Pluto defines a Planet as being a Planet!

[wonky]

In the end, all definitions are arbitrary human constructions, and always will be.

 

[jakethesnake]

<font color="orange">”I understand that is an arbitrary limit, but using the size of Pluto is also an arbitrary limit. But the difference is, as has been stated numerous times, Pluto was only called a planet by MISTAKE, namely that it was thought to be much larger than Mercury. The IAU has now fixed that mistake, as the mistake regarding Ceres and some other asteroids were also fixed. <b>I fail to see what the big fricken deal is. </b>” </font><br /><br /><br />The big fricken deal is you can differentiate between a star and a “Planet” because of the nuclear reaction that occurs due to the mass, quantity of deuterium and gravity, you can differentiate between an “Asteroid” and a “Dwarf Planet” due to its mass becoming great enough to cause it to become spherical and even though these are arbitrary classifications to some extent they are based on something scientifically tangible. <br /><br />Tell me something geniuses:<br /><br /><font color="yellow"> What scientifically tangible event occurs that differentiates a “Dwarf Planet” from a “Planet”? </font><img src="/images/icons/rolleyes.gif" /><br /><br />The answer is you can’t tell me and neither can the IAU and, this is a big fricken deal! <img src="/images/icons/frown.gif" /><br /> <br />So if you’re going to draw a completely uneducated arbitrary line in the sand as you suggest then the IAU should have left Pluto as a “Planet”! <img src="/images/icons/tongue.gif" /><br /> <div class="Discussion_UserSignature"> <strong></strong> </div>

 

[alokmohan]

Since discovery it was supposed to be Lowells planet x.So the confusion.All these are well known stories,I dont know why same repeatation.

 

[kheider]

<font color="yellow">What scientifically tangible event occurs that differentiates a “Dwarf Planet” from a “Planet”?</font><br /><br />Microlensing has shown that small planet like objects appear to be common in our galaxy.<br /><br />Currently theory suggests that once planetesimals (at least in our solar system) reached roughly the mass of Earth's moon they quickly accreted into true planets.<br /><br />Current theory suggests that the average mass of gas giants around stars is a direct function of the mass of the central star and thus a function of the mass of the original interstellar gas cloud.<br /><br />Current theory suggests that the mass of the moons around gas giants (mini-systems) is also a function of the mass of the gas giant. Look at the ratios of Jupiter and Uranus Planet-Moon systems for comparision.<br /><br />Since exo-planets have only been discoverd in the last 10 years, this is all very recent theory. As this theory evolves and matures I expect that Pluto will be considered less and less as a real planet.<br /><br />You may not get an exact scientific answer in your life time.<br /><br /><b>Pluto, Ceres, and Vesta are failed protoplanets.</b><br /><br />-- Kevin Heider

 

[MeteorWayne]

Hey Jake, chill out a bit. You are letting your emotions take over. I understand your frustration, but when you let emotions (I.E you are starting to sort of swear) take over, you only weaken your secular case.<br />I'm working with you here, trying to provide realistic analysis.<br />Don't lose it now! <img src="/images/icons/wink.gif" /><br /><br />The Other Wayne <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[vonster]

<blockquote><font class="small">In reply to:</font><hr /><p>Tell me something geniuses:<br /><br />What scientifically tangible event occurs that differentiates a “Dwarf Planet” from a “Planet”?<p><hr /></p></p></blockquote><br /><br /><br />The object got big enough or small enough that it slipped over the line into a category that made sense to us<br /><br />There is no other real reason for the re-classification, and there is absolutely nothing wrong with re-naming / re-classifying phenomena so that it makes sense to human beings<br /><br />Because without human beings there would be no names for these .. whatever the hell they are objects ... we are the only ones that use them<br /><br />IN the same way that dust devil / tornado / hurricane are names for 'circular wind patterns of different size' ....<br /><br />So are the divisions we are giving to big round objects in space. Who cares if some people dont like it. <br /><br />Many people would rather not have 300 planets to memorize, that have NOTHING in common other than the fact that they are round and orbiting a start in space. <br /><br />We would rather make some distinctions based on size to make it managable and realistic.<br /><br />So get over it already, the topic is annoying<br /><br />.<br />

 

[robnissen]

You have completely changed your position. I think it is intellectually honest to say that any body that orbits the sun and is spherical is a planet. I think such a defintion is unworkable because we will immediately jump from 9 to 12 to 15 planets, with most assuredly 100s in the future. But that is an intellectually honest position. But let me quote from your original post on this thread:<br /><br />"Pluto defines a Planet as being a Planet! <br /><br />. . . Planets have already had a yardstick in which to be compared to “Pluto” and it’s been that way for over 75 years. Anytime a new celestial body has been found in our solar system it has been compared to Pluto to be deemed a Planet or not."<br /><br />So "genius" I have a question for you, what scientific basis, other than historical anamoly do you have for saying Pluto is a planet, but Ceres is not. Let me answer, there IS NONE. So, since you are in agreement with me that we should use a completely arbitrary limit to decide what is a planet (although apparently you are now ashamed to admit it), why should we use an arbitrary limit that is completely based on a mistake, rather than use the limit that has been used for thousands of years (and for hundreds of years by astronomers who knew exactly what they were talking about) and use Mercury as the arbitrary dividing line?

 

[jakethesnake]

<font color="orange">“So "genius" I have a question for you, what scientific basis, other than historical anamoly do you have for saying Pluto is a planet, but Ceres is not. Let me answer, there IS NONE. So, since you are in agreement with me that we should use a completely arbitrary limit to decide what is a planet (although apparently you are now ashamed to admit it), why should we use an arbitrary limit that is completely based on a mistake, rather than use the limit that has been used for thousands of years (and for hundreds of years by astronomers who knew exactly what they were talking about) and use Mercury as the arbitrary dividing line?”</font><br /><br /><br />You say that I have changed my position and in part this is true, I now believe that a definition of a “Planet” was a good thing albeit a very bad definition! <br /><br />Although where I haven’t changed my position is the fact that what you and for the most part everyone else is admitting to is that there isn’t any clear scientific way of differentiating a “Dwarf Planet” from a “Planet”.<br /><br />MeteorWayne is right in that I tend to get a little overly passionate about my position and I’ve taken my chill pill <img src="/images/icons/blush.gif" /> but it is a little madding that a definition was come to that does nothing in the way of defining anything! The only thing that was accomplished by the IAU’s definition of “Planet” is that it adds to the confusion and does nothing to enhance or improve upon what was no definition at all. <img src="/images/icons/frown.gif" /><br /><br /><br /><b>If you read through this thread as it pertains to my position you would have read this and I reiterate: </b><br /> <font color="yellow">This post has educated me enough to show a clear path as to what should have been done. The title and suggestion of this post “Pluto defines a Planet as being a Planet!” still remains in my mind as a correct assessment of what should have been done in the first place. <br /><br />One v</font> <div class="Discussion_UserSignature"> <strong></strong> </div>

 

[jakethesnake]

That's pretty good <img src="/images/icons/laugh.gif" /> and no I don't think it would fit into the politically correct world we live in today. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <strong></strong> </div>

 

[MeteorWayne]

Absolutely true Wonky! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

"<i>MeteorWayne is right in that I tend to get a little overly passionate about my position and I’ve taken my chill pill but it is a little madding that a definition was come to that does nothing in the way of defining anything! The only thing that was accomplished by the IAU’s definition of “Planet” is that it adds to the confusion and does nothing to enhance or improve upon what was no definition at all. </i>"<br /><br />I'm glad you calmed down a bit. Despite the fact that we are on different sides here, I've enjoyed our discussions and have found them educational, forcing me to carefully examine my own position.<br /><br />Which is of course right <img src="/images/icons/smile.gif" /> <img src="/images/icons/tongue.gif" /> <img src="/images/icons/laugh.gif" /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

Just FYI, I am reposting the data from the Pluto Perspectives.<br />I now have a much more comprehensive database.<br />Just to keep it up to date, I have removed "Jake" from the list, sorry Wayne.<br /><br />We can always fool with that later, which I'll be happy to do.<br /><br />Off we go. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[jakethesnake]

Here is an interesting article I thought you might like to read if you haven’t already. Also there are some links to some older articles with varying opinions and insight on this matter at the bottom of the page.<br /><br />http://space.com/scienceastronomy/061121_exoplanet_definition.html<br /><br /> I think it gets to the crux of the issue and that is the IAU’s definition of “Planet” is a narrowing of something that was all encompassing and still should be. It also tries to narrow down a “Planet” dynamically not physically which in part is because most of the planetary scientists who voted Pluto out were dynamicists.<br /><br />Also, thanks for the link to the podcast by Dr. Alan Stern and he basically reiterates what is said in this article along with the quandary of what a Planet should be.<br /><br />http://quantumeditions.com/podcasts/QL_Stern_100206.mp3<br /> <div class="Discussion_UserSignature"> <strong></strong> </div>

 

[jakethesnake]

Well… I hate to beat this old and very dead horse, but I have found a great article that articulates how inept the IAU was in what it arrived at as a definition of what a planet is.

http://news.discovery.com/space/planet- ... ystem.html

The IAU’s definition of a planet completely ignores planets outside our solar system and completely ignores how big a planet can be.

Now that more than 400 planets have been discovered outside our own solar system, we are now beginning to see the vast diversity that planets actually encompass; everything from hot gas giants orbiting close to their parent star to planets with densities comparable to Styrofoam.

Although the planets discovered thus far are planets that orbit their parent star very close in, and are very large due to the techniques use to find them. We are now beginning to see that certain arguments that were used to discredit Pluto as a planet don't hold up so well anymore.

One of the common arguments against Pluto was its orbital plane, and now we are seeing the commonality of planets with eccentric orbits, or planets with orbital planes that greatly diverge from the common plane of its solar system or both.

I think at this point the IAU is looking pretty... and to put it bluntly… STUPID!

I’m can’t wait for the discoveries that await us in the next few years… Go Kepler!!!

 

[Saiph]

Please don't resurrect threads over 4 years old! Well, any really old thread. I understand your post is relevant, but I doubt people will want to slog through this 10+ page thread for your one new relevant post.

Please start a new thread next time....or this time. I'll split this off into a new topic if I've time and a cooperating browser soon...

 

[ramparts]

jakethesnake - yes, new discoveries are made all the time, and sometimes definitions get changed to accomodate our greater understanding. That's why Pluto was reclassified in the first place.

It's very simple - either you have eight planets, or you have dozens, and pretty soon hundreds, of planets in our solar system. I prefer the first one for aesthetic reasons; I think the schoolkids who have to memorize all the planets probably will, too

 

[MeteorWayne]

I also don't think that the intention of the IAU was to define Exoplanets, but rather the specific case of our solar system.

 

[Saiph]

And to be fair, we don't actually know that much about exoplanets yet, so it's hard to come up with a definition that helps draw the line by including them.

As far as I know, all the ones we've found are basically considered actual planets, if an exotic example of the class.

 

[ramparts]

Well, MW, a planet should be a planet no matter where. The definition should hold in any system.

That said, I don't know of any exoplanets discovered which wouldn't meet the criteria set out by the IAU. Things that are very massive are bound to count as planets, and that's all we can find, and will be able to for a while.

 

[jakethesnake]

Please don't resurrect threads over 4 years old! Well, any really old thread. I understand your post is relevant, but I doubt people will want to slog through this 10+ page thread for your one new relevant post.

Please start a new thread next time....or this time. I'll split this off into a new topic if I've time and a cooperating browser soon...

Although this thread is old it has a lot of well thought out arguments and insight that are very pertinent to Pluto being, or not being a planet, as well as what the definition of what a Planet should be.

Why start from scratch?

I think in retrospect this resurrected post highlights how far off the IAU was in their definition of what a Planet is; just four years and 400 plus Planets later and the IAU’s definition of a planet is worthless.

 

[jakethesnake]

jakethesnake - yes, new discoveries are made all the time, and sometimes definitions get changed to accomodate our greater understanding. That's why Pluto was reclassified in the first place.

It's very simple - either you have eight planets, or you have dozens, and pretty soon hundreds, of planets in our solar system. I prefer the first one for aesthetic reasons; I think the schoolkids who have to memorize all the planets probably will, too

We have thousands of rivers on this Planet... should they all be streams because we can't rember all of them???

 

[jakethesnake]

I also don't think that the intention of the IAU was to define Exoplanets, but rather the specific case of our solar system.

I like Dr. Alan Stern’s argument (who leads the US space agency's New Horizons mission to Pluto) of the analogy of rivers… just because you can’t remember the names of all the rivers on this planet doesn’t mean it isn’t a river.

Also, at the time the IAU decided to define what a Planet was (2006) albeit in this solar system, there were many Exoplanets already discovered, so why limit the definition to only this solar system?

Kind of a waste of time if you ask me... :?:

 

[ramparts]

Jake, it's a definition. If you want to define planets so that there's a few dozen of them, I can't prove you wrong. But I'm considering the cultural implications of planets - kids learn about each of the planets in school, how they're special, and that's engrained in our culture. So that seems like a logical place to start when deciding on a definition.

And in the end, it is all just definitions.

 

[jakethesnake]

Jake, it's a definition. If you want to define planets so that there's a few dozen of them, I can't prove you wrong. But I'm considering the cultural implications of planets - kids learn about each of the planets in school, how they're special, and that's engrained in our culture. So that seems like a logical place to start when deciding on a definition.

And in the end, it is all just definitions.

The General Assembly of the International Astronomical Union (IAU) that demoted Pluto, and the intent of these General Assemblies are to decide on specific arbitrary definitions that allow astronomers to talk to one another across language barriers enabling the world’s various science communities to interpret each other's data and are not intended to address cultural implications.

And In my opinion the IAU failed miserably.

 

[ramparts]

But you have yet to explain (at least to me) why you think it failed. Why is your posited definition better for scientific communication than one I'd support, or that the IAU would? Are you a research astronomer?