Plutonian Process
Published 18 years, 3 months pastAs someone who obtained a minor in Astronomy in college, and one of the only people I know who can consistently name the planets in order without having to resort to mnemonics, I’d like to take a moment out from the whole W3C thing to comment on the de-planetization of Pluto.
It’s about time.
Its classification as a planet was never really justifiable, and recent discoveries like 2003 UB313 (Xena) have only served to underscore that fact.
Now, that said, I’m no fan of the “dwarf planet” compromise. That just smells of committee-think, and it’s got to go. For that matter, the newly adopted definition for “planet” is pretty terrible. If it were up to me, I’d go with a definition that was based on orbital characteristics and a minimum surface gravitational acceleration threshold—maybe size and density, too. But none of this “cleared its orbital path” crap.
Furthermore, I think all this a great illustration of how science works. Although it’s quite the fashion to talk about “scientific dogma”, what this shows is exactly how science works. There is no inflexible dogma. As new evidence emerges and is incorporated into the general body of knowledge, the “orthodoxy” changes. There are no absolute truths in science—only the best available information. Once we thought meat transformed directly into maggots; now we know otherwise. Today we think that no physical object can move faster than the speed of light in a vacuum, but tomorrow (or a hundred years from now, or a thousand) we may find we were wrong. It doesn’t mean anyone was wrong in their previous understanding. It means simply that their previous understanding was incomplete.
And that’s fine. In fact, it’s better than fine: it’s expected and, by and large, welcomed. I often wonder if the real conflict between religion and science isn’t that science stands in opposition to religion, which it does not, but that science embodies a way of approaching the world that could not be more different than that taught by most religions. There are no absolutes in science, no final immutable truths, nothing that cannot be supplanted by some new understanding. Change may happen slowly, and it always happens after there is clear and convincing evidence, but it does happen.
As with Pluto. At one time, it seemed like it could qualify as a planet. Now it does not. As we understand more about the universe, we will be able to formulate better definitions of what is a planet and what is not. Maybe that will mean one day re-planetizing Pluto, and if so, then fine. It’s all part of the process—excuse me, the method.
Maybe that’s a lot to hang on a change of classification for a tiny, frozen pile of rock, but it’s true nonetheless. Or at least it will remain true until someone can convincingly show otherwise.
Comments (29)
My favorite is Higgs Boson. Something smaller does exist, doesn’t it. And, for Astronomy, I prefer Ptolemy.
I’ve often wondered how discoveries will affect (if at all) the way we teach science to our children. Will grade school teachers teach that there are 8 planets and several dwarf planets or just teach what they’ve been taught as per the forty year old textbooks they have to teach out of.
Miles: what I hope is that they’ll teach the current understanding and discuss the things I talked about—that our body of knowledge changes due to changes in understanding—and use the fact that the books went out of date as proof of the process at work, and working. It’s a golden opportunity to bring the whole concept of the scientific method home to the kids, and to show them how they can be a part of that process.
Well, an enquiring and honest mind is never going to be satisfied with ancient stories from religious traditions that frame a world-view which supposedly makes sense of the moral guidance offered in those traditions.
On the other hand, Pluto’s planetary status doesn’t give much moral guidance, doesn’t pick you up when you’re down, isn’t something you can build a society on.
Although I agree with your message about science, I don’t think these examples are the best ones to illustrate the point. The redefinition of a planet is a just a change in terminology, and does not redefine any of our understanding of astronomy — no matter how we classify it, the same models describing its behaviour continue to apply. The recategorization doesn’t really demonstrate scientific method. The original discoveries of Neptune and Pluto, on the other hand, do illustrate the process of forming a hypothesis, designing an experiment to find supporting data, and successfully uncovering evidence to support the hypothesis.
I would hesitate at using the question of objects with real mass travelling faster than light as an example, because too frequently people will incorrectly infer from examples such as this that any alternate theory may be equally likely to be true. It is certainly possible that future observations and theories may place our current understanding into a different framework, but it will not invalidate all of the current observations that have confirmed the present theory to a extremely high degree of precision, and any theory that does so is almost certainly incorrect.
The thought that “meat transformed directly into maggots” was not wrong, but simply an “incomplete understanding”? No, often our understanding is incomplete and can be expanded, but at other times it is simply wrong.
“There are no absolutes in science…”. All this means is that science is unable to claim things absolutely, not that absolutes don’t exist. It is usually when science claims absolutes that it comes into conflict with religion, such as claiming that evolution is a fact.
I think a better example that demonstrates the scientific method is how light was once shown to be a particle by some experements and later shown to be a wave by others. The wave theory didn’t invalidate the the results of prior experements, it just showed that there was more to it. Of course we now know it’s an electromagnetic wave.
As for the conflict between religion and science, that’s due to the fact that religion insists on holding onto primitive beliefs that don’t stand up to the scientific method; and so called “christian scientists” that attempt to use unsubstantiated evidence and pseudoscience to support their claims.
Its a pity they didn’t add 3 more “planets”. I would have loved to know what the astrologers would do about that, especially when Xena is in the ascendency! I guess now they can drop all the nonsense about Pluto.
How about Shetland planet? Just like a real planet, only smaller.
> “I would hesitate at using the question of objects with real mass travelling faster than light as an example, because too frequently people will incorrectly infer from examples such as this that any alternate theory may be equally likely to be true.”
What example would you use?
And should you stop saying things that are true, and comprehensible, just because some people may misunderstand or misinterpret them?
> What example would you use?
I gave an example in my comment. The Michelson-Morley experiment is another good example showing how an experimental failure can be as valuable as a success. The evolution of optical theory is also a good example, albeit a complex one (sometimes light is like a wave, sometimes it is like a particle — both concepts need to be used to explain its behaviour).
What’s amazing to me about The Method is that it’s just trial and error. You think of a way things might work, you try it, and if it doesn’t work the way you thought it did, you think of something else. What’s mostly amazing is that it took humans so long to figure it out: what were they using before?
And just to pick nits, your concept of Science may not be at odds with your religious understanding, Eric, but trial and error and religion don’t mix. I’d like somebody to teach the scientific method with the examples in Judges 6 (Gideon and the Fleece). “Okay kids, let’s take this sheepskin out to the parking lot and pray…” And I hope they never teach kids to derive pi from 2 Chron. 4:2. =-)
Scientific method is a bit more than trial and error — I think of it as an attempt to codify the process that any logical person would follow to draw a conclusion based on collected evidence. Trial and error can generally include any and all attempts, without necessarily having any systematic approach.
Isaac:
Ah, but the recategorization has happened because there have been many changes (advances) in our understanding of astronomy over the last seven decades. As I see it, the change of definition is a direct consequence of the scientific method in action, and that’s why it makes a great illustration and teaching point.
As others have said in the comments, this could be stated about anything—if I say, “There is no known compelling evidence that yeti exist, but that does not mean they do not exist,” then someone will take that as an admission that yeti do exist, but my rigid scientific orthodoxy can’t handle challenges to its precious order. Or words to that effect. Which is complete crap, but I’ve seen it happen time and again, as I’ve no doubt you have as well—thus your caution. Superluminal velocities appear to be impossible, given our current understanding of the universe. Many things have seemed impossible in the past, only to have been found to be possible. Other things that seemed impossible turned out to be exactly that. As with any honest scientist, I always keep my mind open, but I also demand compelling evidence before I’ll change it.
The nature-of-light examples are good ones, too, although they make my point just as well, I think. It’s interesting that Michelson-Moreley came up, though, as I almost used it as my example, and not just because it was conducted a few miles from my house.
(I’ll further admit that I deliberately avoided using both evolution and global warming as examples. The last thing I need is a flamewar between the opposing sides of either of those topics to erupt on my site.)
I spoke a bit hastily — I should have said that I would hesitate to give any examples on future theories without explaining the gauntlet any new theory must run before being accepted.
We’ll have to agree to disagree on Pluto. I certainly agree that it provides excellent fodder for discussion on how our knowledge of astronomical phenomena has increased, via the use of scientific method to guide our investigations, and how this has led us to redefine existing terms so that they can be used in future in useful ways. But I disagree that the reclassification of Pluto is a direct consequence of scientific method, as it is not a new hypothesis that is causing the change. To me it is more like the Academie Francaise deciding on the official French word for email (“courriel” — speaking of places near home, this word originated in Quebec, where I grew up).
Here’s a piece, by one of my friends from the world of astronomy, about astronomers as amateur linguists.
The advent of infra-red astronomy in the 80s, and the subsequent discovery of the Kuiper Belt, did change our view of the Solar System. I don’t think that’s reflected in the IAU decision, though, since the definition of the word ‘planet’ wasn’t really tied to our understanding of the physical mechanics of the Solar System. It just meant a hunk of rock or gas in orbit around the Sun.
Oh well, we astronomers like quibbling about semantics, I guess. :)
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[…] Eric’s Archived Thoughts: Plutonian Process “I often wonder if the real conflict between religion and science isn”t that science stands in opposition to religion, which it does not, but that science embodies a way of approaching the world that could not be more different than that taught by most (tags: science religion astronomy) […]
“I think a better example that demonstrates the scientific method is how light was once shown to be a particle by some experements and later shown to be a wave by others. The wave theory didn”t invalidate the the results of prior experements, it just showed that there was more to it. Of course we now know it”s an electromagnetic wave.”
I’m not sure about this. Newton had his corpuscular theory of light, but Young’s two-slit experiment clearly demonstrated that light was a wave. I think the wave theory was held strongly through the 19th Century, with Maxwell demonstrating that light is an electromagnetic wave. Then Einstein published his explanation of the photoelectric effect in 1905, the work which won him the Nobel Prize. Einstein’s theory introduced the concept of photons and I think it’s only then that the particle nature of light was seriously considered again. So Einstein showed that the particle theory had to be taken seriously, and that light behaved as both a particle and a wave.
Then De Broglie came along and we realised that electrons also exhibit wave-like properties, extending wave-particle duality to subatomic particles.
Quick disclaimer: this post may contain generalisations and traces of nuts.
At uni I did a subject called “Philosophy and Science”, class was made up of half philosophy students and half science students. A lot of the science students actually got really angry about the idea that their knowledge wasn’t certain. They insisted that scientific knowledge was set truth – they couldn’t cope with the idea that all those hours of study could be potentially be rendered invalid (although I think that was a particularly pessimistic view of what was being discussed).
I’ve never quite understood how those students could ever do serious scientific research if they were so unwilling to question the established order of things.
An older and more cynical voice also pipes up noting that funding changes the playing field as well. If an established scientist has secured millions in funding based on a particular theory, they’re not going to be happy if that theory is questioned or disproved – especially by a young ‘nobody’. I’ve no doubt that there are times when the established scientist will work to discredit the newcomer; thereby saving reputation and funding. I hope it’s rare – the exception, not the rule.
I’m not sure I agree that this redefinition of the term ‘Planet’ is part of the Scientific Method, or even a Scientific affair.
Isn’t the term planet simply arbitrary? I mean because we live on a big ball as humans we are inclined to revere other big balls–planets.
I understand this change to be simply human, and done for the sake of neatness and order. Not science.
This sounds like the academic field of astronomy that I used to work in. As opposed to the idealised science described by Eric. Of course, those are both extreme examples. Real academic research is somewhere in between.
The conflict between the Steady State and Big Bang theories in cosmology is one good example. Steady State stood, on increasingly flimsy ground, as an accepted alternative to the Big Bang until very recently. It was only microwave background measurements in the early 90s that finally killed it.
I’ve heard Alan Dressler’s Voyage to the Great Attractor, about the measurement of the Hubble Constant, described as a fair book about the scientific process but a great insight into scientific egos. Dressler is not the world’s most humble bloke.
I agree with you completely. When I was taught the planets in school (I don’t ever remember learning a mnemonic) I never questioned anything. I got into high school and discovered some peculiar things about Pluto. I felt then it didn’t deserve to be called a planet. I’m happy for the decision.
The new definition of a planet is, however, completely stupid. The new concept of a “dwarf planet” further complicates matters. If a dwarf planet is not a planet then why does it contain “planet” in its name? Whether you go to the store and buy a baseball hat or a cowboy hat they’re both hats.
There’s been an interesting reaction from the Division for Planetary Sciences of the AAS. they recognise the authority of the IAU to take a decision, but question the new definition.
Dark matter: more interesting news than Pluto being reclassified.
Dark Matter is much more interresting than that boring news about Pluto being reclassified. Bark Bark.
I think it’s actually a pretty clever definition because it’s self-limiting – at exactly the point where there are lots of objects of similar size we might be tempted to call planets, the fact that there are lots implies that none has successfully cleared its orbital path and so none has reached planet status. This way we circumvent the whole issue of hy the boundary on size, density, orbital parameters, or whatever (remember, Saturn is less dense than water), was set here rather than there. It also fits in nicely with the most widely accepted theory of planet formation by accretion onto smaller planetesimals.
Oh and the Dark Matter result probably is more interesting, if only because almost all astronomers believe observations require the existance of DM whilst almost all of the public seem to believe it’s just a conspiracy. I’m pretty sure that says something significant. It seems like an odd thing to spam(?) a blog about though…
I think it’s all rather an artificial argument. After all, what is a “planet”? There is no external agency that came along and said “ok guys, this is a planet”. Rather, “planet” is a label we decided to give to an object in space. If a planet is something we are free to define any way we like, and if we are free to change that definition whenever we like, it seems to me somewhat absurd to argue about it it. Basically there are just a bunch of objects in space, some of which are larger than others. If a gas giant like Jupiter, and a smaller rocky body like Mercury can both classify as planets – well the difference between Mercury and Pluto seems trifling compared to the differnece between Mercury and Jupiter. Daft, if you ask me.
I’m a Christian/Web Developer, and I like to think I know a little bit about science. I think the universe is ~10 billion years old and we evolved from monkeys. I also think God made it and us. I don’t see why this is so hard to grasp for some. I’m glad you see no conflict between science and religion. I just wish more Christians saw it this way.
Pluto is a planet for sure. Next to go is Uranus. http://www.saveplutotees.com keep the faith people.