Tuesday, March 2, 2010

Pluto...NOVA settled nothing

Well, as expected, nothing was settled. There was one highlight and I will mention that in a moment. What this all boils down to is definition...the definition of what a planet is supposed to be definitely clashes with popular opinion and public lore. Frankly, I am getting annoyed with the whole issue for I can understand a mutually accepted position: Pluto can be revered in popular parlance and establish a place in the scientific community though under a different set of classification rules. As I mentioned to another individual we can understand the a by its common name "aspirin" and technically [scientifically] refer to it as "acetylsalicylic acid". Now, what was the highlight...the visit that Tyson made with Tombaugh's widow and children where his son showed Tyson some of the homemade telescopes. They may look crude but functioned.

NOVA's "Pluto Files"

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Laurel Kornfeld said...

The point in Tyson's show was not to settle the debate but to illustrate just how much of a debate it still is, even within the scientific community. Several of the people interviewed noted that a lot of footage taken was not shown, specifically that in which people on both sides debated the Pluto issue.

It is unfair to say the IAU classification rules are THE rules scientists must use when clearly many scientists reject them. Maybe the whole point is in recognizing that we just don't have enough data yet to create a definition of planet at all. This is especially true given that what we are finding in exoplanet systems is providing constant surprises. Do we consider a planet orbiting its star backwards a planet? Do we consider two gas giants in a 3:2 resonance orbit to be planets since they cross one another's orbits?

A year ago, at the Isaac Asimov Memorial Debate, Tyson and six astronomers (three dynamicists and three planetary scientists) posited that maybe it is just too early in the field of planetary science, which is really still in its infancy, to be establishing a formal definition.

Mercury said...


"It is unfair to say the IAU classification rules are THE rules scientists must use when clearly many scientists reject them. Maybe the whole point is in recognizing that we just don't have enough data yet to create a definition of planet at all."

I cannot argue against that in part. But that is science...defining, honing, and redefining based on scientific evidence--not popular consensus. This is how we can categorize phenomena and is always subject to change.

But a question of "who" makes decisions arises. If not the IAU, then who will decide a working hypothesis...the populace? I don't think so.

Laurel Kornfeld said...

Maybe the question of "who decides" is yet to be determined. On one side, we have the IAU, of whom a tiny minority adopted a resolution that is poorly crafted and at least somewhat driven by political motives (dynamicists vs. geophysicists). On the other side, we have planetary scientists who outright reject the IAU definition. These planetary scientists asked the IAU to re-open the discussion at the 2009 General Assembly, and the IAU leadership refused. Thus, we have an impasse with two opposing camps in the scientific community. Add to that the fact that many planetary scientists are not IAU members and that the IAU has still not enacted absentee voting, and it becomes obvious that procedural issues alone are a huge part of the problem.

No one in science has yet formally defined issues at the frontier, such as the definitions of dark matter and dark energy. We have multiple theories based on the data we know. Maybe we just have to accept the same situation when it comes to planets. We are on the verge of major discoveries of new bodies in this and other solar systems that very likely will be unlike anything we know as planets. Remember, we expected other solar systems to be like ours, with terrestrial planets orbiting near the sun, and gas giants orbiting further out, yet we discovered "hot Jupiters" that totally don't fit this model.

Consensus cannot be forced. The likelihood is, some sort of consensus on planet definition will emerge over time as we learn more about these new objects. In the meantime, there is no reason why the issue cannot be left open and explained with two different views (dynamics and geophysics), each of which is equally legitimate.

Mercury said...


I don't understand entirely the dilemma with the IAU. It appears that only Pluto has stirred up emotions and indecision. Take the recent naming of element 112 [Copernicium] by the International Union of Pure and Applied Chemistry [IUPAC]. Since 1981, GSI [GSI Helmholtzzentrum für Schwerionenforschung (Centre for Heavy Ion Research) in Darmstadt, Germany] accelerator experiments have yielded the discovery of six chemical elements, which carry the atomic numbers 107 to 112. GSI has already named their officially recognized elements 107 to 111: element 107 is called Bohrium, element 108 Hassium, element 109 Meitnerium, element 110 Darmstadtium, and element 111 is named Roentgenium. No complaints have come forth and the IUPAC is a recognized authoritative body.

I think your complaint is no so much the loss of status of Pluto as a planet but more frustrated with a definitive definition of what a "planet" is supposed...a criteria established and blessed by some organization that has the authority to declare forceful statements that, in Pluto's case, satisfy the general public and scientists.

Ah, the evolving status of the sciences.