The unique Personality of Light

How much do you think you know about light? I presume you know that it has a finite speed of about 3x108ms-1 and that it travels in forms of waves like that of ripples in water. I suppose you know that its speed is the highest in the universe and nothing in the universe travels faster than it. You may also know that it travels in a straight path. But is that all? Do your limit of curiosity and the chain of questions end here? Are you satisfied with what you know? I bet not.

Light as we knew or assumed to know is not exactly the way we suppose it to be. Most of the things that are in our knowledge about the behavior of light are almost incomplete and to some extent untrue. Physics is weird and full of surprises. Though you think it is over, it never stops amusing you with novel surprises.

The first thing to know about light is that it is wave. It is true as we know it since we started the flight of physics. But it is not the whole legitimacy. Light, not only travels as waves, but it also travels as particle. It has a wave-particle duality. Light is composed of several component rays consisting of microwave, infra wave, gamma rays and visible light and they all exhibit similar characteristics. In the Rutherford’s α-scattering experiment, the unusual behavior depicted by Geiger counter is the proof of the particle nature of light. The photoelectric effect that Einstein led to success is also a remarkable triumph in the world of physics that accounts for the particulate behavior of light.
 

Now we know that light also behaves as particle, it leaves space for further questions as "How it behaves inside a gravitational field?" And I say “Without any doubt”. To search for the facts, it has been proved in 1919 by a British Expedition while observing an eclipse on account for the confirmation of one of the prediction of Einstein's theory of relativity. The theory was that around large masses the space would be curved and so would the path of the particle passing near it. In Short, gravity would affect the course of travel of a particle. In fact it was proved right when the star behind the sun had slightly changed as predicted by the theory of relativity. So, light does not ALWAYS travels in a straight path. It follows the curves of Geodesics.

Bending Of light in a Gravitational field

   

Similarly, another astounding personality of light is its speed. It is the fastest in the universe that we have till now in our knowledge. Nothing except light itself exceeds its speed. But what if someone travels at nearly the speed of light; will they seem like quantum of molecule? It seems logical that we may see the packet of molecules but it is just the opposite. No matter how fast an observer is and he’ll always see the light in its full speed irrespectively. No matter how fast one travels he can never outrun the speed of light. Wonder how?...Wait for the next one!

Speed of LIGHT 300000000 m/s