Books by Yuuki Yamagishi

BOOKS

Where do the numbers in a formula come from?

A shelf of books on numbers, time, light and money, each written by checking one thing at a time.

38 books

The first three

3 books
  • A Single Skin and What It Holds

    Put m = 4π into E = mc² and you get 4πc², the same form as the surface area of a sphere. Stack those skins, and the inside of the ball comes back. A small book that starts from a single skin.

    日本語 · English · Deutsch · Français · Italiano

    View on Amazon View on Google Play Books

  • Put 4π In and See

    Set the mass to 4π and reread the formulas of Newton, Kepler and quantum physics. In some the π disappears, in others it stays; the book sorts out, one by one, whether what vanished was a solid angle, a full turn, or the choice of units.

    日本語 · English · Deutsch · Français · Italiano

    View on Google Play Books

  • Reading the Poincaré Conjecture through Shells of a Sphere

    The Poincaré conjecture was proved by Perelman and others; this book adds nothing to the proof. Using a theorem that counts a ball shell by shell, it reads why the answer is the sphere. The number on a shell is 4π in three dimensions and 2π² in four.

    日本語 · English · Deutsch · Français · Italiano

    View on Google Play Books

Where numbers come from

2 books
  • What Is That Number Recording?

    The speed of light and 137. This book separates the numbers that change when you change units from those that do not, and asks whether a number in a formula records nature or the scale we chose.

    日本語 · English

    Not yet available

  • Where Did That Number Come From?

    Who chose the units? How does dimensional analysis break down? Why does the equals sign have six meanings? A textbook, in sixteen chapters and forty-three exercises, on how to check where the numbers in a formula come from.

    日本語 · English

    Not yet available

Spheres and dimensions

2 books
  • Numbers That Move with the Dimension, and Numbers That Do Not

    The volume of a ball of radius 1 is largest in five dimensions; with radius 2, it is twenty-four. In twenty-one stories the book asks whether a number moves when the dimension changes. It does not claim that higher-dimensional worlds exist.

    日本語 · English

    Not yet available

  • Where Did That π Come From?

    The 4π of a sphere’s surface, the 6π of a ball sinking in syrup, the 8π of the equations of gravity. Across twenty-three formulas the book checks whether each π is a spread in every direction, a full turn, or a number put there by the notation. The same number need not have the same reason.

    日本語 · English

    Not yet available

Time, light and the universe

3 books
  • There Were Four Kinds of Time

    The one word “time” points to four different things: the marks on a clock, the length of a path, the direction of spreading disorder, and the scale of a flow. When someone says time does not exist, this book asks which time they mean.

    日本語 · English

    Not yet available

  • Without Assuming the Speed of Light

    This book does not begin relativity with “the speed of light is the same for everyone”. From Galileo’s ship alone, a formula with a single dial appears. Twenty-three stories sort assumption from measurement and convention. It is not a book that doubts relativity.

    日本語 · English

    Not yet available

  • There Are Three Edges of the Universe

    How many light years to the edge of the universe? Counted on the same model, there are three edges. Twenty-four stories, from the distance ladder to black-hole shadows and rotating galaxies, ask what each number actually measures.

    日本語 · English

    Not yet available

Words and symbols

3 books
  • How Many Meanings Do + − × ÷ = Have?

    The + − × ÷ = learned in primary school, counted again scene by scene. The same symbol does different work in different situations, and this book checks each difference one at a time.

    日本語 · English

    Not yet available

  • The Words of Mathematics Have More Than One Meaning

    “Converges” has four meanings. Distance, completeness, independence, unprovable: in nineteen stories about the words of mathematics, the book asks how many things a single word points to.

    日本語 · English

    Not yet available

  • The Words of Physics Have More Than One Meaning

    There are seven kinds of “mass”: one can be negative, and one changes with the direction of the push. In eighteen stories, from pressure and stability to conservation and symmetry, the book separates what a single word of physics points to.

    日本語 · English

    Not yet available

Everyday puzzles

8 books
  • The Angle of a Rainbow Does Not Contain the Size of the Drops

    The size of the drops does not enter the angle of a rainbow. Rainbows, halos, mirages, the blue sky, soap bubbles: in twenty-two stories of sky, light and colour, the book counts what really decides each one.

    日本語 · English

    Not yet available

  • The Boiling Point Is Not a Property of the Substance

    A boiling point is not set by the substance alone. Pans, kettles, condensation, salt, rust, hourglasses: twenty-eight stories from kitchen and home show that a number is fixed by the substance together with its surroundings. It is not a book of cooking or health advice.

    日本語 · English

    Not yet available

  • A Bicycle Is Not Held Up by Its Gyroscope

    A bicycle does not stay up because its wheels spin; counted out, the numbers are orders of magnitude short. Thirty-three stories of vehicles and motion separate the explanation that feels right from the one that adds up.

    日本語 · English

    Not yet available

  • Measure Two Shadows, and the Earth Comes Out

    Measure two shadows and the size of the Earth appears. Twenty-five stories, from the distance to the Moon to tides and leap years, count how each number was measured. From the same observation, one choice of assumption can shift the answer by forty per cent.

    日本語 · English

    Not yet available

  • Strength Is Not a Constant of the Material

    Strength is not set by the material alone, but by shape, size, direction, how it was made and what it is paired with. Twenty-five stories, from columns and glass to screws and springs, count what decides it. It is not a design manual.

    日本語 · English

    Not yet available

  • A Lifetime of Heartbeats Does Not Depend on Body Weight

    The number of heartbeats in a lifetime does not depend on body weight. Thirty-two stories of living things, from brains, bones and sleep to immunity and striped patterns, ask what each number is counting. It is not a book of medical advice.

    日本語 · English

    Not yet available

  • Why Does a Drum Have No Pitch?

    Why does a drum have no pitch? Seventeen stories, from strings, pipes and octaves to echoes, beats and voices, show that what we took for properties of sound are fixed by shape, ratio and the listener.

    日本語 · English

    Not yet available

  • Solubility Is Not a Constant of the Substance

    Solubility is not set by the substance alone. Twenty-one stories, from colloids and half-lives to osmotic pressure, batteries, rust and catalysts, ask whether the words of chemistry really point to properties of a substance.

    日本語 · English

    Not yet available

Numbers, puzzles and chance

4 books
  • Half of the 15 Puzzle Cannot Be Solved

    Half of all arrangements of the 15 puzzle can never be solved. Twenty-one stories, from Lights Out and Nim to noughts and crosses and Othello, check known theorems by counting every case on small boards. It is not a book of winning strategies.

    日本語 · English

    Not yet available

  • In a 99 % Accurate Test, 9 in 10 Positives Are Wrong

    A positive result on a 99% accurate test may be right 9% of the time or 99%, depending on who is tested. Twenty-eight stories, from the three doors to regression to the mean and significance levels, ask what each number is a number about.

    日本語 · English

    Not yet available

  • The ABC Conjecture Is a Theorem for Polynomials

    The abc conjecture is unsolved for whole numbers, yet for polynomials it is a theorem; the difference is whether you can differentiate. Seventeen stories, from primes and Collatz to the Riemann hypothesis, separate theorem, conjecture and mere counting. No conjecture is proved here.

    日本語 · English

    Not yet available

  • “Unsolvable” Comes in Three Kinds

    The quintic cannot be solved, yet its roots can be written to a hundred digits. “Unsolvable” is about a number and the tools you allow. Twenty-six kinds of “cannot” are checked by actually counting small cases.

    日本語 · English

    Not yet available

Ways of thinking

3 books
  • Six Brakes

    When the same number turns up in different formulas, it is tempting to write that they are the same thing. This is a book of six questions for stopping right there. They came from the author’s own drafts, and in the second half they are turned on themselves.

    日本語 · English

    Not yet available

  • How Outsiders Think

    はぐれ者たちの発想法Japanese edition

    Someone who did not assume the speed of light; someone who read the space of velocities as curved. Stories of people who stood a little off the main road, and of four working habits a self-taught author has relied on.

    Not yet available

  • Zero Tension

    ゼロテンションJapanese edition

    The masters had learned, in their bodies, how the rod tip moves when nothing is biting. Stories of the anglers the author met on a breakwater as a schoolboy, and of how that stance has the same shape as the mathematics of reading causes from results. It is not a fishing manual.

    Not yet available

Numbers of the markets

3 books
  • What Do Chart Tools Measure?

    What do the numbers from chart indicators actually measure? The book checks them against four markets from 2019 to 2024. It is neither a winning method nor investment advice.

    日本語 · English

    Not yet available

  • What Does a Backtest Count?

    Try forty-nine strategies with no real skill and keep the best one, and it will still look good. Twenty-four stories, from maximum drawdown to win rate and expected value, ask what each number is counting. It is not investment advice.

    日本語 · English

    Not yet available

  • A Bar Is a Clock

    A one-minute candle lasts 57.5 seconds at the median, not 60. Time candles, tick candles, renko: in thirteen stories the book asks what each kind of “one candle” holds constant. It is not investment advice.

    日本語 · English

    Not yet available

Money, towns and trades

4 books
  • What Are We Exchanging for Money?

    Behind the Price Tag / What We Eat

    何と何をお金で交換しているのか 値札の向こう/食べるものJapanese edition

    Why did rice balls get dearer? The book divides prices by the hourly wage of each year and, using national statistics, splits where 100 yen goes into six lines. Ramen, kerosene, rent, rice, eggs, beer: a look at what lies behind the price tag.

    Not yet available

  • What Are We Exchanging for Money?

    What We Burn / What We Ride

    何と何をお金で交換しているのか 燃やすもの/乗るものJapanese edition

    Kerosene, petrol, electricity and gas, buses and taxis, new cars, monthly payments, and the money that leaves just for owning a car. The book uses national statistics to count what lies behind the price of what we burn and what we ride. It is not a book about making money.

    Not yet available

  • How Big Must a Town Be for That Trade to Appear?

    その商売は、人口何人の町から現れるかJapanese edition

    “There is nothing in this town.” Using national statistics, the book counted how many establishments of 526 kinds of business exist in every municipality. The number of kinds of business in a town turned out to be set almost entirely by its population. It is not a guide to starting a business.

    Not yet available

  • Reading the Kushiro Region Through Records

    釧路地方を、資料で読むJapanese edition

    What has been caught in the sea off Kushiro? How many days a year is there fog? Why is Kushiro’s soba green? Twenty-seven stories of the Kushiro region in eastern Hokkaido, written from public records. It is not a travel guide.

    Not yet available

Books of pictures

2 books
  • A Field Guide to Patterns Born from Formulas

    Roll a gear and a flower appears; three lines of equations give a butterfly. A field guide of sixty-six patterns computed and drawn from short formulas and rules. Each comes with a picture, its formula and what was checked by counting.

    日本語 · English

    Not yet available

  • Twenty Questions Seen in 3D

    Why can’t you comb away a crown? Why must every world map distort? The captions and pictures of videos that read twenty questions with moving 3D images, gathered in one book. Each chapter also says what it does not claim.

    日本語 · English

    Not yet available

A book of imagination

1 books
  • Building the Universe out of Light

    In the formulas, the speed of light appears raised to the second power, the fourth, and more. Could those exponents be counting dimensions? A book of imagination that keeps verified physics and the dream clearly apart.

    日本語 · English

    Not yet available

For books published only in Japanese, the title shown here is a translation for reference.

Editions