##### Document Text Contents

Page 2

copyright 2006 Benjamin Crowell

rev. August 16, 2017

This book is licensed under the Creative Com-

mons Attribution-ShareAlike license, version 3.0,

http://creativecommons.org/licenses/by-sa/3.0/, except

for those photographs and drawings of which I am not

the author, as listed in the photo credits. If you agree

to the license, it grants you certain privileges that you

would not otherwise have, such as the right to copy the

book, or download the digital version free of charge from

www.lightandmatter.com. At your option, you may also

copy this book under the GNU Free Documentation

License version 1.2, http://www.gnu.org/licenses/fdl.txt,

with no invariant sections, no front-cover texts, and no

back-cover texts.

2

Page 92

92 Chapter 4 Relativity

Page 93

Chapter 5

Electricity

Where the telescope ends, the microscope begins. Which of the two

has the grander view? Victor Hugo

His father died during his mother’s pregnancy. Rejected by her

as a boy, he was packed off to boarding school when she remarried.

He himself never married, but in middle age he formed an intense

relationship with a much younger man, a relationship that he ter-

minated when he underwent a psychotic break. Following his early

scientific successes, he spent the rest of his professional life mostly

in frustration over his inability to unlock the secrets of alchemy.

The man being described is Isaac Newton, but not the triumphant

Newton of the standard textbook hagiography. Why dwell on the

sad side of his life? To the modern science educator, Newton’s life-

long obsession with alchemy may seem an embarrassment, a distrac-

tion from his main achievement, the creation the modern science of

mechanics. To Newton, however, his alchemical researches were nat-

urally related to his investigations of force and motion. What was

radical about Newton’s analysis of motion was its universality: it

succeeded in describing both the heavens and the earth with the

same equations, whereas previously it had been assumed that the

sun, moon, stars, and planets were fundamentally different from

earthly objects. But Newton realized that if science was to describe

all of nature in a unified way, it was not enough to unite the human

scale with the scale of the universe: he would not be satisfied until

93

Page 184

compared to kinetic energy, 45

conservation of, 40

relativistic, 85

moon

distance to, 143

gravitational field experienced by, 27

orbit, 51

motion

periodic, 162

nano- (metric prefix), 11

Neanderthals, 67

neutral (electrically), 97

newton (unit), 47

Newton, Isaac, 93, 151

apple myth, 27

law of gravity, 25

third law, 47

Noether’s theorem, 8

for angular momentum, 67

for energy, 27

for momentum, 43

Noether, Emmy, 8

nuclear energy, 23

Oersted, Hans Christian, 115

ohm (unit), 105

Ohm’s law, 105

ohmic

defined, 105

open circuit, 101

Optics, 27

Orion Nebula, 23

parabola, 50

parallax, 142

parallel circuit

defined, 108

particle model of light, 136

period

defined, 162

Principia Mathematica, 27

principle of superposition, 164

projectile motion, 50

pulse

defined, 164

Pythagoras, 132

ray diagrams, 138

ray model of light, 136

reflection

diffuse, 136

specular, 138

relativity

and magnetism, 116

resistance, 104

retina, 150

reversibility, 144

RHIC accelerator, 83

Roemer, 133

rotational symmetry, 15

schematics, 107

scientific notation, 12

sea-of-arrows representation, 114

series circuit

defined, 108

short circuit

defined, 107

sinks in fields, 114

Sokal, Alan, 31

sound, 168

energy, 22

speed of, 167

sources of fields, 114

spring constant, 163

sunspots, 121

symmetry, 7

rotational, 15

time, 27

translation, 38

Système International, 11

time reversal, 144

time symmetry, 27

torque

defined, 64

transformer, 124

units, conversion of, 13

velocity

addition of, 19

vision, 132

volt (unit)

defined, 102

voltage, 101

wave

184 Index

Page 185

electromagnetic, 126

wave model of light, 136

wavelength, 126

work, 57

Wu, Chien-Shiung, 8

Index 185

copyright 2006 Benjamin Crowell

rev. August 16, 2017

This book is licensed under the Creative Com-

mons Attribution-ShareAlike license, version 3.0,

http://creativecommons.org/licenses/by-sa/3.0/, except

for those photographs and drawings of which I am not

the author, as listed in the photo credits. If you agree

to the license, it grants you certain privileges that you

would not otherwise have, such as the right to copy the

book, or download the digital version free of charge from

www.lightandmatter.com. At your option, you may also

copy this book under the GNU Free Documentation

License version 1.2, http://www.gnu.org/licenses/fdl.txt,

with no invariant sections, no front-cover texts, and no

back-cover texts.

2

Page 92

92 Chapter 4 Relativity

Page 93

Chapter 5

Electricity

Where the telescope ends, the microscope begins. Which of the two

has the grander view? Victor Hugo

His father died during his mother’s pregnancy. Rejected by her

as a boy, he was packed off to boarding school when she remarried.

He himself never married, but in middle age he formed an intense

relationship with a much younger man, a relationship that he ter-

minated when he underwent a psychotic break. Following his early

scientific successes, he spent the rest of his professional life mostly

in frustration over his inability to unlock the secrets of alchemy.

The man being described is Isaac Newton, but not the triumphant

Newton of the standard textbook hagiography. Why dwell on the

sad side of his life? To the modern science educator, Newton’s life-

long obsession with alchemy may seem an embarrassment, a distrac-

tion from his main achievement, the creation the modern science of

mechanics. To Newton, however, his alchemical researches were nat-

urally related to his investigations of force and motion. What was

radical about Newton’s analysis of motion was its universality: it

succeeded in describing both the heavens and the earth with the

same equations, whereas previously it had been assumed that the

sun, moon, stars, and planets were fundamentally different from

earthly objects. But Newton realized that if science was to describe

all of nature in a unified way, it was not enough to unite the human

scale with the scale of the universe: he would not be satisfied until

93

Page 184

compared to kinetic energy, 45

conservation of, 40

relativistic, 85

moon

distance to, 143

gravitational field experienced by, 27

orbit, 51

motion

periodic, 162

nano- (metric prefix), 11

Neanderthals, 67

neutral (electrically), 97

newton (unit), 47

Newton, Isaac, 93, 151

apple myth, 27

law of gravity, 25

third law, 47

Noether’s theorem, 8

for angular momentum, 67

for energy, 27

for momentum, 43

Noether, Emmy, 8

nuclear energy, 23

Oersted, Hans Christian, 115

ohm (unit), 105

Ohm’s law, 105

ohmic

defined, 105

open circuit, 101

Optics, 27

Orion Nebula, 23

parabola, 50

parallax, 142

parallel circuit

defined, 108

particle model of light, 136

period

defined, 162

Principia Mathematica, 27

principle of superposition, 164

projectile motion, 50

pulse

defined, 164

Pythagoras, 132

ray diagrams, 138

ray model of light, 136

reflection

diffuse, 136

specular, 138

relativity

and magnetism, 116

resistance, 104

retina, 150

reversibility, 144

RHIC accelerator, 83

Roemer, 133

rotational symmetry, 15

schematics, 107

scientific notation, 12

sea-of-arrows representation, 114

series circuit

defined, 108

short circuit

defined, 107

sinks in fields, 114

Sokal, Alan, 31

sound, 168

energy, 22

speed of, 167

sources of fields, 114

spring constant, 163

sunspots, 121

symmetry, 7

rotational, 15

time, 27

translation, 38

Système International, 11

time reversal, 144

time symmetry, 27

torque

defined, 64

transformer, 124

units, conversion of, 13

velocity

addition of, 19

vision, 132

volt (unit)

defined, 102

voltage, 101

wave

184 Index

Page 185

electromagnetic, 126

wave model of light, 136

wavelength, 126

work, 57

Wu, Chien-Shiung, 8

Index 185