Quotes about variability

A collection of quotes on the topic of variability, variable, other, use.

Quotes about variability

Emmy Noether photo

“A ring of polynomials in any number of variables over a ring of coeffcients that has an identity element and a finite basis, itself has a finite basis.”

Emmy Noether (1882–1935) German mathematician

As quoted in Morris Kline, Mathematical Thought From Ancient to Modern Times (1972) p. 1153.

Arthur Conan Doyle photo
William Shakespeare photo
James Tobin photo

“There is no reason to think that the impact [of monetary policy] will be captured in any single [variable]…, whether it is a monetary stock or a market interest rate.”

James Tobin (1918–2002) American economist

Source: "A general equilibrium approach to monetary theory" (1969), p. 29 as cited in: Andrés, Javier, J. David López-Salido, and Edward Nelson. " Tobin's imperfect asset substitution in optimizing general equilibrium http://research.stlouisfed.org/wp/2004/2004-003.pdf." Journal of Money, Credit and Banking (2004): 665-690.

Jan Tinbergen photo
Karl Marx photo

“As the variable capital always stays in the hands of the capitalist in some form or other, it cannot be claimed in any way that it converts itself into revenue for anyone.”

Karl Marx (1818–1883) German philosopher, economist, sociologist, journalist and revolutionary socialist

Vol. II, Ch. XX, p. 452.
(Buch II) (1893)

James Tobin photo

“In economic surveys of households, many variables have the following characteristics: The variable has a lower, or upper, limit and takes on the limiting value for a substantial number of respondents. For the remaining respondents, the variable takes on a For the remaining respondents, the variable takes on a wide range of values above, or below, the limit.”

James Tobin (1918–2002) American economist

Tobin, James. " Estimation of relationships for limited dependent variables http://cowles.econ.yale.edu/P/cp/p01a/p0117.pdf." Econometrica: journal of the Econometric Society (1958): 24-36.
1950s-60s

James Tobin photo
Lawrence M. Krauss photo
Bertrand Russell photo
Henrietta Swan Leavitt photo

“Since the [Cepheid] variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual emission of light, as determined by their mass, density, and surface brightness.”

Henrietta Swan Leavitt (1868–1921) astronomer

Periods of 25 Variable Stars in the Small Magellanic Cloud http://adsabs.harvard.edu/abs/1912HarCi.173....1L (1912)

Bertrand Russell photo
Alfred Tarski photo

“For reasons mentioned at the beginning of this section, we cannot offer here a precise structural definition of semantical category and will content ourselves with the following approximate formulation: two expressions belong to the same semantical category if (I) there is a sentential function which contains one of these expressions, and if (2) no sentential function which contains one of these expressions ceases to be a sentential function if this expression is replaced in it by the other. It follows from this that the relation of belonging to the same category is reflective, symmetrical and transitive. By applying the principle of abstraction, all the expressions of the language which are parts of sentential functions can be divided into mutually exclusive classes, for two expressions are put into one and the same class if and only if they belong to the same semantical category, and each of these classes is called a semantical category. Among the simplest examples of semantical categories it suffices to mention the category of the sentential functions, together with the categories which include respectively the names of individuals, of classes of individuals, of two-termed relations between individuals, and so on. Variables (or expressions with variables) which represent names of the given categories likewise belong to the same category.”

Alfred Tarski (1901–1983) Polish-American logician

Source: The Semantic Conception of Truth (1952), p. 45; as cited in: Schaff (1962) pp. 36-37.

John S. Bell photo
Émile Durkheim photo
Lotfi A. Zadeh photo

“A linguistic variable is a variable whose values are words or sentences in a natural or synthetic language.”

Lotfi A. Zadeh (1921–2017) Electrical engineer and computer scientist

Variant: A linguistic variable is defined as a variable whose values are sentences in a natural or artificial language.
Source: 1970s, Outline of a new approach to the analysis of complex systems and decision processes (1973), p. 28

Heinrich Hertz photo

“When a constant electric current flows along a cylindrical wire, its strength is the same at every part of the section of the wire. But if the current is variable, self-induction produces a deviation from this… induction opposes variations of the current in the centre of the wire more strongly than at the circumference, and consequently the current by preference flows along the outer portion of the wire. When the current changes its direction… this deviation increases rapidly with the rate of alternation; and when the current alternates many million times per second, almost the whole of the interior of the wire must, according to theory, appear free from current, and the flow must confine itself to the very skin of the wire. Now in such extreme cases… preference must be given to another conception of the matter which was first presented by Messrs. 0. Heaviside and J. H. Poynting, as the correct interpretation of Maxwell's equations as applied to this case. According to this view, the electric force which determines the current is not propagated in the wire itself, but under all circumstances penetrates from without into the wire, and spreads into the metal with comparative slowness and laws similar to those which govern changes of temperature in a conducting body.
…Inasmuch as I made use of electric waves in wires of exceedingly short period in my experiments on the propagation of electric force, it was natural to test by means of these the correctness of the conclusions deduced. As a matter of fact the theory was found to be confirmed by the experiments…”

Heinrich Hertz (1857–1894) German physicist

"On the Propagation of Electric Waves by Means of Wires" (1889) Wiedemann's Annalen. 37 p. 395, & pp.160-161 of Electric Waves
Electric Waves: Being Researches on the Propagation of Electric Action with Finite Velocity Through Space (1893)

Shiing-Shen Chern photo
Thomas J. Sargent photo
Elizabeth Gilbert photo
David Brin photo

“Rather, for all objects and experiences there is a quantity that has an optimum value. Above that quantity, the variable becomes toxic. To fall below that value is to be deprived.”

Gregory Bateson (1904–1980) English anthropologist, social scientist, linguist, visual anthropologist, semiotician and cyberneticist

Source: Mind and Nature: A Necessary Unity, 1979, p. 56

George Biddell Airy photo
Daniel Dennett photo
Warren Farrell photo
Kenneth Arrow photo
Jacques Barzun photo
Francisco Varela photo
Richard Dedekind photo
Arthur Kekewich photo

“Public policy does not admit of definition and is not easily explained. It is a variable quantity; it must vary and does vary with the habits, capacities, and opportunities of the public.”

Arthur Kekewich (1832–1907) British judge

Davies v. Davies (1887), L. R. 36 C. D. 364; see also Egerton v. Earl Brownlow, 4 H. L. C. 1.

Charles Darwin photo

“But I was very unwilling to give up my belief; I feel sure of this, for I can well remember often and often inventing day-dreams of old letters between distinguished Romans, and manuscripts being discovered at Pompeii or elsewhere, which confirmed in the most striking manner all that was written in the Gospels. But I found it more and more difficult, with free scope given to my imagination, to invent evidence which would suffice to convince me. Thus disbelief crept over me at a very slow rate, but was at last complete. The rate was so slow that I felt no distress.Although I did not think much about the existence of a personal God until a considerably later period of my life, I will here give the vague conclusions to which I have been driven. The old argument from design in Nature, as given by Paley, which formerly seemed to me so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings, and in the action of natural selection, than in the course which the wind blows. But I have discussed this subject at the end of my book on the Variation of Domesticated Animals and Plants, and the argument there given has never, as far as I can see, been answered.”

Charles Darwin (1809–1882) British naturalist, author of "On the origin of species, by means of natural selection"

volume I, chapter VIII: "Religion", pages 308-309 http://darwin-online.org.uk/content/frameset?pageseq=326&itemID=F1452.1&viewtype=image

Francis Darwin calls these "extracts, somewhat abbreviated, from a part of the Autobiography, written in 1876". The original version is presented below.
The Life and Letters of Charles Darwin (1887)
Variant: p>But I was very unwilling to give up my belief;—I feel sure of this for I can well remember often and often inventing day-dreams of old letters between distinguished Romans and manuscripts being discovered at Pompeii or elsewhere which confirmed in the most striking manner all that was written in the Gospels. But I found it more and more difficult, with free scope given to my imagination, to invent evidence which would suffice to convince me. Thus disbelief crept over me at a very slow rate, but was at last complete. The rate was so slow that I felt no distress, and have never since doubted even for a single second that my conclusion was correct. I can indeed hardly see how anyone ought to wish Christianity to be true; for if so the plain language of the text seems to show that the men who do not believe, and this would include my Father, Brother and almost all my best friends, will be everlastingly punished.And this is a damnable doctrine.Although I did not think much about the existence of a personal God until a considerably later period of my life, I will here give the vague conclusions to which I have been driven. The old argument of design in nature, as given by Paley, which formerly seemed to me so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings and in the action of natural selection, than in the course which the wind blows. Everything in nature is the result of fixed laws. But I have discussed this subject at the end of my book on the Variation of Domesticated Animals and Plants, and the argument there given has never, as far as I can see, been answered.</p

“The concepts of purposive behavior and teleology have long been associated with a mysterious, self-perfecting or goal-seeking capacity or final cause, usually of superhuman or super-natural origin. To move forward to the study of events, scientific thinking had to reject these beliefs in purpose and these concepts of teleological operations for a strictly mechanistic and deterministic view of nature. This mechanistic conception became firmly established with the demonstration that the universe was based on the operation of anonymous particles moving at random, in a disorderly fashion, giving rise, by their multiplicity, to order and regularity of a statistical nature, as in classical physics and gas laws. The unchallenged success of these concepts and methods in physics and astronomy, and later in chemistry, gave biology and physiology their major orientation. This approach to problems of organisms was reinforced by the analytical preoccupation of the Western European culture and languages. The basic assumptions of our traditions and the persistent implications of the language we use almost compel us to approach everything we study as composed of separate, discrete parts or factors which we must try to isolate and identify as potential causes. Hence, we derive our preoccupation with the study of the relation of two variables. We are witnessing today a search for new approaches, for new and more comprehensive concepts and for methods capable of dealing with the large wholes of organisms and personalities.”

Lawrence K. Frank (1890–1968) American cyberneticist

L.K. Frank (1948) "Foreword". In L. K. Frank, G. E. Hutchinson, W. K. Livingston, W. S. McCulloch, & N. Wiener, Teleological mechanisms. Ann. N. Y. Acad. Sc., 1948, 50, 189-96; As cited in: Ludwig von Bertalanffy (1968) "General System Theory: Foundations, Development, Applications". p. 16-17

Fritjof Capra photo
George Klir photo
Kurt Gödel photo

“To every ω-consistent recursive class κ of formulae there correspond recursive class signs r, such that neither v Gen r nor Neg (v Gen r) belongs to Flg (κ) (where v is the free variable of r).”

Kurt Gödel (1906–1978) logician, mathematician, and philosopher of mathematics

Proposition VI, On Formally Undecidable Propositions in Principia Mathematica and Related Systems I (1931); Informally, recursive systems of axioms cannot be complete.

“It is known that the mathematics prescribed for the high school [Gymnasien] is essentially Euclidean, while it is modern mathematics, the theory of functions and the infinitesimal calculus, which has secured for us an insight into the mechanism and laws of nature. Euclidean mathematics is indeed, a prerequisite for the theory of functions, but just as one, though he has learned the inflections of Latin nouns and verbs, will not thereby be enabled to read a Latin author much less to appreciate the beauties of a Horace, so Euclidean mathematics, that is the mathematics of the high school, is unable to unlock nature and her laws. Euclidean mathematics assumes the completeness and invariability of mathematical forms; these forms it describes with appropriate accuracy and enumerates their inherent and related properties with perfect clearness, order, and completeness, that is, Euclidean mathematics operates on forms after the manner that anatomy operates on the dead body and its members.
On the other hand, the mathematics of variable magnitudes—function theory or analysis—considers mathematical forms in their genesis. By writing the equation of the parabola, we express its law of generation, the law according to which the variable point moves. The path, produced before the eyes of the 113 student by a point moving in accordance to this law, is the parabola.
If, then, Euclidean mathematics treats space and number forms after the manner in which anatomy treats the dead body, modern mathematics deals, as it were, with the living body, with growing and changing forms, and thus furnishes an insight, not only into nature as she is and appears, but also into nature as she generates and creates,—reveals her transition steps and in so doing creates a mind for and understanding of the laws of becoming. Thus modern mathematics bears the same relation to Euclidean mathematics that physiology or biology … bears to anatomy. But it is exactly in this respect that our view of nature is so far above that of the ancients; that we no longer look on nature as a quiescent complete whole, which compels admiration by its sublimity and wealth of forms, but that we conceive of her as a vigorous growing organism, unfolding according to definite, as delicate as far-reaching, laws; that we are able to lay hold of the permanent amidst the transitory, of law amidst fleeting phenomena, and to be able to give these their simplest and truest expression through the mathematical formulas”

Christian Heinrich von Dillmann (1829–1899) German educationist

Source: Die Mathematik die Fackelträgerin einer neuen Zeit (Stuttgart, 1889), p. 37.

Wassily Kandinsky photo
C. A. R. Hoare photo
William Osler photo

“Variability is the law of life, and as no two faces are the same, so no two bodies are alike, and no two individuals react alike and behave alike under the abnormal conditions which we know as disease.”

William Osler (1849–1919) Canadian pathologist, physician, educator, bibliophile, historian, author, cofounder of Johns Hopkins Hospi…

On the Educational Value of the Medical Society (1903)

Bernhard Riemann photo
Tjalling Koopmans photo
Eduardo Torroja photo

“Construction methods are… variable for each specific material.”

Eduardo Torroja (1899–1961) Spanish architect

p, 125
Philosophy of Structures (1958)

Igor Ansoff photo
Jerzy Neyman photo
Nassim Nicholas Taleb photo
William Bateson photo
George Klir photo
Hugo De Vries photo

“Physiologic facts concerning the origin of species in nature were unknown in the time of Darwin... The experience of the breeders was quite inadequate to the use which Darwin made of it. It was neither scientific, nor critically accurate. Laws of variation were barely conjectured; the different types of variability were only imperfectly distinguished. The breeders' conception was fairly sufficient for practical purposes, but science needed a clear understanding of the factors in the general process of variation. Repeatedly Darwin tried to formulate these causes, but the evidence available did not meet his requirements.
Quetelet's law of variation had not yet been published. Mendel's claim of hereditary units for the explanation of certain laws of hybrids discovered by him, was not yet made. The clear distinction between spontaneous and sudden changes, as compared with the ever-present fluctuating variations, is only of late coming into recognition by agriculturists. Innumerable minor points which go to elucidate the breeders' experience, and with which we are now quite familiar, were unknown in Darwin's time. No wonder that he made mistakes, and laid stress on modes of descent, which have since been proved to be of minor importance or even of doubtful validity.”

Hugo De Vries (1848–1935) Dutch botanist

Species and Varieties: Their Origin by Mutation (1904), The Open Court Publishing Company, Chicago, p. 5-6

N. Gregory Mankiw photo

“Organizational design often focuses on structural alternatives such as matrix, decentralization, and divisionalization. However, control variables (e. g., reward structures, task characteristics, and information systems) offer a more flexible approach. The purpose of this paper is to explore these control variables for organizational design. This is accomplished by integration and testing of two perspectives, organization theory and economics, notably agency theory. The resulting hypotheses link task characteristics, information systems, and business uncertainty to behavior vs. outcome based control strategy. These hypothesized linkages are examined empirically in a field study of the compensation practices for retail salespeople in 54 stores. The findings are that task programmability is strongly related to the choice of compensation package. The amount of behavioral measurement, the cost of measuring outcomes, and the uncertainty of the business also affect compensation. The findings have management implications for the design of compensation and reward packages, performance evaluation systems, and control systems, in general. Such systems should explicitly consider the task, the information system in place to measure performance, and the riskiness of the business. More programmed tasks require behavior based controls while less programmed tasks require more elaborate information systems or outcome based controls.”

Kathleen M. Eisenhardt American economist

Source: "Control: Organizational and economic approaches," 1985, p. 134; Article abstract

“Geography is that discipline that seeks to describe and interpret the variable character from place to place of the earth as the world of man.”

Richard Hartshorne (1899–1992) American Geographer

Source: Perspective on the nature of geography (1958), p. 47

Elizabeth Cady Stanton photo
Frederick William Robertson photo
Henrietta Swan Leavitt photo
Amory B. Lovins photo
Paul A. Samuelson photo

“If the variables are continuous, this definition [Ashby’s fundamental concept of machine] corresponds to the description of a dynamic system by a set of ordinary differential equations with time as the independent variable. However, such representation by differential equations is too restricted for a theory to include biological systems and calculating machines where discontinuities are ubiquitous.”

Ludwig von Bertalanffy (1901–1972) austrian biologist and philosopher

Source: General System Theory (1968), 4. Advances in General Systems Theory, p. 96, as cited in: Vincent Vesterby (2013) From Bertalanffy to Discipline-Independent-Transdisciplinarity http://journals.isss.org/index.php/proceedings56th/article/viewFile/1886/672

“It is not necessary to think of gambling places; the statistician who applies statistical tests is engaged in a dignified sort of gambling, and in his case the distribution of the random variables changes from occasion to occasion.”

William Feller (1906–1970) Croatian-American mathematician

Source: An Introduction To Probability Theory And Its Applications (Third Edition), Chapter X, Law Of large Numbers, p. 253.

Bjarne Stroustrup photo

“Because of the variables and the complexity of their interaction, the data assembled by descriptive musicology yield relatively few observable regularities.”

Leonard B. Meyer (1918–2007) American composer and philosopher

"Universalism and Relativism in the Study of Ethnic music", Ethnomusicology 4, no. 2:49-54 (1960); reprinted in Reading in Ethnomusicology, p. 270-71.

Walter A. Shewhart photo

“Dynamical variables are what count in physics, not coordinate or gauge transformations.”

John Clive Ward (1924–2000) British-Australian nuclear physicist

J. C. Ward, Memoirs of a Theoretical Physicist (Optics Journal, Rochester, 2004).

Georg Cantor photo

“There is no doubt that we cannot do without variable quantities in the sense of the potential infinite. But from this very fact the necessity of the actual infinite can be demonstrated.”

Georg Cantor (1845–1918) mathematician, inventor of set theory

"Über die verschiedenen Ansichten in Bezug auf die actualunendlichen Zahlen" ["Over the different views with regard to the actual infinite numbers"] - Bihand Till Koniglen Svenska Vetenskaps Akademiens Handigar (1886)

“For many purposes of organizational analysis technology might not be an independent variable but a dependent one.”

Charles Perrow (1925–2019) American sociologist

Charles Perrow (1967), in: Industrial Relations Research Association, Proceedings of the ... Annual Winter Meeting, Vol. 19 (1967), p. 163
1960s

Robert A. Heinlein photo

“The problem with managing either a business or a prison by periodic rather than continuous inspection is that the "variables" are likely to be seriously out of control before the discrepancy is noted.”

Anthony Stafford Beer (1926–2002) British theorist, consultant, and professor

Source: Management Science (1968), Chapter 6, The Viable Governor, p. 146.

“Managers construct, rearrange, single out, and demolish many “objective” features of their surroundings. When people act they unrandomize variables, insert vestiges of orderliness, and literally create their own constraints.”

Karl E. Weick (1936) Organisational psychologist

Source: 1970s, Social Psychology of Organizing, (1979), p. 243 ; As cited in: Dr. Adrian McLean (2013), Leaderhip and Cultural Webs in Organisations: Weavers' Tales. p. 213

Wanda Orlikowski photo
Leonhard Euler photo

“A function of a variable quantity is an analytic expression composed in any way whatsoever of the variable quantity and numbers or constant quantities.”

Leonhard Euler (1707–1783) Swiss mathematician

§4
Introduction to the Analysis of the Infinite (1748)

Bernhard Riemann photo
Bernhard Riemann photo

“Let us imagine that from any given point the system of shortest lines going out from it is constructed; the position of an arbitrary point may then be determined by the initial direction of the geodesic in which it lies, and by its distance measured along that line from the origin. It can therefore be expressed in terms of the ratios dx0 of the quantities dx in this geodesic, and of the length s of this line. …the square of the line-element is \sum (dx)^2 for infinitesimal values of the x, but the term of next order in it is equal to a homogeneous function of the second order… an infinitesimal, therefore, of the fourth order; so that we obtain a finite quantity on dividing this by the square of the infinitesimal triangle, whose vertices are (0,0,0,…), (x1, x2, x3,…), (dx1, dx2, dx3,…). This quantity retains the same value so long as… the two geodesics from 0 to x and from 0 to dx remain in the same surface-element; it depends therefore only on place and direction. It is obviously zero when the manifold represented is flat, i. e., when the squared line-element is reducible to \sum (dx)^2, and may therefore be regarded as the measure of the deviation of the manifoldness from flatness at the given point in the given surface-direction. Multiplied by -¾ it becomes equal to the quantity which Privy Councillor Gauss has called the total curvature of a surface. …The measure-relations of a manifoldness in which the line-element is the square root of a quadric differential may be expressed in a manner wholly independent of the choice of independent variables. A method entirely similar may for this purpose be applied also to the manifoldness in which the line-element has a less simple expression, e. g., the fourth root of a quartic differential. In this case the line-element, generally speaking, is no longer reducible to the form of the square root of a sum of squares, and therefore the deviation from flatness in the squared line-element is an infinitesimal of the second order, while in those manifoldnesses it was of the fourth order. This property of the last-named continua may thus be called flatness of the smallest parts. The most important property of these continua for our present purpose, for whose sake alone they are here investigated, is that the relations of the twofold ones may be geometrically represented by surfaces, and of the morefold ones may be reduced to those of the surfaces included in them…”

Bernhard Riemann (1826–1866) German mathematician

On the Hypotheses which lie at the Bases of Geometry (1873)

Joe Zawinul photo
Trygve Haavelmo photo
Russell L. Ackoff photo

“The classical theory of probability was devoted mainly to a study of the gamble's gain, which is again a random variable; in fact, every random variable can be interpreted as the gain of a real or imaginary gambler in a suitable game.”

William Feller (1906–1970) Croatian-American mathematician

Source: An Introduction To Probability Theory And Its Applications (Third Edition), Chapter IX, Random Variables; Expectation, p. 212.

Leonid Kantorovich photo

“Once some engineers from the veneer trust laboratory came to me for consultation with a quite skilful presentation of their problems. Different productivity is obtained for veneer-cutting machines for different types of materials; linked to this the output of production of this group of machines depended, it would seem, on the chance factor of which group of raw materials to which machine was assigned. How could this fact be used rationally?
This question interested me, but nevertheless appeared to be quite particular and elementary, so I did not begin to study it by giving up everything else. I put this question for discussion at a meeting of the mathematics department, where there were such great specialists as Gyunter, Smirnov himself, Kuz’min, and Tartakovskii. Everyone listened but no one proposed a solution; they had already turned to someone earlier in individual order, apparently to Kuz’min. However, this question nevertheless kept me in suspense. This was the year of my marriage, so I was also distracted by this. In the summer or after the vacation concrete, to some extent similar, economic, engineering, and managerial situations started to come into my head, that also required the solving of a maximization problem in the presence of a series of linear constraints.
In the simplest case of one or two variables such problems are easily solved—by going through all the possible extreme points and choosing the best. But, let us say in the veneer trust problem for five machines and eight types of materials such a search would already have required solving about a billion systems of linear equations and it was evident that this was not a realistic method. I constructed particular devices and was probably the first to report on this problem in 1938 at the October scientific session of the Herzen Institute, where in the main a number of problems were posed with some ideas for their solution.
The universality of this class of problems, in conjunction with their difficulty, made me study them seriously and bring in my mathematical knowledge, in particular, some ideas from functional analysis.
What became clear was both the solubility of these problems and the fact that they were widespread, so representatives of industry were invited to a discussion of my report at the university.”

Leonid Kantorovich (1912–1986) Russian mathematician

L.V. Kantorovich (1996) Descriptive Theory of Sets and Functions. p. 39; As cited in: K. Aardal, ‎George L. Nemhauser, ‎R. Weismantel (2005) Handbooks in Operations Research and Management Science, p. 15-26