h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The universe is not merely expanding but accelerating too? Damn. How can that happen? What is the mechanism by which this is occurring? What could possibly be powerful enough to change the velocity of an entire universe? It makes no sense at all. To accelerate something you have to impart energy to it, there is simply no getting around that is there? So where is all this energy coming from? Dark matter energy generators? There must be another explanation for the apparent acceleration of the universe, this one makes no sense.

All we have to do is tap into this energy source to run our TVs, boom-boxes and hair-dryers and we will have an almost unlimited supply of energy. As we drain off the excess we can slow down the expansion of the universe and reach a state of equilibrium. Simple!

You know the saying "Once you remove the impossible, whatever is left, no matter how improbable, is the truth"?

It's a lie.

Something that's impossible simply means that we have to check our preconceived notions. We all have them--without them, we'd have no lens with which to view the universe--and rarely change them. People can fool themselves into just about any belief, no matter how silly. Most do.

Anyway, even if every bit of the universe is speeding along at light speed, you could still get to other portions. You could never get to one going at right angles to your bit, anything with a relative velocity between 90 and 270 degrees inclusive.

The cynical
~gareis

One way the universe can expand is if the cosmological constant is zero. It isn't explained in the article, but the CC is the "force" that repels gravity. Basically, it is the exact opposite of gravity. Whereas gravity gets weaker as the distance between two objects increase, the CC gets stronger. That's why it's more effective over long distances. Therefore, it would actually accelerate over time and push the universe farther apart.

That's crazier than quantum physics. We've seen no other sign of such a force. What would it affect? What is the force carrier? Or are we going by gravity and saying that there's no force carrier?

I'm guessing that whatever carries the force of gravity (gravity waves, the warp in spacetime, etc.) would also carry the force of the CC. Or, I think I remember reading somewhere that empty space would contain it. There is one event that might indicate its presence, and that is the Big Bang. What caused a uniform, incredibly dense, volumeless thing to suddenly explode? The answer might be the CC, since it repels gravity. The problem of course, is that it is weak over a small distance. Its presence could also be linked to the speed of light, though to expound anymore upon that, I will have to refer you to the book, "Faster than the speed of light" by Juao Maguiero (spelling is questionable). It's an interesting book on the theory of VSL or varying speed of light, and its possible replacement of inflation theory. I would recommmend it to anyone curious about the subject matter.

when you say accelerating, what do you mean? do you mean it is increasing or decreasing in speed?

The universe is accelerating at an increased rate.

well i think there are three posibilities

1) the universe will keep expanding to a point of infinite

2) it will expand to a point, stop and reverse and shrink to nothing

3) there is another, but i forgot what it is

The other possibilities:

3) The universe will expand, stop, and not collapse

4) The universe neither expands nor collapses

5) The universe ends somehow between reaching infinity and collapsing

There's a simple answer to these questions... GOD!

Okay, it's a meaningless answer, but it's simple. Saves wear and tear on the brain caused by unnecessary thinking.

No, wait, I know! Love! Love is the answer! Love is the antigravitational force which is causing the universe to expand at an accelerating rate. You know how, when you're in love, you feel light on your feet, like you could almost fly? Well, there you have it.

Love IS the Cosmological Constant!

Alright then. Now that I've figured out the ultimate nature of the universe, what shall I do with the rest of the morning? I don't usually have a beer before noon, but under the circumstances...

One theory is that the universe's expanding at the increasing rate will eventually make our night sky black, as even the stars in our galaxy will move away from us. Then, the solar system would spread apart, removing us from the sun, slowly but surely. Then, I guess the molecules here on earth (and everywhere else of course) would spread apart. Universal equilibrium. This is with a universe with not enough mass (to counteract the pushing away).

The other option is at a point, all the mass finally countacts the pushing away, and the universe recedes unto its self, called teh Big Crunch or (my favourite) Gnab Gib. Everything is sucked back into singularity and (the way I see it) primed for another Big Bang. this is with a universe with sufficient mass.

But of course the experimental evidence seems to point that we do not have enough mass in our universe, as the expansion is accelerating, indeed, the acceleration seems to be increasing.

Scary thought, huh.