A...question.
Aug. 24th, 2012 11:15 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
avevale_intelligencerI'm wondering if it's possible to explain this to me without beginning with "It's not quite as simple as that..." Because I think it kind of is.
As I understand it, it's a basic principle of physics that all motion is relative, that there is nothing in the universe that is at absolute rest. The moon moves relative to the earth, the earth to the sun, the sun to the galaxy, the galaxy relative to the Local Group, and so on outward. I get all that; the first part I understand. It's the second part that gets me.
Because if A is in motion relative to B, then B must in respect of that particular motion be at rest relative to A. For every motion, every expenditure of kinetic energy, there must be a thing which is at rest relative to the moving thing. So surely, eventually, when you get to the end of that long string of movement and sum all the velocities and directions, logically there must be a thing, or a point in space, or a field or something, which is at rest relative to everything. If everything in the universe is moving outwards, there must be an in to be moving outwards from.
There is in the Sagittarian 'verse. Towards the end of the Sagittarian Age, scientists traced back the paths of all known metastellar bodies, based on data collected over the preceding several thousand years, and located a point in space which, according to their findings, approximated to the point of origin of the universe, and a team of specialists used one of the three remaining Gilchrist machines capable of large scale transmissions to travel there. They found, precisely at the indicated point, a roughly spheroidal black rock about eight miles in diameter, and for some years thereafter speculation raged across the nets about whether any of its surface features could be interpreted as deliberate markings, whether its age corresponded to that of the rest of the matter in the universe, and so on; in short, whether it had been put there or just got left behind. No conclusive answers were ever forthcoming; the only solid fact about the rock that could be ascertained was that, as far as could be told, relative to every galaxy, nebula, star, planet and asteroid in the universe, it was at rest. Everything was moving away from it, and had been for billions of years; it wasn't moving at all. And so, as ever, people made up their own minds according to their preferences. But that's fiction, and this is real life, probably.
I realise that this is a variation on the old Unmoved Mover argument which was one of Aquinas's proofs of deity, but that's not where I'm going with this. I would honestly like to know in what way my logic is faulty, if it is. If it can be done in a way that I can see makes sense, that would be good.
And if the Higgs field turns out to be the thing relative to whch everything else is moving, that would be rather neat.
As I understand it, it's a basic principle of physics that all motion is relative, that there is nothing in the universe that is at absolute rest. The moon moves relative to the earth, the earth to the sun, the sun to the galaxy, the galaxy relative to the Local Group, and so on outward. I get all that; the first part I understand. It's the second part that gets me.
Because if A is in motion relative to B, then B must in respect of that particular motion be at rest relative to A. For every motion, every expenditure of kinetic energy, there must be a thing which is at rest relative to the moving thing. So surely, eventually, when you get to the end of that long string of movement and sum all the velocities and directions, logically there must be a thing, or a point in space, or a field or something, which is at rest relative to everything. If everything in the universe is moving outwards, there must be an in to be moving outwards from.
There is in the Sagittarian 'verse. Towards the end of the Sagittarian Age, scientists traced back the paths of all known metastellar bodies, based on data collected over the preceding several thousand years, and located a point in space which, according to their findings, approximated to the point of origin of the universe, and a team of specialists used one of the three remaining Gilchrist machines capable of large scale transmissions to travel there. They found, precisely at the indicated point, a roughly spheroidal black rock about eight miles in diameter, and for some years thereafter speculation raged across the nets about whether any of its surface features could be interpreted as deliberate markings, whether its age corresponded to that of the rest of the matter in the universe, and so on; in short, whether it had been put there or just got left behind. No conclusive answers were ever forthcoming; the only solid fact about the rock that could be ascertained was that, as far as could be told, relative to every galaxy, nebula, star, planet and asteroid in the universe, it was at rest. Everything was moving away from it, and had been for billions of years; it wasn't moving at all. And so, as ever, people made up their own minds according to their preferences. But that's fiction, and this is real life, probably.
I realise that this is a variation on the old Unmoved Mover argument which was one of Aquinas's proofs of deity, but that's not where I'm going with this. I would honestly like to know in what way my logic is faulty, if it is. If it can be done in a way that I can see makes sense, that would be good.
And if the Higgs field turns out to be the thing relative to whch everything else is moving, that would be rather neat.
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no subject
Date: 2012-08-27 02:55 pm (UTC)Not to "everone else" considered en masse, maybe, but that's comparing apples with oranges, or perhaps more accurately *an* apple with Del Monte's entire global delivery chain: You are an individual; they are a collection of separate individuals. If you treat *them* as a single entity, then it's an entity that apparently surrounds you and which suddenly starts expanding. However, compared to each and every other individual in the room, considered one at a time, your motion relative to that individual is equal and opposite to their motion relative to you. Likewise that guy's[POINTS] motion relative to that lady [POINTS WITH OTHER HAND] is equal and opposite to *her* motion relative to him. The same with those two over there... Looks like they've just had a row actually: The separation between them is increasing rather more rapidly than for most other simlarly spaced pairs of individuals I could have picked.
Now, in your party scenario, several factors contribute to the conclusion that their motion is somehow of a different callibre than yours. One is the fact that you're in socking great living room! It's big, it's heavy, and it's counter-intuitive to start thinking of something like that suddenly starting to move relative to a puny human just because another human farted.
But that phrase "starting to move" points to the next issue: You're not describing continuous motion; You're describing a *change* of motion. One minute, all the dancers were moving (on average) in exactly the same way as the room, and the air within it, and the lump of Kensington it's built on. You can call this kind of motion "at rest", if you like, and I can call it "going with the flow, man" if I like. But what happens next is that the partiers notice an odd whiff and so they start *changing* their motion. You don't, so you carry on moving the same way you were before. You still call that "at rest"; I still call that "going with the flow, man". And there's not a single test that anyone's been able to devise that indicates your description is any more or less accurate than mine. We both know why the motion for the other partiers changed; we can both measure how much (if we don't kicked out for getting under everbody's feet with that damn tape measure or accidentally burning some's eye out with the laser range-finder); we can both do the maths to figure out how soon each of them will bump into a wall if they don't change their motion again before that happens, and (as long as neither of us makes a silly mistake like misplacing a decimal point), we'll both get the same answers.
The third thing that makes this difficult is the basic gut-level awareness that "I am not them". When you stand it that room and people start getting further away from you, your immediate perception - espcially since you have not (knowingly) done anything to cause a change of your own motion - is that they are moving away from *you*. But from the perspective of a similarly olfactorily challenged flea sitting on *that lady's* shoulder (How did she manage to get in here? Tsk, tsk, no standards these days...), who knows nothing of the motivations of humans nor the smell of farts, it seems that all the big lumpy host-things, including you, are getting further away from *it*... except for this one it happens to have landed on. (Probably a good reason to keep a tight grip and not let it escape; it might be the only one left in flight range before long!)