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A journal of sorts to record Jonathan Sturm's (and others') thoughts and observations on things worth thinking about. Feedback welcome, but be aware that unless you prominently say you want your communication kept private, I may publish it. |
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Sunday, 28 August 2005
Craig Dumesny wrote:
Hi, I was wondering if you could expand a little on the mod your speaker-building friend did to your DC-Xs. Where they the new Gen 4's? Mine are a little too harsh in the mid/highs and I'd really like to tame them down -- any information would be greatly appreciated. By the way, I found the reference to the mod on your website.
Take care,
Craig, the following photograph should illustrate what I did well enough. The upper terminals connect to the tweeter and the lower terminals connect to the woofers. One of the straps that provides signal from the speaker leads to the tweeter has been replaced by a small, high wattage resistance of the sort usually used in crossovers. In this instance, 3.3 ohms and 5 watts. I suspect I'd be even happier if the resistance was 3.9 ohms, but I have not felt sufficiently motivated to find out:
The speakers are an earlier version of Phil Vafiades DC-Xs and I am still very pleased with them. Unlike the Golden Ears, The Git becomes so swept away by the music, near enough is good enough :-)
Plain English statements can be said to fall into four categories:
- True
- False
- Statements devoid of truth-content
- Undecided -- they may be (or become) true, or false
Such distinctions, or demarcations are the grist of philosophers. It's why we are called nit-pickers (or Pompous Gits). But it's from such distinctions that philosophy addresses such matters as: how or why do we identify a statement as correct or false; how do we reason; what do we mean by knowledge; are values absolute, or relative; what is reality; what things can be described as real? The list is far from exhaustive.
A statement can be self-evidently true: All unmarried men are bachelors, for example. Such a proposition (statement with a truth value) is called a tautology. The proposition from evolutionism: Survival of the fittest, is a tautology. What survives? The fittest. What determines survival? Fitness.
Note that The Git has made an underlying assumption here: that you are not a relativist. Relativists make the claim that language cannot convey meaning since words do not mean the same thing to different people. While partially true, it does make one wonder why they then proceed to write long books about things if there's no possibility of communication. I asked a student of a relativist once why, if my understanding was accurate, did these academics not give wonderful marks for essays totally devoid of meaning. The student said: "But that's exactly what they do!"
Note also that philosophy includes a lot of uncovering of assumptions that lead rational thought astray.
Going back to the main strand of thought, tautologies are far more interesting than they might seem. Natural (or Aristotelian logic) is based on a small number of tautologies. We are not going deeply, or formally, into this. Just enough to get the tips of our toes wet. Usually, we use several propositions to lead to a conclusion. While Aristotle and his followers struggled with plain language to express what we call arguments, thanks to Bert Russell and others, we use a simplified approach these days called Symbolic Logic. Consider the following statements:
If I'm a philosopher, then I am pompous. I am a philosopher, therefore I am pompous.
This can be contracted to:
If p then q, p therefore q
or even further
p --> q, p |- q
where p = I'm a philosopher, q = I am pompous, the --> (arrow) symbol means "if assumption1 then assumption2", and the |- (turnstile) means "therefore". Note that any assumptions, or propositions, that is statements with a truth value, can be substituted for p and q. We can say that if the propositions (assumptions) are true, then the conclusion must be true. This is a valid argument. If the propositions are true, then the argument is a sound argument and we can say we have proved the conclusion. This standard proof is called Modus Ponens and it's one of several, each with their distinctive Latin names. Note here that the propositional variables p, q, and however many else are needed can themselves be the conclusions of prior arguments.
While the Modus Ponens above is valid, the following argument (affirming the consequent) is not:
p --> q, q |- p
Using the previous substitutions, If I'm a philosopher, then I am pompous. I am pompous, therefore I am a philosopher. While The Git may well be a pompous philosopher, it doesn't follow from this invalid argument.
The resemblance of this philosophical matter to mathematics is not coincidental. Students of mathematics and computer logic are still required to undertake their training in these things from philosophers. The type of reasoning is called deduction, but it's not the only form that reasoning takes, the other being called induction.
Consider the following argument:
1. Some philosophers are pompous
2. The Git is a philosopher
3. Therefore The Git is pompous
This looks like a deductive argument, but it's not, it's inductive and is clearly fallacious. On the other hand if we interpreted some as "every philosopher except one", then we have a strong inductive argument. We could strengthen the argument further by saying: "all philosophers are pompous". The question then arises: How do we know that all philosophers are pompous? Do we mean each and every philosopher that ever lived? How about those that have yet to be born? This is not the only problem of induction.
Bert Russell gave the example of the chicken who was fed every day by the farmer. After a large number of repetitions, the chicken concluded that this was the way the Universe was; every day at 8 am food was brought by the farmer for the benefit of the chicken. Except the day that the chicken reached this conclusion, the farmer came with an axe instead, cut the chicken's head off and it went into the pot for dinner. While many believe that many repetitions strengthens an inductive argument, they might not. When he was a tadpole, The Git placed a finger into the electricity outlet and received an electric shock. It didn't take too many of those to conclude it wasn't such a great idea! Most of us need little convincing that when the Americans nuked two Japanese cities during World War II that was a sufficient number to conclude that nuking cities wasn't such a great idea.
Unfortunately, most scientific argumentation is inductive, rather than deductive. A scientific, or inductive proof is not as safe as a deductive, or mathematical proof. We can say an inductive argument is not well grounded and the idea that more repetitions means we can have more faith in an inductive argument seems equally difficult to sustain. Am I really strengthening Hertz's theory about radio waves when I confirm it by listening to the radio? And while a deductive proof is better grounded, it's worth bearing in mind the following valid deductive arguments.
- Ice is not denser than water. So, if ice is denser than water, it floats.
- Ice floats. So if ice doesn't float, it floats.
- It's not the case that, if the number 5 is even, 5 is a prime number. Therefore, 5 is an even number.
If you are not sure why these are valid arguments and you are the curious sort, here's an introduction to Propositional Calculus.
O. V. Quine noted a further difficulty with deduction. The reason we have faith in our deductive arguments is because they worked yesterday, the day before yesterday, the day before that... Just like Bert Russell's chicken.
It's because of these difficulties that Dan Dennett referred to our "almost second-rate rationality" in that fine book of his on the human mind: Freedom Evolves. Interestingly enough for a philosopher, who is supposedly ignored by scientists, he regularly appears at conferences devoted to evolution. The Git also notes that an ex-friend (scientifically trained) once claimed Dan Dennett had claimed that we (humans, not philosophers) don't have minds, only brains. This rather put me off Dennett until Freedom Evolves fell into my hands. It's all about the mind and what it might be and what it does for us. Lots of interesting thoughts to agree and disagree with. Hey, ho...
-oOo-
The Git wrote above that demarcations, or distinctions are something that very much interests philosophers. There's very little point to arguing about something if distinctions cannot be made, or agreed. One that cropped up in philosophy of biology, the current hot Philosophy of Science topic, was the definition of species.
Some more of the correspondence between Robert (the genius who suggested the speaker-fix above) and The Git:
Robert: Other writers have given these and other examples as evidence of speciation. Mutation is the method of acquiring variation, but mutation in response to the need for change can only be achieved by bacteria and other single celled animals. All other animals build up variation, almost in anticipation of a change in the environment. If the intermediate examples in a ring species disappear then all would agree that the two extreme ends are separate species and not just variations of the same species.
The Git: That would make Chihuahuas a different species to Wolfhounds. It is not true that "if the intermediate examples in a ring species disappear then all would agree that the two extreme ends are separate species" since the matter was brought to my attention by a biologist who admitted: "Species are a good-faith guess". There is no universal (among biologists) accepted definition of what constitutes a species.
Robert: A general rule of thumb is mutual infertility of the two variations ie if they can't produce fertile offspring then they are considered separate species. If the birds at the extreme ends of the ring species are infertile, then speciation has occurred. Though physically unlikely, a Chihuahuas could breed with a Wolfhound. There are some fury edges and grey areas to which your friend is most likely referring.
The ring species referred to in the above is the herring gull. They are spread from western Europe, across the whole width of Asia and across North America to the east coast. Each adjacent colony can breed with an adjacent colony, but the colonies of the American east coast and western Europe appear to be mutually infertile.
Some biologists would agree with Robert that if the colonies between the extrema became extinct, then the gene flow that presently operates between adjacent colonies would be cut off and the extrema could then be considered separate species. However, that is an event that has not been observed (except by clairvoyants). There appears to be no obvious reason why the colonies at the extrema cannot interbreed; it's just that the gulls from those colonies perceive each other as not being suitable breeding partners. Pretty much the situation that occurs between Chihuahuas and Wolfhounds. Impala, widespread across southern Africa form several groups and those most spatially separated cannot interbreed. Yet they are taken to be part of a single species.
Consider the following thought experiment. Suppose we agree with Robert that removing the gulls between the extreme ends of the herring gull ring generates two separate and distinct species. If instead we remove two intermediate groups, dividing the ring into three parts, then we will have three species. Divide into four produces four species... If we do nothing, then each gull might be considered to be a separate species.
A further difficulty is posed by non-sexual clones. Dandelions and culinary garlics are examples of species that are reproductively isolated because there is no possibility of sexual exchange of genetic material between each other, never mind other species. If this garlic plant cannot exchange genetic material with that garlic plant over there why aren't they separate species? "They can't produce fertile offspring" yet they are members of the same species. There are animals, such as certain salamanders that fall into the same category.
Then we can consider examples such as Bombina bombina, the European fire-bellied toad and its close relative, the yellow-bellied toad, Bombina variegata. Along a several hundred kilometre central European front, they more or less successfully interbreed. In Australia, Major Mitchell cockatoos occasionally hybridise with galahs. Bacteria that are clearly of radically different types frequently nestle up to each other in order to exchange DNA plasmids.
Could it be that the ability to breed, or not, is not the definitive aspect of species Robert wants me to believe?
But the problem of species definition doesn't end here. There is the problem of species through time. Consider the following: you likely could breed with someone of your parents' generation, and they in turn would have been able to interbreed with their parents' generation and so forth. Sooner, or later, in an unbroken chain, we will reach the generation (according to the Received View) that was the common parent of both chimpanzees and ourselves. The question then arises, where did the divisions between the intermediate species occur? How many were there? How do we decide? If we take the mate-recognition concept as the measure, then the divisions between species will critically depend on where one chooses to place the baseline. Is it not the case that it's a "good-faith guess" as my biologist friend suggested?
There is, in fact, to use Sterelny and Griffiths' words, a flock of species concepts:
Phenetic species concepts define species by appealing to the intrinsic similarities between organisms. The idea is to purge species identification of theoretical commitments.
Biological species concepts define species by appealing to reproductive isolation. One version of the biological species concept is the recognition concept, which defines species as systems of mate recognition.
Cohesion species concepts generalise the biological species concept by recognising that gene flow is not the only factor that holds one population together and makes it recognisably different from others.
Ecological species concepts define species by appealing to the fact that members of species are in competition with one another, since they need the same resources.
Phylogenetic and evolutionary species concepts define species as segments of the tree of life. A species is a lineage of organisms, distinguished from other lineages by its distinctive evolutionary trajectory, and bounded in time by its origin in a speciation event and its disappearance by further speciation, or extinction.
[From Sterelny and Griffiths Sex and Death p 193]
It would be surprising indeed if all of these disparate ways that biologists view species produced agreement on which organisms were members of which species.
-oOo-
All the above is peripheral to the core issue: "How does a random process generate specific complexity?" to paraphrase Paul Davies' words. While many evolutionists claim "abundant evidence" that random mutation must be responsible for evolution, when push comes to shove they have a marked tendency to produce "evidence" that manifestly does not support their claim. In the conversation with Robert, for example, I pointed out that his example was of non-random mutation generating a slight variation of the same genetic function, not a novel function. His response: "ALL mutation is random according to evolution theory." The Git recalled plenty of disagreement on that claim in his reading and decided to plug "non-random mutation" into Google. Here's what came out:
So prevailing is the logic of nonrandom variation that I was at first flabbergasted in my failure to find any biologists working today who still believe mutations to be truly random. Their nearly unanimous acknowledgment that mutations are "not truly random" means to them (as far as I can tell) that individual mutations may be less than random -- ranging from near-random to plausible; but they still believe that statistically, over the long haul, a mass of mutations behaves randomly. "Oh, randomness is just an excuse for ignorance," quips Lynn Margulis.
This weak version of nonrandom mutation is hardly even an issue anymore, but a stronger version is more of a juicy heresy. It says that variations can be chosen in a deliberate way. Rather than have the gene bureaucracy merely edit random variations, have it produce variations by some agenda. Mutations would be created by the genome for specific purposes. Direct mutations could spur the blind process of natural selection out of its slump and propel it toward increasing complexity. In a sense, the organism would direct mutations of its own making in response to environmental factors. Ironically, there is more hard lab evidence at hand for the strong version of directed mutation than for the weak version.
According to the laws of neodarwinism, the environment, and only the environment, can select mutations; and the environment can never induce or direct mutations. In 1988 Harvard geneticist John Cairns and colleagues published evidence of environmentally induced mutations in the bacterium E. coli. Their claim was audacious: that under certain conditions the bacteria spontaneously crafted needed mutations in direct response to stresses in their environment. Cairns also had the gall to end his paper by suggesting that whatever process was responsible for the directed mutations "could, in effect, provide a mechanism for the inheritance of acquired characteristics" -- a bald allusion to Darwin's rival-in-theory Jean-Baptiste Lamarck.
Another molecular biologist, Barry Hall, published results which not only confirmed Cairns's claims but laid on the table startling additional evidence of direct mutation in nature. Hall found that his cultures of E. coli would produce needed mutations at a rate about 100 million times greater than would be statistically expected if they came by chance. Furthermore, when he dissected the genes of these mutated bacteria by sequencing them, he found mutations in no areas other than the one where there was selection pressure. This means that the successful bugs did not desperately throw off all kinds of mutations to find the one that works; they pinpointed the one alteration that fit the bill. Hall found some directed variations so complex they required the mutation of two genes simultaneously. He called that "the improbable stacked on top of the highly unlikely." These kinds of miraculous change are not the kosher fare of serial random accumulation that natural selection is supposed to run on. They have the smell of some design.
Both Hall and Cairns claim that they have carefully eliminated all other explanations for their results, and stick by their claim that the bacteria are directing their own mutations. However, until they can elucidate a mechanism for the way in which a stupid bacterium can become aware of which mutation is required, few other molecular geneticists are ready to give up strict Darwinism.
Well, that certainly seems to eliminate the necessity of randomness generating specific complexity! First random variation's a core belief, then it's a "failure to find any biologists working today who still believe mutations to be truly random". And people express surprise that The Git prefers reading about science to watching TV.
Introduction to Propositional Calculus (and links to other logics)
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Thoughts for the week:
The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt -- Bertrand Russell
-oOo-
It is mystifying that a large part of the community of astronomers and astrophysicists around the world should regard the big bang as a good approximation of something called "the truth" when they are aware of the empirical problems crying out for attention. Can we no longer live with the knowledge that we are ignorant of many things? -- John Maddox
-oOo-
A consistent thinker is a thoughtless person, because he conforms to a pattern; he repeats phrases and thinks in a groove. -- J. Krishnamurti
-oOo-
Those who will not reason, are bigots, those who cannot, are fools, and those who dare not, are slaves. -- Lord Byron
Current Listening:
Santana -- Supernatural
Frank Zappa -- Hot Rats
Joy Division -- Closer
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