Science Forums 2

[CraigD]

Originally Posted by jagadish

the big bang states that after expanding the universe contracts to ite initial form i.e dense massof energy

The currently accepted Big Bang theory does not state that the currently observed expansion of the universe will be followed by contraction into a “big crunch” or “big bounce”. These speculative versions of the theory were taken seriously early in its history, ca. the 1930s and 40s, but subsequent observation has decreased the estimated likelihood of their being correct to effectively (but not certainly) zero.

Originally Posted by Jim Colyer

I find it hard to believe that the universe will die. The fact that it came into existence to begin with leads me to feel this way.

One’s understanding of the meaning of the phrase “death of the universe” is aided, I think, by defining it’s metaphorical language in more precise scientific terms, and exploring current scientific thinking of these more precise ideas.

IMHO, a reasonable definition of a “dead universe” is one with no phenomena in it that we would consider alive. We can be very liberal in defining “alive”, including the most simple imaginable biological life, hypothetical non-biological life such as organized collections of magnetically bound plasma in stars, and self maintaining and replicating machines (ie: Von Neumann machines).

All of these “life forms” have in common the need for energy, as they all must do mechanical work to “live”. Effectively, energy in our universe comes in a few forms:

• differences in heat in neighboring volumes of space;
• the conversion of mater to energy via nuclear fusion, which occurs mainly in stars;
• the conversion of mater to energy via nuclear fission, which occurs in decaying radioactive elements

To the best of our scientific understanding, all of these processes will eventually end everywhere in the universe. At that time, no matter how well-adapted or designed it is, no “life form” will have energy available to it to do work, so none will be “alive”, and the universe can reasonable be considered “dead”. This universe will not lack energy altogether, but none of it will be in a form usable via any possible means, and will continue expanding until any given volume of it is empty.

Our present-day theoretical understanding of quantum mechanics offers the possibility that this very distant future “dead universe” will not continue indefinitely. One hypothesis for the creation of our current universe is that it arose from a very improbably “quantum fluctuation” in the “primordial vacuum” that preceded it. (this idea, notably described by physicist Edward P. Tryon as “our Universe is simply one of those things that happens from time to time”, has been discussed in various hypography threads, such as here)

Originally Posted by Jim Colyer

But what is the alternative to faith? No faith? Where does that lead?

On the very long time frames discussed in this post, our best science suggests that the ultimate fate of the universe is unaffected by our having or not having “faith”.

In the short term, I can’t describe the consequences of faith or its lack only with some specific examples. Richard Dawkins’s lack of faith results in him writing and promoting books that describe religious faith as delusional and unhealthy, such as “The God Delusion”. Frank Tippler’s IMHO excess of faith lead him to write what many consider among the silliest works of nonfictional popular physics, such as ”The Physics of Immortality”. I’ve countless personal anecdotal examples of people who describe themselves as having much faith, and people who describe themselves as having none, who all appear about equal in civility, trustworthiness, and social worth.