The Expanding Nothingness Part II

12/9/07 – 12/15/07

In science, knowledge and research usually expand our view of things. But recent discoveries in cosmology have shrunk our known universe by expanding the unknown universe. In the late 80’s and 90’s, it seemed that we were closing in on some important numbers, like how old the universe is, and how fast it is expanding. By figuring out how fast it’s expanding, we could figure out how long ago it had started expanding, thus determining its age. By this method we had narrowed the age of the universe down to somewhere between 10-20 billion years. Ballpark figure or not, it’s still a staggeringly huge number. Now we know it’s most likely 13.7 billion years. Very old. But it’s a number.

Finding the universal expansion rate required knowing how much stuff there was in the universe, which was thrown into doubt by the discovery of dark matter. We tossed the presumed amount of this mysterious, invisible and as of yet undetected dark matter into the equation, and came up with an expansion rate of somewhere between 70-75 km/sec/Mpc. That means that for every 3.2 million light years of distance, galaxies are receding at 75 km/sec. Though the expansion rate is fast, the funny part of the story is that it’s changing, and it’s not slowing down.

Cosmologists say that the universe is expanding faster than ever. But when questioned as to what is expanding, they say it’s space, which contains about 4% stuff we see, and 96% dark energy and dark matter. Dark matter is a mysterious, theoretical and undetected substance that defies our understanding. And what is speeding up the expansion? Dark energy, a mysterious, theoretical and undetected force that defies our understanding. Swell. So instead of expanding our knowledge base, research has introduced two new facets of the universe that are dark, undetected, and have an almost mythical, unknowable nature. The ultimate fate of the universe, once seemingly around the corner of our understanding, recedes into the distance.

So where do these ideas come from? And what does it do to our understanding of the universe? The idea of dark energy was introduced to explain an observation that was otherwise unexplainable. By looking at a certain type of supernovae (the spectacular explosions accompanying the death of a star) astronomers estimated how far away they are. By using these supernovae as standard candles, they found that, instead of slowing down as expected, the expansion of the universe was actually speeding up. It was quite a surprise, and immediately demanded explanations and theories. Thence came dark energy, a force manufactured to explain the quickening of the spreading out of the stuff that was not really known. Once again, our understanding recedes into the distance.

Do we feel the thinness of the ice of knowledge yet? It seems that we are continually breaking through, falling into the dark chasm of the icy water of the unknown. But that’s the exciting part about science: the cold, wet realization that you’ve got to come up with new ideas to explain the questions that arise from observations. Currently, cosmology is a field of science that demands careful, methodical study, but also demands creative, almost crazy thinking. It’s not for the faint of heart. But the rewards are immeasurable.

Until next week, my friends, enjoy the view.