Expert: Tom Whiting - 3/25/2011

Question
When is the earliest possible 'date' for the death of the universe?

Will We be able to do interstellar space travel?

Answer
Hi Andre,
Several caveats here...
1. Could you define Universes' "death" for me?; some feel that there is no death in the fact that stars get ripped into molecules, then molecules get ripped into atoms, then atoms get ripped into individual protons, neutrons, and electrons, then those get ripped into quarks, and on and on... etc etc.  But not all objects at the same "time"... see #2 below.

2. And then you'll have to define 'date' or more specifically the 'time' for me.  If we pick a date and time for the Solar System, say noon GMT on January 1, 2020, then the date on Alpha Centauri at that instant (nearest star at 4.3 light years) is noon on September of 2015, 4.3 years earlier, on our Gregorian Calendar. It's about 520 AD out on Rigel and the Orion Complex (1500 ly distant), 100,000 years earlier on the other side of the Milky Way, and nearly 3 million years earlier at the Andromeda Galaxy, and on and on at still earlier times in the most distant galaxies right now.  Time, and therefore dates, are not a constant.  Depends on where you're at, and when.

But if you want to disregard all that "factual" nonsense stuff and just 'pretend' instead...
1. The Universe could end today. How? Say the Universe is nothing more than a super-super-super computer designed "simulation"  (nearly 14 billion years old) run by a higher Being (say, God) and He decides to hit the delete key right now, or re-boot the computer. Goodbye Universe right now.

2. Space is expanding, and actually accelerating it's expansion (we know that now) so eventually the older stars and galaxies will begin to suffer from a "Big Rip" in several trillions of years from now (as described in # 1 above).  But if the acceleration is itself accelerating (we're working on that one now) then the life of the current Universe shrinks to about 30 billion more years (a far smaller time frame than the current acceleration staying constant).
3. Heat death (all the hydrogen fuel is used up by the stars) but this also requires trillions of years to happen, as the current 3 degree K. background falls to near absolute zero.
4. (Notice that with an ever accelerating expansion, there is no Big Crunch coming together... that ending has been discontinued and eliminated... can't happen.)
5. If you are just thinking of the Solar System, then our sun begins to enter the Red Giant phase in about 2 billion years, so the trick will be to either move the Earth outward away from the sun, or just get off this 8000 mile rock completely.
Question about interstellar travel... if we have enough time; it probably takes at least a few centuries to develop interstellar space travel, and maybe as long as 10 centuries or 1000 years.

6. Your next question will be, "How can our descendants move the Earth outward"?
By then the energy and technology will allow them to cause say a 100 mile wide asteroid to pass very close to the Earth every few hundred years or so, eventually slowing the Earth down in it's orbit around the sun, causing the Earth to move outward so after a million years of very close passes, we'll orbit the sun at say 110 million miles instead of 93 million miles, gaining us an extra one billion years of time.  QED.
Hope the answer you want is in there somewhere,
Clear Skies,
Tom Whiting
Erie, PA USA