Leaving our universe
Did you have a good weekend? Are you feeling that perhaps you’re not quite ready to get back to work or school today, or perhaps ever? Then you might want to consider Michio Kaku’s fabuous article about escaping our universe. It’s a really good read, talking about the state of our universe as we know it (including its age, 13.7billion years plus or minus a hundred million!) and our thoughts on dark matter and dark energy (did you know that it seems only 5% of our universe is ordinary matter?!)
He then goes on to talk about possible ways we might be able to avoid dying with the rest of the universe when the stars finally run out, and everything that’s interesting in the universe slowly comes to a halt. (Not to worry yet, though - that’s still billions of years into the future, and humans have only been around for a few thousand!) It’s a really good read, and opens up some thought provoking discussions about some of the exotic physics that’s come out in the last 10 years. He’s also written several popular science books, and though I’ve only read one of his it was very good - so I highly recommend him if you see one in the bookstore!
I might be a little quiet for the next couple of days - I’ve got a lot on! - but I’ll post again before the end of the week. Cheers!
Daniel Winter Says:
I only have one pretty good understanding of everything right now. That is that everything is a wave. Whatever is the smallest of everything somehow makes everything wave. This is related to movement. If something moves it always has the shape of a wave, and this is related to randomness. The speed of light is also explained by this wave.
Suppose you are riding a huge wave in the ocean. The only thing you can see is right in front of you. You can predict what will happen to some extent, and you know what just happened. Suppose also that there is a person on the wave behind you, but you can’t see them because they are blocked out from your existence. The only place you exist is on that wave. The only way to get to the previous wave or the next wave is to go faster than the speed of light.
As the universe expands, its energy content is diluted and temperatures eventually plunge to near absolute zero, where even atoms stop moving. One of the iron laws of physics is the second law of thermodynamics, which states that in the end everything runs down, that the total “entropy” (disorder or chaos) in the universe always increases. This means that iron rusts, our bodies age and crumble, empires fall, stars exhaust their nuclear fuel, and the universe itself will run down, as temperatures drop uniformly to near zero.
Just a finicky point, but I don’t think we know whether the entropy of the universe always increases. Why? Because the universe is (by definition, I suppose) a closed system. And if you take the point of view that there is “wavefunction of the universe” which evolves unitarily, then the entropy doesn’t change at all (if the wavefunction is pure, then the entropy vanishes, always.) I tend to believe that this sort of statement is an abuse of thermodyanmics, which has well defined boundaries for when it is applicable, and pushing it outside of its regime of validity is always a dangerous game.