Sunday, August 1, 2010

Nature of Knowledge about Nature

I'm a big fan of shows that talk to scientist. There is a great episode of NOVA where the guys who were trying to be the first to generate Bose-Einstein condensates recount what it was like in the lab moments before their breakthrough. While I don't know much about that area of science, I was captivated by their description of what they were experiencing in those tense hours leading up to their successful experiment. The race to be the first to observe something new in science is high drama as far as I'm concerned. The achievement brought them a Nobel Prize (which is probably the only reason that NOVA made a show about them to begin with), but it also verified a theoretical prediction that had been made decades earlier by, well, Bose and Einstein.

There can be little doubt about the veracity of the predictions made by Bose and Einstein after seeing the exotic state of matter that they predicted be created in a lab. But what about theories that attempt to describe long standing observations? How good does the data need to fit the experiment before we can say that the theory is correct? Any reasonable solution that gives a reasonable fit to a data set can be considered a viable theoretical explanation. How is consensus reached on which explanation is the accepted one? Why is the Big Bang so widely accepted over other explanations for the origin of the universe? People have been looking at the stars for as long as there have been people on the planet. We are awash in data about the nature of the universe. How well do the theories that account for these observations fit the data?

To hear the scientist that they talk to for shows like Through the Wormhole or The Universe, the big questions of cosmology have pretty much been worked out. All that's left is working through the finer details of the Big Bang theory and the origins of our expanding universe. These are the models that the astronomy establishment have accepted as the best possible explanation for the origin and nature of our universe. There are very few people outside of the astronomy researchers who have the technical skills and knowledge to assess the validity of these models to any significant detail. We all just talk their word on it when they invoke terms like dark matter or dark energy to describe why the universe is expanding or some other cosmological observation.

I have never gotten a warm, fuzzy feeling for things like dark matter and dark energy. It's rather odd to think that the vast majority of the energy and matter in the universe is something that has never been detected or experienced. That's not to say that these proposed universal constituents are not present all around us, but at this point they're little more than theoretical predictions. There are plenty of research groups scrambling to observe dark matter or dark energy. They want to win a Nobel Prize and have their own episode of NOVA too. Seeing matter and energy and where we have never seen either feels a little arbitrary, but that's the best explanation that the established astronomers and cosmologists have been able to develop for their expansive data set about the nature of the universe.

It's no wonder that a new theory that claims to explain unexpected aspects of the universe without resorting to vast amounts of unknown energy and matter comes from Institute of Statistics at National Tsing Hua University in Taiwan. Wun-Yi Shu has written a paper that uses physical "constants" as conversion factors for other physical properties of the universe. I really have no way to evaluate his theory (although those that do have several issues with the paper, although I could have done without commentary on the formatting, like that really matters), but the paper does point out that our current theories do not fit the data as well as we might like. The presence of this paper is a reminder that for all that we think we know about the universe, much of that knowledge rests on large assumptions, generalizations, and reasonable conjecture (ie, guessing).

While this paper will likely disappear without leaving a lasting impact on physics, other papers that are just as ridiculed when they first appear may provide revolutionary insights into the workings of our universe. Science is dynamic and evolving. Our imperfect knowledge is constantly being revised. Even the most highly regarded theory can be undermined by a short paper from an unlikely source. That's just the way the world works.

No comments:

Post a Comment