Lois & Clark Forums Forums General Discussion Off Topic The Big Bang and the Universe, part 10: The weirdest new kid on the block

The absolutely weirdest new kid on the block of new cosmology is dark energy. I'm just sayin'.



I became interested in space back in 1969, when I was fourteen. Looking back, I think that what really attracted me to space was the humoungous, outrageous size of it. When I learnt that all stars are suns, I tried to picture how far away those faint little lights in the night sky had to be in order to look as faint as they do if they really are blazing suns, and the thought of it made my head swim. Then I realized that I liked how immense reality had suddenly become when the stars were so unimaginably far away. I'm a claustrophobiac, and cramped enclosed spaces make me panic.



A cramped enclosed narrow cave, oh no!!!



I don't want to be in the desert, but for all of that, the wide open space of a desert appeals to me.

And what could be more utterly unlike cramped enclosed spaces than a universe stretching for light years upon light years in all conceivable directions?

So I liked the universe because of its sheer size. Soon enough I learnt that astronomers believed that space was expanding, becoming even bigger. Fantastic!

But then I learnt that many astronomers believed that space would stop expanding after a while. After coming to a halt it would start contracting instead. It would contract more and more, become smaller and smaller, crash down upon itself faster and faster until it crash-landed on itself and scrunched itself out of existence in a Big Crunch. Well, let me tell you, that was definitely the worst and scariest thing I had heard of in my life.



Imagine the entire universe going down its own drain!

Many astronomers believed that such a Big Crunch would happen. (And most of them believed that after the Big Crunch, the universe would "bounce back" and rise again from its squeezed-out-of-existence ashes in a Phoenix-like fashion.)



The Big Bounce theory. After collapsing back into a single point, the universe is supposed to "bounce back" and rise again, Phoenix-like.

Anyway, the thought of a collapsing universe certainly wasn't something that I worried about on a daily basis, because honestly, I did realize that such a Big Crunch couldn't happen until many billion of years from now at the earliest! And what does it matter to me or to any of us what happens to the universe many billions of years from now? Well, personally I think that most of us like to picture a future that appeals to us or at least does not repulse us, even if we talk about a future when we ourselves must long be dead. And I cared enough about the distant future of the universe to pay close attention when my astronomical magazines wrote anything about the subject. My magazines told me that the ultimate fate of the universe depended on how much matter it contained. If it contained more than "the crucial density of matter", it would collapse. If it contained less than "the crucial density of matter", it would keep expanding forever.



This graph shows the evolution of a forever-expanding (an open) universe, a critical universe (one that balances on a knife's edge between expanding and collapsing, but which eventually avoids collapse) and a collapsing (a closed) universe. The dotted lines shows a theoretical bouncing universe, for which there is no real mathematically stringent theoretical support.

You can imagine what kind of universe that I, the claustrophobiac, was hoping for. Not a collapsing one, that's for sure!

Over the years, my magazines kept reporting how astronomers kept searching and searching for evidence that the universe would indeed collapse. Much to my resentment, the people who wrote the articles in my astronomy magazines seemed to be hoping that the universe was destined to collapse! Clearly they were hoping for a bouncing and "recycling" universe, and then they didn't mind "living through" the horror of a cosmic collapse! Didn't they feel any compassion at all for us poor claustrophobiacs?

However, to my relief, most inventories of matter in the universe did come to the conclusion that the universe probably wouldn't collapse. But the results were inconclusive.

This search for the ultimate fate of the universe (and the attempts to sort of persuade the universe to push itself over the edge to collapse) went on for years. It went on until 1997, when two independent teams who had been studying distant supernovae dropped the bombshell of the century in the laps of the unsuspecting astronomical community.

They announced that the universe was accelerating.



Ann