Knowledge

Talk:Bertrand paradox (probability)

Source 📝

854:
length from 100 chords is to generate 100 chords where the difference in length between two consecutive chords is the same. This way each chord will have the same chance to be chosen. In the problem in question, being R the circle radius, the side of the triangle will be 1.732R. Given a randomly specified length, the probability of the chord this length being greater than the side of the triangle will be (2R-1.732R)/(2R).100%=13.4%. If the 100 chords were generated by dividing the 90° angle in 100 equaly spaced angles, each chord corresponding to each angle will be greater than the corresponding chord generated by random length. Therefore the probability of the chord being greater than the side of the triangle will be higher. 33% greater than 1.732R in the case. If the 100 chords were generated by dividing the radius in 100 points and taking the lengths of the chords passing through each point, each length will be greater than the corresponding length generated by random angle. 50% greater than 1.732R in the case. In the random angle as well as random radius methods, the chord lengths are not equaly distributed in the range since the difference in length between two consecutive chords is not constant. Actually the difference decreases with increasing angle for instance. When you choose the second method you divide the 90° angle in 100 equaly spaced angles and take the chord corresponding to the angle. that will give you the 33% probability. The chords lengths are not equaly spaced. When you choose the third method you divide the radius in 100 equaly spaced points and take the chord passing through it. That will give you the 50% probability. The chords lengths are not equaly spaced. The unique solution is to divide the lengths in 100 equaly spaced lengths. This is equivalent to Jaynes solution by throwing straws onto the circle.
339:
imagine a process of production that is uniformly distributed over side-length. But the question could have been given an equivalent restatement: A factory produces cubes with face-area between 0 and 1 square-feet; what is the probability that a randomly chosen cube has face-area between 0 and 1/4 square-feet? Now the tempting answer is 1/4, as we imagine a process of production that is uniformly distributed over face-area. This is already disastrous, as we cannot allow the same event to have two different probabilities (especially if this interpretation is to be admissible!). But there is worse to come, for the problem could have been restated equivalently again: A factory produces cubes with volume between 0 and 1 cubic feet; what is the probability that a randomly chosen cube has volume between 0 and 1/8 cubic-feet? Now the tempting answer is 1/8, as we imagine a process of production that is uniformly distributed over volume. And so on for all of the infinitely many equivalent reformulations of the problem (in terms of the fourth, fifth, … power of the length, and indeed in terms of every non-zero real-valued exponent of the length). What, then, is the probability of the event in question?
325:
credences. The paradox arises because applications of the principle of indifference to different parameterizations of the problem yield inconsistent results. The wiki is very, very helpful in showing the problem as originally posed and very, very nicely illustrates Jaynes' reply. However, the transformation invariance response given by Jaynes doesn't seem to generalize, at least according to Howson and Urbach in their "Scientific Reasoning: The Bayesian Approach" (2005) (see pages in the 270s/280s). Also, the wiki is not very helpful in showing the generality of the problem of relativity to parameterization for applications of the principle of indifference. Maybe a discussion of van Fraasen's "cube factory" could be added to show how the question about parameterization generalizes. So the short answer is that if you interpret probability as rational degree of belief then the Bertrand paradox might motivate you to give up trying to use the principle of indifference to fix precise prior probabilities and instead motivate you to adopt a theory of imprecise credences. Hope that helps some.
440:
lengths in the population which will relate to a non-uniform distribution of area. If you focus on the area you must consider a uniform distribution of areas which relate to a non-uniform distribution of lengths. In Bertrand’s paradox the focus is the length since the length of the chord is to be compared with the length of the side of the triangle. Therefore the lengths uniformly distributed in the population is the unique solution. This will result in a probability of the chord being greater than the side of the triangle of (2R-1.732R)/(2R) = 13.4%, where R is the circle’s radius and 1.732R is the side of the triangle.
179: 158: 84: 424:
conundrum. Presently the main objection about Bertrand's chord paradox is whether or not it refutes the Principle of Indifference because a particular solution can't be appropriately justified. (The Principal of Indifferent allows a probability to be assigned to each state where there are a finite number of states, e.g. a coin flip or a dice roll.) In reality there isn't a math problem here, only a philosophical one. The philosophical problem is like debating "How many angels can fit on the head of a pin?"
1228:
original research or formulation of an argument. It is, that original work is overly dependent on the author, and that at an encyclopedia managed on a volunteer basis, such a dependence is impractical. Every editor/reader query, "What was meant by... ?" is either managed by a trip to the source cited, or by a post-and-wait episode for the author (or their supporters) to reply to. The former is our way, the latter is not, and is an entirely impractical way for this encyclopedia to be maintained.
74: 53: 692:
answer of 1/2, assuming an infinitely long line so the end of the line isn't hit thus only creating 1 intersection not two. (For a human tossing on purpose a couple of meters would seem more than reasonable for tossing a circle 25 cm in diameter.) To make that model more efficient, consider a multitude of parallel lines a distance 2R apart where R is the radius of the chosen circle. Tossing a circle is now virtually 100% efficient.
552:, but that's not the point. The point is that it's referred to as a paradox and to say it's not when there's no formal definition is POV. And honestly, most paradoxes in science literature are "resolvable" in some sense, or the real-world oddity has a formalizable explanation, unless they are ill-posed or contradictory to begin with. After all, coming up with solutions is the fun of talking about paradoxes! 22: 255:"The argument is that if the method of random selection is specified, the problem will have a well-defined solution (determined by the principle of indifference)" If you specify exactly how the chords are chosen then you don't need the principle of indifference to determine the answer. E.g. uniformly selected start and end points on circle. 669:
terms of secant lines, Jaynes has stated the problem in such a way that there is a unique solution. Jaynes concrete model of straw tossing also has a definite solution, as does any concrete model. However as Friedman pointed out Jaynes is using a fixed length straw. To get exactly 1/2 a straw of infinite length must be used.
959:
projection of that point on flat surface of the circle?? That is main question here! If we are able to make nonlinear transformation why we can't repeat that again and again. Problem is well stated and it is excellent example how we can't insert our assumption. Unique solution is 1/3 -- see: www.bertrands-paradox.com
378:, and the values which correspond to the 'same cube' are exactly the same in number. Applying this to Bertrand's chord problem is trickier, however, because that problem is ill-posed. I am yet convinced that it has a unique solution using this reasoning, but to date I have not taken the effort to formally prove it. 673:
them to form a chord. Over the interval the probability that the chord is longer than the equilateral triangles side is 1. Over the interval (R/2, R] the probability drops from1 to 1/3. Over the interval (R, infinity] the value increase to 1/2. Note that for about 10R the probability is very near 1/2.
1275:
is only applicable in the absence of relevant evidence. The relevant evidence here is that as the point on the radius in method 2 approaches the circumference at a steady speed the shrinkage of the chord accelerates, favoring the longer chords. Applying an inapplicable principle hardly qualifies as
1110:
Jaynes really starts off assuming random lines of the plane in his problem statement. Note that for a circle of radius R, the midpoint of the chord must be within a concentric circle of radius R/2. Crofton showed that for one convex body inside another that the ratio of their perimeters was a measure
884:
Well, information theory says that you are wrong. Bertrand asked for the probability, not the distribution of the chords. So the problem can be rightfully cast into non-parametric statistics. So instead of recording chord length an experimenter just records true(T) or false(F) to the question "Is the
695:
To mull the point over, consider two plastic sheets. One with a circle and a much larger one with parallel lines etched. Is throwing the sheet with the circle any different than throwing the sheet with the lines? As a physics problem there are two frames of reference, but the end result after contact
1605:
You can think of the first point as being fixed, with the tip of an equilateral triangle placed on the first point. Then, the second point is chosen around the circumference at random. Clearly, only the opposite arc generates chords that are longer than the side of the equilateral triangle, and this
853:
The correct answer is 13.4%. The problem asks you to compare the LENGTH of a chord with the LENGTH of the side of the triangle. Therefore the parameter to be chosen randomly is the LENGTH, not angle, nor radius and definetely not point within an area. As an example, the only way to choose randomly a
691:
Another point about the 1/2 solution. It assumes the chord set is derived from the set of random lines in the plane that intersect the circle. Think of the flip problem. Instead of drawing a random line across a circle, how about tossing a circle randomly on a line? That problem unequivocally has an
672:
To understand how the 1/3 and 1/2 answers are related think of using a measuring circle concentric with the chose circle. Let's assume that the radius of the chosen circle is R and the radius of the measuring circle is r. Now we are going to select two points randomly on the measuring circle and use
624:
Jaynes' Solution seems to only make sense if they're saying that there's a random line, and you're looking at the chord where the line passes through the circle. This is a way of constructing a chord with a line and the circle, and you could just as well get method three by doing the same thing with
568:
POV - That's the whole point. Bertrand chose a simple problem that can be analyzed by geometric probability, so a lot of convoluted math isn't needed. This allows the reader to readily understand that the problem can be analyzed from different POV (frames of reference). Supposedly the different POV
355:
Van Fraassen's cube factory is actually solvable: the answer is 1/2 (as posed above). To reach this answer, we merely rely on the metaphysical fact that particles and measurements are discretized. That is, whether we consider the material used to construct the cubes, or the means by which we measure
338:
The following example (adapted from van Fraassen 1989) nicely illustrates how Bertrand-style paradoxes work. A factory produces cubes with side-length between 0 and 1 foot; what is the probability that a randomly chosen cube has side-length between 0 and 1/2 a foot? The tempting answer is 1/2, as we
742:
I thought of this just now as well. But it turns out, the center is the only point where this is not true. The reason is, there is exactly one line that crosses through the center of the circle and the midpoint of a particular chord. If the midpoint of the chord and the center of the circle are the
676:
The gist here is that random secant lines created by choosing two points on circle R are not random lines of the plane. Think about circle 1 meter in diameter and a point, P, 1 astronomical unit away from the circle. At P the lines from circle R are essentially parallel. This is far from isotropic.
668:
Now where Jaynes goes off the rails. A large part the conundrum in Bertrand's chord paradox is puzzling about choosing "random chords" versus "random secant lines" because a chord can be extended to form a secant line, and a secant line has a line segment which is a chord. By stating the problem in
251:
I think this solution paragraph needs adjusting: "The problem's classical solution depends on the method by which a chord is chosen "at random"." It depends on the density measure given to the set of chords. That may or may not depend on your method of choosing a chord. The key thing is the density
1039:
Choose your line at random from all possible lines. Without loss of generality, choose a coordinate system centred on the circle, with the y axis parallel to the candidate line. (There are two ways to do this, rotated 180° from each other. For definiteness we choose the one that gives a positive x
821:
In fact any solutions can be converted to a solution about the density of chords in the circle by a change of variables. Since there are an infinite number of diameters, when considering the density of chords, the center must be an asymptote. Hence the density of the cords going towards the center
1322:
That isn't in fact an issue! Even though the probability of a continuous random variable taking on a particular value is zero, one can instead define a probability density that allows one to compute the probability of a random variable being an element of an open set, and this probability density
958:
we don't compare lenght, we just have to split our set of chords by the limit lenght and the problem is defining that set. The set proposed here by aproach nr 2 or 3 are not regular, because they involve nonlinear transformation. If we assume that mid point represent one chord why we have to make
439:
In order to have a random selection you must establish a process in which each element in the population has equal probability to be chosen. In the case of Van Fraasen's Cube Factory described above if you focus on the random selection of length, then you have to consider a unifom distribution of
404:
We could include this, but there is a big difference to Bertrand's Paradox: with Bertrand's Paradox, we have to apply transformation groups in two-dimensional space, while the cube factory problem is just about finding an uninformative prior probability density on a scale parameter, which is less
891:
Now Information Theory say that the 1/2 solution to the problem is the most random answer. Consider trying to guess if the next chord is longer or shorter. If only 1/4 are actually longer then one should guess F, and would be right 3/4 of the time. However if 1/2 are actually longer then one can
521:
a paradox. To be fair, this is a bit more "paridoxical" in that the Monty Hall problem, while counterintuitive, is well-posed whereas here the issue is that there seem to be multiple interpretations of the problem. However, upon close inspection, it appears that one must conclude that either the
1227:
I would note in addition to the legalistic argument—that we are a confederation held together by a commonly agreed upon set of rules, and so only as strong, in the end, as we are willing to adhere to them—there is a very practical argument in favour of presentation from source rather than ones
423:
The nature of the "paradox" was that there is often more than one way to parametrize a problem involving a continuous variable. So for a circle of radius 1, the chords must be in the interval (0,2], but what is the distribution? Bertrand proposed three different solutions to show why this is a
324:
You might look at the Stanford Encyclopedia of philosophy entry "interpretations of probability" for starters. Many proponents of the "subjective" interpretation of probability as rational degree of belief (or "credence") see the Bertrand Paradox as one motive for having a theory of imprecise
719:
Presently there is a claim that a chord is identified by its midpoint, "A chord is uniquely identified by its midpoint", but this isn't true in the case of the centre of the circle which identifies an infinite number of chords (also diameters), so it strikes me that this claim is incorrect.
1484:
Can someone please give me an opinion on this. Because even if you just look at these two pictures from the post, it will be clear to you that Argument 2 and Argument 3 are the same argument, but someone deliberately put in an extra choice to change the probability between two arguments:
869:
What they are asking you to compare is irrelevant. The point is that "chosen at random" is not well defined. Your argument is heuristic, not mathematical. The mathematical solution to the paradox is to be more specific about what you are asking, since "chosen at random" can't be defined
1040:
value if the line does not pass through 0. If it does pass through 0 then the two orientations are identical.) Thus, the candidate line is defined by its x-coordinate. By the principle of indifference, all non-negative x values are equally likely. Now this line is a chord iff
292:
Can someone in-the-know please talk about the ramifications for probability theory of the paradox? This is more important than having a lot of nice-looking images illustrating the distributions. I am not familiar enough with deep probability theory to write this. Thanks -
625:
random points. Shouldn't it be that line segments are taken at random, and it only works with the line segments that happen to end at the borders of the circle? If you do it that way, the correct answer would depend on how you're distributing the lengths of the chords. —
265:
It says a chord is chosen at random. A chord is a line segment AB where A and B intersect a circle. The uniform distribution of A and B on the circle seems to be a very sensible default interpretation of the problem statement. This gives answer #1, a probability of 1/3.
649:
Many authors have pointed out problems with Jaynes "solution," but I don't recall any that actually point out where Jaynes went off the rails. His statement of the problem is "Bertrand's problem (Bertrand, 1889) was stated originally in terms of drawing a straight
1299:
The key to all this -- the single principle that this whole paradox is a demonstration of -- is simply that there's no such thing as a uniformly random selection from an infinite set. That's the *entire* thing here, and it literally isn't mentioned. That's weird.
1175:
Lets say your curve is a dense spiral in the middle, and from there a short line to the end, so that 99% of the line is close to the center. After picking any angle, the chance of picking a point in the center area (and thus creating a chord long enough) is 99%.
1620:
Ahhhh, you're entirely right, I misread it. Thanks very much for catching it and setting it back so quickly! I was concerned that I was misreading, which is why I brought it up on the talk page well in advance, but despite my attempted caution I had it wrong.
365:
are 1/16, ¼, 9/16, and 1. Of these, exactly half are less than or equal to ¼ in face area. This symmetry persists across volume as well. The idea here is that we recognize that particles and measurements are quantized; in spite of the apparent difference in
817:
You are absolutely right! Bertrand sneakily avoids that consideration. We all learned that a circle has an infinite number of diameters in grade school. Why shouldn't we use the fact that a circle has infinite diameters as a restriction on any possible
1350:, is mentioned prominently in what is currently the "Recent developments" section. If you turn your attention to the two paragraphs at the bottom of page 7 of the paper, you'll see that the authors claim that an arbitrary probability density function 656:
Well he is wrong about that, so the problems with his solution begin with how he paraphrased Bertrand's statement. A reasonable translation of Bertrand's statement is: "A chord is drawn randomly in a circle. What is the probability that it is
1204:? I understand, for the erudition of its members, that Wikiproject Mathematics is given great latitude. But is this not egregious, to ignore and present our own research on the matter (presuming we are not reproducing that of another, and so 653:'at random' intersecting a circle." He then goes on to say "presumably, we do no violence to the problem ( i.e., it is still just as 'random') if we suppose that we are tossing straws onto the circle, without specifying how they are tossed." 870:
unambiguously for all possible situations. The article even discusses different physical models that give the different results. In those cases, the parameter compared is also length, but length is not the uniformly distributed quantity.--
778:
number of chords could be drawn through this point, some of which would be longer than the side of the triangle and some of which would be shorter. Maybe choosing a U(0,2π) angle reproduces Method 3, but that isn't stated in the article.
261:
The problem says "a chord of the circle is chosen at random". It doesn't say "a line was chosen at random and then a chord made from it" so it isn't answer #2. It doesn't say "a chord midpoint is chosen at random" so it isn't answer #3.
590:
The article simply shows how different assumptions about the probability distribution on chords lead to different answers. Nobody is promoting any of these as the "correct" distribution. Opinion has absolutely nothing to do with
1597:
I think you've misinterpreted slightly what the paragraph is saying? You're right in that choosing a point that doesn't lie within that special opposing arc is indeed 2/3, but that's the probability that the created chord is
1554:
Happy to defer to someone on this since I'm not a mathematician, but unless I'm utterly misreading this should be corrected; I'll set a reminder to myself for 2 weeks from now to come back and change it if no one disagrees.
661:
than the side of a inscribed equilateral triangle?" Note here that Bertrand asks about a shorter chord, but his solutions all solve for a longer chord. Thus the convention has been to pose the problem asking for a longer
1303:
There are infinite chords on a given circle, and it is not possible to select an item at random from an infinite number of items, with equal probability for every item. This is a regular and known mathematical fact:
1279:
A few years ago I taught a freshman seminar at Stanford titled "Paradox: bug or feature?" where we encountered some actual paradoxes, some harder than others. This one wouldn't even have qualified as a paradox.
459:...use the distribution, "select two points on the circle randomly with uniform distribution" and use the chord that those two points to make to solve the problem? It seems to give the least bias to the problem. 1542:
The last sentence of method 1: 'The length of the arc is one third of the circumference of the circle, therefore the probability that a random chord is longer than a side of the inscribed triangle is 1/3.'
360:
are ¼, ½, ¾, and 1. Of these, exactly half are less than or equal to ½ in side length. If we maintain that limitation on measurement, but consider the question of face area, we find that the available cubes
1156:
The problem demonstrates ways in which the solution might be 1/4 or 1/2. Are there methods which generate answers outside this range? If so, are they as simple as the methods described, or more complex? ±
1500: 229: 356:
the quantities in question, the available values in our 'random' range are limited. If, for example, we stipulate that we can only measure side lengths at 1/4 foot intervals, our available cubes
1229: 1213: 774:
chord in a circle. Choose a random point within the circle, perhaps U(-r/2,r/2) for the X and Y coordinates and discarding any points falling outside the circle. Once you have this point, an
140: 602:
As described, methods 1 and 2 are not random as the chord is derived from the triangle. I intend to change the description eg so that method 1 says 'pick two points on the circumference'.
1505:
P.s. I am the author and I am curious if any mathematician will finally dare to say something against what is written in the post. Are all mathematicians crooks and cowardly conformists?
1081:
But now what we have is a random radius of the circle, and a chord defined by its intercept of that radius, uniformly distributed along that length. This is identical to method 2. --
1034: 1413: 1316: 1076: 1377: 1172:
There is no lower or upper bound (well ... ~0% and ~100%). Proof: Use the random radial point method, but instead of picking a straight line, pick a curve of any shape
258:"in the absence of further information there is no reason to prefer one over another." This is true. But to be pedantic, the problem statement does suggest answer #1: 1501:
https://www.quora.com/profile/Emil-Enchev-16/Did-you-know-that-the-Bertrand-paradox-is-the-best-indicator-that-mathematics-has-become-a-den-of-crooks-and-low-intelli
916:
In order to arrive at the solution of "method 3", one could cover the circle with molasses and mark the first point that a fly lands on as the midpoint of the chord.
1463: 825:
Now Martin Gardner proposed making random chords from raindrops falling on a circle. But here Gardner sneaks in a different problem. Bertrand didn't ask about a
1415:. These functions, as defined at the top of the page, are nothing more than characteristic functions times a constant, so they obviously can't approximate an 1681: 544:
I've never heard of a formally-defined and accepted definition of "paradox" in mathematics or science. One could consider Hughes's or Quine's types in the
219: 1196:...are the six unsourced distribution graphs and the unsourced closing paragraph of the "Bertrand's formulation of the problem" section not violations of 1671: 130: 1602:
than the side of an equilateral triangle, while the actual question is "What is the probability that the chord is longer than a side of the triangle?"
635:
Jaynes's error is that he is generating random lines in a plane instead of random chords of a circle, thereby ignoring part of the problem statement.
1686: 1007:
It struck me that the maximal entropy solution is to define a "randomly chosen chord" by selecting uniformly from the set of all possible lines in
888:
This isn't far fetched. Think of marking off the side length of the equilateral triangle and just comparing that to the random chord. Works fine!
106: 1666: 195: 1583: 1676: 1308: 1082: 517:
In what sense is it POV? My only real issue with it is the title including "paradox" when it is not a paradox. That seems like calling the
273: 1036:, and accepting only those that happen to be chords of the circle. However it is not difficult to show that this is the same as method 2. 1508: 1097: 966: 727: 1606:
chord covers precisely one third of the perimeter, therefore the probability (according to this method of course) is indeed one third.
1644: 1135: 1112: 944: 896: 834: 700: 678: 570: 425: 1233: 1217: 871: 744: 97: 58: 1078:; and since all we have done is discard the lines that fall outside this range, all values within that range are equally likely. 186: 163: 1305: 920:
Uh... Very colourful, but couldn't we just say one could throw a dart at a round dartboard, and use that as the midpoint? --
1419:
density function. This is hidden by the authors' choice to focus only on the probability mass assigned to a fixed interval
33: 1331: 1547:
that's a typo and is intended to say 2/3, right? The chance of choosing a point (the second chord endpoint) that
1272: 761:
Since the points are being chosen at random in a subset of the real plane, you can just safely exclude (r,θ)=(0,
1312: 1086: 784: 304: 859: 445: 405:
difficult. Do you think this page would profit from more mathematics? Like a section "mathematical details"?
277: 1512: 731: 1648: 1327: 1294: 1285: 1254: 1139: 1116: 1101: 970: 948: 900: 838: 704: 682: 574: 531: 507: 429: 383: 1611: 875: 748: 1493: 1488: 1584:
https://www.uio.no/studier/emner/matnat/math/MAT4010/v17/notater/w-bertrand-paradox-%28probability%29.pdf
855: 806: 780: 441: 1111:
of the lines intersecting the inside body divided by the number of lines intersecting the outside body.
308: 39: 379: 83: 1607: 1090: 629: 178: 157: 1527: 1523: 1470: 1466: 1205: 1010: 962: 723: 269: 1622: 1587: 1560: 802: 21: 1626: 1564: 610: 557: 194:
on Knowledge. If you would like to participate, please visit the project page, where you can join
105:
on Knowledge. If you would like to participate, please visit the project page, where you can join
1382: 1281: 1250: 1096:
The concept of "selecting uniformly from the set of all possible lines" seems ill-defined to me.
527: 518: 503: 89: 1295:
I'm not a mathematician, but it seems like this article doesn't mention the most important point
73: 52: 1043: 1246: 1162: 993: 925: 640: 549: 1353: 1306:
https://math.stackexchange.com/questions/14167/probability-of-picking-a-random-natural-number
1652: 1643:
In the references one of the names is misspelled. The name should be Tissier, not Tissler.
1630: 1615: 1568: 1531: 1516: 1474: 1335: 1289: 1258: 1237: 1221: 1201: 1185: 1166: 1143: 1120: 1105: 997: 974: 952: 929: 904: 879: 863: 842: 810: 788: 752: 735: 708: 686: 644: 614: 578: 561: 535: 522:
problem is ill-posed or else conclude that there is one best interpretation basically using
511: 491: 487: 474: 449: 433: 414: 410: 387: 315: 297: 281: 665:
First a clarification. "a straight line ... intersecting a circle" is called a secant line.
1181: 523: 294: 1574:
Hold on, there are many googleable sources that show that this should indeed be 1/3, see
1579: 606: 553: 1660: 1422: 626: 311:, which is the current scientific view. I'll try to write a note about that shortly. 1324: 1197: 1158: 989: 982: 921: 636: 483: 460: 406: 102: 1575: 1177: 801:, that's essential to this definition. (Excluding the center, as noted above) 191: 79: 312: 943:. Circles have an infinite number of diameters, but circular areas do not. 1551:
lie within an arc of one third the circumference of the circle is 2/3.
1494:
https://qph.cf2.quoracdn.net/main-qimg-1d7020012424e71e226b34e9d650138a
1489:
https://qph.cf2.quoracdn.net/main-qimg-76652df2fdc28fddde42b21fa80c2ae3
605:
This distracted me for quite a while whilst I was reading the article.
545: 1522:
H isn't the midpoint of the red and blue lines in the 5th picture.
1347: 303:
Good idea! What happened was that this and other paradoxes of the
1588:
https://medium.com/quantum-physics/bertrands-paradox-9a6789dcf02e
743:
same point, then it is no longer possible to specify uniquely.--
307:
of probability forced a more stringent approach to probability,
15: 1342:"Solving the hard problem of Bertrand’s paradox" is mistaken 822:
must go to infinity. Thus Bertrand's area solution is bogus.
569:
are due to the fact that a continuous variable is involved.
797:
this point, but only one chord for which this point is the
793:
For any point, there's an infinite number of chords which
1639:
Reference to Tissler is wrong. The name should be Tissier
833:. Raindrops don't know anything about circles per se. 1580:
http://web.mit.edu/tee/www/bertrand/onethirdmath.html
1425: 1385: 1356: 1325:
https://en.wikipedia.org/Probability_density_function
1046: 1013: 190:, a collaborative effort to improve the coverage of 101:, a collaborative effort to improve the coverage of 1457: 1407: 1371: 1131:must be within a concentric circle of radius R/2." 1070: 1028: 885:chord longer than the equilateral triangles side?" 1125:I meant to say that "the midpoint of the chord 914: 1323:will be non-zero in general. Read a bit here: 1003:Possibly easier way to explain Jayne's result? 715:False claim about midpoints identifying chords 8: 1379:can be the limit of a sequence of functions 1576:https://www.cut-the-knot.org/bertrand.shtml 1128:longer than the equilateral triangle's side 988:Is there a well-known citeable connection? 892:never do better than just random guessing. 502:This article looks extremely "POV" to me. 267: 152: 47: 1446: 1433: 1424: 1390: 1384: 1355: 1045: 1020: 1016: 1015: 1012: 526:. Either way, there is no real paradox. 770:The midpoint doesn't uniquely identify 154: 49: 19: 374:available in that range have the same 1267:How is relevant evidence absent here? 1230:2601:246:C700:9B0:E5E5:B1AE:733F:DB51 1214:2601:246:C700:9B0:E5E5:B1AE:733F:DB51 7: 184:This article is within the scope of 95:This article is within the scope of 38:It is of interest to the following 1682:Low-importance Statistics articles 14: 1672:Low-priority mathematics articles 115:Knowledge:WikiProject Mathematics 1152:Is there a lower or upper bound? 1029:{\displaystyle \mathbb {R} ^{2}} 204:Knowledge:WikiProject Statistics 177: 156: 118:Template:WikiProject Mathematics 82: 72: 51: 20: 1687:WikiProject Statistics articles 1590:. You get the point. It should 1346:This paper, which you can read 480:This is equivalent to method 1. 224:This article has been rated as 207:Template:WikiProject Statistics 135:This article has been rated as 1452: 1426: 1402: 1396: 1366: 1360: 1208:)? Reply at your leisure, but 1186:08:49, 16 September 2022 (UTC) 1065: 1053: 998:12:31, 17 September 2012 (UTC) 1: 1475:06:07, 11 December 2022 (UTC) 1336:03:27, 28 February 2023 (UTC) 1259:17:46, 24 December 2019 (UTC) 1238:16:26, 24 December 2019 (UTC) 1222:16:15, 24 December 2019 (UTC) 1091:23:04, 14 November 2012 (UTC) 864:10:42, 23 November 2010 (UTC) 630:03:41, 5 September 2010 (UTC) 550:List_of_paradoxes#Mathematics 475:22:02, 20 November 2008 (UTC) 450:12:23, 23 November 2010 (UTC) 415:18:32, 1 September 2009 (UTC) 316:13:51, 11 December 2006 (UTC) 198:and see a list of open tasks. 109:and see a list of open tasks. 1667:C-Class mathematics articles 1653:20:54, 23 October 2023 (UTC) 1532:05:03, 1 February 2023 (UTC) 1517:14:36, 29 January 2023 (UTC) 1408:{\displaystyle \rho _{n}(x)} 1290:21:55, 24 October 2020 (UTC) 1144:22:32, 26 October 2023 (UTC) 1121:21:35, 26 October 2023 (UTC) 953:21:14, 26 October 2023 (UTC) 905:21:51, 26 October 2023 (UTC) 843:21:09, 26 October 2023 (UTC) 736:23:05, 29 October 2010 (UTC) 709:05:38, 27 October 2023 (UTC) 687:20:54, 26 October 2023 (UTC) 645:14:24, 4 February 2018 (UTC) 579:20:09, 26 October 2023 (UTC) 434:20:03, 26 October 2023 (UTC) 336:Van Fraasen's Cube Factory: 298:18:37, 9 February 2006 (UTC) 288:Ramifications of the Paradox 1677:C-Class Statistics articles 388:18:34, 14 August 2013 (UTC) 1703: 1106:19:14, 15 March 2013 (UTC) 1071:{\displaystyle x\in [0,r)} 753:08:07, 30 March 2011 (UTC) 562:21:40, 8 August 2011 (UTC) 536:13:23, 22 March 2010 (UTC) 512:16:31, 15 March 2010 (UTC) 247:Classical Solution wording 1273:principle of indifference 975:10:14, 11 June 2012 (UTC) 930:18:31, 1 March 2012 (UTC) 811:23:25, 16 July 2023 (UTC) 789:18:38, 30 July 2021 (UTC) 492:08:45, 29 June 2009 (UTC) 282:04:57, 9 April 2024 (UTC) 223: 172: 134: 67: 46: 1631:01:43, 19 May 2023 (UTC) 1616:00:52, 19 May 2023 (UTC) 1372:{\displaystyle \rho (x)} 1317:01:30, 6 July 2021 (UTC) 1167:23:10, 13 May 2013 (UTC) 615:10:05, 6 July 2010 (UTC) 305:classical interpretation 141:project's priority scale 1569:01:56, 2 May 2023 (UTC) 1499:Original Quora's post: 1002: 880:14:23, 7 May 2011 (UTC) 619: 546:Paradox#Logical_paradox 98:WikiProject Mathematics 1459: 1409: 1373: 1072: 1030: 918: 598:Description of methods 187:WikiProject Statistics 28:This article is rated 1460: 1410: 1374: 1073: 1031: 548:, or maybe look over 309:frequency probability 1423: 1383: 1354: 1044: 1011: 935:Flies don't land in 358:based on side length 121:mathematics articles 1480:Have you read this? 939:per se, but rather 210:Statistics articles 1538:Mathematical error 1455: 1405: 1369: 1328:StrawberryLetter22 1068: 1026: 911:Flies and molasses 519:Monty Hall problem 363:based on face area 90:Mathematics portal 34:content assessment 965:comment added by 726:comment added by 587:"points of view". 455:...can we not...? 284: 272:comment added by 244: 243: 240: 239: 236: 235: 151: 150: 147: 146: 1694: 1464: 1462: 1461: 1458:{\displaystyle } 1456: 1451: 1450: 1438: 1437: 1414: 1412: 1411: 1406: 1395: 1394: 1378: 1376: 1375: 1370: 1077: 1075: 1074: 1069: 1035: 1033: 1032: 1027: 1025: 1024: 1019: 977: 763: 762: 738: 620:Jaynes' Solution 230:importance scale 212: 211: 208: 205: 202: 181: 174: 173: 168: 160: 153: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 1702: 1701: 1697: 1696: 1695: 1693: 1692: 1691: 1657: 1656: 1641: 1594:read one third. 1540: 1482: 1442: 1429: 1421: 1420: 1386: 1381: 1380: 1352: 1351: 1344: 1297: 1269: 1194: 1154: 1042: 1041: 1014: 1009: 1008: 1005: 986: 960: 913: 851: 849:Unique Solution 721: 717: 622: 600: 528:—Ben FrantzDale 500: 457: 290: 249: 209: 206: 203: 200: 199: 166: 120: 117: 114: 111: 110: 88: 81: 61: 32:on Knowledge's 29: 12: 11: 5: 1700: 1698: 1690: 1689: 1684: 1679: 1674: 1669: 1659: 1658: 1640: 1637: 1636: 1635: 1634: 1633: 1603: 1595: 1539: 1536: 1535: 1534: 1498: 1481: 1478: 1454: 1449: 1445: 1441: 1436: 1432: 1428: 1404: 1401: 1398: 1393: 1389: 1368: 1365: 1362: 1359: 1343: 1340: 1339: 1338: 1309:69.113.166.178 1296: 1293: 1268: 1265: 1264: 1263: 1262: 1261: 1241: 1240: 1193: 1190: 1189: 1188: 1173: 1153: 1150: 1149: 1148: 1147: 1146: 1132: 1108: 1083:203.20.101.203 1067: 1064: 1061: 1058: 1055: 1052: 1049: 1023: 1018: 1004: 1001: 985: 981:Connection to 979: 956: 955: 941:circular areas 912: 909: 908: 907: 893: 889: 886: 882: 856:Prodrigues1953 850: 847: 846: 845: 823: 819: 815: 814: 813: 781:Frank MacCrory 767: 766: 765: 764: 756: 755: 716: 713: 712: 711: 697: 693: 689: 674: 670: 666: 663: 654: 651: 647: 621: 618: 599: 596: 595: 594: 593: 592: 588: 583:No, these are 566: 565: 564: 539: 538: 524:Ockham's razor 499: 496: 495: 494: 481: 456: 453: 442:Prodrigues1953 437: 436: 421: 420: 419: 418: 417: 397: 396: 395: 394: 393: 392: 391: 390: 346: 345: 344: 343: 342: 341: 329: 328: 327: 326: 319: 318: 289: 286: 274:140.253.50.106 248: 245: 242: 241: 238: 237: 234: 233: 226:Low-importance 222: 216: 215: 213: 196:the discussion 182: 170: 169: 167:Low‑importance 161: 149: 148: 145: 144: 133: 127: 126: 124: 107:the discussion 94: 93: 77: 65: 64: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 1699: 1688: 1685: 1683: 1680: 1678: 1675: 1673: 1670: 1668: 1665: 1664: 1662: 1655: 1654: 1650: 1646: 1638: 1632: 1628: 1624: 1619: 1618: 1617: 1613: 1609: 1604: 1601: 1596: 1593: 1589: 1585: 1581: 1577: 1573: 1572: 1571: 1570: 1566: 1562: 1558: 1556: 1552: 1550: 1546: 1537: 1533: 1529: 1525: 1521: 1520: 1519: 1518: 1514: 1510: 1509:77.85.215.165 1506: 1503: 1502: 1496: 1495: 1491: 1490: 1486: 1479: 1477: 1476: 1472: 1468: 1447: 1443: 1439: 1434: 1430: 1418: 1399: 1391: 1387: 1363: 1357: 1349: 1341: 1337: 1333: 1329: 1326: 1321: 1320: 1319: 1318: 1314: 1310: 1307: 1301: 1292: 1291: 1287: 1283: 1282:Vaughan Pratt 1277: 1276:a "paradox". 1274: 1266: 1260: 1256: 1252: 1248: 1245: 1244: 1243: 1242: 1239: 1235: 1231: 1226: 1225: 1224: 1223: 1219: 1215: 1211: 1207: 1203: 1199: 1192:How precisely 1191: 1187: 1183: 1179: 1174: 1171: 1170: 1169: 1168: 1164: 1160: 1151: 1145: 1141: 1137: 1133: 1130: 1129: 1124: 1123: 1122: 1118: 1114: 1109: 1107: 1103: 1099: 1098:66.188.89.180 1095: 1094: 1093: 1092: 1088: 1084: 1079: 1062: 1059: 1056: 1050: 1047: 1037: 1021: 1000: 999: 995: 991: 984: 980: 978: 976: 972: 968: 967:217.65.193.35 964: 954: 950: 946: 942: 938: 934: 933: 932: 931: 927: 923: 917: 910: 906: 902: 898: 894: 890: 887: 883: 881: 877: 873: 868: 867: 866: 865: 861: 857: 848: 844: 840: 836: 832: 829:but rather a 828: 827:circular area 824: 820: 816: 812: 808: 804: 800: 796: 792: 791: 790: 786: 782: 777: 773: 769: 768: 760: 759: 758: 757: 754: 750: 746: 741: 740: 739: 737: 733: 729: 728:60.240.67.126 725: 714: 710: 706: 702: 698: 694: 690: 688: 684: 680: 675: 671: 667: 664: 660: 655: 652: 648: 646: 642: 638: 634: 633: 632: 631: 628: 617: 616: 612: 608: 603: 597: 589: 586: 582: 581: 580: 576: 572: 567: 563: 559: 555: 551: 547: 543: 542: 541: 540: 537: 533: 529: 525: 520: 516: 515: 514: 513: 509: 505: 504:Michael Hardy 497: 493: 489: 485: 482: 479: 478: 477: 476: 473: 472: 468: 464: 454: 452: 451: 447: 443: 435: 431: 427: 422: 416: 412: 408: 403: 402: 401: 400: 399: 398: 389: 385: 381: 377: 373: 370:, the actual 369: 364: 359: 354: 353: 352: 351: 350: 349: 348: 347: 340: 335: 334: 333: 332: 331: 330: 323: 322: 321: 320: 317: 314: 310: 306: 302: 301: 300: 299: 296: 287: 285: 283: 279: 275: 271: 263: 259: 256: 253: 246: 231: 227: 221: 218: 217: 214: 197: 193: 189: 188: 183: 180: 176: 175: 171: 165: 162: 159: 155: 142: 138: 132: 129: 128: 125: 108: 104: 100: 99: 91: 85: 80: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 1645:99.190.32.88 1642: 1599: 1591: 1559: 1557: 1553: 1548: 1544: 1541: 1507: 1504: 1497: 1492: 1487: 1483: 1416: 1345: 1302: 1298: 1278: 1270: 1209: 1206:plagiarising 1195: 1155: 1136:99.190.32.88 1127: 1126: 1113:99.190.32.88 1080: 1038: 1006: 987: 983:Aleph number 961:— Preceding 957: 945:99.190.32.88 940: 936: 919: 915: 897:99.190.32.88 852: 835:99.190.32.88 830: 826: 798: 795:pass through 794: 775: 771: 718: 701:99.190.32.88 696:is the same. 679:99.190.32.88 658: 623: 604: 601: 584: 571:99.190.32.88 501: 470: 466: 462: 458: 438: 426:99.190.32.88 380:Chrisfl.wiki 375: 371: 367: 362: 357: 337: 291: 268:— Preceding 264: 260: 257: 254: 250: 225: 185: 137:Low-priority 136: 96: 62:Low‑priority 40:WikiProjects 1608:AlteredDesk 872:75.80.43.80 745:75.80.43.80 722:—Preceding 112:Mathematics 103:mathematics 59:Mathematics 1661:Categories 1592:definitely 1524:FRuDIxAFLG 1467:FRuDIxAFLG 1247:WP:SOFIXIT 295:JustinWick 201:Statistics 192:statistics 164:Statistics 1623:eggsyntax 1561:eggsyntax 1417:arbitrary 1202:WP:VERIFY 818:solution? 607:Jimbowley 554:SamuelRiv 252:measure. 1586:or here 1582:or here 1578:or here 963:unsigned 803:--Daniel 799:midpoint 776:infinite 724:unsigned 627:DanielLC 270:unsigned 1600:shorter 1549:doesn't 1212:reply. 1163:" *** " 1159:Lenoxus 1134:herace 990:Shyamal 937:circles 922:Doradus 895:herace 699:herace 659:shorter 637:Ant 222 228:on the 139:on the 30:C-class 1545:Surely 831:circle 662:chord. 484:Hanspi 407:Hanspi 372:values 36:scale. 1249:. -- 1198:WP:OR 1178:Qube0 591:this. 376:count 368:range 1649:talk 1627:talk 1612:talk 1565:talk 1528:talk 1513:talk 1471:talk 1348:here 1332:talk 1313:talk 1286:talk 1271:The 1255:talk 1234:talk 1218:talk 1200:and 1182:talk 1140:talk 1117:talk 1102:talk 1087:talk 994:talk 971:talk 949:talk 926:talk 901:talk 876:talk 860:talk 839:talk 807:talk 785:talk 749:talk 732:talk 705:talk 683:talk 650:line 641:talk 611:talk 575:talk 558:talk 532:talk 508:talk 488:talk 446:talk 430:talk 411:talk 384:talk 313:iNic 278:talk 1251:JBL 772:any 585:not 498:POV 220:Low 131:Low 1663:: 1651:) 1629:) 1614:) 1567:) 1530:) 1515:) 1473:) 1465:. 1388:ρ 1358:ρ 1334:) 1315:) 1288:) 1257:) 1236:) 1220:) 1210:do 1184:) 1165:) 1142:) 1119:) 1104:) 1089:) 1051:∈ 996:) 973:) 951:) 928:) 903:) 878:) 862:) 841:) 809:) 787:) 751:) 734:) 707:) 685:) 643:) 613:) 577:) 560:) 534:) 510:) 490:) 448:) 432:) 413:) 386:) 280:) 1647:( 1625:( 1610:( 1563:( 1526:( 1511:( 1469:( 1453:] 1448:2 1444:x 1440:, 1435:1 1431:x 1427:[ 1403:) 1400:x 1397:( 1392:n 1367:) 1364:x 1361:( 1330:( 1311:( 1284:( 1253:( 1232:( 1216:( 1180:( 1161:( 1138:( 1115:( 1100:( 1085:( 1066:) 1063:r 1060:, 1057:0 1054:[ 1048:x 1022:2 1017:R 992:( 969:( 947:( 924:( 899:( 874:( 858:( 837:( 805:( 783:( 747:( 730:( 703:( 681:( 639:( 609:( 573:( 556:( 530:( 506:( 486:( 471:r 469:O 467:b 465:O 463:t 461:Z 444:( 428:( 409:( 382:( 276:( 232:. 143:. 42::

Index


content assessment
WikiProjects
WikiProject icon
Mathematics
WikiProject icon
icon
Mathematics portal
WikiProject Mathematics
mathematics
the discussion
Low
project's priority scale
WikiProject icon
Statistics
WikiProject icon
WikiProject Statistics
statistics
the discussion
Low
importance scale
unsigned
140.253.50.106
talk
04:57, 9 April 2024 (UTC)
JustinWick
18:37, 9 February 2006 (UTC)
classical interpretation
frequency probability
iNic

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.