[Pramod Desai]

Dear MJA and Neutrallino

Thanks for taking the pain to respond.

If we do not know in what condition and how much of what is seen today is really there today, what is the basis of our calculations? Is it based on the old elementary principle learnt in school about conservation of mass and energy? Which means even if what we see toady is non-existent in the same form as of today, it is still there in some form. Kindly guide. I am trying to inculcate a wonder in the minds of young children about the universe and want to be armed with some basic elemenatry knowldege.

Thanks in advance and regards.

Pramod