Expert: Tom Whiting - 4/8/2009

Question
QUESTION: by accepting the theory we will also be accepting Big Freeze,Big Rip,Big Crunch and Big Bounce
these are theories i read about concerning the end of the universe which one who you think is more likely to happen and when and is there away to prevent it?
and does the big bang contradict the theory of cycle of destruction and rebirth for the universe?

ANSWER: Hi Hamad,
Well, two of those final destruction methods are now eliminated
with the recent discovery that the spacial expansion is actually
accelerating with time.  That automatically eliminates the Big
Crunch (no contraction and collapse on itself)  and the Big Bounce, which is what (is) was called the "oscillating Universe" theory...ie. alternating destruction by a Big Crunch and
Rebirth by another Big Bang.

So that only leaves two final alternatives;
1. The Big Freeze (stars eventually run out of fuel and energy) as the Universe progresses down toward absolute zero from our current
3 degrees Kelvin temperature.
2. The Big Rip, where the acceleration of expansion becomes so fast
exponentially that first galaxies, then solar systems, then stars,
then even individual molecules and atoms are ripped apart by the
spacial expansion.
And since each of these two scenerio's are hundreds of trillions of
years in the future, it's hard to say now which will be the final one.  And no, I can't visualize anything that mortals could do about
it....perhaps a very advanced society could delay the inevitable
by producing a "closed system" around their individual Solar System
if a heat death occurs, but even the closed system would only be
a temporary measure. Eventually even a "closed system" star would
run out of hydrogen fuel.  And I see no way anyone could stop the
accelerating spacial expansion.  But that's all trillions of years
in the future.  (But it just proves the statement that 'nothing'
is forever, not even our own Universe.)

On thing humans CAN do much much sooner is to extend the Earth's life
around the sun, as the sun starts to go into it's red giant stage
in about 2-3 billion years.  We can move the Earth outward a few
more million miles away from the sun to give the planet an extra half
billion years or so of habitable conditions.  By causing an asteroid, say 100 miles wide, to pass just barely in front of the Earth maybe once every 500 years, over a period of tens of thousands of years... the small gravitational nudging will raise the Earth's orbit to a higher (farther) orbit around the sun and give the planet more time as the sun slowly swells into it's red giant stage. Of course, due to the fear of collision, an advanced society would really have to know exactly how to do it, and know exactly what they are doing as there is no room for error.  You want to affect the Earth's orbit, but not collide with it.  I would assume that a few
million years from now, our descendants will be smart enough and
technologically advanced enough, to pull that trick off successfully.
Clear Skies,
Tom Whiting

---------- FOLLOW-UP ----------

QUESTION: you left the other part of the question which is that if one of these events where to occur is there achance for another bang? and if so will it be an identical universe to ours?

Answer
Hi Hamad,
You cannot have another "Big Bang" inside an original Big Bang....
if that is what you are thinking, because we cannot re-create
the Perfect Void required for the large random quantum
fluctuation to occur...

We can create a pretty good vacuum, maybe even a perfect vacuum
someday with zero molecules inside, but we can't stop the millions
of neutrinos (that pass thru our bodies every second, unaffected)  and gravitons and whatever the dark energy component is that we know exists in all space. So it's impossible to create a perfect 'nothing' that existed before the Big Bang, and is probably
a pre-existing requirement for another Big Bang.

If there are other Universes created beyond our Universe, the odds
are that they are not identical to ours. Science can envision
other theoretical universes existing with different number values; ...different Gravitational constant, different values of charges and weights of the various atomic particles, different Planck Constant, different light speed value, etc.
Universes where perhaps matter can't even form up. Turns out that our current Universe is very finely tuned values where a very small
change to even one constant, and we might not even be here.
Whether that was the result of God's work, or just by a lucky random chance in our particular Universe, who knows?
Clear Skies,
Tom