everytime we talk about the cosmos, what we believe now is the only truth, because the cosmos as we see changes all the time - not the cosmos itself, but the way we explain and understand them. the latest that i have studied (please correct me if i am wrong due to my limited knowledge) is about the M-theory, where everything is made of tiny strings (so tiny that there isn't any microscope or experiment to see or detect it), however the strings can be so long that it can be longer than any galaxies. the reason why many neo-physicists are attracted to this new concept these days is because, it can predict many things that are happening in the cosmos. for example, relativity can explain large bodies but not the small ones, becuase relativity rely heavily on constants and vector, however the quantum mechanics explains all the small particles and always have unpredictable results. these two theories can explain everything that we see and know about how and why about the universe is based on 4 forces of nature. but these 4 forces are easily explained by the two theories. So, what physicists think (only think because we don't know), is that if these two theories are united, we will can find a thoery/formula to find the state of universe in the beginning and in the end. so, we will have all our answers. remember, are we alone is not important - due to the fact that there are so many (we don't know how many) galaxies and systems in the sky/universe that there are. with string theory we can predict other dimensions besides the known 4 dimensions. now, when we live in this dimension, there is no way we can see what is happening(at least with these physical eyes) in the 5th, 6th or... 11th. To prove this, there is an experiment being conducted. What they are doing is, creating the scenario of a big bang. the hypothesis is, during big bang (of the many big bangs that happens all the time some where), some subatomic parties when gets hit at the speed of light, it takes a different form and so, will escape to a different dimension. we don't know when the results are coming in, but when some mass is accelerated at the speed of light, but disappears before it reaches the destination, we can deduct that the loss of mass is due to the escape into a different dimension, which will prove the existence of the extra dimension. now coming back to the vedic lieteratures, which predicted all these about 5 thousand years ago. the dwellers in the extra dimension are god(s) - remember small 'g'. so, to have a sight in these dimension, one must have a "divya dristi". now regarding the beginning and end - since the end is the beginning, we do not have to worry about the beginning or the end, becuase it is eternal. we call this Kali - the ultimate reality. to realize Kali, one must become Shiva - the pure one. To realize Shiva one must understand the Veda - the knowledge - and cannot ignore Narayana - the present. When all these are too confusing, we become happy by seeking refuge in the concept of the "Creator".