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. Whenever we will think of matter, we will have to think of space and time. But what is the reason that these four entities are so interlinked? If they have all originated from nothing, then what was there in nothing that could have helped establish this link, this binding in between them? The answer is: Nothing. In nothing there was nothing that could have been the cause of it. So we cannot claim that space, time, matter and energy have actually originated from nothing, because in that case there would not have grown the binding in between them that has been empirically tested and verified many, many times. Rather we should say that all these four have originated from some common source, from some common substance. Metaphorically we can say here that they have some common ancestor. Due to this common ancestry, all these four are actually kith and kin (also a metaphor, not to be taken literally). Due to their common ancestry, they are all naturally related to each other.
This common substance has expressed itself in four different forms, e.g. space, time, matter and energy, but basically at their root all these four are one. Scientists have so far been able to show that only matter and energy are one. We hope that in future a day will definitely come when they will be able to show that space, time, matter and energy – all these four are one.