Good evidence versus Empirical evidence

Discussion in 'Linguistics' started by Michael, Dec 15, 2011.

  1. Michael 歌舞伎 Valued Senior Member

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    The word evidence is used by laymen, scientists and legal experts.

    Do we all agree it must follow an adjective or it doesn't really have much meaning?

    I notice, for example, some people like to use the word "good" to denote a category of evidence. I wonder if they are thinking in terms of direct versus circumstantial evidence? Good actually being direct, which is empirical.

    Does everyone agree with that?

    Should we just drop the "good" evidence and replace it with empirical unless otherwise stated circumstantial? So, we think of categories of evidence with empirical being associated with direct observation (both legal and scientific). Now, this got me to thinking, why don't we say indirect instead of circumstantial? When we infer mass based on an indirect observation of something we can measure, is this "circumstantial"? It seems almost all things we observe in the lab would then be "circumstantial". But, we don't say this, we say indirect measurements (for example: the indirect method of immunohistochemical staining). Lots of things are indirect. Yet, we still consider these observations empirical. Or is it? Which brings us back to "good".

    What do you guys think... this being a Science forum and all :)
     
  2. mathman Valued Senior Member

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    "good" sounds like an evaluation of quality, not what type it is, such as "empirical".
     
  3. ccdan Registered Member

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    There's no "good" or bad "evidence", evidence is just that, evidence and must be objectively verifiable. Circumstantial evidence is not evidence at all in a strict sense, it's just something used for speculation.

    The judicial system is a really bad joke when it comes to this kind of things. Some areas of science are also pretty bad.
     
  4. Fraggle Rocker Moderator

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    It always helps to look up the definition of a word before discussing it. The definition of "evidence" is:
    Wikipedia corroborates this with a definition that is not especially authoritative but is a very good description of the contemporary use of the word in colloquial speech, as well as in the courtroom or the laboratory: "Evidence in its broadest sense includes everything that is used to determine or demonstrate the truth of an assertion. . . . Evidence is the currency by which one fulfills the burden of proof."

    Given that this word is common in colloquial speech, we can't burden it with the specific demands of science or the law and expect laymen to understand us.

    Evidence is anything that helps prove or disprove an assertion. It doesn't need an adjective to play that role in our language. The fact that evidence comes in various qualities, ranging from incontrovertible to ridiculous to fraudulent, does not need to be pointed out to anyone who is reasonably fluent in our language and reasonably familiar with Western culture. Obviously good evidence is evidence that is persuasive and makes a strong case, evidence that requires refutation of equivalent authority to impugn it, based on contradictory evidence which is not reasonably expected to exist.

    The term "bad evidence" is not as often used as "good evidence," because bad evidence is not really evidence at all, since it neither helps to prove or disprove an assertion. I suppose we might speak of "fabulous evidence," "pretty good evidence," all the way down to "promising evidence," but once we drop below that point, then, as I said, what we've got isn't really evidence anymore.

    Circumstantial evidence is quite acceptable in court. "Motive, means and opportunity" are the usual components of circumstantial evidence in American courts and they are often found sufficient to convict defendants if no contradictory evidence is supplied.

    It can be argued that circumstantial evidence is often used in science. The existence of trans-uranic atoms is usually inferred from the traces of their decay without anyone ever observing the actual atoms during their incredibly short half-life. Once you go back beyond the decay period of organic matter (which varies but is seldom more than a few hundred thousand years), all of the science of paleontology is based on the circumstantial evidence of fossils, often mere fragments.

    And how about macrocosmology? What evidence do we have of the Big Bang other than circumstantial?

    As for the judicial system being a joke, that is more the fault of human nature than of the type of evidence used. Human jurors are easily swayed by attorneys who have good theatrical skills. In addition, they are saddled with heavy bias. Most people trust eyewitness testimony because to do otherwise would be to admit that their own memories of events they witnessed might be faulty. Yet it's been conclusively demonstrated that eyewitness testimony is less than 50% reliable.

    So no, I disagree with your suggestion that the only "good" evidence is empirical. To agree would be to revert most of the theories of science back to the status of interesting hypotheses. In fact, I don't think you're using the term "empirical evidence" the way scientists use it anyway. Empirical evidence is evidence that is derived from experience or experiment. It does not require direct observation by human eyes. Which is a good thing because much of what science studies in this century is not visible to the human eye. :)
     
  5. rcscwc Registered Senior Member

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    Evidence is either valid or invalid. Valid evidence is obtained from defect free means. Defective means produce invaslid evidence, like a jaundiced man can testify that milk is yellow, though it is white. His sense of sight is defective, hence his evidence is defective.

    A perfectly valid knowledge can be true or untrue. For example, geo centric system was obtained from a perfectly valid impirical knowledge, yet it is untrue.
     
  6. Fraggle Rocker Moderator

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    What you're saying is that observations must be interpreted before they become evidence.

    The geocentric model of the universe was derived from incomplete evidence. Without telescopes, the Greeks could not see that Mars, Jupiter and Saturn had moons circling them just as our moon circles Earth. They were able to place those planets in elliptical orbits around the Earth without noticing that they were also circular orbits around the Sun. But the much tinier orbits of Phobos, Europa, Titan, etc., could not have been reconciled with the geocentric model, which is why Galileo was called a heretic.

    The Ancients did the best they could with the tools available to them. Their hypotheses were satisfactory for their era. I can't think of a single aspect of Hellenic civilization or daily life that would have had to change to conform to the heliocentric model.

    It's like Relativity. Newton was wrong, but the observations needed to prove him wrong could not be made with the instruments available to him, so his model of the universe was perfectly satisfactory for the people of his time. Even today, none of us will ever travel at even one ten-thousandth the speed of light, so Einstein's subtle corrections to Newton's Laws are utterly irrelevant to us, except for astronomers and people who work with (or are killed by) nuclear energy.
     
  7. lalalandscape Registered Senior Member

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    'Good' evidence does not always equal empirical, or direct. It really depends on the context in which 'good evidence' is being used. For example, one could say that there is 'good' evidence for women being vain because they wear a lot of make up (I don't necessarily agree with this), this isn't direct empirical evidence for vanity, but rather, somebody axiomatically associating vanity with wearing lots of make up. This could be further reasoned with one's understanding that vanity is when one cares too much about their looks, and that make up seeks to improve looks.
     
  8. rcscwc Registered Senior Member

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    Empirical observation must be interpreted. Is milk white or yellow? To a jaundiced eye, it appears yellow. But it IS white. Explanation: One who claims milk is yellow has defective vision. Why is another sceince.

    Geocentric model was based on direct observations, as all planets appear to move around earth. What is the sceintific evidence for helio centric model? NIL, except that it is simpler.

    For a lot of observations optical telescopes were not needed. Why were the orbits of sun and moon could not be circular? Again there was direct empirical observation.

    1. Sun and moon had variable size apparent discs.

    2. Exactly circular orbits would mean their intersection points would be exactly 180 deg apart, but not found to be so.

    Greeks started with exactly circular orbits and for deviations they piled circles upon circles. Indian astronomers did not have such a dogma, and accepted non circular orbits and attempted to derive equations to predict their positions. Greek dogma was adopted by the church.

    If you chuck out the Greek circles and use Indian results, you can still make accurate predictions about positions of planets. Proof of pudding, it is said, lies in eating.

    Sum total is that:
    An empirical theory is valid. It is true till it is proved untrue.
     
  9. ccdan Registered Member

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    I know it is "acceptable" in court, but it shouldn't be. "Circumstantial evidence" is not evidence at all. Any conclusion based on nothing more than "circumstantial evidence" is nothing more than pure speculation.

    The very same human nature allows for non-evidence to be considered evidence. "Circumstantial evidence" is just one example. Jurors simply believe whatever they like to believe. Then there all kinds of pseudo-experts, from psychologists/psychiatrists to fire "experts" and so on, who claim to know the "truth" as to what happened... yet, all of them have one big fear: to have their abilities tested!

    There isn't much science in paleontology.

    Actually we don't have any at all. The Bing Bang is nothing more than theoretical speculation. The same holds true for many other topics related to astronomy, especially topics related to distant objects/phenomena like black holes, quasars, the existence of dark matter/dark energy (which is purely theoretical) and so on..

    I don't think so. The problem is that we have way too much pseudoscience masquerading as science. Most of it is based on fundamentally flawed research methodologies that involve things like "correlation=causation", bad sampling, "qualitative" data and concepts (which shouldn't be used in science at all), confirmation bias. Lots of pretended scientists actually mistake science for statistics.
     
  10. Fraggle Rocker Moderator

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    Color is 100% subjective. Most humans have three types of daylight photoreceptors ("cone cells") in our eyes, which specialize in sensing three ranges on the visible light spectrum: red, green and blue. What we perceive as "yellow" is simply a particular balance of neural signals from those three groups of cells. (Nocturnal photoreceptors or "rod cells" span the entire visible light spectrum and do not distinguish colors. This is why we tend to see the world in strict black-white-grey at night.)

    People with tritanopia have no blue receptors, and they do not see the color yellow. The universe looks quite different to them than it does to us, but to them it's normal.

    Most nocturnal mammals have fewer types of cone cells and a much higher proportion of rod cells. Dogs are extremely colorblind and cats are even worse off, seeing the world as a bland mixture of grey and pink.

    Other types of animals have more types of color receptors than humans. Humans have always wondered how male and female birds of most species can tell each other apart since their coloring is identical. It turns out that they have ultraviolet pigmentation, and that their eyes have a fourth kind of cone cell that is sensitive to ultraviolet. Some insects have as many as seven kinds of color receptors. Bees use this resource to determine which flowers are ripe with pollen. Needless to say, the universe looks a lot more spectacular to the birds and bees.

    In other words, color is purely subjective. There is no objective, scientific definition of the colors we see, merely a dry table of electromagnetic frequencies with no hard-and-fast boundaries between, for example, red and orange or blue and violet. The rather large segment of the human population with various forms of colorblindness do not see them the way you and I do. Many languages do not even define the same palette of colors that we have in English.

    How, then, do you account for all the moons revolving around Mars and the other planets instead of around Earth? Galileo's discovery of the moons of Jupiter was, indeed, the damning evidence that disproved the geocentric model.

    You're selling the Greeks short. They had highly advanced mathematics and were experts in plane geometry. They understood the ellipse and easily calculated the elliptical orbits that matched reality quite well.

    Of course it wasn't until the Law of Gravity was formulated that we understood why celestial bodies move in elliptical orbits.

    All scientific theories fall into that category. As I have often complained, the vocabulary of science is very poor for communicating with laymen. I use the language of the law to define scientific theories as "true beyond a reasonable doubt." This means that occasionally one is proven false (although far more often it merely requires elaboration, such as Einstein's elaboration of Newton's laws), but this happens so rarely that the canon of science is never brought down.

    You're welcome to your opinion but you've been outvoted. The populations of the Western democracies have decided that reliance on circumstantial evidence results in a lower error rate in their justice system than the alternatives. In practice, without admission of circumstantial evidence, in a case with no other evidence juries will typically judge a defendant primarily on his personality, his manner of speaking, and the way he behaves in the courtroom. This allows virtually all con men to go free since they have spent their whole lives polishing their "people skills" and learning to lie convincingly both in speech and body language. And by the same token it results in all defendants with poor people skills being found guilty. Not to mention, all defendants of unpopular religions and ethnic groups.

    To dust off and re-customize the old saying: "Our justice system is the worst in the world... except for all the others."

    You have a rather cynical attitude toward the U.S. court system. Have you ever actually served on a jury? I've been on three, and found the system to be as imperfect as anything devised by humans, but nonetheless acceptable. In one case we let a guy go free because the state simply did not make its case. Even though we all agreed that we'd be uncomfortable if he moved into our neighborhood, we also agreed that our discomfort was not enough to throw the fellow in jail.

    You're talking in sound bites. You're not on the five o'clock news. This is a place of science, or at least that's what we're trying to make it. Since paleontology is regarded as a science on SciForums, please explain why you disagree.

    You could say the same about everything that we're unable to see. And as I noted above, our vision is highly subjective and varies from one species to the next and even from one individual to the next.

    So far all you've done is set yourself up as a curmudgeon, perhaps hoping to win this year's H. L. Mencken Award and be feted in Baltimore. A little curmudgeonry is both entertaining and thought-provoking, but it's also one of those things about which we warn, "A little goes a long way."

    Please elaborate on these accusations. If you're going to log onto a science website and assert that science is bunk (if I understand you correctly), then you need to provide evidence to support that assertion, not just arm-waving.

    As I pointed out earlier, you've already established yourself as the resident curmudgeon. It's time to accomplish something else.
     
  11. rcscwc Registered Senior Member

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    1. Color is not subjective. White is white as white is understood. Everything looks yellow to a jaundiced person. People with tritanopia are color blind, pal. Defective vision.


    2. Most nocturnal animals do not theorise about planetary motion.


    3. A mistake by church about satellites of planets. Church tried very complicated explanation for motion of satellites and failed. Geo centric model does go into such purlie attempt. Jupiter's moons gave damning evidence of foolishness of church position.


    4. I am nowhere selling the greeks short. But they did start with "perfect " circular orbits and got into circles. In fact you are selling Indians, not short but for free. They were no pushovers about geometry, after all they were the first to define the sine of an angle, and table thereof.For moon and sun, non circular orbits were infered. Knowledge of ellipse is one thing, realisation that orbits could be "non circular" is another.


    5. Laws of gravity provided simpler mathematical model for computations. But it still does not explain that what attracts what? But, then GR dispensed with Newton's law, and explained everything with curvature of space.


    6. Yes, every sceintific theory is true until proved otherwise. Unless a new theory replaces it, there would be vaccuum.
     
  12. Fraggle Rocker Moderator

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    We have absolutely no way of knowing whether the colors I see are the same as the colors you see. The arrangement of the spectrum would of course be similar to both of us because to us all colors look like combinations of red, green and blue due to the responses of our photoreceptors to the frequency of electromagnetic radiation in that portion of the spectrum. But for all we know, when I see green my brain may present it to me as the color that you see as purple, or we might each see colors that the other does not see.

    By that reasoning we could say that all dogs and cats are colorblind, even though their vision is normal for a dog or a cat. And a bird would say that humans are all colorblind because we can't see the beautiful ultraviolet tones in their feathers. And of course a bee would pity us for having only three types of photoreceptors instead of seven. "Poor humans, the world must look so drab to them. The can't even see when a flower is ripe with pollen."

    What a shame. They're the ones who can see the night sky! Most birds are totally blind at night; they don't know that things such as stars and planets even exist.

    We have to be careful of our use of the word "theory." As I have loudly complained, scientists are not consistent in their terminology. The Theory of Plate Tectonics and the Theory of Evolution have been proven true beyond a reasonable doubt and are incorporated into the scientific canon. But then they turn around and start talking about String Theory, which is nothing more than some fascinating speculation punctuated by a lot of arm-waving.

    To be fastidious in our terminology, we should call everything a hypothesis until it is, indeed, proven true beyond a reasonable doubt. Then it becomes a theory. But detectives use "theory" to mean an explanation that is probably true but not certain; managers use it to mean a promising suggestion; and laymen use it to mean an idea that popped into their head at random while waiting for the bus. Scientists use it in all four senses. They are the world's worst communicators!

    So it's not entirely true that "every scientific theory is true until proven otherwise." Evolution and Plate Tectonics: yes. But String Theory: no. Not even the Big Bang.
     
  13. rpenner Fully Wired Valued Senior Member

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    Big Bang Empiricism: As far back as we see, the universe of the past was a hotter, denser place, and at one point was so dense and hot that it was glowing and opaque.
    If you assume the known laws of physics hold over billions of years, the detailed distribution of matter, primordial elements, cosmic microwave background radiation, and overall lumpiness is consistent with a universe that was once extremely dense and too hot for nuclei to form that expanded cooled and clumped over 13.7 billion years. Details of the lumpiness suggest this hot universe was incredibly uniform to the point were we probably need new physics (inflation) to explain it.

    It would be nice if we could also explain why there is something and not nothing, but physics is a voyage of discovery and most of the refinements to this world view are going to be incremental except at the point in the opaque, hot, dense past where new physics probably dominates (Terra Incognita).

    Adding Link to similar viewpoint and why it is culturally important: http://scienceblogs.com/startswithabang/2012/10/05/why-i-am-a-liar-straight-from-the-pit-of-hell/
     
    Last edited: Oct 9, 2012
  14. rcscwc Registered Senior Member

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    FR

    Color is attribute and attributes do not exist without being attached to a real, tangible object.
     
  15. Fraggle Rocker Moderator

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    The Second Law of Thermodynamics explains that. It tells us that entropy tends to increase over time, but not monotonically. Spatially and temporally local reversals of entropy are permitted and indeed common, and there is no limit on their magnitude.

    So there is nothing in the laws of nature to prevent a completely empty universe from suddenly hosting a blob of perfectly balanced particles and anti-particles, or whatever the currently fashionable cosmological model postulates. This is merely a local reversal of entropy, and for all we know it may not even be an especially large one by cosmic standards--how many other Big Bangs have occurred that we'll never know about?

    From this point it takes billions or trillions of years for the organization of this growing blob to attenuate, inexorably returning to its original state of total entropy. Or perhaps it's an asymptotic attenuation that never quite achieves the maximum but continues to tend toward it, in accordance with the Second Law.
     

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