Wikipedia:Reference desk/Archives/Science/2012 August 24

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August 24

Brain and Lung Tumor?

Are there any types of cancer or other tumor-causing disease, perhaps zoonotic, in which one might get a single tumor in the brain and a single tumor in the lung, but not detectable anywhere else? I would have thought it rare that, say, lung cancer would metastasize to the brain. μηδείς (talk) 03:15, 24 August 2012 (UTC)

I don't think it's all that rare. Once a cancerous cell gets loose in the blood stream, it can then find it's way to just about any part of the body, and metastasize there. Body parts closer to the original tumor are a bit more likely, but most parts of the body are possible. StuRat (talk) 03:23, 24 August 2012 (UTC)

Brain is among the most common sites for metastasis of lung tumors. Proximity is important for spread by direct invation and via lymphatics, but once hematogenous spread (through the blood) occurs, proximity is unimportant. -- Scray (talk) 03:50, 24 August 2012 (UTC)

Really? I do know what metastasis is, and that the blood goes to the brain directly from the aortic arch. Is there anything specific I can read on lung cancer metastasis to the brain? I am especially curious if there are any other types of cancer and any other non-cancer diseases that act this way. μηδείς (talk) 03:58, 24 August 2012 (UTC)

Yes, pretty much anything that spreads via the blood can act this way, cancer or not. For a non-cancer disease, how about a blood clot ? They can form in one part of the body, dislodge, then cause a serious, potentially fatal, problem when they lodge in the brain. StuRat (talk) 05:02, 24 August 2012 (UTC)

No, that's not really accurate. Blood clots can form in the lungs OR the brain, and they can spread from other sites to the lung or the brain, but blood clots that form in the lungs do not travel to the brain. There are a variety of infections (e.g. bacterial, fungal) that can start in the lungs and spread to the brain. -- Scray (talk) 05:13, 24 August 2012 (UTC)

(ec) The abstract of this review PMID 21167939 highlights important aspects. The full text of this paper PMID 21487419 is freely available on Pubmed Central, with a nice illustration. -- Scray (talk) 05:10, 24 August 2012 (UTC) * μηδείς (talk) 06:02, 24 August 2012 (UTC)

Well, that's an effing scary abstract. Thanks. Still interested to know if there are worms or anything else that can result in just one brain and one lung tumor. μηδείς (talk) 05:25, 24 August 2012 (UTC)

Any organism that can cause a mass lesion/abscess in lung or brain could, theoretically, cause one of each at the same time. Examples include Strongyloides lung or brain abscess PMID 7055453, tuberculosis, and Nocardia, but there are many organisms that can do this; generally, though, it's not too hard to tell infection from tumor once you have good-quality imaging and an experienced doctor. Biopsy is often important to be sure. -- Scray (talk) 00:46, 25 August 2012 (UTC)

Higg's field and energy

Does the Higg's field have an energy density? Perhaps congruent with fermion mass densities? What was Einstein's view of the origin of fermion mass? Underpaidpresidents (talk) 16:48, 24 August 2012 (UTC)

The Higgs field ought to have a vacuum energy density (which would act like dark energy), and it ought I suppose to be negative given how the Higgs mechanism works. And it probably should be huge. What we actually find, though, is a tiny positive vacuum energy density. No one really understands vacuum energy.

I don't know if Einstein had any opinion about fermion mass. I think it wasn't an interesting problem until, at the earliest, the experimental discovery of parity violation in 1957. Einstein died in 1955. -- BenRG (talk) 16:59, 24 August 2012 (UTC)

A machine with free will

Is it possible to create a device which has free will?--130.56.71.53 (talk) 13:40, 24 August 2012 (UTC)

Define free will. Do you and I have free will? A computer will always function in the way it is programmed, even when programmed to reprogram itself. To really answer the question whether there is a fundamental difference between human and artificial decision making, we would have to understand what consciousness is and how we as humans make decisions. The answer will depend on your worldview, e.g. whether you believe in a soul, whether you ascribe to determinism, compatibilism etc. - Lindert (talk) 13:55, 24 August 2012 (UTC)

Neuroscience has proven that humans don't have free will. It is an interesting question to ask though if free will can exist in theory, given our laws of physics. Widener (talk) 05:34, 26 August 2012 (UTC)

Actually, while we currently don't fully understand consciousness and free will, the answer will not at all depend on whether you believe in a soul or not. Goodbye Galaxy (talk) 14:39, 24 August 2012 (UTC)

Not in the sense as being directly relevant to autonomous machines, but it is when comparing a human being to a machine. The concept of a soul (or mind) is linked to having a true 'will', in contrast to a purely materialistic/mechanical understanding of agency. So in determining whether a machine can have a 'free will' in the same sense as we have, this is a valid question. I like a quote by Blaise Pascal on this topic :"Man is to himself the most wonderful object in nature; for he cannot conceive what the body is, still less what the mind is, and least of all how a body should be united to a mind. This is the consummation of his difficulties, and yet it is his very being.". - Lindert (talk) 14:49, 24 August 2012 (UTC)

The Nico robot from Yale has been making news lately because it can reportedly self-identify in a mirror test. Nico's creators have been doing this work for a long time: here's a 2004 press story about "ending artificial intelligence" and to test cognitive theories on the robot. More information is available at Yale Professor Scassellati's robot research web page: " Human behavior has been studied from many perspectives and at many scales. Psychology, sociology, anthropology, and neuroscience each use different methodologies, scope, and evaluation criteria to understand aspects of human behavior. Computer science, and in particular robotics, offers a complementary perspective on the study of human behavior." Nimur (talk) 15:00, 24 August 2012 (UTC)

Quite a lot of people seem impressed by the robot, as they were by the chimps, elephants, magpies, owl, and pigeons (with training, like the robot) that also passed the test. I would like to see some news articles that reach for the opposite conclusion, namely that the mirror test means nothing and all those animals are probably just the same as robots built from protein.  Card Zero  (talk) 16:00, 25 August 2012 (UTC)

Are you thinking of the recent Futurama episode, Free Will Hunting? The answer is trivially yes, if you consider humans devices. Volition is the faculty of humans and other higher animals that lets them choose a course of action when none is forced upon them. Plants and simple animals react automatically to various stimuli, protozoa swim towards or away from various chemicals, plants grow toward the sun. It is automatic and without deliberation. There is no such automatic stimulus that forces you to choose to watch a comedy or a thriller, or decide to go for a walk, rather than watch a movie. If we did not have volition we would likely never get out of bed. Buridan's ass doesn't starve because it does have a primitive form of volition.

A sufficiently complex machine that could learn and which had basic drives could be designed to have, that is, to develop, volition. Not programmed. Designed. We are nowhere near being able to do that, but we know it is possible in principle because we are examples. The freedom of an individual's will is not freedom from the laws of physics, but freedom for external control. Free will is not lack of control, but autonomy--self control. There is no reason to believe a "robot" could not in principle be created which developed volition and possessed autonomy. μηδείς (talk) 17:33, 24 August 2012 (UTC)

To be fair, it's a tautological arguement. We could also have the illusion of volition: that is, we could all be preprogrammed for every single choice we make, down to the smalled minutia, and merely have the illusion that we had had the ability to chose. The key question is how to distinguish between having a genuine choice, and having the illusion of a genuine choice. If you can explain how to tell which state we exist in, it's an interesting answer. Asserting we have volution is one thing, establishing that we do (as opposed to just the illusion that we do) is a different thing. --Jayron32 18:03, 24 August 2012 (UTC)

To have self control, you have to have a self. I agree with Lindert — you can't have a self if you don't have a soul. However this does seem to be getting beyond the scope of the science desk. --Trovatore (talk) 17:51, 24 August 2012 (UTC)

You are begging the question. First, we could arbitrarily assert that maybe we don't "really" exist just as easily as we can assert that maybe we don't "really" have free will--whatever "real" existence and "real" free will are. But the words choice and volition obviously do apply to real world situations. The fact that in reality we only ever follow one course of action at a time doesn't mean that we didn't choose that course of action. And we simply are our bodies. There is no "we" apart from our bodies that would have free will if our bodies didn't "force" the "real" us to do things. We, as the type of bodies we are, have the ability to initiate action among an infinite number of possible paths even if external stimuli are insufficient to force us to act. The fact that our bodies do this according to some biochemical mechanism doesn't mean that it isn't "we" who are choosing, because "we" are those bodies. To focus on the question asked, there is no reason to believe it would be impossible to create a machine that would develop the ability to make choices between various possible courses of action open to it autonomously. The freedom in free will is ethical, not metaphysical. Free will is a moral and legal term describing choices we make deliberately and without coercion by another person. It has nothing to do with the mystical and incoherent notion that we are ghosts trapped in bodies that act against us. μηδείς (talk) 18:38, 24 August 2012 (UTC)

See, I simply disagree with you that we are simply our bodes. If we were, there would be no qualia at all. Physical considerations about our bodies might well explain all externally observable behaviors, but they cannot explain why there is anyone there to notice them. If we were simply our bodies, we would be p-zombies. --Trovatore (talk) 19:10, 24 August 2012 (UTC)

I never said we are "simply our bodies" in the sense of being mere matter. Bodies have substance and form, the have qualities, and stand in relationships. There are all sorts of things, like Beethoven's 9th Symphony, which exists, but are in no way bodies. You seem to be taking a rather naive form of atomistic materialism as your foil. I believe that shadows exist. I do not believe that they are bodies, or have mass. μηδείς (talk) 22:30, 24 August 2012 (UTC)

I've not said one way or the other whether I agree with you or not about whether or not we have volition or free will or choice or whatever series of close synonyms you wish to use. The issue I have raised is whether or not you have logically established that we have such ability. That is, if you are going to make an argument in favor of the existance of volition, you need to use the basic rules of logic to establish that having volition is an unavoidable conclusion to reach, in opposition to the counterproposal, that we merely have the illusion of volution. That is, I'm not arguing whether or not we have volition with you, I'm arguing that you haven't actually established that we do. You've asserted, a priori and without logical connection to established facts, that we do have volition, and have hand-waved away any counterargument that any evidence of volution could be reinterpreted as something else entirely. Calling something "mythical and incoherant" or mischaractizing the opposing proposition in unflattering and belittling terms is not a refutation. It is avoiding the question. The question has been put before you: based on the evidence of what we experience, how does one distinguish between volition (the ability to make choices) and the illusion of volition. --Jayron32 18:59, 24 August 2012 (UTC)

One does not need to "logically establish" (derive from arbitrary axioms?) that which is self-evident. I take it as given that you have the choice whetehr or not to respond to this post. I refuse to attempt to prove that you have that choice, it would be to attempt to prove what is prior by what is subsequent. See Aristotle's Metaphysics: "That nature exists, it would be absurd to try to prove; for it is obvious that there are many things of this kind, and to prove what is obvious by what is not is the mark of a man who is unable to distinguish what is self-evident from what is not." μηδείς (talk) 22:30, 24 August 2012 (UTC)

What makes it self-evident? That you find it inconvenient to need to prove it so? --Jayron32 05:13, 25 August 2012 (UTC)

The concept of logical proof rests on the notion of premises which are assumed to be true, either self-evident or already demonstrated to be based on something prior which is ultimately self evident. You cannot demand proof of everything--that's not a matter of convenience--it's a matter of non-contradiction and infinite regress. That is Aristotle's point. I am quite sure that you know certain things that are self evident. For example, if someone were to punch you in the face, would you want to prove it based on various axioms before you reacted?

It is self-evident that we face all sorts of options among which we can chose and that we do select among those options even when nothing external to us forces one on us. The fact that we do make such choices is what the name volition is applied to. The self-evident facts lead to the naming of the concept. We don't start with some concept volition out of no where and then seek to find facts in reality to prove the concept is valid. Likewise, we all know of cases where we have done things because we were happy to do them of our own accord, or cases where we did things we would not otherwise have done were we not threatened by others. This is self evident. We name acting of our own accord free will and acting under threat as coercion, because it is useful to name these things, not because we started with a concept free will from out of the blue and then sought to find things in the real world that prove its existence. The facts are prior, and do not require proof.

If a determinist wants to argue that we don't "really" have free will, he is not actually denying that there is no difference between an individual doing what he wants gladly and being coerced by some other individual to do something he would not otherwise have chosen. He is not using the term free will in the original sense. It is up to him to come up with a coherent explanation of what it is he is denying. Ultimately what the determinist is saying, although he will rarely admit it, is that he is not free because his body forces him to do things he would otherwise not have chosen to do. To him, his body is essentially another person from his "true self". The ironic thing is that the determinist poses as paragon of science, yet treats himself as a ghost imprisoned in a zombie. μηδείς (talk) 18:12, 25 August 2012 (UTC)

The key distinction in your punching example is the difference between an observable action, and the explanation for that action. We wouldn't have to debate that the punch occured. What would need explanation is why the punch occurred. I'm not asking that you prove that humans (or any living thing) performs certain behaviors, what I am asking is for a simple proof of the explanation that they perform those behaviors because they had the option to do something else. If I push a ball down a hill, it rolls to the bottom. If the ball is self aware, and believes itself to have had the option, and believes that it chose to do so, or more to the point, that it was programmed to believe that it chose to do so, how does the ball distinguish between that state and a state where the ball went down the hill because of it's own choice? The axiom is that the events happen. The two opposing propositions are the reasons why the event happen. What is the reason to pick one proposition over the other, besides "because I say so" or "because it is obvious". What makes it obvious? --Jayron32 20:48, 25 August 2012 (UTC)

"If the ball is self aware"? You are happy to entertain such nonsense as balls being self-aware, but hold that it is controversial whether people make choices between options? That is precisely the sort of thing I am not willing to take seriously. I already told you that whatever the mechanism by which your body makes decisions, you are your body, and if nothing outside your body coerces it, your body's decision is free. If you disagree with that, it is up to you to coherently explain why you are not your body, or why the uncoerced actions of your body are unfree. μηδείς (talk) 02:25, 26 August 2012 (UTC)

I've never said that I was anything more than my body. You just invented that objection to my request as an attempt to deflect from the actual question. Let me simplify the question before you, because you have either redirected it or patently refused to answer it every time it was posed. What is the evidence that volition is a phenomenon, and why does that evidence point unambiguously towards volition existing? As an aside, I am finding fault with your arguments, not your conclusions. I have never once said, or implied, or made any statement which could reasonably interpreted to mean that we don't have volition. What I have said was that you have provided no argument or evidence to that effect. I have no problem with your conclusions. It's your methods that you use to get there that are faulty. --Jayron32 02:31, 26 August 2012 (UTC)

You are faced with an infinite number of options at any point, and yet you act. You can have Chinese, Italian, pancakes, dogshit, or an infinite number of combinations, or nothing, for dinner. Yet you act. That is what is called volition, that you act, although no force like sunshine on a plant makes you grow automatically, without you making or refusing to make a choice. That is what is called volition. The fact of your acting even though nothing external to you forces you to do so exists (whatever you call it) and we give it a name, in this case, volition. Asking that it be proved to be volition means you know what volition is ahead of the facts of reality that prompt you to name a real phenomenon. That is the essence of foolishness. I apply names to real phenomena that already exist in reality; I don't start with a bunch of meaningless concepts, then look for things in reality to fill them. Do you? Unless you radically change your line of questioning I doubt I will answer you further on this topic. I now what I know. If you don't find what I have to say helpful, then far be it from me to waste your time in debate. μηδείς (talk) 04:03, 26 August 2012 (UTC)

But am I somehow exempt from the laws of physics that govern how electrons move and interact with matter? Do the chemical reactions in my brain some get allowed to violate the rules which determine how chemical reactions happen outside of my body? What is it that allows me to escape the fundemental laws of the universe that the plant, in your example, is bound to follow? --Jayron32 05:41, 26 August 2012 (UTC)

I never said that. (You do seem to be getting closer to my point, though.) I offer no mystical action of electrons or particles. If it is a fact that your body behaves a certain way, then it is a fact. You are your body. Free will is however your body acts when it is not coerced by wills outside of it, which is an ethical concept, not how it magically acts when it is free of the laws of physics, which would, if it were coherent, be a metaphysical concept. No one is free of his body. We are our bodies. It should not bother anyone that he is his body, unless he wants to pretend that he is a ghost that will survive the decomposition of his zombie. I hope that is clear. μηδείς (talk) 06:19, 26 August 2012 (UTC)

I think you are wrong. We are not our bodies, and yes, we do have souls, and they will survive the decomposition of the body. Whether that is a comforting fact or not is a separate question. --Trovatore (talk) 06:25, 26 August 2012 (UTC)

Well, I think that emphatically ends the discussion. I hope for your sake you are right that we survive our deaths, although I doubt it. And I am surprised you still accept the materialist concept of determinism, even when it is both false scientifically and philosophically unnecessary. God bless. μηδείς (talk) 06:57, 26 August 2012 (UTC)

Trovatore, I always suspected we think alike about the fundamental things, and now I know it. My only qualification to your statement is that, while it is indeed true that we are not our bodies, we're intimately tied to our bodies and cannot escape them except through the death of the body. Come sit by me, I'm sure we have a lot more things to agree about. -- ♬ Jack of Oz ♬ ^{[your turn]} 09:31, 26 August 2012 (UTC)

The model of free will which I personally prefer is that free will is neither random nor determined - not the result either of quantum noise or of the orderly operation of physical law - but rather reflects a causality violation induced by the localized and highly regulated use of precognition, otherwise a dangerous and pathological condition. If you have a machine that spits out a number a second before you enter it, and you feed it the number it itself spit out, then it has free will. Nothing in this universe determines what that number will be, nor is it random. Some authors such as Roger Penrose have speculated on weird quantum phenomena in the nervous system, though I don't think this is what he had in mind. In any case, some unusual phenomenon would be required. I am suspicious that mental states as we experience them do not correspond one-to-one with physical states of the underlying "machinery", and thus the subjective appearance of reversal of entropy or other causality violations may be possible even though physical laws are not broken in terms of the technologically observable qualities of the system in which they are encoded. The machine would need to duplicate this alleged mode of functioning, which even I postulating it have only the haziest notion about. Wnt (talk) 22:12, 24 August 2012 (UTC)

My pet goldfish has more "free will" than any machine anyone has ever invented. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:13, 24 August 2012 (UTC)

Correct. Your pet goldfish has a rudimentary faculty of volition, it is self-determined, rather than externally constrained, and it surpasses the nature of any so-far artificially designed agent. μηδείς (talk) 22:33, 24 August 2012 (UTC)

A machine with free will (arbitrary break 1)

We are all mathematical algorithms, there is no such thing as a physical universe, all that exists is math. Qualia are computational states of algorithms. Count Iblis (talk) 22:38, 24 August 2012 (UTC)

We are not mathematical algorithms at all, there is no such thing as math: all that exists is the physical universe.... AndyTheGrump (talk) 22:44, 24 August 2012 (UTC)

The truth, as usual, lies somewhere between those 2 extreme positions. -- ♬ Jack of Oz ♬ ^{[your turn]} 22:49, 24 August 2012 (UTC)

No. The truth is that all that exists is the physical universe by definition. To say otherwise is farcical. 203.27.72.5 (talk) 23:21, 24 August 2012 (UTC)

Not to spoil the fun by throwing in a reference (which suggests this should really be running on the humanities desk, or maybe misc, since we're well into philosophy and logic), but try some Wittgenstein:

1 The world is all that is the case.

1.1 The world is the totality of facts, not of things.

1.11 The world is determined by the facts, and by their being all the facts.

1.12 For the totality of facts determines what is the case, and also whatever is not the case.

1.13 The facts in logical space are the world.

1.2 The world divides into facts.

1.21 Each item can be the case or not the case while everything else remains the same.

Tractatus Logico-Philosophicus. 86.169.212.200 (talk) 21:05, 25 August 2012 (UTC)

Correct me if I'm wrong, but haven't later philosophers rejected this position - including Wittgenstein himself? AndyTheGrump (talk) 04:15, 26 August 2012 (UTC)

It is still true that math exists. To say otherwise would cause great distress to the workers at the Mathematics Reference Desk. And it is still true that not everything is math. And it is true that not everything is encapsulated in "the physical universe". For example: ideas, thoughts, feelings, mathematical concepts ... -- ♬ Jack of Oz ♬ ^{[your turn]} 05:09, 25 August 2012 (UTC)

What is an thought besides a collection of electrical signals firing along synapses in your brain? Is that not physical? --Jayron32 05:15, 25 August 2012 (UTC)

Let me just point out that 203.27's supposed "definition" of the universe pre-supposes that everything in the universe is physical. That is just about the most unscientific and prejudiced and close-minded position one could possibly take. It's also not a universe that I have any knowledge or experience or understanding of. -- ♬ Jack of Oz ♬ ^{[your turn]} 10:11, 25 August 2012 (UTC)

I'll note by my personal crazy model above, everything actually isn't math - math is deterministic, and the point of the causality violation is to create an opening for something outside the known universe, beyond our ability to examine and perhaps to comprehend, to potentially affect it. The free-willed decisions actually all become boundary conditions of the universe. Wnt (talk) 12:50, 25 August 2012 (UTC)

It is a World 2 object in Popper's three worlds ... besides being a collection of electrical signals firing along synapses in your brain. To put it that way is true, but reductionist - other collections of electrical signals firing in your brain might not be thoughts, but smells, or migraines, or fits, so a higher-level description is commonly more meaningful. (Wait, all those things are probably world 2 objects as well. Damn. Still, a thought is a thing in its own right, an emergent thing.)  Card Zero  (talk) 15:40, 25 August 2012 (UTC)

You are correct- things like mathematical and sciontific concepts are not part of the physical universe by any menes.Aliafroz1901 (talk) 10:45, 25 August 2012 (UTC)

Or maybe they are, the jury is still out, but the effort put into discussions like this are probably better put into articles like physicalism. Sean.hoyland - talk 11:20, 25 August 2012 (UTC)

Yeah, but then we'd need sources. Philosophy is like feces or potential employees - everyone has excess to give away, but who wants to consume it? Wnt (talk) 12:46, 25 August 2012 (UTC)

Like I said above, everything is math. When we assume that what we experience is a physical world that is somehow more than a purely mathematical entity, we actually don't know what that fundamentally is. So, assuming that a physical world that is different from pure math exists is religion, it isn't science. Most scientist do believe in a physical world, but then more than a century ago, most scientists were deeply religious people.

If you feel pain, then this is not fundamentally caused by electrical signals, it is caused by the computation your brain performs. A huge analogue computer that would run the same algorithm as your brain is running and processing the same data would experience the same pain, even though it consists of gears. Count Iblis (talk) 19:10, 25 August 2012 (UTC)

So, if nothing physical exists then what's running the algorithms? 203.27.72.5 (talk) 20:20, 25 August 2012 (UTC)

The algorithms are not really run, they only exist in a mathematical sense. All possible algorithms thus exist. One of these algorithms is the formal description of your brain at this moment when you read this part of the sentence, one slightly different algorithm is the formal description of your brain at this slightly later moment when you read this. Count Iblis (talk) 04:07, 26 August 2012 (UTC)

To answer the original question, it is easy to create a machine with free will as it is conventionally defined. The creation process is called Procreation. --BozMo talk 21:34, 25 August 2012 (UTC)

Our brains can take in information and we can use that information — plus our existing world views, emotional states, and what have you — to make deliberative decisions about our actions. We can weigh possible outcomes, things we desire or desire to avoid, and come to conclusions. We can even come to very unintuitive or unexpected conclusions. We can use information, values, and empathy to decide what sorts of activities we agree we feel comfortable undertaking, and those which we would desire to never undertake. To me, this is as much as anyone seems to ever really mean by "free will" — I don't actually see debates about causality and materialism to be germane to the topic. Even setting aside the question of what consciousness really is — we have no clue, and it is a mighty significant thing to know nothing about when talking about such things — to me all anyone really wants to know is, "Are we responsible for our actions? Do we actually make decisions?" We feel that we are. We act like we are. Very few people who are not looking to excuse their prior actions ever seem to really ascribe to the philosophy that they are completely out of control of their own actions. That strikes me as pretty "good enough." I am not quite willing to say that my consciousness is totally illusory — it feels pretty "real" to me, and though that is just one datapoint, over time I've come to believe (when I ignore all of the postmodernism and language-games talk that was drilled into me by professors and try to evaluate it in a completely honest, personal way) that it's actually a pretty significant datapoint.

But moving to the meat of the original question: I see no a priori reason to think that we could not imbue a machine with the same faculties as a human brain. This would include whatever appears to be a component of "free will", as defined above. How to do this, I have no idea, and I doubt anyone else alive does either. The human brain is still virtually terra incognita when it comes to understanding the physical basis of consciousness. I suspect we're still a long way off from making sense of it. We probably need to make sense of what makes us us before we can make other things us. --Mr.98 (talk) 01:54, 26 August 2012 (UTC)

Bodies (hylomorphic substances) and those things that exist in relation to bodies (aristotelian categories) exist. Mathematics doesn't exist by itself. If it did, would it be in base two? Or base ten? Or base e? The assertion is absurd. Mathematics is a perspective on reality that observes quantity but ignores quality. Consciousness is not a thing, or a body. Consciousness is a relationship, a sort of harmony that exists between certain types of bodies, in respect to their forms, and mathematics is a complex sort of such relationship. To insist that mathematics as such existed back when there were only fish or only molten planetoids or dense clouds of plasma makes as much sense as insisting that documentary films did. μηδείς (talk) 02:18, 26 August 2012 (UTC)

Medeis - I am not sure I completely follow what you mean by "mathematics doesn't exist by itself". Your analogy with documentary films (which I think we can agree have a form of existence) seems to imply that mathematics exists in some sense of "exists", just not "by itself". Is that correct ? If so, can you clarify what "by itself" means by giving an example of something that does "exist by itself" ? Gandalf61 (talk) 09:00, 26 August 2012 (UTC)

Fundamentally, existence just is what it is. We use various concepts to manipulate it mentally, allowing us to act effectively in it. We view reality fundamentally as consisting of entities, "things", which exist in themselves. We can say, there is a tree, there is a person, there is a rock. Entities have attributes (qualities) and exist in certain relationships. A ball can be red, can be round, can have all sorts of attributes. But we don't talk of there being a red, or there being a round, walking down the street, apart from a red or round thing. Attributes exist, but they don't exist in themselves, but rather of entities.

Likewise relationships. To be aware of, to be as big as, to be the father of, these relationships exist between entities (and in more complex ways, like analogies, which are relationships between relationships, and so on.) Again, we do not (unless we lose focus) talk about an "aware of" (i.e., a consciousness) or an "as big as" walking down the street independent of any entity. Don't get me wrong, redness doesn't exist any less than ballness or nearness. They all exist. An entity is the sum of its attributes and its relationships through time. It is also the sum of its substance (or "parts") and of its form (or "shape").

All of these things are real. Sweetness is real--it just doesn't exist on its own, or separate from a sweet thing and a creature capable of tasting it. Sweetness is a relational attribute, not a thing, not a part of a thing, not an atom. See Aristotelian category for some of the various ways in which we say things exist.

Mathematics is a complex set of ideas (which are relations, not entities) about quantitative relationships. Mathematics is quite real, but it is an abstraction that exists as a relation between conscious entities and their environments. And the form in which we express those relations is to some extent arbitrary. We can cut an apple in two equal pieces (the same as 10 equal pieces in base two) and talk about 1/2 of it or 50% of it. The thing itself is what it is, the mathematical description of it is just as real, but real as a relation between us as conscious measurers and the entities in question.

Humans are quite adept at abstraction. We can ignore our senses for the moment and picture everything in terms of its mathematical description (pythagorean idealism) or in terms of atoms and void (naive/reductive materialism) or in terms of minds and Ideas (Platonism). And we might in flights of fancy even be tempted to say that only numbers or particles are real. But without our direct awareness of entities and attributes (the ability to read the red hand on the meter of the geiger counter) we would have no contact with them. Numbers and particles and the like cannot claim to be real if the perceptions they are abstracted from are not. μηδείς (talk) 19:20, 26 August 2012 (UTC)

Suggested reading in order of difficulty: Ten Philosophical Mistakes by Mortimer Adler, Introduction to Objectivist Epistemology, 2nd Ed. by Ayn Rand, An Introduction to Logic by H. W. B. Joseph μηδείς (talk) 19:46, 26 August 2012 (UTC)

Okay, so when you say "We view reality fundamentally as consisting of entities ...", does this mean that the distinction you are making between entities, attributes and relationships is a function of how we (i.e. human beings) perceive reality, not something that is inherent in reality itself ? So categorising a tree as an entity is a subjective judgement, not an objective fact ? That makes sense to me because singling out the tree rather than its branches, leaves or cells, or the forest of which it is a part, or the acorn from which it grew, or the planks which it will become is clearly a somewhat arbitrary slicing of reality. Gandalf61 (talk) 11:57, 27 August 2012 (UTC)

Very pertinent question. Remember that consciousness is a relationship between a certain type of being and its environment. If we were beings of a vastly different scale, galactic or atomic in size, we would obviously have different ways of perceiving reality. If one takes the consensus view of quantum mechanics, it is unlikely we would perceive atoms the way we as humans perceive billiard balls. (I don't want to endorse any theory a priori here, philosophy doesn't entitle us to speculate on facts that only science can discover.) If we were "atomies" we would not perceive trees directly, or likely even color, given the scale difference. But our scientists might discover these things in the way that ours have discovered radio waves and that the Milky Way is a spiral galaxy. Whether or not "atomies" would apprehend things in terms of entities and events is a matter of speculation.

But the fact that we perceive things that way is not subjective, so much as relative, and relative in an objective way. Humans have an objective nature--their brains and sense organs have a definite nature; they work in a definite way. Reality has a definite nature--it is what it is. Our consciousness of reality is veridical if it conforms to the nature of our sense organs and of reality. We can open our eyes and carefully observe things, or stick our fingers in our ears and hum, or have our tea-leaves read instead of our MRI. The fingers-in-the-ears or the tea-leaves strategies are the subjective ones. They are the ones where the subject creates the contents of its consciousness without relation to the facts of reality. The people who open their eyes and see reality are the ones getting objective knowledge--even if one man is colorblind, and the other not, the statement "this is the way these things look to me in these circumstances" is objectively true for both.

The mistake would be to insist that the concepts of entity and attribute and relation are intrinsic to reality. It would be just as presumptuous to say those concepts exist in reality as its ultimate fundamental makeup without relation to our consciousness of reality as it would be mistaken to say those concepts exist only in our minds without relationship to reality. For most of the history of philosophy people have insisted on an a priori metaphysics. "Ultimate" reality is: earth, air, water and fire; atoms and void; number and harmony; spirit and clay. That is substituting metaphysics for science. And it means every scientific discovery threatens to overthrow your philosophy. Things are what they are. Our concepts are useful if they conform to our means of comprehending reality. Concepts like substance and form; entity, attribute relation (and event, and so forth) are invaluable. Most philosophical mistakes result from their misapplication. Consciousness is not an entity. Evil is not a substance: "It contains pure evil!") Ideas are not things. But neither are these things unreal.

On the nature of concepts and objectivity as relational, read Introduction to Objectivist Epistemology. On the ubiquity and danger of category mistakes read Ten Philosophical Mistakes]. μηδείς (talk) 16:52, 27 August 2012 (UTC)

Okay, so without the relationship that we call conciousness (and, specifically, human conciousness or something very similar to it) there can be no entities that we call trees or rocks, in the same way as there can be no mathematics without conciousness. Gandalf61 (talk) 09:13, 28 August 2012 (UTC)

The notion that the reality of the universe could exist purely as mathematics is, well, disturbing for a number of reasons, not the least of which is, that for every irrational number A.BCDEFGHI..., there are truncated versions A.0, A.B, A.BC, A.BCD, etc. So for every instant in the cosmos when you're sitting there reading this message the way you think you should be, there are an infinite number of instants where you're sitting there missing your feet, legs, waist ... and an even "larger" infinite number where they're replaced with some other thing, cat bodies, refrigerators, Cthulhean monsters. But I think that because the existence of a single perfect, "properly formed" moment in space and time is so infinitely unlikely amid the mass of numbers, and we perceive (I hope) such an instant presently, it is therefore equally improbable that this model of the formation of reality is truth. Wnt (talk) 10:28, 26 August 2012 (UTC)

That's (sort of) an analogue if the Boltzmann brain problem for the mathematical universe. But then all known physical theories of the universe suffer from the same disease. However, I have found a solution to this problem for the case of the mathematical multiverse, which is natural, not some ad hoc fix, which doesn't have an analogue for "physical theories". Count Iblis (talk) 15:20, 26 August 2012 (UTC)

I'm not familiar with Boltzmann brain, but the "paradox" they describe in that article is easily solved; I've ranted on about it here half a dozen times before. We are always in a state of relatively low entropy because we always keep moving the goalposts. The universe apparently gets larger and cooler in very rough proportion to its age, and the time its residents are willing to wait for "interesting events" expands in like proportion. From the subjective point of view, the most important laws of physics are always changing. Someday protons will be exotic particles found only in cutting edge laboratories, but the people studying them will be made out of "neutrino nuggets" or something, tiny insubstantial particles that take billions of years for one tick of the clock to pass. But I digress, and admittedly, on a favorite crank idea. Wnt (talk) 03:50, 27 August 2012 (UTC)

http://arxiv.org/abs/1202.4545

"The Relativity of Existence Stuart Heinrich (Submitted on 21 Feb 2012 (v1), last revised 23 Aug 2012 (this version, v2)) Despite the success of modern physics in formulating mathematical theories that can predict the outcome of experiments, we have made remarkably little progress towards answering the most fundamental question of: why is there a universe at all, as opposed to nothingness? In this paper, it is shown that this seemingly mind-boggling question has a simple logical answer if we accept that existence in the universe is nothing more than mathematical existence relative to the axioms of our universe. This premise is not baseless; it is shown here that there are indeed several independent strong logical arguments for why we should believe that mathematical existence is the only kind of existence. Moreover, it is shown that, under this premise, the answers to many other puzzling questions about our universe come almost immediately. Among these questions are: why is the universe apparently fine-tuned to be able to support life? Why are the laws of physics so elegant? Why do we have three dimensions of space and one of time, with approximate locality and causality at macroscopic scales? How can the universe be non-local and non-causal at the quantum scale? How can the laws of quantum mechanics rely on true randomness?"

Count Iblis (talk) 23:33, 26 August 2012 (UTC)

You don't need to write a paper to explain why existence exists. It takes just six words: There was nothing to prevent it. μηδείς (talk) 02:23, 27 August 2012 (UTC)

Wow, all this, and nobody's yet pointed out that we do have a very thorough article called Free will. Red Act (talk) 03:39, 27 August 2012 (UTC)

LOL, we can put this discussion into BJAODN. ibicdlcod (talk) 15:03, 27 August 2012 (UTC)

This thread is about to be archived, so I have answered Gandalf61 here: http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#Would_entities_exist_without_minds_to_distinguish_them.3F μηδείς (talk) 17:15, 28 August 2012 (UTC)

Low signal to noise ratio

I'm looking for a word to describe the problem caused by a low signal-to-noise ratio. I'm thinking of a word like distortion but I can't figure out what the correct word is. ike9898 (talk) 18:12, 24 August 2012 (UTC)

I've always heard it called "noise". If there is a low signal-to-noise ratio then, by definition, what you have is too much noise. --Jayron32 18:23, 24 August 2012 (UTC)

...or too little signal. StuRat (talk) 19:36, 24 August 2012 (UTC)

If you're talking about the response of an analytical instrument, you may be approaching the detection limit. 203.27.72.5 (talk) 20:01, 24 August 2012 (UTC)

"noise" is the word I would pick too. Sean.hoyland - talk 06:10, 25 August 2012 (UTC)

How about "static" or "radio interference". ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:55, 24 August 2012 (UTC)

The problem? There are many different problems associated with poor signal-to-noise ratio! There is bit error in digital communications; there are false detections; missed detections; in the analog domain, there is poor signal intelligibility; frequency discrimination error; in control systems, there are invalid or uncommanded actuations; ... outside of communications, there are other fields with signal-to-noise problems: in music, there are aesthetic considerations to poor signal integrity; ... Without a little context to define the problem, we can't really ascertain the correct word to describe it. Nimur (talk) 00:30, 25 August 2012 (UTC)

I see. The context has to do with a laboratory method for measuring a physical property.

In which case the correct term for the problem is noise or perhaps random error. Wickack60.228.241.5 (talk) 06:13, 27 August 2012 (UTC)

...which could be coherent or incoherent (random) noise. Sean.hoyland - talk 16:34, 27 August 2012 (UTC)