obscurus

Don't be too sure - in Scandinavia, fewer than 15% of the population profess to hold any religious beliefs, likewise Japan, China and France have very similar levels of secularism. True - the human ability to develop a theory of mind (that is, imagine what someone else is thinking and predict/influence their behaviour - a very useful ability, and one that was critical to our evolution) leads to an all to common error of assuming that a theory of mind can be applied to things that do not have a mind, like the weather, the sun, & the Universe in general. People operating under this fundamental error of thought invent gods as proxies for mindless things beyond their control, projecting anthropomorphic personalities on them and then trying to influence their behaviour through prayer, sacrifice and so on. People living in heavily hierarchical societies also run into a problem of ultimate authority - they realise that a king or president or whatever is ultimately a human being just like them, so they then invent an even higher authority (God) so that the king etc. can become an agent of this deity and therefore more than just a mere human. The monarch's power then becomes absolute, divine and unquestionable. While this arrangement creates a society with a tight degree of control and cohesion, it fails when people actually start thinking for themselves and start to wonder if maybe there is a better way of organising society than in a rigid hierarchy propped up by fantasies of deities and divine blessings. In genuinely democratic societies that encourage freedom of thought, religion will always die a slow death, because religion requires total indoctrination and enforcement from childhood to death to maintain its grip.

Scratch those crappy cars, get a Toyota Camry hybrid, or just about any other hybrid electric car for that matter. Toyotas are the most reliable cars you can get (in my experience). Don't get a Prius though, as they are poorly designed in terms of rear window visibility. If you have loads (and I mean loads) of money to splash out, get one of these: http://www.venturi.fr/us/fetish/specs/specs.php3

Fuck, that beats some of my efforts, and I thought I had Long-Poster's Syndrome (LPS)!

Along the lines of Gildoran's comments, the only reason you can say that the physical does not account for the mental is because of the complexity of analysing the system. But this leads to a false line of thought. There is no separation between your consciousness and the underlying neural activity that drives it. You only think there is becasue you are able to think about your own thoughts in an abstract way. In fact, it can be very easily shown that your consciousness is determined by your brain. For example, if a particular area of the optic lobe of the brain is destroyed, that person will not only lose their sight, but their ability to remember things they have seen, and even their ability to conceive of what sight is, or was like. It becomes like sight never existed for that person. Clearly, the consciousness of vision arises from this part of the brain. Similarly, with blindsight, a person can see without being conscious of seeing, due to brain damage. And many other mental functions have been linked not only to particular areas of the brain, but particular neurones in the brain. Things like memories are not the absolute, factual things we perceive them to be, bt rather, the brain takes vague bits and pieces of information we receive through our senses and thoughts, and then reconstructs them each time we recall them. Not only that, but every time you remember something, that memory changes slightly. You can alter the way a person thinks and feels by altering their brain. You can turn a mild mannered reserved person into a sociopath by disabling the areas of the brain that handles inhibions and empathy. This permanently changes that person's personality. Everything you think is you is defined by a particular configuration of atoms in a watery sac, and as soon as that configuration changes, you change. When you die, that sac of chemicals changes into a form that can no longer support any of the things we perceive as consciousness. here is a link for you to consider: http://www.newscientist.com/article.ns?id=...line-news_rss20 There is no reason at all to think your consciousness is anything more than the temporary activity of neurones in your brain.

Indeed, Buddhism is an interesting case, as it is both atheistic and denounces the concept of immortality of the personality. Buddhism is more a philosphy that has become a religion due to zealotry and misinterpretation. Buddha was not a god, rather someone who had acheieved enlightenment. In Buddhist philosophy, enlightenment means the complete destruction of the self as distinct from the rest of the universe. Then there are the animistic religions (the most primitive of all religions), which do not recognise personal immortality or gods. Animists regard everything in the universe as parts of the same thing that change over time. Everything is said to be alive, even things like rocks or dried up skeletons, so in that sense, you are "immortal" in animist eyes, as you don't die, you just change state, and merge with the universe. In terms of what is currently understood by science, everything is just a temporary configuration of space-time, there is no discrete "self", it is just an illusion. and the universe itself appears to be finite and mortal. All religions have pretty much the same thing to say when it comes to how you live your life and treat others, and it is all self-evident to anyone who bothers to think about it. Jesus had nothing really profound to say about anything that none of a thousand "prophets" and self-help gurus before and after him all over the world hadn't figured out. Jesus was no different to Tony Robbins or Deepak Chopra - someone who could spin the bleeding obvious, infuse it with some mystical bullshit about God or angels or chakras or some similar rubbish, and milk thousands of gullible dimwits out of their ability to think for themselves, if not their money. And then people use these religions, tack on their own bits to advance their own agendas, and it becomes a hodgepodge that can be used to justify any kind of behaviour you like.

In terms of natural landscape generation, no it won't. I'm only referring to the forests in Oblivion, which uses the SpeedTreeRT middleware http://www.speedtree.com/ to generate thousands of completely unique, animated trees at run time, which is far less time consuming than modelling and animating thousands of different tree models by hand. Obviously, some things cannot be generated procedurally in any convincing way, such as buildings and artificial structures, which will need to be modelled by hand for the most part. But hand modelled objects can be textured procedurally very effectively - you can apply all kinds of weathering and grime algorithms to generate grime maps for models, and there are a number of tools out there that greatly automate character modelling, so that you can start off with a basic humanoid prototype and apply all kinds of procedural deformations to generate thousands of unique characters. The obvious downside to all this is that games will become less distinct from each other unless the game designers really put their efforts into tweaking the procedurally generated content with their own stamp. But then regardless of how you do it, the more detailed and realistic games become, the less visually distinct they will become, and the more the authors will have to focus on gameplay dynamics, plot and story development to distinguish their games. Compare Crysis and Haze ( http://hazegame.uk.ubi.com/ ) - two completely different game engines, two different games that look almost identical in a number of screenshots. They both have a high level of visual detail and realism, and the more of that you have, the harder it is to make your game look distinct from any other from a few screenshots. Personally, I think this is great, becasue once the eye candy has reached a point where it can't get much more realistic than it is, the only way game designers can distinguish their products will be through gameplay and story, meaning these elements will be likely a lot better than they have been of late. It is the stories and gameplay that makes a game great, not so much the quality of the graphics, though that certainly helps.

Exactly. What on Earth would you want a HUD for?

I am not whining because Pluto was reclassified, I am whining because of the dubious grounds on which it was reclassified. If the IAU comes up with a scientifically defensible defintion of a Planet that excludes Pluto or any other object from planetary status, that is fine. But at the moment, I and a very large number of other scientists, regard the currrent definition as unscientific bunk. It isn't the semantics that bothers me, it is the lack of scientific rigour and lack of consistency and clarity that causes me such consternation. At the moment, there are potentially a number of objects that are bigger than Mercury that would now classified as "Dwarf Planets", yet somehow Mercury retains its status as a planet. There are now a huge number of extrasolar planets that are no longer planets becasue of sloppy wording by the IAU. Most of the planets in the Solar System do not pass the criterion of "clearing their neighbourhood", and vague as it is, there is no way you can say Pluto isn't a planet without also demoting Neptune. And arguably any planet with moons has failed to clear it's neighbourhood, and thus isn't a planet. Sloppy wording and inconsistent reasoning are where my issues lie, not with semantics as such. Redefine your terminology if you will, but at least be consistent and clear. And you are the one who needs to grow up if you think that by expressing a perfectly valid opinion I am somehow comparable to Hitler. I find that rather offensive, frankly. Instead of arguing your case coherently (which you normally at least attempt to do), you simply back out without even trying to counter my arguments, (which incidentally, are shared by a very large number of my fellow scientists, so it is not as though I am alone in my opinions) and launch dubious ad hominem insults at me. Real mature, oDD. @Dram: "Uranus DOES rotate around a single axis, though it is a wierd one. Or are you referring to that it also orbits the sun and thus means it has 2 axes?" Well, like all planets, Uranus has precessional motion, meaning it's axis of rotation moves around a bit, however, Uranus' axis of rotation was highly altered by a passing planet sized object at some point, and it is still not really stable. Since a planet's axis of rotation can potentially be easily changed by a passing mass, it is a very poor criterion on which to define something. @Ishtvan: "I'm pretty sure the tendancy to form a sphere shape depends heavily on the materials making up the object. It's not just self gravity that nudges things in the direction of sticking together and minimizing surface area for a given volume with a sphere shape. There are also contact forces, hydrogen bonding, interface energies between different materials, etc." Material density is really the only major factor in determining the size at which self gravity will collapse an object into a spherical shape. A low density cloud of gas will need to be much bigger than a lump of rock to collapse into a spherical shape under it's own weight. The material on object is made of will of course affect this behaviour, but if you are going to use material as a criterion, then you need to create a new set of classifications. Gaseous objects will need a different name to rocky objects, which will need a different name to liquid objects etc. You can't just say everything that is made mostly of water in a solid state isn't a planet, everything else is - there is no consistency there at all. @Gildoran: "My point is that you're arbitrarily assuming that having "planet" describe the size/shape of something is superior to describing its behavior. There's nothing inherently wrong with choosing a definition of "planet" such that Earth would no longer be a planet if it were ejected from the solar system..." Good point. See oDDity, these are the sort of arguments you could have used, as an alternative to childish personal attacks. However, to be scientifically useful, a classification scheme that defines the fundametal class of an object needs to be able to do so in the context of the object in isiolation, without reference to other objects where possible. I suppose you could have a scheme where the base category is simply "object", and "planet" is an object with certain properties, such as above a certain size, orbiting a star etc. I wouldn't have a problem with that per se, except that it creates issues of clarity of its own, and measn that if you come across an Earth-like object deep in interstellar space, you need to invent yet another term to describe it. My preferred option is to minimise the number of definitions and classes by using a hierarchical system, rather than coming up with a special name for every possible object in every possible situation.

Your definition is way, way too complicated, and has several problems with it. First, using absolute units, such as suggesting that the object have a volume of 27,832,317mi^3, is totally out of the question. Such a measure is arbitrary in the extreme, and relies on too meany other things being defined. You need to be able to frame it in the context of a unit independent measure, such as the ratio of the polar to equatorial diameter, corrected for distiortions caused by orbiting masses and axial rotation. Second, rotation is irrelevent. your definition would exclude Uranus, whuch has a somewhat complex rotation, and it doesn't account for objects that barely rotate at all. I don't know why you even thought that was worth mentioning, it seems like a pretty bizarre criterion, frankly. Third, it doesn't take into account objects ejected from the orbit of a star, and are located in interstellar space. A simple definition is all that is required: Object is large enough to form a spheroid (as measured by the above test - a polar to equatorial ratio corrected for distortion of approximately 1:1) by self gravity is all you need. If you want to make a distinction between stars and planets, you can add the clause that it is not so large that it spontaneously initiates a fusion reaction. Of course, you will have to arrive at a somehat arbitrary decision as to how much of a deviation from spheroidal is acceptable, but that is kind of moot when you have corrected for things that will distort a planet's shape. If your definition is more complex than that, you are barking up the wrong tree. There are billions upon billions of planets in the universe, I don't know why people want to keep coming up with contrived reasons to limit the number to 8 or less.

Rubbish. You just have to ditch your preconceptions about what a computer game can or should be. If all people thought the way you do, there would never be any innovation and we'd all still be chasing antelopes with rocks and digging for tubers. The easy way is the boring way - it has been done before. Take the hard path, it is infinately more rewarding in the end. I am all for adding unpredictability to AI, and I can't think of any technical reason why it can't be done. It would create a completely new gameplay dynamic, one that I look forward to eventually experienceing, though I don't expect it from TDM. But then I'm not an AI coder, so I guess I'll just have to take what I can get...

The thing you have to remember is that next gen game engines will make much more use of procedural content generation. This will mean that games 1. take less time to make and 2. will have richer and more detailed content than ever before. Tools like SpeedTree allow a mapper to proceduraly generate an entire forest of fairly realistic, unique animated trees (used to good effect in Oblivion). There are a number of game engines that include a range of tools to generate all kinds of content automatically, and all the mapper has to do is refine and tweak things, rather than worry about lots of little details everywhere. The upshot of all this? Two or Three years from now, game engines will be tools that very small dev teams (maybe even single individuals) can use to create an entire game using procedural content generation. The mod scene will flourish once again...

The word "moon" is just a redundant equivalent of the word "satellite". They really mean the same thing AFAIAC. Which is all the more reason to avoid vague terms like "clearing the neighbourhood", and also why you should avoid definitions that make reference to other objects, or particular temperatures as much as possible. It needs to definable without using arbitrary units of measurment. And it needs to work regardless of where something is. It is difficult though, because there will always be things that are borderline between one class and another.

The reason it is wrong is that it is fairly likely that there are numerous planets that have been ejected from their original orbit around a star, and are drifiting in interstellar space. It would be silly to call an object similar to Mars a planet when it is orbiting a star, and something else when it isn't. Planets are wanderers of the heavens - whether or not they are wandering near a star is not relevant to their base level object class. Defining something as a satellite when it is orbiting somehting is appropriate, becasue the definition describes a behaviour that is particular to that circumstance. Earth is a satellite of the Sun, so calling something a planet and a satellite is fine as they are not mutually exclusive. Planet descibes what the object is satellite describes what it does. So the reasons it would be wrong to use some kind of orbital information when describing a planet are: *Redundant terminology - the word satellite already describes one object orbiting another. *Needless exclusivity - the same object becomes different things depending on where it is if you use orbital information to define it. A planet is the same thing wether it is a billion light years form any other object or it is in a complex orbit around several other bodies, or something in between. *Things need to be classifyable without reference to other things (as much as is possible), before you start layering other categories on them. You should be able to define a planet without referring to orbits, stars, neighbourhoods etc, and you should be able to do it in a way that does not involve the use of arbitrary units of distance etc. You can then layer information on top of the base category when and where it is relevent. E.g Europa is a planet (as far as I am concerned), that is also a satellite of Jupiter which happens to be a satellite of Sol. Calling one type of object a planet becasue it primarily orbits the Sun and another a moon because it primarily orbits a planet is silly IMO. There are moons of Jupiter and Saturn which are clearly the same class of object as Mars or Mercury (or Pluto).

Apparently quite a few professional astronomers (and quite probably a majority - the IAU vote was cast by a small majority of 400 or so astronomers, which is hardly representative of the wider opinion of astronomers) - see the link in one of my previous posts. oDDity: "interesting that you think shape is relevant but nothing else is, just because that's how you happen to want it to be." Shape as a result of self-gravity is relevant becasue it is a consistent and scientifically definable way of classifying something. Since an object's temperature will vary immensly depending on its location, age and other variable which are highly mutable, it is a poor choice for classifying an object. Stellar objects can move around a lot. You don't like things made of ice being called planets, but what about liquid water? A gaseous planet of water vapour? You could use material to classify something as being a planet, but again, you run into problems if you are not careful. Jupiter is made primarily of hydrogen gas, and we call it a planet. Venus is made of rock with a thick atmosphere of carbon dioxide. And most planets are made of a number of materials in layers, so your definition could end up being quite complicated if you base it on material. And you would have to be careful not to be too arbitrary here - excluding water ice out of all the materials planets can be made of makes no sense at all. I could just as arbitrarily say that becasue Jupiter is not made primarily of rock, it isn't a planet. As you may have gathered, I am not too impressed with the way the IAU has been officially defining things, as they are using highly arbitrary and unscientific definitions for things, which as a scientist, irritates me no end. You would never get away with that in any other scientific field. And there are a substatial number of professional astronomers who would agree with me (the IAU vote on the definition of planets was very close, and was not really representative of the wider astronomical community). oDDity: "Hang on though, any drop of liquid becomes spherical in space, regardless of its mass, so obviously the material is relevant." No, a drop of liquid can assume a spherical shape due to surface tension, not self-gravity. Actually, any drop of liquid will do this to one degree or another, and they form a blob that wobbles around, and is not consistently spherical. So should we exclude all planets in a liquid state? Gildoran: "While I agree with the idea of calling anything with enough mass to be spheroid a planet, I don't see why orbits and behavior and such can't be taken into account for scientific terminology; how else do you define a "moon" or "satellite"? (surely those are useful scientific terms) And I don't see anything wrong with taking into account the material something is made of, the way terms like "gas giant" do." Sure, but the term "planet" should be the base category, upon which things can be subcategorised. "planet" means "wanderer" in Greek, and is quite appropriate for things floating around in space. Personally, I would classify moons as planets where they fit my definition, and calling them moons or satellites would simply be a descriptor of their current location. If say, Ganymede or Titan happened to be orbiting on their own, they would be called planets, unequivocally. In fact, a large number of the moons of Saturn and Jupiter are considerably larger than Mercury. They are planets that just happen to be orbiting bigger planets, and this is why an object's position or orbit should not be a consideration for the base classification. If I were to use oDDity's "logic", I could arbitrarily say Mercury isn't a planet becasue it is too small and too close to the Sun, Jupiter isn't a planet becasue it is made of gas and is too big, Neptune isn't a planet becasue it hasn't "cleared its neighbourhood", Uranus isn't a planet becasue its axis of rotation is at a wildly different angle to the rest of the other planets, Venus isn't a planet becasue it is too hot and rotates the wrong way on its axis, etc. Now that would be pathetic, oDDity. You need to get over your ice phobia. You need a scientifically based classification that avoids arbitrary and sloppy definitions as much as possible, that can be applied to any object, anywhere.

It all has to do with evolutionary history. Reptiles and birds have 3-4 visual pigments, and can see red very well. Mammals started out as nocturnal critters that had no need to see red light, since there is not much around at night, and lost the visual pigment that is sensitive to red light (a red flag appears black to a bull). However, some groups of mammal, notably the primates (we are primates), re-evolved a visual pigment that is sensitive to red light, however, it is far less sensitive than the one that reptiles and birds still posess, so we don't really se reds as well as we think. Pretty much all other mammals bar primates have dichromatic vision (humans, apes and monkeys have trichromatic vision): their cones detect light in the ultraviolet-blue range and in the yellow-green range, and most nocturnal mammals have far more rods than cones, further limiting their colour perception and ability to resolve detail. Nocturnal animals also tend to be very short-sighted. Diurnal animals (including us) have corneas and lenses that block UV light, even though their cones can detect it, to prevent damage to the retina during the day. If you have cataract surgery, you will theoretically be able to see UV for the first time. Most night-time wildlife photography is shot using red filtered lights, and sometimes with red filters on the camera lens - nocturnal animals are oblivious to it, and are unaware that there is any light source.

Here you go then: http://www.abc.net.au/science/news/stories...40687.htm?space http://www.abc.net.au/science/news/stories...19677.htm?space http://www.abc.net.au/science/news/stories...96218.htm?space http://www.newscientistspace.com/article.n...line-news_rss20 http://www.newscientist.com/article.ns?id=...line-news_rss20 And here is a very pertinent link: http://news.bbc.co.uk/2/hi/science/nature/5283956.stm "Dr Alan Stern, who leads the US space agency's New Horizons mission to Pluto and did not vote in Prague, told BBC News: "It's an awful definition; it's sloppy science and it would never pass peer review - for two reasons. Pluto discoverer Clyde Tombaugh pictured in 1980 (AP) Pluto was discovered in 1930 by the American Clyde Tombaugh "Firstly, it is impossible and contrived to put a dividing line between dwarf planets and planets. It's as if we declared people not people for some arbitrary reason, like 'they tend to live in groups'. "Secondly, the actual definition is even worse, because it's inconsistent." One of the three criteria for planethood states that a planet must have "cleared the neighbourhood around its orbit". The largest objects in the Solar System will either collect together material in their path or fling it out of the way with a gravitational swipe. Pluto was disqualified because its highly elliptical orbit overlaps with that of Neptune. But Dr Stern pointed out that Earth, Mars, Jupiter and Neptune have also not fully cleared their orbital zones. Earth orbits with 10,000 near-Earth asteroids. Jupiter, meanwhile, is accompanied by 100,000 Trojan asteroids on its orbital path. These rocks are all essentially chunks of rubble left over from the formation of the Solar System more than four billion years ago. "If Neptune had cleared its zone, Pluto wouldn't be there," he added. Stern said like-minded astronomers had begun a petition to get Pluto reinstated. Car bumper stickers compelling motorists to "Honk if Pluto is still a planet" have gone on sale over the internet and e-mails circulating about the decision have been describing the IAU as the "Irrelevant Astronomical Union". "

I remember reading it in an article apearing in New Scientist a few years ago. The idea was that the thick atmosphere was quickly stripped off by the solar wind (which would have been much stronger then than it is now) very early in the Earth's history, and Earth was struck by Orpheus later. Supposedly there is some physical evidence to back this up in the concentrations of hydrogen found in rocks, and the fact that Earth still has a strong magnetic field also supports this theory, as strong magnetic fields are expected as a result of rocks being crushed into a superfluid metallic state by tremendous pressure and spinning around, but it has been a while since I read it. I shouldn't have said many theories, as I know of only one for sure. Whoops I think the idea has been somewhat discredited by the discovery of numerous extrasolar Gas Giants orbiting very close to stars. None of the accretion models do a very good job of explaining the characteristics exhibited by these big planets in other systems, so there is plenty of room for any and all solar system formation models to be wrong. The fact that Venus has a very slow retrograde orbit indicates that it either collided (or nearly collided) with something very big in the past, or it itself was flung from a very different location and captured into a new orbit by the Sun - it is a big presumption to think it formed where it is now (and this is really the case with all planets). Either way, planets move around, and for all we know, half of the planets in our solar system could have formed in another star system, and were later captured by the Sun. But then this is why orbital patterns should never be used as a criterion for classifying stellar objects, as planets, stars, asteroids etc get flung around so often that you can really only guess at what hapened - there is too much going on to model, and the physics is too complicated for even present day super-computers to handle. The orbit of an object should be completely disregarded as a criterion when deciding whether something is a planet. IMO.

Well, actually you are sort of right, the cones that detect yellow-green light are the most sensitive, however, at night time very little yellow light is emitted by most natural sources (light reflected off the moon shifts to blue due to the atmosphere), and emitted and reflected light tends to have less yellow in it. But if there is a fire or some other source of yellowish light, it will drown out other colours, and yellows will be especially visible.

That depends on your definition, and there are a few floating around. Many astronomers would classify Jupiter as a Brown Dwarf for the simple reason that it emits more energy than it receives form the Sun. And many models of Solar System formation predict that the Earth was once more like a gas giant, having a much thicker atmosphere than it did now. However, recent discoveries of extrasolar planets have put most of the more popular theories of planetary formation in the garbage bin. oDDity: The material an object is made of is irrelevant to wether or not you classify it as a planet. That is an entirely arbitrary and pointless distinction. It makes no difference if it is made of ice, granite, methane, peanut butter or brie. And again, it should make no difference what the object is orbiting, or if it is orbiting anything at all - that is irrelevant. Earth would remain a planet if it were flung far into interstellar space, it would be a planet if it was composed entirely of water ice. Defining a planet by the temperature it has, or especially used to have is a monumentally stupid idea. Temperature is irrelevant. Again, you are proposing a ridiculously complex and baseless definition of planets purely to satisfy your strange and inexplicable dislike of small icy objects - did you choke on an ice cube or something as a child?

They did go with my definition (see criterion b ), they just tacked a lot of useless fluff onto it that just about rendered the final definition worthless. I would simply scrap a ) and c ) of the IAU definition. But you are correct, there is a bit of arbitrariness here. Saturn is substantially out of round - you could arguably say it isn't round enough to be a planet. So you would have to take a somewhat arbitrary ratio of the polar radius and the equatorial radius as your definition of "round", taking into acount the rotational velocity of the planet, as this will distort the "roundness" - if Saturn were to stop spinning on its axis (and had no rings or satellites), it would become perfectly round. You can't avoid being arbitrary here, but you can minimise the degree by avoiding vague, poorly thought out classification systems. Regardless, the criterion of roundness is far less arbitrary and far more scientifically based than the other two that were tacked on. a ) is no good because an objects orbit should be irrelevant to its clasification, and at the very least "Sun" should be changed to "Star" in order to include other planetary systems, c ) is no good because it is too vague and poorly defined.

The cones most sensitive in low light peak at 420nm, which is a bluish(450nm) violet (400nm). Your rods have a peak sensitivity at 498nm, which is bluish-green. The cones that see red light have the lowest sensitivity, so as long as you take a lot of the red out of the ambient lights for a night time scene, it will look about right.

Sure you are correct insofar as we can arbitrarily call anything by any name we like. But you are wrong about it not being stupid. It is stupid because the definition is unclear and vague. If they had come up with a consistent, logically tenable system for classifying stellar objects that happened to change Pluto's object class, I would be fine with that. As a biologist, I'm used to the classification of organisms changing as the need for further distinciton is required, or more information makes old classification schemes unworkable. And that is the other reason why the IAU's decision is stupid. It is unworkable. It creates a situation where it is extremely difficult to know what someone is talking about when they say "planet", and it will take an inordinately long time to work out whether an object meets criterion C of the scheme, since it is unclear about what it means, and it is difficult to assess how many objects are in the neighbourhood of another object, and what you define as the "neighbourhood" of a planet or otherwise. And it makes it difficult for astronomers to classify extrasolar objects, because the IAU in its typically narrowminded way failed to consider objects beyond the orbit of Sol. A classification sheme isn't just for the purpose of having fancy names to muse over. It is a functional system for communicating useful information, and analysing the world. Scientific terminology needs to be much more rigorously thought out than just any old twit arbitrarily naming things as they please.

Quite the contrary, they made a definition that was far too narrow, and even then, one of the criteria for planethood is so vague and poorly defined that you can fudge anything in or out on a whim. It has nothing to do with science. This is exactly what is happening - most of the planets (especially Jupiter and Mars) routinely cross the orbits of a range of objects, and pretty much every planet crosses the orbit of some other body at some point or another. So by the very definition set by the IAU, you can scrub Earth, Mars, Jupiter, Saturn, Uranus, and probably Neptune off the list, because the criteria for planethood are now so vague and open to interpretation that you can fudge all kinds of things to justify some object not being a planet. A definition of planethood should have nothing to do with how close it is to a star, what angle it orbits it at or anything else that cannot be observed in isoloation. Suppose some object passing through the Solar system ripped Mars out of its current orbit into a new orbit in the Kupier belt, and at a wildly different angle to the orbit of the other planets. Would you then say it isn't a planet, because it no longer sits in some arbitrary orbit? A hierarchical classification system similar to the one used to classify living things is appropriate, even if it means that the number of known planets in the Solar system shoots up to twenty million. A classification system based purely on an emotional dislike of Pluto and other large objects in the Kupier Belt is grossly inappropriate and has no place in serious scientific discussion. I should point out that the vote was very close, and had more Astronomers bothered to participate (most Astronomers regard the IAU as a bunch of largely irrelevant wankers, so they don't often participate unfortunately), the definition I am endorsing would have gotten up (it looked like it would for a while), and you would have had to add another 3 planets at minimum (not counting the 50+ known extrasolar planets that have now been demoted to who knows what). From the IAU website: "The IAU members gathered at the 2006 General Assembly agreed that a "planet" is defined as a celestial body that (a ) is in orbit around the Sun, (b ) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c ) has cleared the neighbourhood around its orbit." a - What about objects orbiting stars other than the Sun? After all, there are over 50 (and counting) things that used to be called planets orbiting other stars. Now we have to come up with a new classification for them as well. Stupid, stupid, stupid. Does not exclude Pluto, however. b - I agree with this one, this is the only part they got right, and it certainly does not exclude Pluto. c - WTF? This excludes just about everything, including the Earth as being a planet - by this criterion, only Mercury makes it in. But it is so arbitrary and vague - you could take this to mean just about anything. From the IAU website: "(1) A "planet" is a celestial body that (a ) is in orbit around the Sun, (b ) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c ) has cleared the neighbourhood around its orbit. (2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b ) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape , (c ) has not cleared the neighbourhood around its orbit, and (d) is not a satellite. (3) All other objects except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies". " This is a needlessly complicated definition. They should have used a nested, hierarchical classification system, that used simple terminology for each class. The above classification system is contrived soley for the purpose of excluding Pluto and other objects, and serves no other purpose. It is useless for any other practical purpose. They didn't define satellite very well either - a planet is still a satellite of a star, and this bizarre scheme puts a lot of objects into a wierd classification limbo. This would not happen if they used a hierarchical classification system, where an object can fit into several categories at once.

Yes, but now we have a semantic definition for planets that is utterly useless. I mean really, utterly, incomprehensibly useless. And by the new definition of what constitutes a planet, it is more like 2 or 3 planets now, as under the new definition, almost everything that anyone would consider to be a planet fails to meet the standard. Vague wishy-washy definitions like "clearing the neighbourhood of objects" have no place in science. If a biologist tried to apply the same type of definition to a new species, they would be rightly ridiculed. A definition of a class of objects is useless if you cannot use the terms to define something in isolation. The new IAU nomenclature is equivalent to classing whales as fish becasue they live in the sea, and bats as birds because they fly. It would be better to simply class all big round things that don't emit more energy than they absorb as planets, then create subclasses from that in a hierarchy of terms, the way living organisms are classified. Now, we have to come up with a new term to describe any object that is in nearly every way identical to say, Earth, but just doesn't happen to be orbiting the Sun, or is "too far away" or some such irrelevant nonesense. What do you call an earth-like object orbiting another star now? Under the new IAU definition, it can't be a planet, simply as it is not orbiting the Sun. That is just retarded. Are you going to invent a whole new class of objects for every star system that has a planet-like object orbiting it? What do you call a planet not orbiting anything? This creates entirely unnecessary and unwieldy classification problems. You can expect this definition to substantially change. I would be quite happy if the IAU chose to refer to Mercury, Pluto, Charon, Xena et al as "Minor Solar Planets" and Venus, Earth, Jupiter, Saturn, Uranus and Neptune as "Major Solar Planets", since it allows you to have your small number of important solar bodies separate from the multitude of other planetoids without resorting to dodgy semantics and kludgy, unworkable definitions and classification systems. Pluto is a planet by any sane definition. It might be a minor and fairly insignificant planet, and it can be both a planet and a Kupier belt object, but it is still big enough to form a round shape under its own gravity, and does not emit more radiation than it receives, so a planet it is AFAIAC.

This decision is unlikely to stand for long, because by the new definition the retards at the IAU have come up with, now technically, Earth, Mars, Jupiter, Saturn, Neptune are no longer planets because they have failed to "clear their neighbourhoods of other object". Venus rotates the wrong way to be a planet under the new definition. And the same goes for about 50+ extrasolar planets, becaue they don't happen to orbit around the Sun. Of course it is all arbitrary semantics anyway, but the definition they have come up with for planets is the most inconsistent, unscientific rubbish I have ever heard. This ruling by the IAU will almost certainly be overturned at the next meeting of the IAU, as most astronomers are more than a little bemused by it, and think the decision was very poor and based on emotion, not reason (they simply coundn't handle the idea of there being thousands of planets and having to come up with names for them). Defining a planet in terms of its orbit, whether it has asteroids near it etc is just plain stupid. Really stupid. A definition of an object should stand regardless of where the object is or what it is doing. A planet is a planet whether it is orbiting close to a star or drifting a trillion light years from any other object. It should be definable in terms of universal physical constants, hence, defining a planet as an object that becomes roughly spherical under the gravitation of its own mass is the best and least arbitrary definition. Just as I am defined as a human being by my anatomical features, so should a planet be defined in terms of its physical features alone, and not those of things that may or may not be near it. And there is no reason Pluto cannot be both a planet AND a Kupier belt object, just as Jupiter is both a planet AND a brown dwarf star, just as I am a human being and an Australian.