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About BaalChatzaf

  • Rank
  • Birthday 08/24/1936

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  • Gender
  • Location
    Currently residing in New Jersey, the Bad-a-Bing State.
  • Interests
    mathematics, physics, alternative energy sources.

    I am also involved in preparing recorded books for blind and dyslexic folks.

Previous Fields

  • Full Name
    Robert J. Kolker
  • Description
    I am retired, but far from inactive. A day without a twenty mile bicycle ride is a day without joy.
  • Favorite Music, Artworks, Movies, Shows, etc.
    Music: Mozart, Bethoven. Movie: Casablanca. Favorite Philsopher: David Hume
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  1. BaalChatzaf

    Aristotle's wheel paradox

    Yellow marks three times longer than the orange marks.
  2. BaalChatzaf

    Aristotle's wheel paradox

    15/5 = 3/1
  3. BaalChatzaf

    Aristotle's wheel paradox

    I have a challenge. Models a slipping wheel on a track. See if you can do it. I can but I will hold off until you guys try it.
  4. BaalChatzaf

    Aristotle's wheel paradox

    Actually "concentric" is an adjective which describes a ---set--- of objects all with the same center point.
  5. BaalChatzaf

    Aristotle's wheel paradox

    Ad hoc arithmetic? If you want to do physics, then shut up and calculate
  6. As long as we are agreed this is science FICTION, I am willing to be amused.
  7. Weather manipulation, at this juncture, is completely beyond any reliable technology we have. There are conditions where rainfall can be induced, but they are rare. In general weather is a chaotic dynamic process, it can be reliably predict past 3 days and it certainly cannot be controlled by any human technology.
  8. BaalChatzaf

    Aristotle's wheel paradox

    Ask yourself what does it mean for a wheel to roll without slipping. It means that if a wheel of radius R turns through an angle A, the center moves R*A. So when A = 2*pi (one turn) the center moves a distance equal to the circumference of the wheel. (A is measured in radians).
  9. BaalChatzaf

    Aristotle's wheel paradox

    Here is a thorough analysis of the Wheel "paradox" problem. It addresses itself to the issue of the relation between a thought experiment and a real physical experiment. Have a look:
  10. BaalChatzaf

    Aristotle's wheel paradox

    little wheel slips and drags over its track, the purple line in your diagram. By the way, the center of both wheels is one and the same point.. From the wiki article on Aristotle's wheel "paradox" --- "One way to understand the paradox of the wheel is to reject the assumption that the smaller wheel indeed traces out its circumference, without ensuring that it, too, rolls without slipping on a fixed surface. In fact, it is impossible for both wheels to perform such motion. Physically, if two joined concentric wheels with different radii were rolled along parallel lines then at least one would slip; if a system of cogs were used to prevent slippage then the wheels would jam. A modern approximation of such an experiment is often performed by car drivers who park too close to a curb. The car's outer tire rolls without slipping on the road surface while the inner hubcap both rolls and slips across the curb; the slipping is evidenced by a screeching noise" Here is the entire article:'s_wheel_paradox#Analysis
  11. BaalChatzaf

    Aristotle's wheel paradox

    wrong. The small wheel slips and drags because the center is carried horizontally by the outer wheel. Do the math and you will see your error. Or as I sometimes say "shut up and calculate".
  12. BaalChatzaf

    Aristotle's wheel paradox

    There is no paradox. Please see: The small wheel mounted on the same hub as the big (outer wheel) slips and drags.. For an angle theta that a radius turns the center is moved 2*pi*theta*R horizontally where R is the radius of the larger outer wheel. This exceeds 2*pi*theta*r where r is the radius of the smaller innerwheel. R > r so the distance that the center goes during a turn of angle theta is greater than the smaller inner wheel would have gone if it did NOT SLIP. The resolution of the so-called paradox is that the inner wheel slips by the quantity 2*pi*theta* (R-r). As the article I quoted states the appearance of a paradox is based on the false assertion that the existence of a continuous one to one function between the points on the circumference of the inner and outer wheels in implies the length of the arc on the inner wheel corresponding to a turn of d theta (in infinitesimal turn) equal the length of the corresponding arc on the outer wheel. Not so. the length of the outer arc is to the length of the inner arc as R is to r. Problem solved. It is unnecessary to fall into the philosophical tar pit of Logical Positivism which denies an external reality and asserts all we have are relations between data, i.e. perceptions of the outer reality. This is sometimes called phenomenalism. It says that either there is no outer (external) reality or all that our minds can ever get are the experience of the outer reality (if it exists). This is also the premise that Kant used. He said there is an external reality, but we only get what the mind filters in (of it). To be truthful, I do not know of a satisfactory resolution of the disconnect between the external or "real" reality and the perceived reality that our intellects can deal with. I do not resolve the paradox (I am sorry to say). I AVOID the paradox by resorting to the "shut up and calculate" tactic in which I get an answer that conforms to what I experience each and every time I make a measurement and calculate an assertion of what I will measure. This approach is never wrong, but it is totally unsatisfying to those who insist that the :"real" reality is there and can be experienced or sensed. Kant denied this. Me? I avoid the disagreement. I beg you to forgive me for not resolving the question you raised. The best I can do for you is clarify the problem, but I still leave you with the problem. Sorry about that.
  13. BaalChatzaf

    Toronto Mass Shooting

    quid custodiet ad ipso custodii?
  14. BaalChatzaf

    Intelligence programmable? Quote Binswanger

    Binswinger's grasp of the history of the human species is very much in error. Our kind of human did not emigrate from Africa until about 60,000 ybp. This was the second wave of emigration by homo sapien. The first successful emigration of hominids from Africa eas Neanderthal, about 300,000 ybp. Neanderthal was very successful but the Ice Age and the competition from Homo Sapien Sapien finished Neanderthal off about 35,000 ybp. Homo Sapien Sapien had a more gracile skeleton than Neanderthal and was less muscular. However Homo Sapien Sapien caught on to human networking, exchanging ideas and trading stuff so had much better hunting technology than did Neanderthal. There is evidence that limited mating took place between H. S. S. and H. N and Homo Sapien Sapien outside of Africa acquired Neanderthal genes to a limited extent. The Human Race as it is currently constituted has about 1 % of genetic material inherited from H. Neanderthal. Our kind of human survived because he learned to use his wits and indulge in abstract thought to some degree. We can tell from the cave paintings that some of our ancestors has a "good eye" and artistic imagination.
  15. BaalChatzaf

    Praise to the Rescuers

    At least three genuine cheers for the rescuers he freed 12 boys and their team coach from a water blocked cave. They were volunteers. They differ from normal people in several ways. Like firemen who run into burning buildings while "normal" people flee from them, these brave souls took their chances swimming in total darkness to bring light, food and other supplies to the trapped boys and their coach. Sadly, one of the rescuers became lost and drowned. However, that unfortunate soul know the hazards before he went into the caves and went into the cave in spite of the hazard. We also note the Elon Musk proposed building a boy size submarine to get the lads out. Which is better than building a Hyperloop system to rescue the kids.