"Causality" or "determinism"?
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From: Remus Shepherd on 5 Mar 2010 09:52 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. > So shouldn't > science-minded people embrace the term "determinism" just as much as > we do "causality"? Many do. > 2. In your opinion, do the terms "simplicity" and "complexity" need > particular definitions in each case of use in order to make sense? It entirely depends upon the context. Compared to mammals, amphibians are not complex...but amphibians are incredibly complex compared to annelids or to a stone. > Do we need to define simplicity/ > complexity any further than to degree of atomic/biological/ > technological organization? No, that's why context was invented. > 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. > 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. > And for that matter, > are we really sure that photons, etc. have a dual nature, and that > they don't just become particles when they need to interact with > something as particles, i.e. that they are actually not waves and > particles at the same time, but can change between those states > depending on the environmental circumstances? That's actually the way it works. The 'dual' nature of quantum objects is an artifact of our limited viewpoint as large, classical-physics experiencing beings. In reality these things just are what they are; something we do not have language to describe in any way other than to describe them as seemingly paradoxical objects. This is a semantic problem, that's all. .... ... Remus Shepherd <remus(a)panix.com> Journal: http://www.livejournal.com/users/remus_shepherd/
From: nuny on 5 Mar 2010 10:01 On Mar 5, 3:51 am, Tue Sørensen <sorenson...(a)gmail.com> wrote: > On 5 Mar., 03:44, "Inertial" <relativ...(a)rest.com> wrote: (snip) > > We know in quantum physics that things are probabilisitc .. eg the decay of > > particles into other particles is actually random .. you cannot determine > > when it will happen. > > The way we understand it now, anyway... No, from what we see when we actually look. Worse, *what* will happen is not completely predictable; there is more than one way for many kinds of particles to decay. Look up the term "decay channel". Mind you that's not "theoretical", it's "experimental". Mark L. Fergerson
From: Tue Sorensen on 5 Mar 2010 10:48 On 5 Mar., 15:52, Remus Shepherd <re...(a)panix.com> wrote: > In rec.arts.sf.science Tue Sorensen <sorenson...(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. Good! :-) > 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... > > So shouldn't > > science-minded people embrace the term "determinism" just as much as > > we do "causality"? > > Many do. Good! > > 2. In your opinion, do the terms "simplicity" and "complexity" need > > particular definitions in each case of use in order to make sense? > > It entirely depends upon the context. Compared to mammals, amphibians > are not complex...but amphibians are incredibly complex compared to > annelids or to a stone. Precisely. > > Do we need to define simplicity/ > > complexity any further than to degree of atomic/biological/ > > technological organization? > > No, that's why context was invented. So does it make adequate sense to say that hydrogen fusion in a star is a simple process (all the circumstances, like gravitational pressure, considered) while life on Earth is highly complex? > > 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 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? > > 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. But we can describe electromagnetic radiation as pure energy, can't we? When particles annihilate, much of the energy they contain will be released as EMR, right? And only little "leftovers" will become smaller particles (neutrinos or whatever)? > > And for that matter, > > are we really sure that photons, etc. have a dual nature, and that > > they don't just become particles when they need to interact with > > something as particles, i.e. that they are actually not waves and > > particles at the same time, but can change between those states > > depending on the environmental circumstances? > > That's actually the way it works. The 'dual' nature of quantum objects > is an artifact of our limited viewpoint as large, classical-physics > experiencing beings. In reality these things just are what they are; > something we do not have language to describe in any way other than to > describe them as seemingly paradoxical objects. This is a semantic > problem, that's all. :-) So, all we need is to rephrase our theories? - Tue
From: Tue Sorensen on 5 Mar 2010 10:49 On 5 Mar., 16:01, "n...(a)bid.nes" <alien8...(a)gmail.com> wrote: > On Mar 5, 3:51 am, Tue Sørensen <sorenson...(a)gmail.com> wrote: > > > On 5 Mar., 03:44, "Inertial" <relativ...(a)rest.com> wrote: > > (snip) > > > > We know in quantum physics that things are probabilisitc .. eg the decay of > > > particles into other particles is actually random .. you cannot determine > > > when it will happen. > > > The way we understand it now, anyway... > > No, from what we see when we actually look. Yes, but we may simply be seeing things as too complex for our current theories to handle. > Worse, *what* will happen is not completely predictable; there is > more than one way for many kinds of particles to decay. Look up the > term "decay channel". I certainly will! Thanks. - Tue
From: rotchm on 5 Mar 2010 10:59
On Mar 4, 8:37 pm, Tue Sorensen <sorenson...(a)gmail.com> wrote: > I have a few questions that I would like people's expert input on... > > 1. Don't the terms "causality" and "determinism" actually mean the > exact same thing? No, the concepts and definitions are different. Here are two examples where: 1) Non-causal deterministic situation: Midway between two distant firecrackers an observer sends a light signal to explode the fk's. They thus explode simul. This is a deterministic situation, in that knowing the rules ( observer sends signal, fk's setup to explode on reception of signal) we can predict what will happen: if observer sends signal, the fk's will explode simul. However, the two events "explosions" are non- causal events. A consequence of them being non causal is that there exists inertial frames where one explodes first then the other, and in other i-frames, its the other that explodes first...Causality is also about time ordering. 2) causal non-deterministic situation. Two fk's are setup such that the right one is set to only explode ( with probability 99.99%) when it receives the "explosion" of the left one. i.e. the right one should explode but due to qm, it may not with probability 0.01%. This is a non deterministic situation because the rules are non- deterministic. The individual outcomes can not be predicted. However, the explosion of the right fk is causally connected to the left fk. If the right fk explodes then we can conclude that the left one has exploded too, and *prior*. A consequence of this is that in *any* i- frame, the two events ( explosions) will remain causal, will keep the same time ordering: Left explodes before the right one. Now, on to a concise definitions ... |