Universe... and the mind

At times I sit all alone in my balcony during the wee hours at night gazing at the sky, looking at the Big Dipper , which is called the Saptha Rishi mandal in Sanskrit, and gazing at billions of stars remembering my child hood poem on the twinkling stars and forgetting the time.

There always remains an intriguing question which science and philosophy find it very difficult to answer. "What is reality?"

 Is what we as humans 'see' be proclaimed as reality? Are the billions or trillions of stars whose light infact has left them millions of years ago be perceived as reality?

If there was no evolution, would the planets or even matter would have ever existed - as what we see are the by products of our well developed conscious minds?

Science states that such questions are invalid. The so called consciousness is not a valid concept as per science. 

And then comes the concept of time.  Wikipedia defines time as follows:

Time is a measure in which events can be ordered from the past through the present into the future, and also the measure of durations of events and the intervals between them.^{[1][2][3][4][5][6][7]} Time is often referred to as the fourth dimension, along with the three spatial dimensions.^[8]

As per the definition there are three key elements: past present and future. But what exactly is "past", "present" and future and more specifically "present"


                                                                                                                                    --Continued.....