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The center of gravitation is also just a simplification, or how scientists call it: "a model". Actually everything gravitates around everything else, as the art
by narnianal 7y ago
The center of gravitation is also just a simplification, or how scientists call it: "a model". Actually everything gravitates around everything else, as the article also explains.
Models, or simplifications, aren't bad though. Because what value can you get out of "everything gravitates around everything else"? Not much. But if you use a model, you can use the model to explain what happened in the past and use it to make an approximated assumption about the future. You can use it to guide decisions, and you can use it to focus on more details in other areas. E.g. if you don't use the actual trajectory of everything but a model, you can still calculate where Mars will be when you reach it if you start right now from point X on Earth. Of course the center of Mars will not be at exactly the same point, but it will be a good enough approximation that you can start planning resources required to get there, and it can help you decide if "now" and point X are good inputs to that travel plan.
Models are a good, helpful tool. They are just not explaining everything, and that on purpose, and as a human we always need to be aware of that models are just models and not reality.
- azernik 7y ago> Because what value can you get out of "everything gravitates around everything else"? Expensive numerical simulations!
- groestl 7y agoOr semi-esotheric bestsellers!
- narnianal 7y agoSimulations with numbers are also models. You can make them indefinitely more complex and still have a model that is only an approximation of reality.
- wdewind 7y ago> In that Empire, the Art of Cartography attained such Perfection that the map of a single Province occupied the entirety of a City, and the map of the Empire, the entirety of a Province. In time, those Unconscionable Maps no longer satisfied, and the Cartographers Guilds struck a Map of the Empire whose size was that of the Empire, and which coincided point for point with it. The following Generations, who were not so fond of the Study of Cartography as their Forebears had been, saw that that vast map was Useless, and not without some Pitilessness was it, that they delivered it up to the Inclemencies of Sun and Winters. In the Deserts of the West, still today, there are Tattered Ruins of that Map, inhabited by Animals and Beggars; in all the Land there is no other Relic of the Disciplines of Geography. https://en.wikipedia.org/wiki/On_Exactitude_in_Science https://en.wikipedia.org/wiki/On_Exactitude_in_Science
- earenndil 7y agoI would say, rather, that models are not approximations of reality, but descriptions of it.
- partomniscient 7y agoJust like the maps are not the territory, but like maps, models/descriptions can become out of date.
- shaftway 7y agoHow about predictions?
- earenndil 7y agoNope. You can use them to make predictions, but they are not in themselves predictions.
- NeutronStar 7y ago> "everything gravitates around everything else" for thing in solar_system: thing.gravitate_around(everything_else.center_of_mass)
- rolltiide 7y ago> Actually everything gravitates around everything else, as the article also explains. What helped me understand it the most was an answer to this question: "Where does the Solar System end" "When the dominant gravitational influence is not the Sun" it seems like it is always a loaded question because it is relative to the body being talked about and not its own moons, but it really just comes down to gravitational influence.
- matt-attack 7y agoLet’s say all the planets’ orbits decayed and ultimately spiraled into the sun. Wouldn’t that be a possible end to the solar system? I mean it’s just be a sun at that point. But I think the Sun would still be the dominant gravitation force.
- rolltiide 7y agoWould require all asteroids, debris and everything in the ort cloud to be in it too, which would be impossible. But honestly not sure what semantic nuance you are playing devil’s advocate on
- omazurov 7y ago> Models are a good, helpful tool. They are just not explaining everything, and that on purpose, and as a human we always need to be aware of that models are just models and not reality. Do we have anything else but models?
- dotancohen 7y agoIt is repeated in all these super-pedantic threads. All models are wrong. Some models are useful.
- jaredklewis 7y agoIndeed. As I learned from a link posted to HN the other day, apparently there is a name for this tension between the accuracy and comprehensibility of models: Bonini's paradox. https://en.wikipedia.org/wiki/Bonini%27s_paradox https://en.wikipedia.org/wiki/Bonini%27s_paradox