Man of Random Science: The Beauty of Scientific Uncertainty
Quick, how many planets are in our solar system? No googling. I'll accept eight or nine as answers. If you want to be in line with current teaching standards, we have eight. If you refuse to bow to the whimsical tyranny of the IAU (viva la revolucion!) there's nine. Or is there....... Way back in the misty dawns of time, also known as the late-90s, I got my first college degree in philosophy. A few of my friends who took the entry level courses with me swore off philosophy for life because the field is devoid of answers. You read, you write, you argue, you move on to the next set of questions. Drinking was also an integral part of that equation but it rarely appeared in the official syllabus.
I was reminded of all this as I read Darling Don's last post about the spectrum of scientific endeavor and how the sciences are divided and often valued based upon how "hard" or "soft" they are. I know for a fact that some of my philosophy refugee friends found themselves in the sciences and I have to wonder if they ever saw the irony in that for even the hardest of the hard sciences, the answers are "good enough" as opposed to "correct" and quite often the correct answer changes faster than a freshman philosophy major deciding he's an existentialist after reading his first excerpt from Nietzsche.
Back to the planets. The current definition of a planet is threefold, determined in 2006 by the International Astronomical Union; First you must orbit the sun. Secondly, you must be massive enough that you are generally spheroid. Thirdly you must have cleared your orbit of significant debris. That last part of the definition is what doomed Pluto to it's reduced status. Travelling along with the Lord of the Underworld are a number of other icy bodies, referred to as "Trans-Neptunian Objects", that clutter up the neighborhood.
Take away the third planetary qualifier and you could include not only Pluto but also Eris which can be argued to be the larger of the two. As astronomy techniques to identify these distant objects advance, that number could rise significantly higher, causing much consternation to the people who write mnemonics to memorize the names of things.
The complications have grown even greater of late. The outer planets were discovered before we could clearly view them and evidence for their existence was found in gravitational perturbations in the orbits of the planets we know. How do we know that Neptune is out there even if we don't have the optics to spot it? Well, by the way Uranus wobbles. (Read this last sentence out loud. If you don't giggle, ask a teenager to read it. If you still don't get the joke I feel very sorry for you.)
Turns out there's a wobble in the orbit of Pluto, suggesting that there are gravitational tugs on that little ice-ball we have yet to identify. It's inspired theories of a Planet X, Nibiru, (google Nibiru cataclysm and get ready to follow that particular information wormhole straight to Crazytown), and most recently several academic papers suggesting there might be two planet-like objects hidden away in the dark recesses of our solar system. (second paper here)
To be clear, the dominant science right now says there are eight planets and a bunch of Trans-Neptunian objects of varying size and the recent papers are based on the study of 13 of these objects and admits that more observations need to be made before the hegemony of the current view is threatened. But this just highlights the ever-shifting sands of science and how the quest for certainty and THE ANSWER is an overly simplistic view of a complex universe.
The point is that uncertainty is inherent to any study and science is no exception. Ideas, opinions, and perceptions of the physical world are all subject to change and there is no reason to think that science will ever reach THE answer. Like many things in life, the beauty of the endeavor is in the journey.