Dragonfly

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Posts posted by Dragonfly

  1. Watch out for equivocation. Something can exist as an abstract concept or as an entity in reality.

    So what would make you think that a unicorn is anything other than an abstract concept--to the extent that you want to exclude this from the definition?

    I don't want to exclude it from the definition, you can always make a definition more detailed to narrow down the concept, but that doesn't make the simpler definition wrong.

  2. But let's take your standard at face value. According to you, God exists by definition. Correct?

    Watch out for equivocation. Something can exist as an abstract concept or as an entity in reality. The concept "God" certainly exists and can be defined, but that doesn't necessarily imply that "God" exists in reality. "Nothing" also exists as a concept, but does that imply that "nothing exists"?

    Here is the same methodology.

    "A unicorn is a horse with a horn on its forehead."

    "God is the spirit that created the universe."

    Since you are positing that observed existence is not fundamental to a definition, I have no idea how you intend to distinguish between real and unreal.

    Simply by talking about the thing, discussing the evidence for or against its reality. We can define the Higgs-boson. Does it exist? We don't know yet. In 1930 Pauli proposed for theoretical reasons the existence of a electrically neutral particle, zero or near-zero mass and spin 1/2, later called the neutrino, that was undetected at the time. So it was defined, but it was unknown whether it really existed. In 1956 the neutrino was experimentally detected and since then known to exist. So what's really the problem?

  3. Actually it is an incorrect definition and you make it a straw man.

    No, there is nothing incorrect in that definition. That we can expand the definition to include the fact that such an animal plays a role in mythology is not relevant. It just doesn't exist in reality - as far as we know. Perhaps we'll discover one day such an animal. Does the "incorrect" definition then suddenly become "correct"? Of course not, we've then only discovered that the set of entities conforming in reality to that definition is not empty, as we thought at first.

  4. You cannot have your cake and eat it too.

    You mean like defining wrong definitions as ipso facto *not* definitions?

    You keep confusing statements about already defined concepts with statements defining concepts. They may be expressed with exactly the same sentence, but the meaning is quite different. The first can be wrong, but are no definitions, the second can't be wrong, but may be inconvenient because they may deviate from common usage.

  5. Of course as a statement about the already defined concept "man" it would be incorrect, but then it's not a definition.

    Of course it is, and that's the point, that it would be an incorrect definition of the creature "man."

    In this sentence either "man" has already been defined, then this cannot be a definition, only a description of the already defined concept, or this is a definition of "man", that cannot be wrong (as "man" has not yet been defined yet, this sentence gives the definition), you can only say that it doesn't correspond to the generally accepted definition of "man" or as far as we know to anything in reality (like unicorns or angels, which by the way do have wings). You cannot have your cake and eat it too.

    ADDENDUM: Re your post #506: Incurable case of the analytic/synthetic dichotomy.

    Of course it's incurable as there is an essential difference between analytic and synthetic statements.

  6. Here are 3 definitions of 'man'.

    1. Man is an animal with rationality

    2. Man is an animal with the ability to pass knowledge from one generation to the next using complex symbolic schemes and various media

    3. Man is an animal with rationality and wings

    Possibly the first is more general and the second more specific in its description about how this "rationality" is used. Neither of these is incorrect but they are different and they lead to different points of view of, or concepts of man. But the 3rd one is just plain "incorrect" in the sense that there is no such thing.

    A unicorn is a horse with a horn on its forehead (and some other characteristics). Is that definition incorrect? After all, there is no such thing! So your definition 3 is not incorrect, it only doesn't correspond to an entity in real life (as far as we know, have we looked in the Andromeda galaxy yet?). Of course as a statement about the already defined concept "man" it would be incorrect, but then it's not a definition.

  7. See the last two paragraphs of my post above re an "incorrect" definition. I'll repeat part of the last paragraph. Suppose someone defines "light" as "waves which travel via a mechanical ether." Are you going to say that this definition isn't incorrect?

    No, as a definition it isn't incorrect, but it doesn't correspond to something in reality. Note that there is an ambiguity in the sentence "light consists of waves which travel via a mechanical ether": you can interpret this as a definition of light, but also as a statement about a characteristic of the concept "light" that already has been defined. In the first case it isn't incorrect, but doesn't have a representation in reality, in the second case it is incorrect, but then it's no longer a definition, but a statement about the properties of the already defined concept "light".

    Regarding your claim that one first has to define a concept to have a concept

    That's not what I said, the discussion was about the question whether a certain definition "matches" a concept. To answer that question you must first somehow define that concept, if only at the primitive level of a small child by pointing and saying "that thing" (and calling "that thing" an "ent" isn't incorrect, it's only not so useful for moving on in the world, therefore it can profit from learning generally accepted definitions).

  8. You can't define a concept, you can only imagine it. If I imagine a horse, but define 'horse' as a cow then it is an incorrect definition.

    What you imagine is irrelevant. Nobody can know what you're imagining, people can only judge what you define on its own terms. You might for example give a generally accepted definition of a horse, while you're imagining a cow or a unicorn. Your definition might also be unconventional, i.e. you define a horse with the attributes of a cow, which would be impractical due to communication difficulties, but it wouldn't be incorrect, you'd only choose a different and possibly confusing term. In general it's advisable to use generally accepted definitions to avoid communication problems, but sometimes a new and different definition may be useful, as long as you clearly state what your new definition is and why you use it.

  9. Definitions are used to identify concepts. If the definition does not match the concept then one might say it is incorrect or false. This is all Rand is saying, IMO.

    Does not match what concept? You'll have to define that concept first, so you're back to square one. One definition may be more practical than another one, but as long as a definition is not contradictory in itself, there is no "incorrect" definition. That a definition may not correspond to something in real life is not relevant, you can very well define gnomes, unicorns and circles.

  10. I've tried to stay out of this islam discussion, but I no longer can keep silent, I'm getting sick of this eternal appeasement of the islam. Americans are often quite naive in this regard, behaving like Chamberlain with his "peace in our time". Well, only 0.8% of the population of the US are muslims, while this percentage in the Netherlands is 5.6%, so we have a bit more experience with these people, and believe me: this experience is far from positive to put it mildly. People who dare to identify and warn against this danger must be continuously heavily protected (remember Hirsi Ali, Wilders, Van Gogh?), it's rather cheap to criticize their behavior from a comfortable armchair. The islam is a barbaric and primitive doctrine that is no less evil than nazism. And talking about bigotry: this Vlahos person justifies the stoning of adulterers! And we should respect that kind of bigotry??! Such a regression into the primitive middle ages is what will be your future if you continue to appease those people, believing all that spurious "peace" talk. Ask for example the non-muslim people in Malmö in Sweden what they think about the islamization of their city, that was once a quiet and peaceful place. Googling "Malmö" and "muslims" may be revealing!

  11. Here's one example: I would say that the attacks on me about the quoting function are snarky or mean-spirited because you, DF, and Michael are intelligent enough to know that they are irrelevant to my criticism of bad grammar, bad writing earlier on this thread.

    I think it's no coincidence that you now omit your criticism that was in fact the immediate cause of the resurgence of the discussion about your way of quoting, namely your criticism of John Dailey. You didn't criticize his bad grammar nor his bad writing, no, you criticized his use of squiggles, and the fact that he didn't want to change his distracting layout style, calling it the "I Am Howard Roark, Super-Individualist syndrome". That was a glaring example of the pot calling the kettle black, so you shouldn't be surprised that people reacted to that remark.

  12. > AFAIK nobody else on this list thinks so, on the contrary [DF]

    Argument dismissed: First, numbers don't make truth. Second, you can't even tell that because only a handful of people have expressed an opinion.

    This is not a discussion about which method is objectively the "best", this is about (gasp!) having consideration for other people who object to your method of quoting, and in that case numbers do count. You mentioned yourself your objections against the squiggles of John Dailey and now you're surprised that other members on this forum object to your method of quoting?

  13. Subject: the nature of light and whether or not it (might) require a medium

    > Einstein however then came up with the simple solution of the principle of relativity and the constance of the speed of light, which solved in one stroke all the problems and which didn't need the ether hypothesis. This was sufficient reason to conclude that the ether didn't exist.

    DF, you are making -exactly- the mistake Rand referred to and Ted restates. You can't conclude with certainty an ether *doesn't* and *can't* exist because it's not 'necessary' to explain something.

    Now you're smuggling a new term into the argument, namely "certainty". There is no certainty in science, even Rand admitted that, only did she use the weasel term "contextual certainty". Further you conveniently omit the other part of the argument, namely that there has never been any empirical evidence for the existence of the ether.

    > Compare the argument with the argument against the existence of a personal God who interferes with the lives of people

    The difference is that the concept of God is contradictory. That is not true of the -metaphysical possibility- of a substance that is so tenuous that it is hard to detect and has very little effect on what passes through it.

    That is a straw god argument. There are many different versions of the concept God (BTW, when I use the term "personal God", I mean a God as some intelligent being who can and does interfere with the world and the people within it, not some vague concept that is more or less equivalent with "nature"), and many of them are not contradictory. That some people for example assign the contradictory property of "omnipotence" to him is not relevant. You can imagine a God that is not literally "omnipotent", but nevertheless very powerful. Other examples are: Zeus, pixies, little invisible demons, some "intelligence" that steers evolution in a particular direction, etc. We don't hesitate to state that those entities don't exist, because 1) there has never been any empirical evidence for them and 2) we have better explanations for the phenomena that are claimed to be caused by those entities.

    > There hasn't been any empirical evidence for the existence of the ether

    Well, physics has been discovering new phenomena, that there are smaller things than the atom for a long time now. Particles with half-lves less than a nanosecond, things that can only be detected at the bottom of deep wells or caves.

    The fact that they are hard to detect does not mean they are impossible or that we have discovered everything.

    So you mean that you can't say that gnomes and fairies don't exist, because they might be only detected at the bottom of deep wells or caves?

    > Phenomena for which the concept of a luminiferous ether was hypothesized to explain them, can be explained by a simple and elegant theory, without any reference to an ether.

    1. The idea that other kinds of waves (or wavicles - things with wave-like and particle-like properties) require a -medium- to carry them which moves compressively (sound waves don't travel in space) or up and down (water waves) suggests that light might. Michelson-Morley suggests that it is hard to detect not that it cannot exist, just like those subatomic particles I mentioned went undetected fro most of human history. We already know that how electromagnetic waves travel (the right angles stuff) is more complex than the way water and sound waves travel.

    You don't understand the essence of the MM-experiment. If the ether is a medium that carries light rays, we can measure the movement of that medium by measuring what the light rays do, how thin or tenuous the ether is doesn't matter at all, by definition light should follow the movement of the ether, so we can measure that movement of the ether by measuring what the light rays do. Because of the movement of the Earth around the sun the speed of light would be different when light moves parallel to the movement of the Earth and when it moves parallel, this difference should have a certain value that can be measured. However, in the experiment there was found no difference at all. Of course the precision of the experiment was limited, but it was high enough to conclude that the speed difference was at least much less than the difference based on calculations with the speed of the Earth around the sun. Recently this experiment has been repeated with lasers, resulting in a null result with extremely high accuracy.

    2. What modern physicists often persist in doing (and it looks like I'm going to have to include you in this) is being satisfied once "the equations are satisfied."

    3. Too often they are quite happy with not being able to -- or not attempting to -- understand the underlying *metaphysical* phenomenon:

    What IS light? Is it a wave or a particle? Or a new kind of phenomenon? What is it exactly? And don't tell me what its properties are. We already know that.

    This is a good example how philosophers today misunderstand the essence of science. An explanation of a phenomenon is its properties, there is no other explanation. What scientists do is to find regularities in those properties, physical laws, and if possible to find more general, more encompassing laws that in their turn explain those laws, etc. We don't know whether this chain will ever end, or that we finally will find an all-encompassing theory, a "theory of everything". Questions like "what is a photon or an electron really?" are meaningless, metaphysical nonsense, we can only describe their properties and try to find laws that describe their behavior.

    4. Referring back to point one: the fact that light can be bent by everyday media (the phenomenon of refraction...as when you look at a 'bent' stick in water) is suggestive that light might interact with even a very tenuous medium, at least to the extent of needing to be carried by it.

    Unbridled fantasies that are not supported by any empirical evidence are not science. That light can be bent by material media can be explained by the interaction of light with the atoms and molecules of those media, for which there exists abundant empirical evidence. There doesn't exist any evidence for the existence of the ether, let alone for "interactions" of light with it (how would those interactions be effectuated?). We could as well imagine that little demons are bending light rays, that theory has the same scientific status.

  14. To whoever made the snarky reply about the quote function {DF? Ellen?], I've already explained why in my view, the method I'm using is better and simpler, takes up less space, and avoids 'nesting'. Plus on this site, it's abused. People quote what A said then nest what B said inside it and nest A gain inside it. And pretty soon a page has been taken up and you have to flip back a few pages.

    That's a weird argument, not using a certain option because some people abuse that option.

    The only reason you use your way of quoting is because you think it's better, AFAIK nobody else on this list thinks so, on the contrary. The IHRSI syndrome indeed. What is the difference with John Daily's use of squiggles that you criticized? He used them because he thought it was the best way to start a paragraph, while nobody else on the list did. Mote, beam, pot, kettle.

  15. There was a guy who used to post on every Oist board (Morganis something?) who would start every paragraph in every post with a squiggle (~). No matter how politely you pointed out to him that it was distracting to the reader, nothing whatsoever would persuade him to change. It was the IAHRSI (I Am Howard Roark, Super-Individualist) syndrome. And how dare you criticize me.

    Yes, I know that kind of person. He continues for example to use a completely inadequate way of quoting (pointed out to him many times by several readers), but nothing whatsoever will persuade him to change.

  16. It is not clear to me what Rand means here. My understanding is that many attempts were made to discover the ether and all failed. So it was not some "epistemological" process that lead scientists to deny the existence of the ether - it was experiments. Then, faced with no medium for light waves to travel in, physicists had to come up with some other explanation that accounted for the facts, ie. special relativity.

    Indeed, Rand's remark doesn't make any sense, she doesn't understand what she's talking about. From the definition of the ether (as a medium for the transmission of light) you can derive certain properties, for example the movement of the Earth with respect to the ether. Experiments (notably the Michelson-Morley experiment) couldn't detect any movement however, and attempts to save the ether notion (like the dragging theory) were also falsified. Only Lorentz came up with a rather contrived solution, including length contraction and time dilation, where he in fact discovered the equations of special relativity (which therefore also bear his name as Lorentz transformations). Einstein however then came up with the simple solution of the principle of relativity and the constance of the speed of light, which solved in one stroke all the problems and which didn't need the ether hypothesis.

    This was sufficient reason to conclude that the ether didn't exist. Compare the argument with the argument against the existence of a personal God who interferes with the lives of people:

    1. There hasn't been any empirical evidence for the existence of the ether, all the experiments for detecting the ether led to contradictions with the definition of that ether.

    2. Phenomena for which the concept of a luminiferous ether was hypothesized to explain them, can be explained by a simple and elegant theory, without any reference to an ether.

    Conclusion: the ether doesn't exist.

    The same argument can be used mutatis mutandis against the existence of a personal God, and in that case Rand didn't say "You cannot arbitrarily restrict the facts of nature to your current level of knowledge", implying that you cannot rule out the possibility that God in fact does exist. She was definitely not an agnostic in that regard. Peikoff didn't improve her reputation by publishing that passage.

  17. I have two questions:

    First, what difference, if any, is there between these two statements?

    1) Space is curved.

    2) Light travels a curved path through space.

    It isn't quite that simple. We can only speak about light traveling a curved path through space if space is globally euclidean and there is only a local disturbance that causes the light path to deviate from the global pattern of straight lines (in the euclidean sense). Example: the deviation of the light of a star that is visually close to the sun. We don't see a curved light line, but we conclude that there is a deviation from straightness by comparing the relative position of that star when the sun is visually close to that star (which is only visible during a total eclipse) with its position when the sun is farther removed from the star. However, when space is globally curved (assume for simplicity with a homogeneous curvature), it's no longer trivial to conclude that light is "bent" (doesn't follow straight lines in the euclidean sense), as all light rays in such a space will look straight to any observer in that space. How do we in practice determine whether something (a ruler for example) is straight? By comparing the line of its edge with a light ray, so we would gauge the trajectory of a light ray with a ruler that was gauged by a similar light ray. What would seem to be straight lines in such a space are in fact geodesics that are not straight in the euclidean sense. Nevertheless we can measure the intrinsic curvature of such a space by measuring the Riemann tensor or the sum of the angles of a triangle (measured by light rays, what else?).

    Second, does the notion of "spacetime" include anything significant beyond saying that space and time are not independent variables?

    Anything significant? Well, this notion that space and time are not independent variables amounts to the special theory of relativity. It's a fairly simple theory (in contrast to the general theory with its messy tensor calculations), but it has had an earthshattering impact: it turns out that simultaneity is a relative notion, that time is not absolute, but different for different moving inertial frames with the twin paradox as consequence, that mass is equivalent with energy, to name a few consequences. I'd say that this was rather significant, yes.

  18. I don't know enough about Rembrandt and Michelangelo to comment on their teaching abilities. I know they were great painters, but would you call them great painting teachers?

    Rembrandt had many students who perhaps didn't surpass him, but who nevertheless became great masters themselves: Gerard Dou, Govert Flinck, Ferdinand Bol, Carel Fabritius, Nicolaes Maes (see also here), Samuel van Hoogstraeten, to name a few. You can check their work with Google images. Not a bad result for a teacher I'd think. They all did find their own distinctive style and didn't become Rembrandt epigones.

  19. Just a minute: who, reputable whom, is claiming the universe is not expanding and why?

    --Brant

    not heard of it

    sorry to have missed this conversation's nuance

    That is in fact what this whole discussion is about. I suggest you start to read the thread from the beginning.

  20. Another empirical falsification of this version of the shrinking theory: the observed redshift of galaxies would be independent of the distance. The distance between the centers of the galaxies would remain the same, the only increase in distance would be due to the simultaneous shrinking of any two galaxies, independent of the mutual distance of their centers. In fact the redshift increases with increasing distance, so this theory is not correct.

    But what of an observer on the shrinking arm of a galaxy observing a star on the shrinking arm of another galaxy? Could a redshift be observed?

    I didn't say that you wouldn't observe a redshift, shrinking galaxies would in general result in some change in distance, but independent of the distance between the centers of those galaxies, and moreover, in one half of the cases the change would be a decrease in distance (if the observers are sitting on the relatively distant arms of those galaxies), so you'd see as much blueshifts as redshifts.

  21. 1. If you mean that the galaxies are shrinking in the usual sense, standards of measures based on atomic data (like a coalescing gas cloud): the answer is no, as no such systematic shrinking is observed. If it were true, we would observe it in our own Milky Way, that the distances of all the stars in the Milky Way would systematically decrease. This is definitely not the case.

    Another empirical falsification of this version of the shrinking theory: the observed redshift of galaxies would be independent of the distance. The distance between the centers of the galaxies would remain the same, the only increase in distance would be due to the simultaneous shrinking of any two galaxies, independent of the mutual distance of their centers. In fact the redshift increases with increasing distance, so this theory is not correct.

  22. I think the only relevant question is can you (or anyone) disprove my proposed alternate model? Can you demonstrate that the laws of physics definitely rule out the idea that the distances between centers of galaxies generally remain constant and that the galaxies are shrinking in size?

    Two possible answers, depending on what you're implying with your model:

    1. If you mean that the galaxies are shrinking in the usual sense, standards of measures based on atomic data (like a coalescing gas cloud): the answer is no, as no such systematic shrinking is observed. If it were true, we would observe it in our own Milky Way, that the distances of all the stars in the Milky Way would systematically decrease. This is definitely not the case.

    2. If you mean that not only the galaxies, but also all the matter, atoms, wavelengths etc. are shrinking, the answer is that you're merely assigning a new meaning to commonly used words, without changing any of the physics, see my post here.