Friday, February 17, 2012
We know that our universe is expanding. This is contrary to what we know about physics: Gravity pulls all matter together, and the universe has a very large amount of matter, so this matter should be pulling itself together. Not so -- every distant object we can see is moving away from us at an ever-growing rate. One proposed explanation for this is Dark energy -- a hidden energy spread throughout all space that is accelerating everything away, and fills the fabric of the entire universe. If it exists, it represents 73% of all mass-energy of the universe. And I want to use it to power my gadgets. Wait, what? A dark energy to electric converter would gain power from fundamental facts of existence without having to look for external fuel. The only waste product would be heat, and the more you use it, the more you slow down the expansion of the universe. It would be interesting to see if this only slows it down in the area, suggesting an even spread of energy that can be used up, or if it slows down the universe, suggesting some sort of cosmological constant. All other forms of energy would be obsolete, and all of what I previously wrote about unlimited energy sources would come to pass. Of course, if we used too much, we might accidentally trigger a big crunch. In the big crunch, gravity overwhelms the universe's expansion, and the universe starts to pull together again. Some physicists even describe the "arrow of time" reversing, meaning that time goes backwards to the big bang, but they've never offered more than a hand-wave to justify this claim. This big crunch would have some rather inconvenient events when distant stars began interfering with asteroid orbits, leading to more large asteroid collisions. Then when those stars get too close to us, Earth fries. Eventually the entire universe gets mashed into a single point of zero dimensions. It may trigger a second big bang at that point, or it may just sit in near-non-existence for the rest of time. The only reason I'm not holding my breath on this is that we're not even entirely sure that dark energy really exists. It may be a completely different thing that cannot be tapped for energy.