Try to imagine, if you will, an universe that has no beginning in time and no end in time. Its state is said to be steady. But that is impossible to imagine, is it not, impossible to reconcile with our current concept of time. There is no forever in the past or in the future, time must have a stop.
So now try to imagine an universe that began all of a sudden, in a great big soundless "bang," emerging out of . . . nothing. But that too is impossible to imagine, impossible to reconcile with our concept of time. We cannot possibly escape the question "what happened before that?" And similarly if we try to imagine an universe that peters out into nothing at all, we ask "and then, after that?"
Even to imagine the world continuing after one's own expiry is difficult. Will it be real? Will we ever somehow find out what happens in 2100, 2800, and 20000?
Anyway, the point of all this is that our concept of time is faulty. As shewn above, it cannot be infinite, and it cannot be finite. So we had better start all over again and reinvent a better time had we not? Let's not make it a dimension at all this time round!
We cannot but agree, Sydney Grew! Time may be ultimately an illusion! As you read this sentence, you probably think that this moment—right now—is what is happening. The present moment feels special. It is real. However much you may remember the past or anticipate the future, you live in the present. Of course, the moment during which you read that sentence is no longer happening. This one is.
In other words, it feels as though time flows, in the sense that the present is constantly updating itself. We have a deep intuition that the future is open until it becomes present and that the past is fixed. As time flows, this structure of fixed past, immediate present and open future gets carried forward in time. This structure is built into our language, thought and behaviour.
Yet as natural as this way of thinking is, you will not find it reflected in science at all. The equations of physics do not tell us which events are occurring right now—they are like a map without the “you are here” symbol. The present moment does not exist in them, and therefore neither does the flow of time. Additionally, Albert Einstein’s theories of relativity suggest not only that there is no single special present but also that all moments are equally real.