In
, celebrated mathematician Ian Stewart uses a handful of mathematical equations to explore the vitally important connections between math and human progress. We often overlook the historical link between mathematics and technological advances, says Stewart—but this connection is integral to any complete understanding of human history.Equations are modeled on the patterns we find in the world around us, says Stewart, and it is through equations that we are able to make sense of, and in turn influence, our world. Stewart locates the origins of each equation he presents—from Pythagoras's Theorem to Newton's Law of Gravity to Einstein's Theory of Relativity—within a particular historical moment, elucidating the development of mathematical and philosophical thought necessary for each equation's discovery. None of these equations emerged in a vacuum, Stewart shows; each drew, in some way, on past equations and the thinking of the day. In turn, all of these equations paved the way for major developments in mathematics, science, philosophy, and technology. Without logarithms (invented in the early 17th century by John Napier and improved by Henry Briggs), scientists would not have been able to calculate the movement of the planets, and mathematicians would not have been able to develop fractal geometry. The Wave Equation is one of the most important equations in physics, and is crucial for engineers studying the vibrations in vehicles and the response of buildings to earthquakes. And the equation at the heart of Information Theory, devised by Claude Shannon, is the basis of digital communication today.
An approachable and informative guide to the equations upon which nearly every aspect of scientific and mathematical understanding depends, In
is also a reminder that equations have profoundly influenced our thinking and continue to make possible many of the advances that we take for granted.

Some years ago, "new math" took the country's classrooms by storm. Based on the abstract, general style of mathematical exposition favored by research mathematicians, its goal was to teach students not just to manipulate numbers and formulas, but to grasp the underlying mathematical concepts. The result, at least at first, was a great deal of confusion among teachers, students, and parents. Since then, the negative aspects of "new math" have been eliminated and its positive elements assimilated into classroom instruction.<br />In this charming volume, a noted English mathematician uses humor and anecdote to illuminate the concepts underlying "new math": groups, sets, subsets, topology, Boolean algebra, and more. According to Professor Stewart, an understanding of these concepts offers the best route to grasping the true nature of mathematics, in particular the power, beauty, and utility of <i>pure </i>mathematics. No advanced mathematical background is needed (a smattering of algebra, geometry, and trigonometry is helpful) to follow the author's lucid and thought-provoking discussions of such topics as functions, symmetry, axiomatics, counting, topology, hyperspace, linear algebra, real analysis, probability, computers, applications of modern mathematics, and much more.<br />By the time readers have finished this book, they'll have a much clearer grasp of how modern mathematicians look at figures, functions, and formulas and how a firm grasp of the ideas underlying "new math" leads toward a genuine comprehension of the nature of mathematics itself.

PREFACE TO THE FIRST EDITION
This book is intended for readers in transition from school mathematics to the fully-fledged type of thinking used by professional mathematicians. It should prove useful to first-year students in universities and colleges, and to advanced students in school contemplating further study in pure mathematics. It should also be of interest to a wider class of reader with a grounding in elementary mathematics seeking an insight into the foundational ideas and thought processes of mathematics.
The word ‘foundations’, as used in this book, has a broader meaning than it does in the building trade. Not only do we base our mathematics on these foundations: they make themselves felt at all levels, as a kind of cement which holds the structure together, and out of which it is fabricated. The foundations of mathematics, in this sense, are often presented to students as an extended exercise in mathematical formalism: formal mathematical logic, formal set theory, axiomatic descriptions of number systems, and technical constructions of them; all carried out in an exotic and elaborate symbolism. Sometimes the ideas are presented ‘informally’ on the grounds that complete formalism is too difficult for the delicate flowering student. This is usually true, but for an entirely different reason.
A purely formal approach, even with a smattering of informality, is psychologically inappropriate for the beginner, because it fails to take account of the realities of the learning process. By concentrating on the technicalities, at the expense of the manner in which the ideas are conceived, it presents only one side of the coin. The practising mathematician does not think purely in a dry and stereotyped symbolism: on the contrary, his thoughts tend to concentrate on those parts of a problem which his experience tells him are the main sources of difficulty. While he is grappling with them, logical rig- our takes a secondary place: it is only after a problem has, to all intents and purposes, been solved intuitively that the underlying ideas are filled out into a formal proof. Naturally there are exceptions to this rule: parts of a problem may be fully formalized before others are understood, even intuitively; and some mathematicians seem to think symbolically. Nonetheless, the basic force of the statement remains valid.
The aim of this book is to acquaint the student with the way that a practising mathematician tackles his subject. This involves including the standard ‘foundations’ material; but our aim is to develop the formal approach as a natural outgrowth of the underlying pattern of ideas. A sixth-form student has a broad grasp of many mathematical principles, and our aim is to make use of this, honing his mathematical intuition into a razor-sharp tool which will cut to the heart of a problem. Our point of view is diametrically opposed to that where (all too often) the student is told ‘Forget all you’ve learned up till now, it’s wrong, we’ll begin again from scratch, only this time we’ll get it right’. Not only is such a statement damaging to a student’s confidence: it is also untrue. Further, it is grossly misleading: a student who really did forget all he had learned so far would find himself in a very sorry position.
The psychology of the learning process imposes considerable restraints on the possible approaches to a mathematical concept. Often it is simply not appropriate to start with a precise definition, because the content of the definition cannot be appreciated without further explanation, and the provision of suitable examples.
The book is divided into four parts to make clear the mental attitude required at each stage. Part I is at an informal level, to set the scene. The first chapter develops the underlying philosophy of the book by examining the learning process itself. It is not a straight, smooth path; it is of necessity a rough and stony one, with side-turnings and blind alleys. The student who realizes this is better prepared to face the difficulties. The second chapter analyzes the intuitive concept of a real number as a point on the number line, linking this to the idea of an infinite decimal, and explaining the importance of the completeness property of the real numbers.
Part II develops enough set theory and logic for the task in hand, looking in particular at relations (especially equivalence relations and order relations) and functions. After some basic symbolic logic we discuss what ‘proof ’ consists of, giving a formal definition. Following this we analyze an actual proof to show how the customary mathematical style relegates routine steps to a contextual background—and quite rightly so, inasmuch as the overall flow of the proof becomes far clearer. Both the advantages and the dangers of this practice are explored.
Part III is about the formal structure of number systems and related con- cepts. We begin by discussing induction proofs, leading to the Peano axioms for natural numbers, and show how set-theoretic techniques allow us to con- struct from them the integers, rational numbers, and real numbers. In the next chapter we show how to reverse this process, by axiomatising the real numbers as a complete ordered field. We prove that the structures obtained in this way are essentially unique, and link the formal structures to their in- tuitive counterparts of part I. Then we go on to consider complex numbers, quaternions, and general algebraic and mathematical structures, at which point the whole vista of mathematics lies at our feet. A discussion of infinite cardinals, motivated by the idea of counting, leads towards more advanced work. It also hints that we have not yet completed the task of formalising our ideas.
Part IV briefly considers this final step: the formalisation of set theory. We give one possible set of axioms, and discuss the axiom of choice, the continuum hypothesis, and Gödel’s theorems.
Throughout we are more interested in the ideas behind the formal façade than in the internal details of the formal language used. A treatment suitable for a professional mathematician is often not suitable for a student. (A series of tests carried out by one of us with the aid of first-year undergraduates makes this assertion very clear indeed!) So this is not a rigidly logical development from the elements of logic and set theory, building up a rigorous foundation for mathematics (though by the end the student will be in a position to appreciate how this may be achieved). Mathematicians do not think in the orthodox way that a formal text seems to imply. The mathematical mind is inventive and intricate; it jumps to conclusions: it does not always proceed in a sequence of logical steps. Only when everything is understood does the pristine logical structure emerge. To show a student the finished edifice, without the scaffolding required for its construction, is to deprive him of the very facilities which are essential if he is to construct mathematical ideas of his own.
I.S. and D.T. Warwick October 1976

Uncertainty is everywhere. It lurks in every consideration of the future - the weather, the economy, the sex of an unborn child - even quantities we think that we know such as populations or the transit of the planets contain the possibility of error. It's no wonder that, throughout that history, we have attempted to produce rigidly defined areas of uncertainty. However, over the centuries pioneering mathematicians and scientists began to reduce wild uncertainties to tame distributions of probability and statistical inferences. But, even as unknown unknowns became known unknowns, our pessimism made us believe that some problems were unsolvable and our intuition misled us. Worse, as we realized how omnipresent and varied uncertainty is, we encountered chaos, quantum mechanics, and the limitations of our predictive power. Bestselling author Professor Ian Stewart explores the history and mathematics of uncertainty. Touching on gambling, probability, statistics, financial and weather forecasts, censuses, medical studies, chaos, quantum physics, and climate, he makes one thing clear: a reasonable probability is the only certainty.

Infinity is an intriguing topic, with connections to religion, philosophy, metaphysics, logic, and physics as well as mathematics. Its history goes back to ancient times, with especially important contributions from Euclid, Aristotle, Eudoxus, and Archimedes. The infinitely large (infinite) is intimately related to the infinitely small (infinitesimal). Cosmologists consider sweeping questions about whether space and time are infinite. Philosophers and mathematicians ranging from Zeno to Russell have posed numerous paradoxes about infinity and infinitesimals. Many vital areas of mathematics rest upon some version of infinity. The most obvious, and the first context in which major new techniques depended on formulating infinite processes, is calculus. But there are many others, for example, Fourier analysis and fractals. In this Very Short Introduction, Ian Stewart discusses infinity in mathematics while also drawing in the various other aspects of infinity and explaining some of the major problems and insights arising from this concept. He argues that working with infinity is not just an abstract, intellectual exercise but that it is instead a concept with important practical everyday applications, and considers how mathematicians use infinity and infinitesimals to answer questions or supply techniques that do not appear to involve the infinite.

◎用數字思考事物的本質，揭開暗藏在背後的演算祕密！
想像有個很大的數，如果要寫下來，長度會橫跨宇宙。
本書裡就有這樣的數，還有你能想到的及無法想到的各種數──
實數、虛數、有理數、無理數、正數、負數、簡單的數、複雜的數。
著名數學作家伊恩．史都華探究了從0到無限大的數的奇特性質，
讚歎古代數學家的獨到智慧，告訴大家數字的演進歷程。
數學不只與數有關，但支撐整個學門的仍是數。每個數都是獨一無二的個體。
就連在最不起眼的數字上，通常也能找到獨特之處。
數字是入口，是讓我們潛進奇奧數學世界的途徑。
你會明白數字的歷史演變，欣賞數字模式的美，了解數字的用法，
驚歎於眼前的意外驚喜：「我竟然不知道56這麼有趣！」但它真的就是這麼有趣。
電腦排序、隨機選擇、訊息加密、臘腸形狀，都隱含趣味十足的數字。
有了一流數學名家的內行指引，你會發現無限大竟然也能分大小。
你還會發覺，原來自己生活在11維空間裡。
凡是喜愛數字的人，或是目前以為自己不喜歡數字的人，
都會從本書中讀出無限的樂趣！
◎小數字、大數字以及生命和宇宙的數學教室，不可思議的39堂數字課
●二進位制起初是個數學怪物，科學領域少了負數將分崩離析，困惑數百年來天才數學家的各種觀念如何變成今日這般理所當然？
●為什麼數學家要用鮮為人知的符號來代表一個數？這個宇宙對我們使了什麼殘酷的詭計？
●「雲朵不是球形，山不是錐體，海岸線不是圓形，樹皮並非平滑的，閃電也不會呈直線」，這些形狀如何改變了我們世界的模樣？
●地球上的波會引起地震，聲波會產生樂音。數學如何讓我們聽見美妙的音樂？
●壁紙圖樣有17種對稱，粒子物理學的標準模型中有17種基本粒子，用尺規作圖可以作出正17邊形。17這個數為什麼這麼妙？
●最小的無限大是多大？無限大的數是什麼數？弄清楚數字到底有多大很重要嗎？
●很多人說42這個數無聊至極，它真的那麼索然無味？

Ian Stewart explores the astonishing properties of numbers from 1 to10 to zero and infinity, including one figure that, if you wrote it out, would span the universe. He looks at every kind of number you can think of -- real, imaginary, rational, irrational, positive and negative -- along with several you might have thought you couldn't think of. He explains the insights of the ancient mathematicians, shows how numbers have evolved through the ages, and reveals the way numerical theory enables everyday life.Under Professor Stewart's guidance you will discover the mathematics of codes, Sudoku, Rubik's cube, music, primes and pi. You may be surprised to find you live in eleven-dimensional space, that of the twenty-three people on a football pitch two are more likely than not to share the same birthday, and that forty-two is a very interesting number.Professor Stewart's Incredible Numbers will delight everyone who loves numbers -- including those who currently think they don't.

Mathematician Ian Stewart tells readers what he wishes he had known when he was a student. He takes up subjects ranging from the philosophical to the practical--what mathematics is and why it's worth doing, the relationship between logic and proof, the role of beauty in mathematical thinking, the future of mathematics, how to deal with the peculiarities of the mathematical community, and many others.

The brilliant "sequel" to one of the all-time classics of popular mathematics.
In 1884, Edwin A. Abbott published a brilliant novel about mathematics and philosophy that charmed and fascinated all of England. As both a witty satire of Victorian society and a means by which to explore the fourth dimension, Flatland remains a tour de force. Now, British mathematician and accomplished science writer Ian Stewart has written a fascinating, modern sequel to Abbott's book. Through larger-than-life characters and an inspired story line, Flatterland explores our present understanding of the shape and origins of the universe, the nature of space, time, and matter, as well as modern geometries and their applications. The journey begins when our heroine, Victoria Line, comes upon her great-great-grandfather A. Square's diary, hidden in the attic. The writings help her to contact the Space Hopper, who becomes her guide and mentor through eleven dimensions. Along the way, we meet Schrödinger's Cat, The Charming Construction Entity, The Mandelblot (who lives in Fractalia), and Moobius the one-sided cow. In the tradition of Alice in Wonderland and The Phantom Toll Booth, this magnificent investigation into the nature of reality is destined to become a modern classic.

" Stewart writes with such compelling clarity that general readers can share in the intellectual daring of his perspective." — Booklist An invitation to a hidden world In Life’ s Other Secret, mathematician and award-winning science writer Ian Stewart reveals the way mathematics describes the origin, structure, and evolution of life. Featuring a sumptuous gallery of color illustrations demonstrating nature’ s intricate wonders, here is an intriguing invitation to enter a world deepe than DNA, a world where number series bloom in springtime and equations gallop across the plains. From the latest theory of how life started to the rules governing the shapes into which animals grow to the ancient patterns of evolution, Stewart illuminates the fundamental forces that shape our world.

本书是享有世界声誉的不朽名著，由Richard Courant和Herbert Robbins两位数学大家合著。原版初版于1941年，几十年来一直畅销不衰。书中充满了数学的奇珍异品，生动有趣地描绘出一幅数学世界的画卷，让你如入宝山，目不暇给。第2版由著名数学家Ian Stewart增写了新的一章，阐述了数学的最新进展，包括四色定理和费马大定理的证明等。.
这是一本人人都能读的数学书，将为你开启一扇认识数学世界的窗口。无论你是初学者还是专家，学生还是教师，哲学家还是工程师，通过这本书，你都将领略到数学之美，最终迷上数学。