Pluto is not a planet.

alokmohan · Jan 17, 2006

Pluto is planet by convention only.

rfoshaug · Jan 17, 2006

Well, since "planet" is a human-defined term without a clear physical definition, even Jupiter is a planet by convention only. <div class="Discussion_UserSignature"> ----------------------------------My minds have many opinions </div>

mlorrey · Jan 17, 2006

I made a small error there as well: the ecliptic is the plane of Earth's orbit, not Earth's equator. Venus and Mercury have a negative angle while the outer planets have positive angles wrt Earth's orbital plane. WRT the confusing text you quoted, I meant that the effect of the Sun collapsing orbits to its equator should decrease with distance from the Sun, since it is a gravitation-based effect. The Sun has the least angular momentum because it is at the center. The fulcrum in any system has the least angular momentum, as it is playing the part, more or less, of 'immovable object' to its planets. As for why Jupiter is where it is while many other solar systems we know of have jovians orbiting close to their primaries: firstly, such extrasolar planets are going to be detected first because they have the greatest gravitational influence on their primaries due to their size and close orbits. So that is what is called by statisticians as a "selection effect". We don't know the true distribution of planet sizes and orbits out there because our current scientific techniques can best detect the biggest and closest only, so that is what we are seeing.... It is like biologists saying that giant squids are impossible for decades, all because they didn't have the ability to explore those depths with regularity: their research techniques had a built in selection effect that prevented them from seeing the full range of possible squid species sizes. I suspect that solar system's ultimate configuration is highly dependent upon the orbit of the first large planetary object to coalesce. It will tend to capture and shepherd all other objects gravitationally, and either fling them out of the system, into the star, digest or disintegrate them, or force them into an orbit that is resonant in some way to the progenitor planet. In our system, Jupiter has done this, and the jovians have become gas giants primarily by absorbing billions of years of comet

Philotas · Jan 17, 2006

Yup. If you ask the regular man in the street, he`ll probably come with that it is a big, circular object orbiting a star. We should keep it like that, with a few scientific touches. <div class="Discussion_UserSignature"> </div>

harmonicaman · Jan 17, 2006

Just like Bode's Law turned out to be a mere coincidence, the real definition of what constitutes a "Planet" will really have to wait until we have definitive observations of planetary systems other than the Solar System. What about the case of a Brown Dwarf system which has several "Asteroid" sized objects in orbit around it. Would we then call these objects "Planets"? And what about the case of a really massive star or black hole with several suns in orbit and an "Asteroid belt" made up of debris the size of our Earth? Would the objects orbiting the other stars in the system be called planets or moons? Different types of star systems will require new types of planet catagories and they won't be the same as we use in our own Solar System. We really have no idea of the possible configurations of Solar Systems that are out there.

CalliArcale · Jan 17, 2006

<blockquote>In reply to:<hr />hmm. funny. my last 2 posts including one for this thread were erased. never recorded. ??? <hr /></blockquote> I could swear I responded to one of them too! That's very very weird.... I can assure it was nothing intentional. Disturbing, though. They don't seem to have broken off into their own thread either. I have no idea what happened to them. EDIT: Nevermind, I got confused. I responded to you in a completely different thread. There are too many threads on this question. Maybe it's time to lock a few of them, to avoid confusion? Thoughts, anyone? <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

mlorrey · Jan 17, 2006

Brown dwarves exhibit deuterium fusion. Until that happens, it is just a gas giant. The very use of the word 'dwarf' for such a large body implies that it is a star, which requires fusion.

bonzelite · Jan 17, 2006

i will continue dialougue about the angular momentum that is observed in the sun versus what it should be for nebluar collapse theory to fully exite me. essentially everything is to have originated from stellar matter, so that the planets and all existing material within the boundaries of the solar system are of stellar origin. the protoplanetary disk is the sun. the disk coalesced, collapsed, flattened out, otherwise compacted --this act of compaction created, should have created, more and more angular momentum as the solar system drew itself into a spinning structure, an analouge being an olympic figure skater drawing inwardly their center of mass to spin faster and faster and faster. this is not what is observed. and the extrasolar planets that have been discovered are closer to their sun than is Mercury to our sun. far far closer in. some of them are so close to the primary that they are the celestial equivalent distance of an arm's reach away from the sun. and these planets are gaseous, not terrestrial. even if there are many other terrestrial planets farther out that are not yet detected, this violates accretion by order of composition, adding in another inconsistency with accretion theory (mind you, it is highly doubtful in many of these cases that yet another planet that is rocky is between the super gas giant and the primary star --there simply isn't enough space. some of these planets nearly are touching their sun). we then throw in highly inclined orbital geometries of recently discovered KBOs, orbital resonances with Neptune and it's possible perturbative influences earlier on nothwithstanding, and this even further challenges accretion theory as it is commonly drawn out.

bonzelite · Jan 17, 2006

yeah. i have no idea why the forum acted in this fashion. maybe it is my browser that is the problem. i was using Safari, then switched to Explorer. and the prob stopped, but now in Explorer, i must post first, then it posts incorrect spacings, then i must choose "edit," and then repost it in the same form in order for it to preserve the paragraph spacings. otherwise it jumbles everything into one dense paragraph. i don't understand. ???? maybe create a master thread about this planet naming stuff. somehow combine all of them.

mlorrey · Jan 17, 2006

All I can say to that is that if physicists with years of training have trouble solving the three body problem, how predictable do you think a solar system is with thousands or millions of bodies? You are dealing with chaos theory and any one of thousands or millions of resulting equilibria states. Trying to feel it out intuitively is not going to result in an opinion that reflects all possible results. Proto-stellar disks generally do not originate independently, they are usually borne of nursuries, likely with lots of objects and materials tossed out by earlier stellar children impinging upon them. As for Nemesis, that is a theorized stellar companion to the Sun, orbiting 1-2 light years out in an eccentric orbit, that causes the 26 million year cycles of cometary bombardment of the inner planets. If its orbit is at a significant angle to the ecliptic, it could have progressively greater influence on the outer planets, especially during its perigee periods. Here is another thing to consider: in what direction does the progressive ecliptic tipping point? Shouldn't the mass of the core of the Milky Way galaxy have some gravitational influence, as well, on orbital drift?

bonzelite · Jan 17, 2006

"If you can't do the math, your opinion means squat." this is where you and i are at total odds, btw --math is not science. it definitely supports science. but you cannot go basing major reasoning and theory about our origins based solely on math. math creates artificial systems of reasoning that may bear no resemblance to real events. this why we have dark matter, the big bang, black holes, string theory --these are all untestable and unproveable and completely in the realm of conjecture. and these modes of thought dominate cosmolgy today, to a tragic fault. in many cases, many, math means squat. and anyone with simple intuitive reasoning who pays attention can pose threatening questions to the sophisticated mathematical fantasies that are passed of as incontrovertible truths. as well, it is standard fare for the math-skewed politician scientist, once cornered like an animal, to resort to marginalizing the "intuitive" skeptic as an uneducated child who "cannot do the math." the thing is, the questions i pose to challenge the status quo about this topic are real and valid and render very basic key questions unanswerable by mathematical politicians. i'll step off the soap box now <img src="/images/icons/smile.gif" />

yevaud · Jan 17, 2006

Bonz: Math is a science. Math resembles real world events because it can *precisely* model them. Step by step by step. And as observations crawl in, the math mostly predicts what we see. When it doesn't the model is discarded or refined, as the case may be. Brutally and without regret, unless you're that South Korean "scientist" in the news of late. Look where trying to cheat got him: meaning, look at his results - fabricated, not real, therefore his hypothesis and technique were fundamentally flawed. And he refused to alter it, so he cheated instead. Moron. Not everyone in a scientific field "try's" to demean a novice or amateur in a scientific endeavor. Some do. The urge to rant is always there, among all of us. <img src="/images/icons/wink.gif" /> You have to be able to express what you mean in their language. Not just saying, "well I think or I see." Otherwise, you go down wrong paths in the pursuit of the truth. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

bonzelite · Jan 17, 2006

i hear what you are saying. but the debate will rage on. math is not inherently bound to the physical world. for practical purposes we can consider it independent of the known laws of physics, nature, biology, etc. alone, math is not science. it can serve science most definitely. and it does this quite well. the most useful thing about math is that it can create nearly boundless models. these models may reflect the known (or expected) laws of nature, or laws that the mathematician makes up out of the blue. math has the magical property of being able to create alternative universes with alternative realities. the only rule is that these models must have an internal consistency: they can't contradict their own rules. modern cosmology, however, is famous for contradicting itself whenever it needs to. and we are asked to just buy it. in this way, math is an out of control stepchild who needs a spanking <img src="/images/icons/wink.gif" />

yevaud · Jan 17, 2006

Yeah, but there are also very odd conditions in which math *can* contradict itself. But that's when a duality in a condition exists. For example, something can be one thing, then another, depending. A Photon comes to mind. So yes, math can seem contradictory at times. But it still is accurate in modelling events. Remember, much of math takes observation and builds the model from the first equation onwards, to describe what's observed, how it acts, it's properties, and so on. It's not guessing, it's describing. I think what you're actually talking about is that speculative form of math that describes a theoretical event or object, as yet unobserved or experimentally confirmed. Edit: In short, much of math as we know it is terribly abstract. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

CalliArcale · Jan 17, 2006

<blockquote>In reply to:<hr />i was using Safari, then switched to Explorer.<hr /></blockquote> Not to get too far off topic, but I find things to be much more predictable with Safari than with Explorer. I loathe IE. I only use it when I absolutely have to (in other words, when a site is using ActiveX controls or another Microsoft-proprietary technology). You can also try Firefox, a slimmed down and very powerful version of Mozilla. IE will not be supported for Macintosh for much longer (I assume since you have Safari that you are a Machead like myself <img src="/images/icons/wink.gif" /> ), but Firefox and Safari will go on! Firefox behaves much like Safari. I'll pass your post on to the admins, to make sure they are aware of it. Don't know if they'll be able to do much debugging based on that, but at least then they'll be able to watch for more problems like that. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

CalliArcale · Jan 17, 2006

Going back to something that I think got overlooked: <blockquote>In reply to:<hr />the Nemisis issue i am not aware of. do you have any links to this information? <hr /></blockquote> Nemesis is a hypothetical star (presumably faint) orbiting the Sun which periodically perturbs comets out of the Oort cloud and into the inner solar system. There is no real evidence for or against Nemesis; it's as hypothetical as can be. However, the lack of evidence for it, while not evidence of absence, is certainly conspicuous. Nemesis must be either small or dark or both to have gone undetected so long, unless it does not in fact exist. The idea goes something like this. Paleontological records show a rough pattern of extinction events, possibly due to cometary impacts. Perhaps this is because something is disturbing the orbits of protocometary bodies out in the Oort cloud on a regular period, such as perhaps a very distant companion star to our Sun which has not yet been detected. (Some have suggested that it may in fact be one of several known stars, orbiting so far out we haven't actually determined that it is in fact orbiting the Sun.) Another idea is that Nemesis is actually several stars which aren't orbiting the Sun but which have made relatively close flybys in relatively recent times, grazing the Oort Cloud and sending comets on a path which would eventually get them into the inner solar system. A related idea is Planet X, a large planet in the outer solar system which has not yet been detected but which is responsible for perturbing the orbits of Oort cloud objects, turning them into comets. The Nine Planets has a section about Nemesis in their page devoted to hypothetical planets. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

bonzelite · Jan 17, 2006

I think what you're actually talking about is that speculative form of math that describes a theoretical event or object, as yet unobserved or experimentally confirmed. Edit: In short, much of math as we know it is terribly abstract. yes. we have agreement there <img src="/images/icons/wink.gif" /> now only if you'd come over to the dark side and agree that much --a lot-- of cosmology is preoccupied with this kind of math<img src="/images/icons/laugh.gif" /> tehehehe tehehehe tehehehe

bonzelite · Jan 17, 2006

yeah, i like the compactness and ease of use of Safari; i don't like Explorer, but i find some sites run better on that. i do have a Mac. i will check out Firefox. thanks for the support in this matter. we'll see if anything comes out of it. about Nemesis. this seems like a totally hypothetically created thing to explain what is nearly entirely unknown. the outer solar system is very exotic and mysterious, so we have planet X and Nemesis. with the growing number of KBO planets, i would buy the idea of dozens of planet X's, actually, before it's all said and done.

mlorrey · Jan 18, 2006

Actually, Calli, there is a significant amount of evidence for it: a) the paleontological records are far more than a 'rough' pattern. They show a solid pattern of one or more extinction events within 1 million years of a regular 26 million year cycle. Statisticians say this is impossible over so many cycles to be considered "rough" or 'random'. B) This is reinforced by various extinction records of various clades, and is often supported by iridium concentrations or other isotopic evidence indicative of extraterrestrial origin. c) other astronomers have shown that a statistically significant number of long period comets originating from a 'hot spot' in the sky have reconstructed original apogees that describe an arc through the outer Kuiper Belt/Inner Oort Cloud that, if part of the orbit of an undiscovered body, would have an orbital period of approximately 26-30 million years. This group of astronomers proposed the Nemesis hypothesis independently of Alvarez and his allies that have found the geological/paleontological data. Thus, you have two independent sources of data that describe something that behaves the same and can be the cause of both phenomena. Astronomers who have predicted this objects orbit say it is likely a large brown dwarf or a small red dwarf, likely one of the 5,000 red dwarfs in the sky that are known but whose distance from us has not yet been measured. If it is a brown dwarf the search will get much much harder, given it would be about 1.0-1.5 ly away at the moment (the last pass through the inner Oort was about 5 million years ago). Nemesis has nothing to do with Planet X. Planet X is the fancy of some Von Daniken-like kooks who rely on Sumerian records and a retired US Naval Observatory astronomers distorted statements to claim that Nibiru, the home planet of the Sumerian Gods (one of which was the Jewish and Christian God El/Enki/Yahweh), comes streaking through the solar system every

mlorrey · Jan 18, 2006

Bonzelite, Regarding my sigline: I am patently tired of people around here making completely bald faced and unsupported claims (or dismissing well proven arguments made by others) without a scintilla of scientific evidence, references to published studies, or demonstrating support for their argument through mathematical analysis. You probably notice that I do a lot of the latter in my posts. When it comes to orbital mechanics, THERE IS NO SUBSTITUTE FOR DOING YOUR HOMEWORK. Whether it is going to Jupiter or Pluto, or arguing about what is a better propulsion system, etc. MATH IS KING. I come from an engineering background, not scientific. Intuition only means something in engineering if it is supported by the math. An engineer whose intuition disagrees with his math, and goes with his intuition, tends to fail at engineering. Engineering is all about math. Do you think the Romans ever built a bridge or a stadium on intuition? Back then the penalty for screwing up was getting fed to the lions, not just a pesky liability suit. You can bet they did the math. Math may not be science, but it IS engineering. If you can't prove the validity of a design with math, well, its just a pretty drawing or sculpture. Doesn't mean it isn't valid, just that you don't have the maths to prove it is so. When millions or billions of dollars are on the line, and often many human lives, you can bet that math is the be-all and end-all. Bankers and lawyers don't give a flying frig what your intuition tells you. If you can't prove it mathematically, you don't get the money.

bonzelite · Jan 18, 2006

"MATH IS KING" i am glad to at least have your agreement that math is not science, however in concert the disciplines function. math is king when it serves and delivers --like an errand boy. in context of cosmology, a lot of it is absolute mathematical contrivance, with pyramids of models created to describe theory. cosmology is not civil engineering or aerospace. little is served but conjecture. what is delivered is largely untestable theory. and very little of it is factual. for example, a singularity is a mathematical device only. it otherwise has no tenable application to reality. and further models that are devised around the premise of infinite coordinate time due to time dilation, total collapse of spacetime curvature, are completely theoretical. instead of seriously questioning the angular momentum deficiency of the sun, this is glossed over and explained away by myriad complexities that are untestable. a balance of math and science that provides something tenable is the best marriage of the two, and, in a sense, they become one. but cosmology today, that is supposedly in the realm of science, has been nearly entirely replaced with mathematical systems only. to me, this represents a tragic failure of vision and in the wrong direction to point the ship. math is not king in any way and has overstepped it's propriety of function.

alokmohan · Jan 18, 2006

Planet is very old concept havig historical background.Planets means wondering stars and ancients distinguished them from fixed star ,star we call them.Ancients were not clear that planets are small.Hence the that we see.Pluto was discovered by Tom baugh by telescope and he was seaching for larger than life planet.Pluto is not what was being searched for.

mikeemmert · Jan 18, 2006

bonzelite; I have been noticing in several posts that you have mentioned the lack of the sun'ts angular momentum with regard to the rest of the solar system. For instance: (bonzelite): " instead of seriously questioning the angular momentum deficiency of the sun, this is glossed over and explained away by myriad complexities that are untestable." For lurkers, the problem here is that the sun rotates quite slowly, so in spite of it's huge mass, it has little angular momentum; however the planets, with orbital velocities of many kilometers per second, have huge angular momenta. Angular momentum is mass x radius x angular velocity. RPM, engine speed as measured by a tachometer, is angular velocity, only measured in units useful for describing engine speed, different units are used to describe astronomical bodies (the Greek letter omega is the shorthand for that measure). How did the material that makes up the Sun, which is nearly all the matter in the solar system, get rid of it's angular momentum so that it could stop orbiting the center and fall into the ball of the Sun? I started a thread on that, "Rainbow Tornado Speeds Away From Young Star": http://uplink.space.com/showthreaded.php?Cat=&Board=sciastro&Number=425114&page=4&view=collapsed&sb=5&o=0&vc=1 This post had nothing to do with Cherenkov radiation, but somehow the thread wound up being all about that. Perhaps the angular momentum of the Sun was carried away by Herbig-Haro objects. The link posted above has links to Herbig-Haro objects. Briefly, Herbig-Haro objects are jets of material capped by a shock wave speeding away from the poles of young protostars. Unfortunately, Herbig-Haro obje

CalliArcale · Jan 18, 2006

mlorrey, regarding Nemesis, my point was that there is no evidence Nemesis actually exists -- just some very compelling hints that something might be out there. Nobody's detected Nemesis. That doesn't mean it's not there. Just that nobody's found it. Planet X has been hijacked by the Nibiru crowd (mainly because a lot of more serious astronomers have abandoned the search for it), but the notion actually goes back quite a ways. It hasn't always been connected with comets, though. I agree that the Nibiru crowd are way out on the fringe. "Nutty Nancy" is easily the best example of these. She's a complete flake, in my opinion. She keeps predicting that Nibiru will destroy the Earth on a specific date, which she changes every time the last predicted date goes by without any destruction. <img src="/images/icons/tongue.gif" /> <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

mikeemmert · Jan 18, 2006

Hi, Calli, how r u this morning?<blockquote>In reply to:<hr />Planet X has been hijacked by the Nibiru crowd (mainly because a lot of more serious astronomers have abandoned the search for it), I agree that the Nibiru crowd are way out on the fringe.<hr /></blockquote>I kind of have to answer the other poster through you since he insinuated that I need to be taken out and shot, and I hotly disagree with that sentiment! (That was a PM growing out of the New Horizons thread when I tried to show what the "nutty protesters" were really trying to get at and got a reflexive, knee jerk reaction.) It's a big problem when people hijack an idea. I wondered what happened to the Nemesis idea. The guy who proposed it wound up running a restaurant. Tragically, he was a better scientist than restauranteer. Nevertheless, Sepkoski and Raup's idea has serious problems quite aside from it's guilt-by-association social problems. "a) the paleontological records are far more than a 'rough' pattern. They show a solid pattern of one or more extinction events within 1 million years of a regular 26 million year cycle. Statisticians say this is impossible over so many cycles to be considered "rough" or 'random'." I looked at that data and it didn't really seem to be that strongly correlated. The pattern had gaps in it with no extinctions. The peaks were off a little in many cases. Unfortunately I am going from memory, but I will leave it to the other poster to post that, and also about how long it takes a comet, once perturbed, to actually make a collision and how that would affect the correlation between a Nemesis orbit and how well the peaks fit a sinusoidal pattern. " B) This is reinforced by various extinction records of various clades, and is often supported by iridium concentrations or other isotopic evidence indicative of extraterrestrial origin."<f></f>

Pluto is not a planet.

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