From Einstein’s special theory of relativity we come to know that matter and energy are equivalent. Matter is concentrated energy and energy is diluted matter. Again from GTR we come to know that space, time and matter are so interlinked that there cannot be any space and time without matter. Similarly there cannot be any matter without space and time. So we see that all these four are interlinked; we cannot think of any one of these four entities singularly, isolatedly. Whenever we will think of energy, we will have to think of matter.