foofighter Posted February 28, 2008 Share Posted February 28, 2008 I recently read in The Counter Creationism Handbook, in response to "everything must have a cause, therefore the universe must have a cause" that certain exceptions to the rule exist. One example was that the process of radioactive decay is causeless. Can anyone who knows some physics please elaborate on this concept in layman's terms? How can radioactive decay have no cause? All of our common experience dictates everything has a cause. Also, does anyone know of any other exceptions to causality besides radioactive decay? thanks -ben Link to comment Share on other sites More sharing options...
Klaynos Posted February 28, 2008 Share Posted February 28, 2008 I would say the cause is to reduce the energy of the nucleus.... not sure that counts as a cause for individual decays though... Link to comment Share on other sites More sharing options...
DrP Posted February 28, 2008 Share Posted February 28, 2008 I agree - I think the author doesn't really know what they are talking about - of course it has a cause! It happens to make the nucleus more stable as Klaynos said. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted February 28, 2008 Share Posted February 28, 2008 No, the whole point of the decay being truly random is that it can't have a cause. Sure, the nucleus loses energy, becomes more stable, entropy increases, etc... but why does a specific nucleus decay at a specific time? I've previously argued that the law of cause and effect seems incompatible with quantum randomness. Ah, here it is Link to comment Share on other sites More sharing options...
John Cuthber Posted February 28, 2008 Share Posted February 28, 2008 Don't worry about it until someone tells you what caused God. So far as is known, the decay is random ie it has no cause. Also,the assertion "everything must have a cause" has been made but no proof has been offered. Ask for proof. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted February 28, 2008 Share Posted February 28, 2008 Don't worry about it until someone tells you what caused God. What do you mean? Are you saying God isn't eternal? So far as is known, the decay is random ie it has no cause. Also,the assertion "everything must have a cause" has been made but no proof has been offered. Ask for proof. That would be the Law of Cause and Effect. It's even good enough for philosophers. Link to comment Share on other sites More sharing options...
swansont Posted February 28, 2008 Share Posted February 28, 2008 Reducing the energy isn't a cause, though. The lower state is always present, yet the decay takes time before it occurs. Radiative decay requires there be a mode of the vacuum into which the atom may couple (eliminating these modes keeps the atom from decaying), so these may be induced by vacuum fluctuations. But you've just moved one step back to what causes the vacuum fluctuations. "All effects require causes" seems to be some sort of conventional wisdom, but not actually based in science AFAIK. Link to comment Share on other sites More sharing options...
Severian Posted February 28, 2008 Share Posted February 28, 2008 "All effects require causes" seems to be some sort of conventional wisdom, but not actually based in science AFAIK. It certainly was rooted in science until they made observations which indicated it wasn't true. That is the problem with people who have scientific 'faith' - they think that because all scientific data supports one hypothesis it must be true. In actuality, all hypotheses can only be proven false, or assigned a probability based on how well supported by the evidence they are. This probability though is highly subjective and contains all sorts of assumptions, so one has to be very careful when claiming something to be scientific 'fact'. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted February 28, 2008 Share Posted February 28, 2008 "All effects require causes" seems to be some sort of conventional wisdom, but not actually based in science AFAIK. I think that I would phrase it such: "The Law of Cause and Effect isn't based on science, science is based on the Law of Cause and Effect." Because if there is no cause for an effect, then there is no explanation for it either and hence no scientific explanation. The simplest answer to every question would be, it just is. Link to comment Share on other sites More sharing options...
SkepticLance Posted February 28, 2008 Share Posted February 28, 2008 Someone correct me if I am wrong. As I understand it, the decay of a single nucleus is essentially causeless, and can be assigned a probability. eg. The chance of it decaying over the next million years is 50%. Otherwise known as the half life. I am not a nuclear physicist and my understanding may be wrong. However, I have always imagined the decay of a single nucleus as a form of quantum tunnelling, based on (say) a neutron. There is a small but finite probability, due to quantum uncertainty, that the neutron will find itself outside the zone in which the strong nuclear force holds it in. As and when that happens, said neutron wanders off on its merry way. And the nucleus falls apart due to the loss of the neutron. When we look at enough such nuclei, and apply probability and statistics, we can say that a certain fraction of those nuclei will suffer this fate in a particular time. Since the basic reason for the decay is quantum uncertainty, then effectively there is no specific cause. Am I wrong? Link to comment Share on other sites More sharing options...
fredrik Posted February 29, 2008 Share Posted February 29, 2008 All of our common experience dictates everything has a cause. Also, does anyone know of any other exceptions to causality besides radioactive decay? In my personal view at least, as per a epistemological view (that I consider to be the best setting to understand QM) the notion of classical causation can not be defined. What we observe are correlations. And while the plausability for existence of some speculated "causal relation", increases as we consistently keep observing that there are correlations, there is never a hard implication between correlation and causation. Even if we don't KNOW, it certainly seems like the best possible bet, to place our bets as per the "causation" plausibly "suggested" by our observed and retained history. So IMO, "causation x->y" as a law, in the first place is emergent from our observational history of correlations. So there is no a priori reason why correlations always suggest a consistent causation. And even when it does, there is a limited confidence in this causation, that we might try to measure by the amount of evidence we have suggesting it's plausability as per bayesian reasoning. My suggesting is to start from the logical end. Why do we expect causality in the first place? This is in fact asking for the causality between information an expectation. Which is exactly what's going on in QM. /Fredrik In classical mechanics causations tells us what happens given the initial state. Initial Condition -(Classical.LAW) -> Prediction of Observations Classically the causation itself are assumed to be objective and certain, and the only uncertainty lies in the initial conditions. An improved analysis of that might question the notion of causation. It is obvious that even is we think the causation is certain, we still have to discover it, as we discover the laws of nature. And un analysis of this process of discovery, suggest that there is always a uncertainty in the causation itself. The creation of causality expectations lies at the level: Experience of observations -> Processing of records -> Expectation on probable correlations IMO, this added level of analysis is a first conceptual step of appreciate QM. It also reveals that the expectations are dynamical things. Information about possible initial conditions -(Quantum.LAW)-> Expectation on possible Observations However the remaining causal determinism in QM, is the one between initial information and expectations. This means that QM says that given a specific initial information, there is an "optimum betting". This is what QM models. The question is what optimum betting really means? I like to think of it as the "most probably" betting, taken over the set of all possible betting algorithms. But the natural expectation out of this is that the betting algorithms themselves evolve, and thus that the determinism left in QM, is subject of analogous critics as the one in classical mechanics. I personally consider the resolution of this to consider the "betting computations" to be manifested by the observers microstructure. And evolving the betting algorithms means evolution of the observer. And the criteria for evolving is clearly the observers self-preservation. At this point one really als questions the observer! And one might ask things that, what is the simplest possible observer? Which amounts to ask for "elementary particles", because these guys are indeed the simplest possible, but nontrivial (distinguishable) observers! I think the conceptual view this present is very attractive and plausible. But the exact meaning of this, and realisation in the mathematical formalism of QM is still not understood. ( About the complex amplitude and QM superposition, my current working hypothesis is that the key to understanding this better is in the step "processing of records". I've been thinking of this for a while but still await progress. Analysis of the "processing of records" under the constraint of limited information capacity, and also relatively speaking (time) since time is just relational changes, may suggest that there is a natural "optimation problem" whose best (most probably) solution is the superposition. This process takes time, and would be related to decoherence and coherence (multidirectional). But I'm still thinking about that and I'm inconclusive. ) /Fredrik Link to comment Share on other sites More sharing options...
swansont Posted February 29, 2008 Share Posted February 29, 2008 Someone correct me if I am wrong. As I understand it, the decay of a single nucleus is essentially causeless, and can be assigned a probability. eg. The chance of it decaying over the next million years is 50%. Otherwise known as the half life. I am not a nuclear physicist and my understanding may be wrong. However, I have always imagined the decay of a single nucleus as a form of quantum tunnelling, based on (say) a neutron. There is a small but finite probability, due to quantum uncertainty, that the neutron will find itself outside the zone in which the strong nuclear force holds it in. As and when that happens, said neutron wanders off on its merry way. And the nucleus falls apart due to the loss of the neutron. When we look at enough such nuclei, and apply probability and statistics, we can say that a certain fraction of those nuclei will suffer this fate in a particular time. Since the basic reason for the decay is quantum uncertainty, then effectively there is no specific cause. Am I wrong? Alpha decay is based on tunneling in this fashion, but other modes are not. Beta decay rely on the weak interaction, and photons on the electromagnetic. Link to comment Share on other sites More sharing options...
SkepticLance Posted February 29, 2008 Share Posted February 29, 2008 Thank you, swansont, for the clarification. Link to comment Share on other sites More sharing options...
foodchain Posted February 29, 2008 Share Posted February 29, 2008 I think a philosopher would just ask what is cause and effect. I think that question alone would jam this entire process until all atomic decay that could occur, did occur. We know atoms decay, we know this because of science. I thank science for that fact that atoms decay. I don’t know why the decay past the mechanics of atomic decomposition of atoms. I know this is open to change, the cause being humans asking questions and finding the right way to get an answer that works. I mean we could say hey you know look at all the worthless babble going on in chemistry, I mean subjectivity in that field, or the design of a nuclear reactor I could only suggest as being highly dubious and fraught with danger. Its not scientific faith to understand oxidation, the word could be replaced by a number and most likely is in every implementation but regardless of that performing the factual steps in a chemical experiment gives you the same predictable results. I don’t have faith that my light bulb works, I do for how long though LoL. Link to comment Share on other sites More sharing options...
John Cuthber Posted March 1, 2008 Share Posted March 1, 2008 "That would be the Law of Cause and Effect. It's even good enough for philosophers." Possibly, but it isn't actually true in this case. Link to comment Share on other sites More sharing options...
Riogho Posted March 1, 2008 Share Posted March 1, 2008 I recently read in The Counter Creationism Handbook, in response to "everything must have a cause, therefore the universe must have a cause" that certain exceptions to the rule exist. One example was that the process of radioactive decay is causeless. Can anyone who knows some physics please elaborate on this concept in layman's terms? How can radioactive decay have no cause? All of our common experience dictates everything has a cause. Also, does anyone know of any other exceptions to causality besides radioactive decay? thanks -ben Causeless, No. Spontaneous, Yes. Link to comment Share on other sites More sharing options...
John Cuthber Posted March 1, 2008 Share Posted March 1, 2008 OK, what's the cause; why does a particular atom fall apart at some particular time? Link to comment Share on other sites More sharing options...
Riogho Posted March 1, 2008 Share Posted March 1, 2008 The electroweak interaction. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted March 1, 2008 Share Posted March 1, 2008 The electroweak interaction. Yes, but that alone doesn't explain why it sometimes decays and sometimes remains undecayed. The electroweak force is the mechanism, not the cause. For example, when I drop an object, it falls because of gravity. But the cause of it falling is the letting go, as the gravitational force was always acting on it even before it fell. Link to comment Share on other sites More sharing options...
Riogho Posted March 1, 2008 Share Posted March 1, 2008 The electroweak interaction only happens during certain circumstances. Link to comment Share on other sites More sharing options...
John Cuthber Posted March 2, 2008 Share Posted March 2, 2008 "The electroweak interaction only happens during certain circumstances." What circumstances? (And how does the nucleus "sample" the external world to find out if these circumstances apply?) Anyway, I'm still waiting for someone to explain what caused God. If the theists are permitted an uncaused God that breaches the laws of cause and effect (but without having to produce any evidence for Him) then I don't see why I can't say that the big bang has no cause. Perhaps it was similar to (albeit unimaginably bigger and longer lasting than ) the real observable popping into existence of particles. The Casimir effect shows us that things flit into existence briefly. The spontaneous, uncaused, existence of particles is a real property of the universe. All it takes is one phenomenally large example and you have a big bang. Putting God into this just adds to the difficulty. It's easier to come up with a big bang than a thinking, deliberately acting, God; just look at the relative complexity of the 2 ideas. Link to comment Share on other sites More sharing options...
YT2095 Posted March 2, 2008 Share Posted March 2, 2008 what caused God. Infinity. Link to comment Share on other sites More sharing options...
iNow Posted March 2, 2008 Share Posted March 2, 2008 And... it's turtles all the way down. Give me a break. Sorry, but IMO, adding some unprovable ethereal conjecture to the situation does nothing in terms of explanation, is of little or no utility, and only adds warm fuzzies to those who choose to accept the god concept. Link to comment Share on other sites More sharing options...
YT2095 Posted March 2, 2008 Share Posted March 2, 2008 so you think God had a mommy and daddy that fancied a shag one day? How incredibly Human of you! Link to comment Share on other sites More sharing options...
iNow Posted March 2, 2008 Share Posted March 2, 2008 so you think God had a mommy and daddy that fancied a shag one day? How incredibly Human of you! Moot question. I don't think there is a god. Either way, we should probably stop here or continue via PM since we're derailing the thread. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now