Article Series 3. Continuation of Gravitational Bending of Light and a sequel to Quantum Mechanics of Light.
Mass-Energy Equivalence
This principle revolutionized physics over a century, But unfortunately people now are still unaware of this beautiful equation. The Equation,
signifies that anything that has mass has an energy associated with itself. And the speed of light is a proportionality constant that helps us to calculate their energies.
Special Relativity was the basis for formulating this equation. Even though there are many mathematical foundations to understand this better, I will try to explain it in the simplest language.
According to Einstein, if we travel faster, the heavier we get. This might seem impossible, but it is true and it is happening everywhere. A family traveling in their car, puts on more weight while traveling.
If you haven't inferred it yet, then I would explain it in simple terms. Firstly, what do you need to move a ball from one place to another? Most people will say 'Work'. And they are correct, but what is work? By definition, Energy is the ability to do work. No Energy no work. By way of example, if you kick they ball by giving a specific amount of force, the force given by to the ball, is a direct way of passing your energy to the ball. Now assume that it is an isolated system, and there is no friction. The energy passed on to the ball is its kinetic energy. Since this ball has its own kinetic energy now, it will travel in a straight line forever. Now that Einstein has showed us the relation ship b/w Energy and mass we can understand that this ball's mass should be increased since energy level is raised. Ergo, velocity and mass are also related. This is why the faster you travel, the heavier you get.
Unfortunately, this is the reason why nothing can travel faster than light. Mathematically speaking, if you reach the speed of light, your mass will tend to infinity and you will need infinite amount of energy to keep pushing you to keep you at that particular speed. Therefore, anything that mass is incapable of achieving the speed of light.
You see, that is also the solution of how photons that are mass-less particles are capable of traveling at the speed of light.
Energy of photons
According to Mass-Energy Equivalence, photons who are mass-less are supposed to be energy less. But they aren't and you know it, because you know that plants get their energy from sun's light. If photons do have energy, then does that mean Einstein's equations are wrong? Certainly not.
Quantum Physics gives us the solution for this question. It says that light is an electromagnetic wave that is a form of energy. And its Energy is dependent on its frequency not with mass.
This is one of the famous equations in Quantum physics, in fact this too was formulated by Einstein. He found this relationship when he was working on photoelectric effect. He used Planck's idea. The 'h' in the equations stands for Planck's constant which is a physical quantity that is extremely small and is used mostly in the field of Quantum Mechanics, since it deals with microscopic things.
Deriving the Energy of a photon from Mass-Energy Equivalence.
Mass-Energy Equivalence
This principle revolutionized physics over a century, But unfortunately people now are still unaware of this beautiful equation. The Equation,
signifies that anything that has mass has an energy associated with itself. And the speed of light is a proportionality constant that helps us to calculate their energies.
Special Relativity was the basis for formulating this equation. Even though there are many mathematical foundations to understand this better, I will try to explain it in the simplest language.
According to Einstein, if we travel faster, the heavier we get. This might seem impossible, but it is true and it is happening everywhere. A family traveling in their car, puts on more weight while traveling.
If you haven't inferred it yet, then I would explain it in simple terms. Firstly, what do you need to move a ball from one place to another? Most people will say 'Work'. And they are correct, but what is work? By definition, Energy is the ability to do work. No Energy no work. By way of example, if you kick they ball by giving a specific amount of force, the force given by to the ball, is a direct way of passing your energy to the ball. Now assume that it is an isolated system, and there is no friction. The energy passed on to the ball is its kinetic energy. Since this ball has its own kinetic energy now, it will travel in a straight line forever. Now that Einstein has showed us the relation ship b/w Energy and mass we can understand that this ball's mass should be increased since energy level is raised. Ergo, velocity and mass are also related. This is why the faster you travel, the heavier you get.
Unfortunately, this is the reason why nothing can travel faster than light. Mathematically speaking, if you reach the speed of light, your mass will tend to infinity and you will need infinite amount of energy to keep pushing you to keep you at that particular speed. Therefore, anything that mass is incapable of achieving the speed of light.
You see, that is also the solution of how photons that are mass-less particles are capable of traveling at the speed of light.
Energy of photons
According to Mass-Energy Equivalence, photons who are mass-less are supposed to be energy less. But they aren't and you know it, because you know that plants get their energy from sun's light. If photons do have energy, then does that mean Einstein's equations are wrong? Certainly not.
Quantum Physics gives us the solution for this question. It says that light is an electromagnetic wave that is a form of energy. And its Energy is dependent on its frequency not with mass.
This is one of the famous equations in Quantum physics, in fact this too was formulated by Einstein. He found this relationship when he was working on photoelectric effect. He used Planck's idea. The 'h' in the equations stands for Planck's constant which is a physical quantity that is extremely small and is used mostly in the field of Quantum Mechanics, since it deals with microscopic things.
Deriving the Energy of a photon from Mass-Energy Equivalence.
This video clearly illustrates the notion of Energy of light.
Prerequisites: Introduction to Special Relativity and a bit of elementary mathematics.
Rephrasing the postulate of General Relativity: Anything that has mass, energy/momentum follows the geodesics( Straight line in a curved geometric surface) path of the curvature made by another object.
Prerequisites: Introduction to Special Relativity and a bit of elementary mathematics.
Rephrasing the postulate of General Relativity: Anything that has mass, energy/momentum follows the geodesics( Straight line in a curved geometric surface) path of the curvature made by another object.
Ergo, light is can be bent due to any strong gravitational field. Einstein gave this solution to Arthur Eddington, a famous British astronomer to test this theory. He said the stars behind the sun would be seen some where else due to the bending of light. The Theory of Relativity was confirmed by Eddington in 1919 during a solar eclipse. Eddington observed from the images that light from stars passing close to the Sun was slightly bend, so the stars were out of their positions. This discovery made Einstein popular. And finally Newtons theory of Gravitation was thrown out and General Relativity was its fine replacement.
No comments:
Post a Comment