of physics in relation to it hold good in their simplest form and they hold good in relation to any other system of coordinates K' moving in uniform translation relative to K.

The theory has two postulates as suggested by Einstein-

The principle of Relativity- The laws of physics do not change whether in two frames moving relative to each other

Invariant Light Speed- The speed of light i n vacuum or c never changes and is independent from state of motion and relative frames.