Darrell Hougen

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Posts posted by Darrell Hougen

  1. 16 hours ago, Jon Letendre said:

    It’s a character flaw. It is observable from where I am but only he may understand its origins or motivation. It is one of the more irrational ones, too. It has always deeply amazed and puzzled me. I’ve seen many cases.

    Another, similar, is the liar who sticks to the lie even after plain demonstration of its status as a lie. It’s like they think plausible doubt is still somehow maintained  Of course the way to preserve one’s reputation at that point is to reverse oneself, but they imagine that the better way is to prove to you that they neither care about the truth nor see you as someone who deserves any. Comically irrational.

    Who you gunna believe, me or your lyin' eyes?

  2. On 1/14/2019 at 4:32 AM, Jonathan said:

    Here it is again:

    46637986672_1b52e34b48_b.jpg

     

    Hi Jonathan,

    To be honest, I'm not sure what you're doing above myself. I know the equations of perspective projection for a pin-hole camera:

    X = x/z

    Y = y/z

    where (X, Y) are image coordinates and (x, y, z) are world coordinates. But, that doesn't help much if I don't know where the camera is positioned or what the viewpoint is.

    Alternately, I know that in the absence of distortion, straight lines in the world produce straight lines in the image. I also know that a rectangular solid in general position generates three vanishing points --- 3 point perspective. Using the two posts at the ends, it would be pretty easy to find one vanishing point. However, I'm not sure if there is enough depth information to accurately calculate the positions of the other two.

    So, perhaps you have some method based on triangles or something for drawing the relevant lines. What lines are required for determining the foreshortened shape of the wheel when it gets to the right-hand side? I know it should be an ellipse, but I don't know how to determine the eccentricity with the information given.

    Anyway, I could look it up, but I'm just curious what you're doing.

    Darrell

  3. Let me take this discussion in a slightly different direction.

    It turns out that people have widely varying levels of ability to recognize faces. There was a 60 Minutes episode on this topic. At one end of the spectrum are the so called "super recognizers" who are able to walk down the busy streets of New York City bumping into people and remember virtually all of the people they meet. They might run into someone in the afternoon and say, "Oh, I saw that guy over on 23rd street this morning." One woman who was being interviewed was shown a high school year book picture of someone and she figured out right away that it was a picture of Mike Wallace. At that time, I believe, Mike Wallace was dead and gone so she couldn't have seen him recently.

    On the other end of the spectrum are people who have a very difficult time recognizing faces. Some people have a difficult time recognizing friends. Some have trouble recognizing their own family members. Some men had difficulty recognizing their own wives. And some people even had difficulty recognizing themselves in a mirror.

    But, even the people who had difficulty recognizing themselves were able to recognize ordinary objects --- a cup, a table, a chair, a car, etc. So, it seems like facial recognition is a very specific mental function. It is a function that is handled by a very specific part of the brain. That makes sense because facial recognition is very important to humans so having a particular part of the brain dedicated to facial recognition makes it possible to recognize subtle differences between faces that might not be immediately obvious with regard to other kinds of objects. Although we might learn to recognize particular apples, for example, differences between apples aren't as immediate and obvious as differences between faces.

    One man on the 60 Minutes program was discussing how he had learned to recognize himself by concentrating on individual parts of his face. He would look at his lips, his mustache, his nose, his eyes, etc., and could convince himself that he was looking at himself by studying his face carefully. Presumably, he could apply the same method to recognize other people as well --- I have a big nose; my wife has a small nose, etc.

    From the foregoing conversation, it would seem that visuospatial/mechanical reasoning is another specialized mental function. So, one has to wonder whether a person that lacks the ability to easily and naturally perform such reasoning can learn to answer questions about mechanics by concentrating on simple aspects of the problem and reasoning at a higher, conceptual level about their interrelationships.

    I should say that know that I have limitations of my own. I'm lousy with people's names. When I was young, I realized I didn't know the names of the some of other students in one of my elementary school classes and made the unfortunate decision at that time that it wasn't important and that I didn't care. As I grew to adulthood, I realized that my inability to remember people's names was a definite handicap, so I reversed my earlier attitude and attempted to get better at remembering. When I watch a movie, I attempt to name the actors and actresses in it. At the end of the movie, I watch the credits to try to learn new names. When I meet people, I focus on getting to know their names. Sometimes, I still forget to pay attention, but I try.

    Not everyone has such difficulty with names. My own daughter has a natural ability to learn people's names. She's in her twenties now, but when she first started kindergarten, she learned the names of all of her classmates before the first week was out. She must have gotten that gene from her mother.

    At any rate, I don't know the extent to which cognitive deficits can be compensated for, but I find the question interesting. I also wonder if there are other kinds of common cognitive deficits.

    Darrell

     

  4. On 12/19/2018 at 2:37 PM, anthony said:

    We gotta cue in a dose of reality to puncture the slippist balloon.

    I ask that anyone goes look at a car wheel. At least for once do some visualization of the original entity: an everyday wheel in motion.  See the car maker's badge in the center of the rim which is at the center of a tire? Nominate that to be the inner wheel. Same exercise, just that this tiny circle makes it more graphic.

    Observe carefully: as the tire makes one revolution, so does the badge make one revolution. But the badge is +/- 6 cms. in diameter, the tire diameter +/-  60 cms. Further, the badge can be calculated to revolve about 18cms. and the tire's track is 1.8meters --their relevant circumferences!. Strange!  What's going on here?

    Therefore the outer wheel traverses a distance 1.8m. But equally does the badge/inner wheel travel this far, despite a differential of 1:10 circumference. Strange!

    Any slippage observed - or needed to be induced?

    Nope. The wheel (and Aristotle's diagram of a wheel) behave as their reality dictates. The single driver and cause is the motion of the outer wheel, the inner wheel conforms.

    Perhaps if one imagines a wheel containing an infinite quantity of inner concentric circles, each of which has a 'turn speed' - i.e. tangential velocity - which decreases as their radii decreases, one can imagine a physical, inner wheel transposed onto any circle - and not relevant if a very small wheel or one almost the full size of the outer wheel.

    These varying tangential velocities of the imagined 'concentric circles' are what 'hold' (so to speak) the turning wheel together. Mess with them at any point, and THEN you will get slip/skid inside the wheel, causing jamming and breakage.

    While a few respondents have appeared to have taken Vt into account, they don't seem to get the ramifications of it  - or - have argued that Vt is precisely what causes/necessitates track and slip. (Placing the cart before the horse). 

    From the get-go, the entire premise of inducing track/slippage, clearly has been built on the wheel - only - possessing *angular* velocity. Thereby, erroneously assuming upon a velocity which is identical at any point inside a wheel (and of a wheel within the wheel).

    I.e. True, the rpm's are a constant--but the Vt is variable, the product of angular velocity -and- radius..

    If angular velocity were all there is, a wheel self-evidently could not function, not to mention this denies the observable identity of a wheel. From one faulty premise, all subsequent exploratory stages will be faulty also. ("Cognition", mechanics, experiment, etc.)

    Hi Tony,

    There are basically three scenarios being discussed:

    1. An ordinary wheel or tire that runs on a road or track.

    2. A pair of adjacent wheels or gears that run on adjacent rails or tracks at appropriate levels.

    3. A bottle or Dixie cup whose ends run on widely spaced rails or tracks --- widely spaced relative to the sizes of the ends.

    Your explanation works perfectly fine in the first case, but it doesn't begin to explain the other two scenarios. You agreed that a cone shaped object would veer off to one side, but you haven't explained why you think that to be the case.

    Darrell

     

     

     

  5. On 12/13/2018 at 10:09 AM, anthony said:

    Arguments are being made by analogy, metaphor, simile. That's unsatisfying. All good and fine as instruments toward understanding and communication, but they can't substitute for reality, nor reasoning. As with Max's comparative allusion to vectors and your sliding car. An object in flight is either level, rising or falling. A car tyre is either biting or sliding. At any instant in time. An entity cannot do all/both "at the same time and in the same respect". (That both have forward velocity has to be taken as the given).

    Hi Tony,

    Mathematically, it is possible for a tire to roll and slide at the same time. What happens at the molecular level is another question. It is quite possible that the molecules of the tire temporarily adhere to the road surface and then jump to a new location.

    Consider what happens when you drive your car. If you turn a corner, then different parts of each tire are simultaneously moving at different speeds relative to the surface of the road. Assume you turn left and consider the left front tire. The left side of the tire travels a shorter distance than the right side of the tire as you go around the corner. Since the left side and right side of the tire have the same diameter, either one side or the other or both must be simultaneously rolling and sliding. Whether it is true simultaneity or the molecules in the tire are temporarily adhering to the surface before jumping to a new location is anyone's guess at this point. Perhaps there is some information online that would answer the question. But, if it is easier for you to grasp the idea of high-speed microscopic deformations of the tire than the mathematical explanation using the continuum, then I would have no argument against your point of view.

    Darrell

  6. On 12/2/2018 at 5:07 PM, Jonathan said:

    False. The inner wheel will roll. It will not slip at all. It is not physically possible for it to slip. Its cable prevents any slippage. The inner wheel will roll without slippage until it reaches the end of its cable, which is one rotation.

    False. The two wheels are affixed to one another. When one completes a full rotation, the other does as well. However, since the large wheel must over-spin in comparison to its surface (any point on its perimeter will create a prolate cycloid during the wheels' motion), it will have travelled a distance shorter that its circumference, and its cable will have let off slack (the length of the slack will be equal to the length of the large wheel's circumference minus the length of the small wheel's circumference).

    Bob, you're not properly envisioning the scenario, especially the effects of the cables. I would suggest building a model and observing how the reality of it differs from your mistaken imagining of what happens. A couple of spools of thread with different diameters, glued together and a nail for an axle would work.

    J

    Hi Jonathan,

    It's funny how adding the cables actually made the problem more difficult for some people to understand. I would have thought it would have made things simpler.

    Darrell

  7. On 12/13/2018 at 3:11 PM, anthony said:

    Very nice! Lucid illustrations we could have used earlier.

    I've questions about veering "toward the small end because the small end doesn't go as far as the big end".

    1. As I see it, R and r are now equivalent. [R] You have raised the small end to compensate for the diameters, so aren't they equal?

    2. The neck's lesser rotating speed Vt compensates for its smaller diameter. If the speed was constant, - i.e. higher - yes, we'd have veering in that direction.

    3. The contact made at all points (for large and small diameters between a plane and a circle) is theoretically the same.

    So, will it veer?

    Hi Tony,

    No, raising the small end doesn't compensate for the difference in the diameters. It doesn't make them equal. The big end still has diameter = 2R and the small end still has diameter = 2r.

    Think about it --- you're still calling them the "big end" and the "small end". If you can't discern the difference between the two ends, why do you have two different names for them? The fact is that the two ends are different. That fact is both perceptually obvious and logically required. Simply raising up one end doesn't change its size.

    Now, what happens when the bottle rolls? Every time the big end rotates by one complete rotation the small end does too. I think you agree with that. In the case I pictured, the bottle will probably fall off the rails before it rotates one complete time, but the same logic applies to part of a rotation.

    If the big end rotates by a tenth of a rotation, so does the small end. Now, without slipping, that means that in one tenth of a rotation, the big end will travel 2 * pi * R / 10 inches and the small end will travel 2 * pi * r / 10 inches. And, if R > r, then 2 * pi * R / 10 >  2 * pi * r / 10. It has to be that way. That is what logic demands.

    The tangential speed of the small end during rotation is less than the tangential speed of the big end. That is true. But, the fact that the tangential speed of the small end is less than that of the big end means that the small end is traveling more slowly than the big end. That's because the speed of the center of each end relative to the rail on which it rides is equal to the tangential speed of a point on the circumference relative to the center of that end. If that is hard to understand, don't worry about it right now. Concentrate on what I said above. If the big end is bigger than the small end, then it must travel farther in the same amount of time if neither end slips.

    So, yes, the bottle will veer off to the side.

    Darrell

     

     

     

  8. On 12/11/2018 at 1:54 PM, anthony said:

    To "perform the experiment properly" would require fine adjustments. Height, weight distribution, and friction/drag - equalized. I've mentioned that near-perfect "balance" is the prerequisite. The elevated track needs precise compensation for the different diameters, and fine measurements  using specialized instruments to observe the contact/or slippage of the neck. I have got close to achieving balance with rough tests.

    When "slippage"? - when firm contact? When sliding and when rolling? How does one observe the distinction, in practice? This cannot be validated in an average home experiment I think.

    .

    "5. The neck protrudes from one end of the bottle. Since the neck of the bottle protrudes from one end of the bottle, the two ends of the bottle move at different speeds. That causes the entire bottle to turn in the plane of the floor and veer off toward the smaller end".

    Well, no. This is rather begging the question and a non sequitur. WHY do "different speeds [tangential velocities?] ... cause the entire bottle to turn...and veer off...?

    (btw, though you do not refer to this, It is worth bringing up that the diameter of the neck vs. diameter of the bottle is not a factor. Mathematically, the meeting point of a line and a circle has no dimension. Practically, the contact is identical for all diameters of objects, and can be eliminated here).

    We have already established that the small wheel/large wheel rotate at different tangential velocities --BUT, still identically maintain all the other factors - translational speed; equal rotation; combined distance covered. Therefore, tangential velocity-difference is the only possible explanation for the small wheel's circumference being far less than total travel distance.

    IOW, V(t) is a property or feature of the wheel.

    As read above from Max: "The difference in tangential velocities explains why slipping *does* occur". Untrue. A causal reversal. Tangential velocity is a characteristic of the wheel, slippage is an abnormality/and or intervention.

    Anyhow, for now I have been entertaining the idea of a track without slippage, while not accepting a 'track' with slippage. As close an approximation to a 2-D Aristotle diagram, as possible, can be seen in that video demonstration above. All ~three~ circles conform to each other and to those lines, the represented 'tracks'.

    Hi Tony,

    You're really making this way more complicated than it needs to be. I've created some admittedly low quality images to help visualize what I'm talking about.

    image.png

    If the bottle were rolling on the floor, it would probably make contact with the floor in many places. However, we can simplify things by assuming that it only contacts two points. Imagine that they are two rails that go into the page.

    In the first figure, I've shown the situation when the two rails contact the body. In this case, the diameter of the bottle at each point is equal to R, so both ends of the bottle roll at the same speed.

    image.png

    In the second figure, I've shown the body of the bottle supported at one point and the neck supported at one point. Again, imagine rails going into the page. Here, the large end of the bottle will roll more quickly than the small end. If the angular speed of the bottle is w, then V = Rw and v = rw. Or, after some time, the distance rolled by the big end is D = 2 * pi * R and the small end rolls 2 * pi * r. The result is that the bottle veers toward the small end because the small end doesn't go as far as the big end.

    image.png

    I think that what you're imagining is a situation in which the body and neck are both supported. In this case, the coefficients of friction and weight distribution do indeed matter. However, it's not necessary to consider this case. It just confuses the issue. Depending upon the friction and weight distribution, the third case will either be more like the first case or more like the second. Perhaps it will be somewhere in between and the speeds will be between the two cases. However, we need not be overly concerned with the third case. The first two cases are sufficient to illustrate Aristotle's paradox. Whoever invented "Aristotle's paradox" is saying that case 2 will behave like case 1 when they are clearly different.

    I hope that clears things up for you.

    Darrell

     

     

  9. 9 hours ago, anthony said:

    Here's a good question:  What do a science experiment, a piece of abstract art and an item of "fake news" have in common?

    First, are they all "reality"? Certainly (they exist, they are things). Second, are they all corresponding to reality? Not always, yes, seldom or never, - no particular order.

    A. They are all man-made.

    Each was invented and created and passed through some individual's conscious mind. He put his personal stamp (or at times, bias) on it. But here's the thing, all of them give many undiscerning observers the 'suggestion' of being the 'metaphysical given' -- i.e. "reality" itself. In that ambiguity lies all the equivocations common today (and why people's thinking is screwy). Which example IS representative of reality, is up to the individual's b.s. detector: i.e. does this integrate with what I know?

    Hi Tony,

    An automobile was invented, created and passed through some individual engineer's conscious mind as it was being designed, built, and tested. Does your car fake reality as you drive it down the road? Or is it constrained by reality to act in accordance with its nature?

    Darrell

     

  10. On 11/29/2018 at 8:25 AM, Jonathan said:

    Do you notice anything in addition to the circles and lines?

    Can you see the yellow and orange segments? How about the letters identifying point on the circles and lines? Can you see them?

    See them now? Okay, now watch point E in comparison to point A (actually, first spit out your gum -- we don't want you multitasking while trying to do this). Okay. Which point, E or A, is traveling faster? Which is covering more ground/space in the same amount of time?See? It's pretty easy if you look and keep your attention on it.

     

    On 11/30/2018 at 7:54 AM, anthony said:

    You take reality from animations. Experiments online. Any and all may have a bias to what the maker wishes.

    Explain why there is, apparently, 'slippage' in this depiction of the inner wheel's motion. Or unequal contact.

    Is there grease on the track? Are the wheels not supported equally? One track slightly too low for the different diameters? More friction on the lower surface?

    Just as easily, the greater wheel can be "made to appear" to 'slip' instead.

    Hi Tony,

    Yes, you can think of the upper track as being greased. The upper track has zero friction. Only the bottom track has friction. In addition, the two wheels rotate together.

    Aristotle's paradox essentially states three things:

    1. The small circle and big circle rotate and translate together --- they are rigidly connected to each other.

    2. The big circle rolls on the lower line.

    3. The small circle rolls on the upper line.

    But, that's impossible. Those three statements can't all be true at the same time. One of the statements must be false.

    So, Jonathan decided to keep statements 1 and 2 and abandon statement 3. He created a video which is consistent with statements 1 and 2 but in which the small circle slips while it is rotating and translating on the upper line. It would have been impossible for him to create a video which was consistent with all three statements at once.

    A. Statement 2 implies that in one revolution, the big circle travels a distance equal to 2 * pi * R.

    B. Statements 1 and 2 together imply that the small circle also travels a distance equal to 2 * pi * R.

    C. Statement 3 implies that in one revolution, the small circle travels a distance equal to 2 * pi * r.

    For C I'm also making use of statement 1 since it says that the small circle and big circle rotate together. Therefore, if the big circle rotates by 2 * pi radians the small circle must also rotate 2 * pi radians.

    So, conclusions B and C contradict each other. However, if we get rid of assumption 3, then conclusion C goes away. Conclusions A and B are consistent with each other, so there is no problem.

    Of course, it would be possible to abandon assumption 1 or 2 instead. The big circle could slip on the lower line instead. We just need to understand that it is impossible for 1, 2, and 3 to all be true at the same time. The statements taken together are internally inconsistent. Therefore, it is impossible to find weights or friction coefficients that make all three statements true at the same time.

    Darrell

     

     

     

     

     

     

     

  11. On 12/7/2018 at 5:11 PM, anthony said:

    Darrel, This discussion revolves round matching theory and practice. I think one has to continuously move between them, comparing one with the other.

    Having said that, I take reality/practice as the only guide, and if theory doesn't concur with that, I dump the theory.

     I began with a bottle simply rolling on a floor (of course rolling presupposes a degree of friction). From this alone you can see that the bottle is a total entity which covers a distance y after x rolls - and its neck rolls correspondingly with it. It would be ridiculous to insist on measuring the neck's circumference, 3.14in, and deduce - 10 rolls of the neck = 31.4 in ... therefore the bottle rolled 31.4 in!

    Obviously not. The bottle's circumference is the determinant of distance covered -- and the neck's circum is superfluous.

    So far this practical test is keeping with the theory of the paradox diagram and validating that. ie.The inner wheel has nothing to do with distance.

    Trying to now reproduce this action on a second track. I said earlier that the conditions of the bottle on the floor, with its neck moving and turning unimpeded without contact, must be precisely adhered to, in order to conduct an experiment.

    A proper experiment has to faithfully re-create reality, so to speak, not add more variables. That brings up an error I made about "frictionless" supports. This is wrong. We need friction and weight for rolling to take place. But - this must be equalised for the whole bottle.

    I argue that the bottle can be balanced to roll on a 'track' as it did on the floor. Straight. With rolling, i.e., no slip/slide of the neck (inner wheel) -- and because of their different tangential speeds, the neck turns slower. By your example, the bottle will cover 94.2in.here, too

    If a bottle will roll on its own, what difference do 'tracks' make? Why should the neck change the behavior of the bottle? It is the 'inner wheel', so that depends completely on the outer.

    (But I can see why 'track-slippage is so important to everyone. All the arguments here rely on it exclusively - no track, no slippage). 

    Similar to a penny-farthing bicycle, while not on the same axle and unequal revs, a larger (drive) wheel is the only wheel that matters for distance. The little one runs along with it (and doesn't 'slip')

    Hi Tony,

    Sorry about the delay in getting back to you. I didn't get online during the weekend.

    I agree that theory and practice must be consistent and I think you will find that they are if you follow closely what I am saying.

    If a bottle rolls on the floor with no support for the neck, then it will roll straight (if the neck is not too heavy). It will roll straight because the body of the bottle is the only part of the bottle in contact with a supporting surface --- the floor. Therefore, there will be no friction between the neck and the supporting surface. The only friction will be between the body of the bottle and the supporting surface. Therefore, the body of the bottle controls the behavior of the bottle and the behavior of the neck is completely dependent upon the body of the bottle, as you said.

    However, if the neck of the bottle rests on a supporting surface, the behavior of the bottle should change, should it not? If the conditions of an experiment change, wouldn't we expect the results of the experiment to change as well?

    If the support that is constructed for the neck of the bottle provides significant support for the neck and has significant friction, the results of the experiment should change. Of course, if the support doesn't support a significant amount of weight or doesn't have significant friction, then it will have minimal to no effect on the experiment. However, if a significant fraction of the weight of the entire bottle including both the neck and body is supported by a supporting surface and if that surface has significant friction so that it causes the neck to roll on its circumference, then the behavior of the entire bottle must change.

    If the body of the bottle rolls on its circumference and the neck rolls on its circumference, then the bottle will veer off to the side. That will happen because:

    1. The neck of the bottle has a smaller circumference than the body.

    2. The neck is rigidly connected to the body.

    3. The neck rolls on its supporting surface.

    4. The body rolls on its supporting surface.

    5. The neck protrudes from one end of the bottle.

    Since the neck of the bottle protrudes from one end of the bottle, the two ends of the bottle move at different speeds. That causes the entire bottle to turn in the plane of the floor and veer off toward the smaller end.

    That is not a mathematical conclusion. That is a logical conclusion. It logically follows from the proper identification of the concepts involved and their relationships. If you think the conclusion is incorrect, please show which concept is improperly conceived or how the reasoning is flawed.

    Also, if you perform the experiment properly, I am certain that the results will confirm the correctness of the logical argument.

    Darrell

     

     

     

  12. 1 hour ago, anthony said:

    He who can't see in the video that the smaller circle is turning slower is vision-impaired or illogical.

    BOTH circles traverse the same circumference-length - yes? (the larger one's)

    Both circles begin and finish their rotation at the same time and same point - yes?

    Therefore, what is the only differentiation?

    The turning speed of the small vs the big circle.

    I realize great investment has been made by some in 'tracks and slippage'. Preconceptions can lead to fixation or rationalizing.

    Tony,

    What is the "turning speed"?

    Also, you didn't respond to my last comment. It's hard to maintain the continuity of a conversation if you don't respond.

    Darrell

  13. On 11/27/2018 at 3:22 AM, merjet said:

    Also, the journal article ‘Aristotle's Wheel: Notes on the History of a Paradox’ by Israel E. Drabkin, which is referenced 6 times (!) in the Wikipedia Article includes the following:  For though the smaller circle traverses a distance equal to that traversed by the larger, it does not keep pace with the larger by sliding over the tangent, if by ‘sliding’ we mean that a point on the circumference is at any time in contact with a finite segment of the tangent” [my bold].

    Hi Merlin,

    This is a technical objection that has very little to do with the current discussion. The small wheel rolls and slides simultaneously so that the tangent point changes continuously and no point on the circumference of the wheel ever contacts more than a single point on the track.

    We haven't even gotten to the finer points of the discussion. Based on the description on Mathworld, Aristotle's paradox may have to do with both the mapping between points on circles of differing sizes and on the differing lengths of the circumference. For example, any radial line intersects both the big circle and small circle at exactly one point. That shows that there is a one-to-one mapping between points on the small circle and points on the big circle. How is it then that the two circles have different circumferences?

    Darrell

  14. 3 minutes ago, anthony said:

    As before, and on off-set tracks which are almost frictionless like blades (to equalize drag), the distance moved is the same for both - 94.2in. That means the different tangential velocities, slower for the neck and slightly faster for the big wheel (bottle) ~do~ matter. The small wheel laterally moves the large wheel's circumference/distance in an equal 10 revolutions ~because~ it has less rotation speed. As before, the circumference of the small wheel plays no part in travel distance, that's determined by the big one (like a rolling cartwheel in relation to its inner hub). 

    The bottle "could be rolled fast or slowly", yes, that's not relevant. What matters is the relative revolving speeds of outer and inner wheels, bottle and neck.

    Hi Tony,

    Okay, so the offset track is almost frictionless so that the small wheel veritably slides across the surface, barely disturbing the path of the body of the bottle. Is that what you're saying?

    If that's what you're saying, then you are correct that the neck of the bottle will move with the body and that the distance moved will be 94.2 inches for both.

    Darrell

     

  15.  

    20 hours ago, anthony said:

    Briefly, I maintain that placing the bottle/combined cylinders onto two tracks (one beneath the neck, the other beneath the bottle, and compensating for their radii difference) is not going to, in essence, change anything about their combined motion. The "neck" or smaller wheel, turns slower (as we know)  in the same time as the main bottle turns slightly faster, therefore without slippage, and the two finish at the same endpoint after a rotation by each.

     

    13 minutes ago, anthony said:

    Distance traveled = 94.2in for the bottle AND, 94.2 for the neck. The (inner wheel) neck's distance entirely depends on the (outer wheel) bottle's travel distance, not its own circumference .

    Hi Tony,

    But, if the neck of the bottle rolls on a separate track (or book, for example) then according to my calculation above, it only travels 31.4 inches.

    distance traveled = N * pi * d = 10 * pi * 1 =~ 31.4 inches.

    If there is something wrong with my calculation, what is the problem?

    The tangential velocity doesn't really matter in this case because the bottle could be rolled fast or slowly. The only important thing is the total distance traveled.

    Darrell

  16. 13 minutes ago, anthony said:

    Okay, obviously not what I intended, but true - I take your point. I guess you take mine.

    How bout simplicity: You swing a rope around your head to which are attached a weight half-way along and a weight at the end. Which moves faster?

    The one at the end, obviously. Now go back and look at the post where I put numbers to your theory.

    Darrell

  17. 4 hours ago, Jonathan said:

    I agree with the above.

    No, it's not at all about being impolite because of someone's not understanding something. It's completely about their condescension, their evading questions, immediately rejecting substantive content without even taking the time to absorb it. And their name-calling.

    Initiating bad. Retaliating good.

    J

    Point taken.

    • Thanks 1
  18. 3 minutes ago, anthony said:

    Darrell, a simple reply suffices.

    Hi Tony,

    Sorry, I couldn't resist.

    In reality, if one moon were farther away from the planet than the other, it would be moving more slowly than the one that was closer. They couldn't possibly stay in sync if they were at different distances from the planet. I just found your example amusing.

    Anyway, go back and look at my other post which was more serious.

    Darrell

  19. 18 hours ago, anthony said:

    Jesus, try harder! 😉 Does nobody get relative velocity in a circle? If two moons are in orbit around your planet (!) and visibly stay permanently close together, but you know that one is much more distant - which one is moving faster?

    Okay everyone, who votes that we try to explain orbital mechanics to Tony?

  20. 18 hours ago, anthony said:

    I feel we are talking past each other, Darrell. I haven't that I recall, talked about leveling (maybe, once, loosely) and certainly not "leaning".

    To get back on point,  I believe this is all about a second 'track' for the inner wheel? Is that right? This is best depicted by the cylinders I mention. The cylinder assembly is indeed not leaning to one side--a sectional view represents two wheels, one "larger than the other" accurate to the wheel diagram.

    Briefly, I maintain that placing the bottle/combined cylinders onto two tracks (one beneath the neck, the other beneath the bottle, and compensating for their radii difference) is not going to, in essence, change anything about their combined motion. The "neck" or smaller wheel, turns slower (as we know)  in the same time as the main bottle turns slightly faster, therefore without slippage, and the two finish at the same endpoint after a rotation by each.

    Hi Tony,

    Okay, let's put some numbers to our theory.

    Let's say we have a bottle with a neck that is 1 inch in diameter and a body that is 3 inches in diameter. Then, if the bottle rolls completely around 10 times, how far does the body travel? How far does the neck travel?

    distance traveled = number of revolutions * pi * diameter = N * pi * D

    So, for the body of the bottle,

    distance traveled = 10 * pi * 3 =~ 94.2 inches

    For the neck of the bottle,

    distance traveled = 10 * pi * 1 =~ 31.4 inches

    Darrell

  21. 1 hour ago, anthony said:

    I pick up at point 4. When the axle has been raised onto a rail (or track), to exactly compensate for the radii disparity, you have eliminated the bias. If indeed the conjoined wheels would rotate at the same tangential velocity, the assembly would veer off. But do they? No, and you have also confirmed this recently. Now they are fixed together as a single unit, the small wheel rotates one rev to the big wheel's one revolution. The small one must turn slower, proportionately, so completing its rotation at the same point, same distance, and no veering- off.

    Darrell, the "logic" begins with that circle diagram, which one can confirm or reject by a comparison to facts: Seeing and knowing wheels in motion. In all wheels there cannot -possibly - be slippage. Otherwise, a wheel can't function.

    Observe a 'circle' inside any wheel - i.e. an imaginary inner wheel - Watch it closely, and it does and must outrun the length of its circumference (for one turn of the main wheel). No one can refute this fact.

    It *has to*, by definition, it is a smaller i.e., a lesser circumference circle.  If it were extremely tiny in relation to the big wheel, anyone could see this effect instantly, I surmize. Lateral distance covered would now be many times this little circumference.

    And visibly, it doesn't slip. Now, if that 'circle' were "extruded" to be a second, inner wheel - and placed level on a track - what can change?

    So Aristotle's diagram is true to reality, uncontradictory. (in his terms, one might call the large wheel the "prime mover"- the cause - of which the small wheel's motion is an effect and which has no influence on proceedings). 

    All that's missing is an explanation of the phenomenon, and most certainly in my view, it is in that disparity between the tangential velocity of the wheels. You've not taken that into account. 

    Hi Tony,

    The "bias" is not caused by the fact that the cone or cup or wheel assembly is leaning to one side. It is caused by the fact that one wheel is larger than the other. Therefore, leveling the assembly has no effect on the "bias."

    Tangential velocity is the velocity of a point on the circumference of a wheel relative to the center point of the wheel. The assembly veers off because the tangential velocities of the two wheels are different. If the tangential velocities were the same, the assembly would not veer off even if one end were higher than the other.

    Darrell