Let us suppose that there exists a field of study in which people take established facts about the world and extrapolate upon them wildly; where bizarre–though interesting–ideas are routinely advanced with no more basis than the fact that they could conceivably turn out to be true, within accepted limits, if someone only knew how to look hard enough, or they might be true in a Universe different than our own. Let us suppose that people take these speculations, and build entire edifices and systems of belief upon them: new ideas extrapolated from new ideas based on things which might–only might–be true; a metaphorical castle in the clouds. Now let us suppose that no one, at present, has any idea whatsoever how to test the overwhelming majority of these theories against real-world observations, and some of them can’t be tested at all. And let us suppose that this field of study is called “theoretical physics.”
I have, for the last several years, proudly called myself a theoretical physicist. But as I sat through one lecture after another during a conference on the subject this week, I found myself more interested in how I could use these theories in science fiction stories than I was the theories themselves. And that, in turn, got me thinking: in the absence of any experimental or observational evidence, is what we are doing really science, or is it just some sort of incredibly elaborate science fiction?
There certainly is a place for purely theoretical speculation in the scientific method. But at what point does this speculation stop being helpful? At what point does it become irresponsible? If we propose a multiverse, for example, to avoid problems with the inflation hypothesis, and just say that there an are an infinite number other “bubble-universes” with different configurations and different laws of physics out somewhere beyond the edge of the visible universe, does this actually give us a deeper, more profound understanding of reality? Or does this just allow us to shunt-off problems with our cosmological models by postulating the existence of solutions that we will never be able to see?
Now I love speculation*, and I love science fiction, but if I’m going to do that as a career, then I’m inclined to do it in name as well as deed, while preferably writing in a more engaging style. As for physics, however, I have probably been spoiled by my recent reading of papers in less-speculative areas of the science, which, while less sexy, at least have the benefit of producing results.
*The coolest theory I’ve heard about recently is “dark electromagnetism,” which postulates that the invisible dark matter which supposedly accounts for 27% of the mass-energy in the universe interacts amongst itself using a sort of bizzaro-world equivalent of electrodynamics. It appeals to me greatly as a science fiction aficionado, but frankly, at present it seems to be on the level of those astronomers of yesteryear who used to suppose that there were dinosaurs on Venus because all they could see were clouds.