It appears we no longer have 9 planets in our solar system. Gash :(
http://news.bbc.co.uk/1/hi/sci/tech/5282440.stm
The page has a bunch of stats about Pluto, and it has 3 of it's own moons AND is still having a probe sent to it in 2015 - so I don't see why they should downgrade it. Oh well. I guess it's only a planet! :p Or...was only a planet.
man, now all these kids who are presenting dioramas of the solar system are getting BIG FAT Fs today!
Hooray for science!
Also... it's a little known fact but in the early 1900's 4 scientists went on an expedition to Pluto, then known as Planet X... I hope to tell you more about it some day!
Yes well, the weak have to go... Besides it was in the local newspaper the other day that they are planning on naming new planets to our solar system. things like Xerox-4 and stuff, but who knows, in fact, who cares.
Oh.
When I read the title, "Pluto is no more," I immediately pictured it exploding.
Some people like fireworks.
The thing is, if pluto can be considered a planet, then so can about 50 other things floating around our solar system...
I thought it would be "kinda neat" to have 12 official planets, but somehow having 8 seems empty. Its like we've taken the smallest kid on the football team and kicked him out.
I was hoping it was about a particular disney character..
The label of a giant ball of rock orbiting my sun being changed affects my life so much :(
I always preferred Goofy or Donald, anyway...
Well, I think it's a shame - merely because I was educated to know there were 9 planets, and that it could well be the last planet with a cool name. All the new ones are Syntax-32 or A48GIF2 etc... Still, I'm into astronomy and the night sky, but I guess some of yous aren't. That's fine.
Because for you people, I found this.
(http://www.abc.se/~m8100/images/death.gif)
Well, after revising the technicalities for what is considered a planet, they say that now there are more then three other "objects" that could now be considered planets. So in getting smaller, we may even expand.
Poor Pluto. Since we no longer want him/her in our solar system, maybe we can find somebody in another galaxy to take him/her in. I guess we'll have to put him/her up for adoption and hope some other galaxy is looking to add more planets to their solar system.
Bye Pluto, i never met you, but you'll always be family to me. :'(
My
Very
Energetic
Mother
Just
Sent
Us
Nine.....
....nine what? there's nothing for my mom to send us anymore :'(
I'm just wondering how long it will take before planets get renamed due to corporate sponsors. I see in the future Jupiter becoming Planet Microsoft, or Venus becoming Planet AOL. It will happen. It seems every corporation has to have their name on everything, just like sports stadiums do in the US.
Imagine, Planet Earth, sponsored by Gatorade....oh damn them!! :)
edit: Next Mittens on Pluto
Stupid scientists. What do they know, really? Somebody should hit them all with a ball peen hammer.
Pluto is dead. Long live Pluto!
Quote from: Domino on Fri 25/08/2006 02:05:38
I'm just wondering how long it will take before planets get renamed due to corporate sponsors.
I was just thinking the other day, "I wonder if they'll ever be able to project something on the moon" I'm sure they could send up some satelite projector and have an image big enough that we could see from earth. It would be totally going too far though. Virgin Moon
As far as Pluto maybe not being considered a planet, it's still a rock that orbits the sun, it's not like anything is going to physically change. I remember seeing on the news the other night they were going to honour Pluto by having another class of smaller planet type things and call them Plutons
Quote from: Timosity on Fri 25/08/2006 07:09:49
I was just thinking the other day, "I wonder if they'll ever be able to project something on the moon"
I heard Pepsi were considering it.
EDIT: I was reminded of the Red Dwarf thing when I first read about Pepsi as well. I guessed that this was what the book was satirising. Also, Coke Adds Life!
Reminds me of that bit in the Red Dwarf book, where they make hundreds of stars go supernova to spell out "Coca Cola" in the sky.
I don't know what I'd think about that, but I certainly wouldn't think about drinking pepsi. :=
Jurij Alekseevič Gagarin could have told us this many years ago!
Quote from: Ali on Fri 25/08/2006 10:51:22
Coke Adds Life!
I just had a mental image of god looking at the earth, then at his bottle of coke, then back at the earth again, then back to the coke.
EDIT:
Sounds more like a Dr Pepper advert.
"Whats the worst that could happen..."
You spelled Dr Pepper correctly. Good work!
That had me worrying there for a moment, anxiously searching for traces of sarcasm.
Its... not a difficult word... or are you refering to the obvious mispelling "Dr. Pepper"?
EDIT:
Because, as we all know, there hasn't been a period in the name "Dr Pepper" since the 1950's.
And since Pluto is not a planet anymore, they'll make the sun a planet instead, and the Earth must take over as a the sun.
Escape while there is time, fools!!
just a thought
The scientists agreed that for a celestial body to qualify as a planet:
it must be in orbit around the Sun
it must be large enough that it takes on a nearly round shape
it has cleared its orbit of other objects
Pluto was automatically disqualified because its highly elliptical orbit overlaps with that of Neptune. It will now join a new category of dwarf planets.
So if pluto has been told it cant play anymore then why can neptune its his daft fault he was in the way
Dam sea god
Quote from: Domino on Fri 25/08/2006 02:05:38
I'm just wondering how long it will take before planets get renamed due to corporate sponsors. I see in the future Jupiter becoming Planet Microsoft, or Venus becoming Planet AOL. It will happen. It seems every corporation has to have their name on everything, just like sports stadiums do in the US.
Imagine, Planet Earth, sponsored by Gatorade....oh damn them!! :)
edit: Next Mittens on Pluto
Everybody knows its google earth... ;)
But seriously on taking away a planet, ummm what are they paying the morons making these decisions?
Hows about all the morons doing that donate all the money to cancer or something...
I look here our goverment is changing the street names... its costing 100 of thousands if not millions but ja
we have nohting better to pay our taxes on than changing street names... like I said who employs these
morons.
:(
I guess that reclassifying celestial bodies probably isn't these scientists' main job. I also suspect that they are far from morons.
EDIT: Though, I do agree with you about renaming streets. Round the corner from me 'Mad Alice Lane' has been renamed 'Three Cranes Lane. That's much worse!
Quote from: Afflict on Sat 26/08/2006 07:29:17
I look here our goverment is changing the street names... its costing 100 of thousands if not millions but ja we have nohting better to pay our taxes on than changing street names... like I said who employs these morons.
I've said it before and I'll say it again... democracy just doesn't work...
renaming streets and reclassifying celestial bodies are far from the same. You say it's costing "100 of thousands if not millions" to rename streets and saying that if it costs that much to rename streets how much did it cost to reclassify an entire planet?!
No one has to print street signs up and remove and replace every one for Pluto.
What will astrologists do now? Recognise that the have been making mistakes since 1930? Or recognise Pluto as a planet, and, therefore, recognising they have NEVER made a good astrological prediction (Since they should consider Ceres, Xena, blah, blah...)?
Astrology is a dead end. Whatever they do, it will imply that they astrological charts are uncorrect. ^_^
Funny...
Planets and asteroids and these new "dwarf-planets" and stuff all orbit the sun anyway, it's just a more streamlined system of classification due to size. "Demoting" Pluto from being labelled a planet to a dwarf planet is not saying "oh we were wrong before!1!", it's just a demonstration that as we know more and more about our solar system, sometimes we have to re-evaluate previous conclusions.
Funnily enough, re-evaluation and cross-examination of prior evidence and conclusions is part of all sciences, otherwise we'd never make any progress.
Well, all I know is that I heard on the news that it will cost quite a few millions to destroy and replace the school textbooks regarding Pluto. Add all the non-school textbooks too..
Just thinking about all that wasted paper...
And to make matters worse, there are references to Pluto at almost everything I can think of.. from the odd bedroom poster with the solar system to the odd coffee cup collection with the planets illustrated.
I wonder how this affects the people who deal with Astrology.. now that Pluto is not a 'real' planet anymore.
-What? You where born under a Pluto alignment? *pat pat* I am so sorry dear.. *pat pat*
Edit: Spelling
EDIT: He...PureGhost, read my post two posts above, you are exposing exactly my point...
Reply for Becky :)
But as for astrologists, the discovery of "planets" of the same (or bigger) size than Pluto, and the same characteristics, should Ã, be a "We were wrong".
Because consequently, if they consider Pluto a planet, they should make the astral charts with 12, not 9.
Anyway, as you said, re-evaluation is for sciences, and Astrology is not a science, but folklore for dumbs.
Yeah, and science was wrong about the earth being flat and geocentrism but that this has been corrected and amended is a good thing, right? Or should we all continue being ignorant in the face of contrary evidence? :)
Btw, astronomy is a science, astrology is the horiscope stuff.
Edit: Aw man Nacho, I've been missreading you XD Sorry :P
PureGhostGR, how often do they destroy text books? How often do they have to print new posters and other text books? I feel that people only think of the cost to do these things when it's something "high profile" like demoting a planet.
But either way I would like to hear an astrologist fight back against this one.
Whether Pluto is a planet or not isn't really a scientific question - or wasn't, rather. Previously to this, there was no scientific definition of the word "planet". That was the whole point of the exercise. According to the one they decided on, it's not one in the scientific sense, since they couldn't come up with a sane (i.e. not ridiculously gerrymandered) one that limited our solar system to the nine classical planets. Seriously, though, I actually agree it was probably a waste of time and effort (although that's no reason at all to abolish the IAU), because it's so meaningless. It changes exactly nothing about what science knows about Pluto or Ceres or anything else - all it does is potentially help improve clarity in future scientific writing here and there.
I don't really understand your replies, Becky, we are basically agreeing.
Science implies that anything we think it's correct can be wrong, therefore, we will never stop in a static degree of knowleadge. Even what we think it's correct might make our grandchildren laugh in some years.
Astrology should be considered nowadays as one of this things that deserve to laugh at. The thing is that we basically can't laugh because this swindlers are robbing money from the dumbs and credulous.
EDIT: I saw your edit, Becky... Was the problem that you thought I was attacking astroNoMy, and not astroLoGy? No probs...
Nacho, yes, I just realised (and edited my previous post) to show that I'd been missreading your posts as "astronomy" and not "astrology" :P I'm sorry!
MrColossal, actually I am not really for or against the process of demoting Pluto. I am only puzzled by the willingness to replace the textbooks and spend millions on it (only) because the incident got media publicity.
Keep in mind.. when in school, we (meaning I) had textbooks printed almost a decade before my birth. (apparently they had invented paper back then)
Quote from: Becky on Sat 26/08/2006 16:35:17
Yeah, and science was wrong about the earth being flat
Off topic, Terry Jones the comedio-historian argues that science never thought the world was flat and I've often suspected the same. The Ancient Greeks knew the world was round, and in the Inferno Dante travels through the centre of the globe. Apparently Irving Washington started the myth.
I have read the same about the earth being flat and the scientific community not really adopting that in a natural history book I read by Stephen Jay Gould.
New versions of textbooks are printed every year, so it's not like they wouldn't have anyway, with numerous other small changes. How long it'll take before all the textbooks in schools list 8 planets instead of 9 I don't know... probably a long time because it's not really an important change for most people learning science, it is handy to have a solid definition for such a commonly used word in astronomical circles though.
Anyone that doesn't like it for some reason can keep calling Pluto the 9th planet of the solar system. There are plenty of words that differ in meaning from scientific to common usage.
Textbooks are generally a mangled version of what was cutting edge 3 decades ago anyway.
On the bright side, if we take all the "incorrect" textbooks, we'd each get an instant collectable. Then we could wait some 50 odd years and pass it along as a family heirloom, until some stupid descendant would sell it at an auction and make thousands of dollars off of it.
Quote from: Fuzzpilz on Sat 26/08/2006 16:38:36Previously to this, there was no scientific definition of the word "planet". That was the whole point of the exercise. According to the one they decided on, it's not one in the scientific sense, since they couldn't come up with a sane (i.e. not ridiculously gerrymandered) one that limited our solar system to the nine classical planets.
It sounds like they could have used the assistance of some of those people that negotiate athletes' salaries. I'm sure they could have come up with some sort of "Pluto clause" or something .... :)
The article linked in the first post originally had a comment about "erasing" Pluto out of the textbooks. Makes you kind of wonder how this is done: will they in fact "erase" Pluto, or just add a blurb about it being "reclassified?" Makes you kind of wonder what's been "erased" in our textbooks before now ....
NEWZ UPDATE!!!11
http://uncyclopedia.org/wiki/UnNews:Vogons:_Earth_no_longer_a_planet
Also, if you actually go to the source rather than rely on watered down soundbites on news pages you can read about the details of their silly re-classification scheme.
http://www.iau2006.org/mirror/www.iau.org/iau0603/index.html
It was a rather amusing read. Scientists/astronomists every so often get an urge to be recognized and remembered. This is such a case. We've went with a simple but effective definition of a planet for many years but now it's extremely necessary to create an overcomplicated one? And why does it have to include 'clearing the neighborhood around its orbit'? It seems rather arbitrary that planets can no longer be planets if they move in an elliptical--and bear in mind that Pluto's orbit is somewhat elliptical--orbit--yet that's one of the definitions of a dwarf planet as well! The 'very nearly' clause in their definition is absolutely arbitrary as well. What classifies very nearly spherical? They haven't bothered to release evidence of what 'very nearly means' aside from our existing 8 planets and Pluto, so I really can't respect this kind of arbitrary science. I'd still like to know why they feel that 'clearing the neighborhood' around its orbit is tantamount to a planet's behavior. Does this mean if Venus' orbit shifts slightly and its path overlaps with Saturn it will become a dwarf planet as well? According to the new definitions the answer is yes. Bollocks.
Quote from: Mr Flibble on Fri 25/08/2006 23:23:22
That had me worrying there for a moment, anxiously searching for traces of sarcasm.
Its... not a difficult word... or are you refering to the obvious mispelling "Dr. Pepper"?
EDIT:
Because, as we all know, there hasn't been a period in the name "Dr Pepper" since the 1950's.
No sarcasm. I was serious. I was referring to the fact that there's no period.
Sarcasm: I think we should destroy Pluto with explosives.
If Pluto isn't a proper planet anymore, where does that leave Charon? It can't be a dwarf planet itself, as it doesn't orbit the sun.
does it get down-graded from a moon to "one large lump of rock"?
How sad. :'(
Since the centre of gravity of the Pluto-Charon system isn't within either body, it's actually a binary dwarf planet, both are going around the sun together, as opposed to one doing so and the other around it.
At least, as far as following the straightforward definitions we have now, which are far far better than the old definition which....didn't exist and therefore had little practical value in such a state of being.
Quote from: ProgZmax on Mon 28/08/2006 05:45:33
We've went with a simple but effective definition of a planet for many years but now it's extremely necessary to create an overcomplicated one?
As far as I know, there was no clear definition for planets, but I might be wrong. The definition that I knew was that a planet is a celestial body that orbits a star and does not shine with its own light. A comet can easily make this definition, while we clearly don't intend to classify it as a planet.
Quote
The 'very nearly' clause in their definition is absolutely arbitrary as well. What classifies very nearly spherical? They haven't bothered to release evidence of what 'very nearly means' aside from our existing 8 planets and Pluto, so I really can't respect this kind of arbitrary science.
"Very nearly" is actually a fairly close definition. It means, that the planet has large enough mass so that gravity can distort it's shape into a perfect sphere.
However, all planets rotate around their axis (it's impossible to not to*), and the forces that awake because of the rotation slightly distort the shape to "very nearly spherical": the planet is squeezed along the rotation axis and bulges out a bit along its equator perpendicular to the rotation axis.
So, if a celestial bode doesn't have a large enough mass, gravity will not be strong enough to distort its shape.
* A planet *may* lose its angular momentum over time, due to forces acting on it and stop rotating. Earth, for example, will stop rotating in the distant future, becase tidal friction is slowing down its rotation.
Quote
I'd still like to know why they feel that 'clearing the neighborhood' around its orbit is tantamount to a planet's behavior. Does this mean if Venus' orbit shifts slightly and its path overlaps with Saturn it will become a dwarf planet as well? According to the new definitions the answer is yes.
All planets orbit their star in an elliptical orbit. Even a theoretical perfect circle orbit is elliptical, as a circle is just an extreme case for an ellipse. Anyway, Pluto's orbit is highly elliptical and tilted, which suggests that it didn't form as planets of the solar system, but in some other way.
I actually find it somewhat amusing to see what people think about Pluto. I just came back from Washington DC and I saw that inside the space museum, the part regarding Pluto was framed black and someone put a flower under it. :)
Pluto is not going away, it's going to be a named part of the solar system, it just won't be called a "planet" anymore.
QuoteAs far as I know, there was no clear definition for planets, but I might be wrong. The definition that I knew was that a planet is a celestial body that orbits a star and does not shine with its own light. A comet can easily make this definition, while we clearly don't intend to classify it as a planet.
1. A nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves. In the solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
It's a simple definition agreed, but it has worked for years.
Quote"Very nearly" is actually a fairly close definition.
Hogwash. Quantify very nearly for me. All of the planets swing in elliptical orbits, whether extreme or not. Nevertheless, Pluto's orbital shape isn't the issue here, it's the overlap with Neptune.
Observe:
(http://www.windows.ucar.edu/pluto/images/orbit_plot_outer_sm.jpg)
(http://physics.uoregon.edu/~jimbrau/BrauImNew/Chap13/FG13_20.jpg)
You will note that the only anomaly Pluto seems to suffer from is sharing an overlapping path with Neptune. This seems like a rather poor reason to discount Pluto as a planet and makes the new definition seem arbitrary to me. Why? A meteorite impact of sizeable mass could push any of the planets in our system off orbit just enough to create a similar situation, and then by the new definition they would no longer be planets. Based on articles I have read, it seems more likely to me that the definition was made to quell the Xena (UB313) and Ceres controversy that has sprung up in the last few years.
http://www.nasm.si.edu/ceps/etp/pluto/pluto_orbit.html
maybe this will help understand pluto's orbit better than your images.
http://www.space.com/scienceastronomy/solarsystem/pluto-ez.html
some pluto facts!
Quote from: ProgZmax on Mon 28/08/2006 09:05:21
1. A nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves. In the solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
It's a simple definition agreed, but it has worked for years.
You must have used a different source than I did for the planet definition. This itself shows that there was a problem with that definition, since we came up with two different (albeit very close) definitions. So having a unified definition is actually good, because there is only one way to define a planet.
Anyway, there is no clear-cut definition for asteroids, either.
Quote
Hogwash. Quantify very nearly for me. All of the planets swing in elliptical orbits, whether extreme or not. Nevertheless, Pluto's orbital shape isn't the issue here, it's the overlap with Neptune.
Of course it is not the *shape* that is the issue (I didn't imply it was. Pluto actually has a fairly spherical shape, but that partly comes from the fact that it's a binary system with Charon, so tidal forces help to achieve the sperical shape.)
The issue is the *mass* and the *force of gravity* that awakens from that mass. A planet - according to the new definition - should have enough mass to generate sufficient gravity to form a sphere on its own, without outside help.
This is also the reason for the clause to "clear the neighborhood": if a planet is massive enough, it'll have enough gravity to attract smaller bodies from a distance, thus sweeping an elliptical path in the accretion disk around a newly formed star. A small body would have a lot less gravity (gravity weakens according to the inverse square law), so it would have a lot less chance to do the same.
That's why there are no significant bodies around the orbit of Mercury, Venus, Earth, Mars, etc. - they swept a significant path out by accreting matter from the dust when they formed.
-------
Note: I think you have a misunderstanding here. I just realized, that when you talk about shape, you talk about the shape of the orbit, right? Ignore this if not.
The shape of the orbit was not even a concern for Pluto - it was the *mass* of the planet that was a issue. The shape of the orbit didn't matter at all - it is not a requirement for a planet (even according to new rules) to have a nearly circular orbit. The requirement is to have a nearly spherical shape for the *planet* itself.
-------
And I think it is wrong to ask for an actual, quantified rule. Astronomers are well aware that the classification is artificial - it's really there to help sorting different bodies in the sky better. If we started quantifying, we could have 9 categories for planets right away.
So "very nearly spherical" tells us a good rule of thumb to make a decision, especially because we use the mass and the force of gravity as the basis, which are well-known quantities for known celestial bodies.
Mr. Colossal's links are right: there is no overlap between the orbit of Pluto and Neptune. The problem is that Pluto has a tilted orbit, so it implies that it didn't form as part of the planet formation process in the solar system.
When a star forms, a significant amount of matter orbits it, shaped like a wide, narrow disk, in the plane of the star's equator. This accretion disk is the source for the planets' material: there are different chunks of matter in the disk. Larger chunks have slightly greater gravity, so they have a better chance of attracting other (smaller) chunks and become even larger. But this results in planets in the plane of the accretion disk. Pluto could not have formed this way because of its tilted orbit - it must have joined the inner solar system in a different way and got hooked by the Sun's gravity.
The diagrams showing the orbit of Pluto are generally wrong, they're just simplifications to make the representation easier. Actually, when the distance between Pluto and the Sun is higer, the distance between Pluto and Neptune is almost two times the distance between Pluto and the Sun.
Neptune is 30 AU from the Sun and Pluto reaches 50.
Quote from: ProgZmax on Mon 28/08/2006 05:45:33
... if you actually go to the source rather than rely on watered down soundbites on news pages ...
Yeah, it does seem like a strange exercise. One thing that caught my attention is that this definition only applies to stuff in our solar system (since it explicity requires orbit around our Sun). This would imply that "planet"-like objects orbiting other stars have a different name, and are presumably described by a different definition. Indeed, Wikipedia describes them as "extrasolar planets" and their definition seems to depend on whether they're big enough to cause fusion (i.e. "they're not a star"). Talk about arbitrary.
It also seems strange that they're trying to classify these objects based on how they orbit the sun. It seems akin to classifing birds based on how they fly. I would think a more "scientific" method would be some physical critera that distinguishes planets from other objects. A quick search of Wikipedia would seem to indicate that all planets have a distinguishable core, as opposed to comets and asteriods which are basically rocks in space. Of course, this definition would seem to still leave out Pluto, but it seems like more solid reasoning to me than the fact that Pluto has a different orbit from the other planets.
Quote from: EagerMind on Mon 28/08/2006 17:41:30
Yeah, it does seem like a strange exercise. One thing that caught my attention is that this definition only applies to stuff in our solar system (since it explicity requires orbit around our Sun). This would imply that "planet"-like objects orbiting other stars have a different name, and are presumably described by a different definition. Indeed, Wikipedia describes them as "extrasolar planets" and their definition seems to depend on whether they're big enough to cause fusion (i.e. "they're not a star"). Talk about arbitrary.
Nothing is arbitrary here. The limit that a planet doesn't cause fusion is the same as saying it doesn't have its own light, so it's really the same definition. You can replace Sun with the name of the other star and you get the same definition of a planet. The mass limit that causes nuclear fusion is very well known, and nothing is arbitrary about that.
We only know of *huge* planets in other star systems, simply because planets do not have their own light and it's very complicated to detect even a really big one. For big bodies, this definition is fine and when we discover smaller planets, we can see if the entire definition is good enough to cover all things that we would "instinctively" call a planet, but not others.
Quote
It also seems strange that they're trying to classify these objects based on how they orbit the sun. It seems akin to classifing birds based on how they fly.
I think you misunderstand it - no one is classifying celestial bodies based on their orbits. They're classified based on their mass - read my previous entry. The shape of the orbit is irrelevant.
The problem with Pluto's orbit is that it crosses the ecliptic plane of the solar system - this plane is well established by the orbits of other planets. So it tells us that 4.5 billion or so years back there was a disk of material around the Sun and the planets formed from this. The 8 planets' orbits fall very nearly into the same plane, with Mercury having the greates deviation, 7 degrees. Pluto has a much greater deviation, 17 degrees, which tells us that Pluto didn't form the same way.
Quote
I would think a more "scientific" method would be some physical critera that distinguishes planets from other objects.
There isn't any. The only really distinguishing property is mass. In our solar system, planets are made of different material, they have different sizes, different densities, different rotations, etc. Mass is pretty much the only thing that can be used as a general measure.
I'm starting to get the feeling that there's more to the story here than has been let on. Don't get me wrong, I'm not necessarily disagreeing with reclassifying Pluto, I'm just trying to understand the reasoning behind it. Traveler, you've provided the best reasons that I've seen so far.
But consider the news article that was originally linked to. It stated that the main impetus for the reclassification was to prevent having 50 planets in our solar system. But (as the article also states) if we're trying to describe the solar system "as it really is, not as we would like it to be," why would the number of planets in our solar system be any concern? Simply having too many planets seems like a bad reason, because than any distinction we make to keep the number down will be arbitrary. Discovering some new information or new understanding of our solar system that reveals some fundamental difference between Pluto and the rest of the planets seems like a good reason.
There also seems to be problem with the new definition. One of the requirements is for a planet to have "cleared its orbit of other objects," and Pluto is eliminated because it overlaps with Neptune. But doesn't the door swing both ways? Can't we say Neptune hasn't cleared Pluto from it's orbit, and therefore isn't a planet either? There must be a piece missing here.
Quote from: Traveler on Mon 28/08/2006 23:10:35Quote from: EagerMind on Mon 28/08/2006 17:41:30
Yeah, it does seem like a strange exercise .... Talk about arbitrary.
Nothing is arbitrary here.
I wasn't actually referring to the definitions themselves being arbitrary, but I may not have made that clear. My comment was referring to the fact that there are different definitions for planets and intersolar planets, with Wikipedia suggesting that there isn't even an agreed upon definition for intersolar planets. Functionally these definitions may be the same, but it implies to me that, realistically, we're approaching this from different angles.
Surely, it's reasonable to assume that whether we're talking about our own solar system or anyÃ, number of others, we're comparing apples with apples. Of all the uncountable number of solar systems in the galaxy, why should we assume ours is special, especially with how little we actually know? Let's get down to one definition and start trying to prove (or disprove) it.
QuoteI think you misunderstand it - no one is classifying celestial bodies based on their orbits. They're classified based on their mass ....
The problem with Pluto's orbit is that it crosses the ecliptic plane of the solar system ... which tells us that Pluto didn't form the same way.
This seems reasonable, and certainly points out something fundamentally different about Pluto from the rest of the planets. But I'm having a hard time seeing the connection to mass, or that this is the intention of the new definition. If this is the case, it would imply the following:
1. There's a relation between how big something is and its ability to wander through space (i.e. planets can't wander).
2. Pluto's orbit doesn't match the other planets', so it must have wandered in.
But if this is our intention - to define planets as something that was originally formed in the system in which it currently orbits - why not just make that the definition?
Quote from: EagerMind on Wed 30/08/2006 05:18:17
...Traveler, you've provided the best reasons that I've seen so far.
Thank you, I'm glad to be of help. :)
Quote
Simply having too many planets seems like a bad reason, because than any distinction we make to keep the number down will be arbitrary.
Keep in mind, that the definition of a planet (or any other celestial body) will necessarily be arbitrary. Nature itself doesn't care about classifications: these bodies simply exist. The need to classify them is a human need, so we introduce categories.
The reason for the definition being arbitrary is simple: celestial objects come in all sizes (the range is continous, like the range of rational numbers), while we want just a few distinct categories. Pluto was not excluded because astronomers wanted to exclude it - it got excluded because the rule that we use to determine if an object is a planet doesn't apply to it.
QuoteOne of the requirements is for a planet to have "cleared its orbit of other objects," and Pluto is eliminated because it overlaps with Neptune. But doesn't the door swing both ways? Can't we say Neptune hasn't cleared Pluto from it's orbit, and therefore isn't a planet either?
"Clearing its orbit" means that the planet must stand out. This is not a quantitative measure, but one can say by looking if an object stands out. Pluto is really part of a set of other objects (maybe part of the Kuiper belt), which orbit the Sun beyond the orbit of Neptune. Pluto (and the other objects in that area) are just too small to generate enough gravity to attract all other small bodies from the region - so they cannot stand out, they appear as part of a crowd.
Now, the distance between Pluto and Neptune is really big. Pluto's orbit is tilted and the orbital cycles of Neptune and Pluto are such that when Pluto comes close to Neptune's orbit, Neptune is always far away from there.
Here comes the requirement of mass: Pluto couldn't possibly clear Neptune out of its orbit if they actually got close to each other (it's waaay too small), while Neptune could easily digest Pluto. And if you look at the general neighborhood of Neptune, you'll see that there is nothing in its path - it's really clear, just like the other planets.
QuoteFunctionally these definitions may be the same, but it implies to me that, realistically, we're approaching this from different angles.
I believe the reason for this is that we know almost nothing about planets in general. We (humans) never left the Solar system and we detected only somewhat more than 100 planets in other solar systems. These are mainly gas giants, simply because a planet doesn't shine with its own light, so any smaller planets will be flooded out by their star's light. Huge planets can be detected by measuring the drop in brightness of their star when the planets periodically cross the line of sight between the telescope and the star.
On the other hand, we have a fairly good knowledge about the planets in our Solar system and the new planet definition is generic enough to use as a starting point to classify extrasolar planets.
QuoteBut I'm having a hard time seeing the connection to mass, or that this is the intention of the new definition. If this is the case, it would imply the following:
1. There's a relation between how big something is and its ability to wander through space (i.e. planets can't wander).
There is no such relation. Any object in space can wander anywhere, as long as it's not under the influence of a greater mass that forces it to orbit (or fall in.) This is why I wrote that the orbit itself is irrelevant for the planet definition.
Greater mass results in greater gravity, which helps the object to attract smaller objects (thus to "clear the neighborhood" and stand out.) Attracting small objects increases the object's mass and its ability to attract other objects further.
Quote
2. Pluto's orbit doesn't match the other planets', so it must have wandered in.
But if this is our intention - to define planets as something that was originally formed in the system in which it currently orbits - why not just make that the definition?
Pluto's orbit is really just one of many similar objects at the edge of the inner Solar system. Don't forget that the Solar system doesn't end with Pluto's orbit: there are the Kuiper belt and the Oort cloud out there with tens of thousands of objects of different sizes and orbits. Most of these are very far away and very small, so we never saw them, but they're still there and they all orbit the Sun.
So Pluto didn't have to wander in from outside the Solar system - it comes from a region where there are many other objects with similar sizes and orbits. (Pluto's orbit is quite typical of Kuiper belt objects. This may have been one factor in not classifying it as a planet anymore. I think, though, that the linked article is in error stating that this was the sole reason.)
Edit: some typos fixed.
This thread made me dig out my old Astronomy text book i had for the semester i took of it.
"Discovering the Universe" by Neil F. Comins and William J. Kaufmann III
(http://img228.imageshack.us/img228/8006/plutoxc6.gif%3Cbr%20/%3E)
That last collumn is "Magnetic Field" and says Pluto's is unknown, yet it has been mentioned before in this thread...is my reletivly new text book out of date? (I mean discluding Pluto's status loss.
You know, I feel I could make an adventure out of this, "Pluto: The Little Planet That Couldn't."
Honestly...
Who cares?
Apart from the fact (I heard it, don't know if its true), that it's the only planet discovered by Americans I simply don't understand it.
Every forum I've been has a thread about poor pluto...
weird...
PS. Interesting though, as you get to leatn a little astronomy :D
So... somebody cares?
You're right Nik, who cares... Let me just go into every thread on this forum talking about anything and write "Honestlly, Who cares!" in it.
Maybe if you phrased your question: "Does this class changing have any significance to the average person or is it mostly a classification thing that astronomers and scientists will use to further a general understanding of the universe?" your post wouldn't have seemed so rude.
To answer your hypothetical question I fear that the classification changing does have an impact on the average person and all it will do is help feed a distrust in science that I feel is held by many people. "Oh those scientists! This is what they're wasting our money on!" "I'm still going to say Pluto is a planet! These scientists have no idea what their talking about!" "If they were wrong about Pluto for so many years they must be wrong about other things therefore you can't trust them!
I really don't see it as rude but if people thing that my post is rude I do apologize for it. I didn't mean to be rude, and usually I'm not. So sorry for that Eric, Farl and everybody else.
The thing is that I see this kind of thread in every forum and it's made an impression on me.
Now about your answer to my (hypothetical) question, and thanks for actually answering it. The thing is that we're talking about a simple definition here. It is not about trusting the scientists.
You talk about wasting money. The internet is a great tool, but here we are arguing about (almost) nothing, which is usually the case in most forums. Heck the internet costs a lot of money to maintain, no? But here we are wasting it. Don't think I'm rude but in comparison to wlking on the moon, or saving Earth from a meteor catastroph, defining the term planets and taking out Pluto seems tiny, same as having the internet and this thread (or any thread that I've started :D). See what I mean?
My who cares comment, came along with an excuse that
QuoteEvery forum I've been has a thread about poor pluto...Weird
.
Anyways, free forum, free talk (that's why I posted in the first place), keep discussing ;D ;D Who am I to start stoping threads?
EDIT: BTW I just fail to see the importance of that. Maybe it's me (probably it is me...)
Well of course poor Pluto! For the majority of us alive today, it is a "known" planet, and we surprisingly - live on a planet. Sure, we don't think about it that often - hence litter, slums, global warming etc, but there are times when we really do think about "our" planet at least - major natural disasters - of which there's been a buttload in the last couple of years. So there is a relevance in it for most of us. :)
Still if we were to decide that Earth is no longer a planet. Or rather called a planet, but fgfgfg! That wouldn't change anything. Remember you're using nicknames (I'm not lol). You're mark, mOds. What if you go to another forum and name yourself something else? ;)
It wouldn't change what it physically is, sure - but it would certainly change how we go about talking about it, how we relate to it etc, and this could lead to confusion. As would me changing my nickname on another forum. People would think I'm two completely seperate and different entities, and not just one.
Yeah. I was confused at first when this Nacho guy showed up.
Quote from: Nikolas on Wed 30/08/2006 15:43:38
You talk about wasting money. The internet is a great tool, but here we are arguing about (almost) nothing, which is usually the case in most forums. Heck the internet costs a lot of money to maintain, no? But here we are wasting it.
Eric wasn't exactly talking about wasting money, per se. He was saying that this change in terminology may cause people to view scientists' actions as a waste of money. His interest wasn't in whether they're wasting money, but in the effect it has on the general public.
BAN THE GENERAL PUBLIC!!1!
also, Erenan is right, I was quoting hypothetical people.
What Mr. Colossal said about the public is unfortunately true. Many people will see this reclassifying as an act of incompetence and this is magnified by the media. You see all the "poor Pluto" stories because it's summer and nothing happens, so reporters have to make a big story about nothing.
Science makes progress by reevaluating known facts to see if they can be organized into a more logical system. This involves reclassifying things, like it happened to Pluto. But in that sense Nikolas is right - it's not as big a deal as the media pushes it down our throats. But as I (and others, on these forums and elsewhere) said: Pluto is not going anywhere, it'll still be a *named* part of the Solar system and it'll still be investigated to extract more information about it.
As a matter of fact, I don't really care, if Pluto is a planet or not. What I care about is that now there is a clear, logical (and wonderfully simple) definition for what a planet is. I'm such a geek that I'm actually glad about this. :)
Sh*t Erenan! I have "The AGSer formerly know as Farlander" under my avatar... I am not diguising me or something... ;D
Anyway, Nikolas, your post hasn' t been rude to me, but saying "Who cares" after 4 pages or hot arguments sounded in my head like a "You all ares silly, I ares the smart ass, I don't like this thread, so, move one to one I like most, end of the discussion!11!"
I know this wasn' t not your intention because I think I know you quite well from msn, but it has still been a bit annoying.
No need to apologize, though.
Quote from: Traveler on Wed 30/08/2006 08:04:10
Keep in mind, that the definition of a planet (or any other celestial body) will necessarily be arbitrary.
Which is exactly what all the hub-bub's about!Ã, :)
I did a little reading on my own, and came across this article on Wikipedia (http://en.wikipedia.org/wiki/Definition_of_planet) about the definition of planets. It's a bit technical in parts, but I thought it was a good summary of all the issues, and it definitely shows that there's far from agreement on this issue. Traveler, unfortunately a lot smarter(?) people than you and I are having troubles resolving this.Ã, :)
Quote from: Traveler on Wed 30/08/2006 18:24:27What Mr. Colossal said about the public is unfortunately true. Many people will see this reclassifying as an act of incompetence and this is magnified by the media.
I agree. I think the lesson here should be a little eye-opening to everyone. I tend to have faith that a global community of specialists (not all of whom are in agreement and will continue to work towards some resolution) tend to know what they're doing. But I think the media - perhaps in trying to simplify this for the general public - has mis-portrayed the whole issue.
The media has framed this as: Scientists think there are too many planets in our solar system. Since Pluto has a different orbit than the other planets (specfically, it overlaps with Neptune's), they've decided it's no longer a planet.
But anyone who does a little digging on their own (and how many people do that?) will discover that this doesn't appear to be the case at all. Pluto's orbit in relation to Neptune doesn't seem to have anything to do with this. Instead, it appears that new discoveries have placed Pluto in a field of objects of similar composition, some of which are bigger than Pluto itself. So, does this mean that Pluto is really a planet, or just another object in this field of stuff? Certainly a valid question in light of new evidence. This is a perfect model of how the scientific process is supposed to work.
In short: don't necessarily take for granted everything the press is trying to feed you!
Quote from: Traveler on Wed 30/08/2006 18:24:27What I care about is that now there is a clear, logical (and wonderfully simple) definition for what a planet is.
I'll agree that the new definition seems reasonable. I think the problem is (as I just discussed) that it hasn't been put into its correct context.
Quote from: Nikolas on Wed 30/08/2006 15:43:38The internet is a great tool, but here we are arguing about (almost) nothing, which is usually the case in most forums. Heck the internet costs a lot of money to maintain, no? But here we are wasting it.
Nikolas, I think everyone respects your opinion that this isn't an important issue for average bubba. Heck, I'll wholeheartedly agree that whether we call Pluto a "planet" or "dwarf planet" has no impact on my life - but I do think it makes for an interesting discussion.
But I'm not sure how you can call this a waste of time/money? Especially in the context of a community that's focused on the discussion and creation of a genre of games that has been defunct for 15+ years. (I don't mean adventure games as a whole, but rather the low-res, 2D Sierra/Lucasfilm games that we specifically focus on). Hopefully you don't think this whole community is a waste of time?Ã, :)
Hopefully you can see we're not really just talking about whether we call Pluto an apple or an orange. But we've gotten into the nature of the scientific process itself and the role/behavior of the media. I think these are certainly important issues to everybody!
Hem...
I don't consider this, or any thread to be a waste of time. It was just an example. Don't take it the wrong way.
I use the internet as a tool and I have found jobs over the internet! No it's not a waste of money or time or anything. Although sometimes we do things that are not very important.
I love this forums! :)
(I love MODS)
Quote from: Nikolas on Wed 30/08/2006 21:06:00It was just an example. Don't take it the wrong way.
Don't worry, no hard feelings! I guess the loss of Pluto has everyone on emotional edge. Poor, poor Pluto.Ã, :)