"Causality" or "determinism"?
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From: Tue Sorensen on 5 Mar 2010 17:18 On 5 Mar., 23:14, Erik Max Francis <m...(a)alcyone.com> wrote: > Tue Sorensen wrote: > > But presumably there is still a single universal frame of reference, > > isn't there? > > No, of course there isn't one. Didn't Wayne just say that there is? - Tue
From: Erik Max Francis on 5 Mar 2010 17:18 Remus Shepherd wrote: > In rec.arts.sf.science Tue Sorensen <sorensonian(a)gmail.com> wrote: >> 1. Don't the terms "causality" and "determinism" actually mean the >> exact same thing? If processes follow the rules of causality, then the >> outcomes are also determined, aren't they? > > 'Causality' says that one effect follows a cause. If processes follow > that rule then the outcomes are determined, yes. But 'determinism' is > the philosophy that *everything* follows that rule. They're not quite > the same, but they are related. > > Causality is to determinism as traffic rules are to the highway system. > If people follow them, the roads work as intended. But we can't guarantee > that everyone follows the rules. This is overstating it. Causality means that effects follow after causes, not the other way around. That's all -- nothing about predictability. Determinism means that you can predict all future states of a system given the complete state of the system at some specified time. We have good reason to believe that our Universe is causal, but not deterministic (e.g., quantum mechanics). >> 3. About the dual nature of a wave/particle; when a particle and an >> anti-particle annihilate and become energy, does this represent a real >> transition from matter to energy? Or does "energy" here just mean a >> jumble of teensy-weensy elementary particles? > > It means energy, which then creates a jumble of elementary particles > that may or may not be larger or smaller than the particles you started > with. > > Think of a dollar and an anti-dollar colliding and bursting into flame. > You might think you have $0.00, but the energy of their conflagration is > worth something -- possibly more than the $2 you started with. No, not really. Particle-antiparticle annihilation may result in other particles than photons if you're dealing with collisions of complicated particles like hadrons, but the total energy (mass energy plus kinetic energy) of the resulting particles is equal to the total energy (again, mass plus kinetic) of the particles the annihilated. Energy is still conserved locally. >> If the particles really become energy, do we know exactly how? > > They don't 'become energy'. They cease to exist. Conservation of > energy says that the energy has to go somewhere, so the universe uses it > to make new particles. A better way to say it is: All particles contain energy. Photons are a particular type of particle that really isn't much more than energy itself. -- Erik Max Francis && max(a)alcyone.com && http://www.alcyone.com/max/ San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis Exercise is wonderful. I could sit and watch it all day. -- Louis Wu
From: Erik Max Francis on 5 Mar 2010 17:25 Tue Sorensen wrote: > On 5 Mar., 18:47, thro...(a)sheol.org (Wayne Throop) wrote: >> Or put another way, causality says that after the fact, effects have >> specific causes. Determinism says, that even before the fact, >> all causes have specific effects. Sort of. > > I'm still having difficulty telling them apart. Surely both causality > and determinism are essentially saying that everything that happens in > the universe is deterministically causal (and causally deterministic)? No. They mean quite different things. Causality means effects follow causes. Period. That's all. Determinism means that you can predict all future states of a system once you know the state of it at some particular time. Deterministic systems are obviously causal, but there's no reason for causal systems to be deterministic. Examples using probabilistic effects were given. Our Universe appears causal, but not deterministic. >> In QM, the assertion is that >> there's no additional information to be had; no "hidden variables". > > Which is precisely why I claim that QM is bad science. It has just > decided that the rabbit hole doesn't go any deeper, and stopped trying > to go further. It's more philosophy and mysticism than science. It makes testable predictions, and those predictions have been confirmed to great accuracy. You may find it metaphysically or psychologically distasteful, but it's science, and it works. > Despite being a Dane myself, I am totally on Einstein's side and > totally against Bohr and Heisenberg. We need to uncover a deeper > structure, and once we do it will become clear that there isn't > anything truly random and merely probabilistic. God indeed does not > play dice. That's a statement of personal preference and wish, not a testable prediction. Our Universe is under no obligation to be the way you wish it to be. -- Erik Max Francis && max(a)alcyone.com && http://www.alcyone.com/max/ San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis Exercise is wonderful. I could sit and watch it all day. -- Louis Wu
From: Erik Max Francis on 5 Mar 2010 17:28 Remus Shepherd wrote: > In rec.arts.sf.science Tue Sorensen <sorensonian(a)gmail.com> wrote: >> I'm still having difficulty telling them apart. Surely both causality >> and determinism are essentially saying that everything that happens in >> the universe is deterministically causal (and causally deterministic)? > > Let's try this: Determinism says that everything happens for a > reason. Causality says that every reason causes something to happen -- > but that doesn't mean some things can't happen without reason. That sounds even more confusing; actually, it sounds like things are a bit turned around. Causality simply means that all effects are preceded by their cause. It doesn't mean that everything is caused by something, or that every thing causes something to happen. -- Erik Max Francis && max(a)alcyone.com && http://www.alcyone.com/max/ San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis Exercise is wonderful. I could sit and watch it all day. -- Louis Wu
From: Tue Sorensen on 5 Mar 2010 17:30
On 5 Mar., 18:03, Remus Shepherd <re...(a)panix.com> wrote: > In rec.arts.sf.science Tue Sorensen <sorenson...(a)gmail.com> wrote: > > > On 5 Mar., 15:52, Remus Shepherd <re...(a)panix.com> wrote: > > > ? ?Causality is to determinism as traffic rules are to the highway system. > > > If people follow them, the roads work as intended. ?But we can't guarantee > > > that everyone follows the rules. > > As far as the laws of physics are concerned, isn't it reasonable to > > presume that the rules will be followed? Of course, I realize it > > depends on how accurately we understand the rules... > > But some of the laws appear to be, 'Do whatever you want'. :) A particle > in a superposition of quantum states ends up in one chosen at random. There > may be a means by which consciousness forces quantum states into a directed > collapse. (See the Quantum Zeno effect.) Don't believe in that. > It isn't deterministic when part of the rules say to roll dice and consult > a table in a DM's guide somewhere. You can't predict what's going to happen > in that case. If there is randomness or free will (which, in physics terms, > may as well be randomness) then determinism doesn't exist. I believe in determinism and also in free will. The rules of determinism are just different at the quantum level, and it's the interaction between the material determinism and the quantum determinism that makes free will possible. That's my story and I'm stickin' to it! :-) > > > ? ?Think of a dollar and an anti-dollar colliding and bursting into flame. ? > > > You might think you have $0.00, but the energy of their conflagration is > > > worth something > > A lot of cents and pennies? :-) > > > -- possibly more than the $2 you started with. > > Okay, this I have to inquire about: where does this "possibly more" > > come from? > > Because mass can be converted to energy, and vice versa. If the particles > are in a low-speed collision, you only have their mass and a little bit of > kinetic energy to work with. But if they're in a high-speed collision, they > have a lot of energy, and their total energy (mass + kinetic) might be enough > to create something with much more mass than the original particles. But, > of course, it will have much less velocity. Ah, right. > > When particles annihilate, much of the energy they contain will be > > released as EMR, right? > > EMR is made of particles -- generally photons. > > When particles annihilate, they turn into particles (mass) with some > kind of velocity (kinetic energy). There's no such thing as 'free floating > energy'. Isn't that exactly what EMR is, though? Superpositional lightspeed waves that only rarely, under certain circumstances, act as particles? > It is bound up in either mass, kinetic energy, or potential energy. I think EMR qualifies as "energy" too. I know it's difficult to put into equations, but essentially I think we have to operate with such a thing as free-floating energy, and electromagnetic radiation is the main form of it. After all, perhaps the most cental process in all the universe - stellar fusion - concerns vast quantities of matter being transformed into energy (and hence comprises a major illustration of E = mc2). I think the proper way of comprehending the universe is to understand how matter and energy behave in relation to each other, not just in Einstein's equation but concretely in the physical universe. - Tue |