# The Flying Circus of Physics

The Flying Circus of Physics by Jearl Walker (1975, published by John Wiley and Sons; "with Answers" in 1977; 2nd edition in 2007), is a book that poses and answers 740 questions that are concerned with everyday physics. There is a strong emphasis upon phenomena that might be encountered in one's daily life. The questions are interspersed with 38 "short stories" about related material.
The book covers topics relating to motion, fluids, sound, thermal processes, electricity, magnetism, optics, and vision.
There is a website for the book which stores over 11,000 references, 2,000 links, new material, a detailed index, and other supplementary material. There is also a collection of YouTube videos by the author on the material. See External links at the bottom of this page.
Jearl Walker is a professor of physics at Cleveland State University. He is also known for his work on the highly popular textbook of introductory physics, Fundamentals of Physics, which is currently in its 12th edition. From 1978 until 1990, Walker wrote The Amateur Scientist column in Scientific American magazine.

## Examples

Typically, the questions posed by the book are about everyday phenomena that most people do not think about. For example, here is question 4.78, "A Candle Flame":
   How does a candle burn; that is, how does it consume its fuel? Why is the light from a candle flame largely yellow, and why do blue regions usually form along the side of the flame? (Fig. 4-12) Why is there a dark cone between the wick and the yellow part of the flame? Why do some candles smoke; why do some flicker? Why is soot from a flame black, and yet white vapor is emitted from a candle that has just been extinguished?
Note that this question is actually a series of closely related sub-questions. This is often the case. Here is another example; this one is an excerpt from question 5.2, "Lightning: People, cows, and sheep":
   ... If a person is caught outdoors during a lightning storm, what can the person do to reduce the danger? For example, should the person hide beneath a tree or stand in an open field? Should the person stand still, crouch, or run? Why can a person's hair stand up, and is that a sign of danger? ...
Here is a third example; this one is an excerpt from question 6.1, "Rainbows":
   ... Normally, you see only one rainbow, but sometimes you might find two, each a partial circle around a common point. What is that point? Why is the color sequence of the two rainbows reversed? Why is the region between the rainbows relatively dark? Why is the upper rainbow broader and dimmer than the lower one? ...
Many of the short stories are descriptions of particular events. For example, item 1.54 is the short story "Bomber crashes into Empire State Building." The story describes how this actually occurred in 1945 and what happened to the bomber, the building, and one of the elevators.

## History

As is discussed in the preface of the book, the idea for the collection of real-world physics phenomena started when Jearl was a graduate student teaching assistant, and was asked by a student to give an example of how physics had anything to do with her life. The collection grew steadily over time, and he gave it a name that he thought would attract attention. Eventually it became large enough and popular enough to justify publication. The original 1975 edition provided no answers to the questions, but did provide references to use as a starting point. This was followed in 1977 by a modified 1st edition that included a section at the back with answers or partial answers to the questions. The author continued to work on the project and 31 years later, in 2006, the 2nd edition was released. It is a major expansion of the material and the answers now immediately follow the questions. The references for the 2nd edition are kept in an online website (see External links below) along with other useful material. The book has been translated and published in 11 different languages, the colorful covers of which can be seen here.

## Reception

The various editions of the book all received highly favorable reviews.
The reviews make it clear that the book poses questions about the real world that most readers will find interesting and which present challenges at all levels of expertise from high school science student to professional physicist.
Edward Adelson, physicist at Ohio State University writes of the 2nd edition: "Jearl Walker, known for writing of exceptional clarity in his editions of Fundamentals of Physics by Halliday, Resnick, and Walker, has offered us a new, expanded version of The Flying Circus of Physics, his collection of natural phenomena and physics oddities. ... This book, full of examples you will want to think through or discuss with friends, also includes phenomena that have not yet been fully tested or explained. It is easy for a physicist to become immersed in this book and ignore colleagues, spouse, children, and earthquakes."
A staff writer for Goodreads said in a review of the 2nd edition: "Wiley published the first edition of Jearl Walker’s The Flying Circus of Physics, which has sold over 100,000 copies and become a cult classic in the physics community. The Flying Circus is a compendium of interesting real world phenomena that can be explained using basic laws of physics. This new edition represents a thorough updating and modernization of the book. The new edition gives us the opportunity to highlight Jearl’s creativity, his communication skills, and his ability to make physics interesting."
Thomas E Taylor, at the University of Arizona, says in a review of the 1st edition (with answers), "Jearl Walker's 'Flying Circus of Physics' is so fascinating that it is difficult to review. In 174 pages, no less than 618 "just-for-fun" problems are posed regarding things that we see in everyday life. ... While this little book comes with 'physics' in the title, it obviously transcends that single science (if indeed it can be isolated). My students not only read it with enthusiasm, they also try out the things that are listed. And, with time, they resist looking at the answers until they have thoroughly experimented with each phenomenon."
Brian E Woolnough of University of Oxford says of the 1st edition (with answers) "Now and again there is published a book which comes like a breath of fresh air through the existing tomes in that field; such a book is The Flying Circus of Physics by Professor Jearl Walker - It is a delight to peruse. ... Having met Jearl Walker I know that he would hope that his book would make people realize that physics is not an irrelevant, esoteric art which is the sole preserve of those who communicate with advanced mathematics. On the contrary, there is physics all around us, and an appreciation of this can make the whole of our life more enjoyable and more fun."
Douglas D. Smith, a high school teacher, in a review of the 1st edition (without answers), says "The book is especially valuable to a general science teacher but has many items that relate to high school chemistry. One successful use of the book was to give students the opportunity to choose one of the phenomena and find answers to the related questions by checking into the references."
In a review of the 1st edition (without answers), Robert H. Romer, a physics professor at Amherst College, says "I recommend this book without reservation to everyone who enjoys physics, who knows the subject and who wants to learn more about its application to real phenomena. My major worry about the book is my fear that it might be mistaken for an 'elementary' book. It is true that no quantum mechanics is needed, for instance, to grapple with these questions, but at least with many of these questions, you will not get far without a sound knowledge of classical physics."

## Brief Contents

Preface Chapter 1. Slipping Between Falling Drops. (Motion). Chapter 2. Racing on the Ceiling, Swimming Through Syrup. (Fluids). Chapter 3. Hiding Under the Covers, Listening for the Monsters. (Sound). Chapter 4. Striking at the Heat in the Night. (Thermal Processes). Chapter 5. Ducking First a Roar and Then a Flash. (Electricity and Magnetism). Chapter 6. Splashing Colors Everywhere, Like a Rainbow. (Optics). Chapter 7. Armadillos Dancing Against a Swollen Moon. (Vision). Index

## Contents

The following is a full listing of the titles of the questions and the short stories, which may be quite useful for determining if a particular topic of interest is addressed in the book. The questions themselves are usually much longer than the titles and often contain numerous sub-questions.

### CHAPTER 1: Slipping Between Falling Drops (MOTION)

1.1 Run or walk in the rain? 1.2 Traffic platoons and gridlock 1.3 Shock waves on the freeway 1.4 Minimum trailing distance for a car 1.5 Running a yellow light 1.6 Spinout during hard braking 1.7 To slide or not to slide 1.8 Skidding to a stop 1.9 SHORT STORY: Some records for skid marks 1.10 Woodpeckers, bighorn sheep, and concussion 1.11 SHORT STORY: The game of gs 1.12 Head-on car collision 1.13 SHORT STORY: Playing with locomotives 1.14 Rear-end collision and whiplash injury 1.15 Race-car turns 1.16 Sprint tracks 1.17 Takeoff illusion 1.18 SHORT STORY: Air Canada Flight 143 1.19 Fear and trembling at the amusement park 1.20 SHORT STORY: Circus loop-the-loop acts 1.21 Catching a fly ball 1.22 SHORT STORY: High ball 1.23 Hitting a baseball 1.24 Legal passes in rugby 1.25 Juggling 1.26 Pole vaulting 1.27 Launch of an atlatl and a toad tongue 1.28 Slings 1.29 Tomahawks 1.30 Bolas 1.31 Siege machine 1.32 Human cannonball 1.33 Basketball shots 1.34 SHORT STORY: Records in free throws 1.35 Hang time in basketball and ballet 1.36 Golfing 1.37 SHORT STORY: Curtain of death of a meteor strike 1.38 The high jump and the long jump 1.39 Jumping beans 1.40 Somersault of a click beetle, attack of a mantis shrimp 1.41 SHORT STORY: Some record lifts 1.42 Chain collisions 1.43 Dropping a stack of balls 1.44 SHORT STORY: A crashing demonstration 1.45 Karate 1.46 Boxing 1.47 Skywalk collapse 1.48 World Trade Center collapse 1.49 Falls from record heights 1.50 A daring parachuting rescue 1.51 Cats in long falls 1.52 Land diving and bungee jumping 1.53 Trapped in a falling elevator cab 1.54 SHORT STORY: Bomber crashes into Empire State Building 1.55 Falls in fighting, landing during parachuting 1.56 Beds of nails 1.57 Hanging spoons 1.58 Trails of migrating rocks 1.59 Hitches 1.60 Rock climbing 1.61 Rock climbing by bighorn sheep 1.62 Pulling statues across Easter Island 1.63 Erecting Stonehenge 1.64 Lifting the blocks for the Egyptian pyramids 1.65 A Slinky 1.66 Leaning tower of blocks 1.67 Leaning tower of Pisa 1.68 Falling dominoes 1.69 Falling chimneys, pencils, and trees 1.70 Breaking pencil points 1.71 Failure of a bridge section 1.72 Jackknifing of a train 1.73 Bowling strikes 1.74 Shots in pool and billiards 1.75 Miniature golf 1.76 Super Ball tricks 1.77 Racquetball shots 1.78 SHORT STORY: A controversial goal 1.79 Tennis 1.80 Bicycles and motorcycles 1.81 Motorcycle long jumps 1.82 Skateboards 1.83 Pitching horseshoes 1.84 Spinning hula hoops and lassos 1.85 Yo-yo 1.86 Unwinding a yo-yo 1.87 Driving through the sound barrier 1.88 SHORT STORY: Spin test explosion 1.89 Kayak roll 1.90 Curling 1.91 Tightrope walk 1.92 Bull riding 1.93 Tearing toilet paper 1.94 Skipping stones and bombs 1.95 Spinning ice-skater 1.96 Spinning a book 1.97 Falling cat, astronaut antics, and fancy diving 1.98 Quadruple somersault 1.99 Tumbling toast 1.100 Ballet 1.101 Skiing 1.102 Abandoned on the ice 1.103 SHORT STORY: Rotation sequence matters 1.104 Personalities of tops 1.105 SHORT STORY: A headstrong suitcase 1.106 Tippy tops 1.107 Spinning eggs 1.108 Diabolos 1.109 Rattlebacks 1.110 Wobbling coins and bottles 1.111 Judo, aikido, and Olympic wrestling 1.112 Bullet spin and long passes 1.113 Pumping playground swings 1.114 Incense swing 1.115 The pendulum in the pit 1.116 Inverted pendulums, unicycle riders 1.117 Carrying loads on the head 1.118 Carrying loads with oscillating poles 1.119 Coupled pendulums 1.120 Spring pendulum 1.121 The bell that would not ring 1.122 Spaghetti effect 1.123 The spider and the fly 1.124 Footbridge and dance floor oscillations 1.125 Precariously balanced structures and rocks 1.126 Sinking of the nuclear submarine Kursk 1.127 Detection by sand scorpion 1.128 Snow waves 1.129 Football-stadium wave 1.130 Body armor 1.131 Archer's paradox 1.132 Oscillating plants 1.133 Oscillating tall buildings 1.134 Diving from a springboard 1.135 Fly casting 1.136 The Falkland Islands battle, Big Bertha 1.137 Jack and the beanstalk to space 1.138 Spring fever and the standing of eggs 1.139 Moon madness 1.140 Gravity hill 1.141 Falling through the center of Earth 1.142 Stretching of plastic shopping bags 1.143 Giant's Causeway and starch columns 1.144 Broken fingernails 1.145 Crumpling paper into a ball 1.146 Playful to tragic examples of explosive expansion 1.147 Why a hanging picture becomes crooked 1.148 A two-spring surprise 1.149 Stability of a pop can 1.150 Wilberforce pendulum 1.151 Drag racing starts 1.152 Turn or stop 1.153 Slipping past a bus 1.154 Compression region in sticky tape 1.155 Bobsled in a curve 1.156 Too quick to slide 1.157 The home of the Little Prince 1.158 Parachuting with a pumpkin 1.159 Pulling in a feisty fish 1.160 Fiddlesticks 1.161 Rotor on a notched stick 1.162 Shot put and hammer throw 1.163 Jumps during downhill ski race 1.164 Pulling a tablecloth beneath dishes 1.165 SHORT STORY: Pulling with teeth 1.166 Jerking chair 1.167 Lifting a person with fingers 1.168 Rockets, and a problem with an iceboat 1.169 SHORT STORY: Earth to Venus 1.170 A choice of hammers 1.171 Pressure regulator 1.172 Sliding a stick across fingers 1.173 SHORT STORY: Giant tug-of-war 1.174 Shooting along a slope 1.175 Starting a car on a slippery road 1.176 Balancing a tire 1.177 Carnival bottle swing 1.178 Hanging goblet. ready to crash 1.179 Breaking a drill bit 1.180 Swinging watches 1.181 SHORT STORY: Flattening the Golden Gate Bridge 1.182 Hunting by railway vehicles 1.183 Oscillating car antenna 1.184 A ship's antiroll tank 1.185 Road corrugation 1.186 Seeing only one side of the Moon 1.187 Intelligence satellites 1.188 Air drag speeds up satellite 1.189 Moon trip figure eight 1.190 Earth and Sun pull on Moon 1.191 Gravitational slingshot effect 1.192 Making a map of India 1.193 Shaving with twin blades 1.194 The handedness of river erosion

### CHAPTER 2: Racing on the Ceiling, Swimming Through Syrup (FLUIDS)

2.1 Race cars on the ceiling 2.2 Drafting 2.3 Aerodynamics of passing trains 2.4 Collapse of the old Tacoma Narrows Bridge 2.5 Aerodynamics of buildings 2.6 Kites 2.7 Ski Jumping 2.8 Speed of a downhill skier 2.9 Boomerangs 2.10 Throwing cards 2.11 Seeds that spin 2.12 Flying snakes 2.13 Air drag on tennis balls 2.14 Veering a football around a defensive wall 2.15 Golf-ball aerodynamics 2.16 Baseball aerodynamics 2.17 Cricket aerodynamics 2.18 Birds flying in V formation 2.19 Speed swimming in syrup 2.20 Contrails 2.21 Inward flutter of a shower curtain 2.22 Prairie dog and giant ant nests 2.23 Bathtub vortex 2.24 Vortex in a cup of coffee 2.25 Gathering of tea leaves, spinning of olives 2.26 Meandering rivers 2.27 Bird spinning in water 2.28 Water climbing a spinning egg 2.29 Circular water-flow pattern in a sink 2.30 Water level in canals 2.31 Solitary waves 2.32 Tidal bores 2.33 Tides 2.34 Tides in the Bay of Fundy 2.35 Dead water 2.36 Tornadoes 2.37 SHORT STORY: Looking up into a tornado 2.38 Waterspouts and funnel clouds 2.39 Dust devils, fog devils, and steam devils 2.40 Ring vortexes 2.41 Siphons and toilets 2.42 Lizards walking on water 2.43 Lead bar floating in a boat 2.44 Floating bars and open containers 2.45 Hole in a dam, ship in dry dock 2.46 g-LOC in pilots 2.47 Blood circulation in snakes, giraffes, and tall dinosaurs 2.48 Did the sauropods swim? 2.49 Gastroliths in dinosaurs and crocodiles 2.50 Coanda effect 2.51 Teapot effect 2.52 Ascents after deep diving 2.53 Snorkeling by people and elephants 2.54 Deep diving submarine escape 2.55 Lake Nyos disaster 2.56 SHORT STORY: House-hopping, and riding the skies in a lawn chair 2.57 Flow of medieval cathedral window glass 2.58 Strange viscous fluids 2.59 Soup reversal 2.60 Bouncing liquid stream 2.61 Rod-climbing fluids 2.62 Liquid rope coils 2.63 Water waves 2.64 Extreme and rogue waves 2.65 Waves turning to approach a beach 2.66 Waves pass through a narrow opening 2.67 Seiches and sloshes 2.68 Wakes of ducks and aircraft carriers 2.69 Surfing 2.70 Porpoise and dolphin motion 2.71 Edge waves 2.72 Beach cusps 2.73 Oil and waves 2.74 Floating drops 2.75 Splashing drops 2.76 Bubbles in soda, beer, and champagne 2.77 Soap bubbles and beer foams 2.78 Bursting bubbles 2.79 Whales and bubble nets 2.80 Water striders 2.81 Beading on rods and saliva threads 2.82 Rain harvesting by desert lizards 2.83 Prey harvesting by shorebirds 2.84 Drops and liquid films on solid surfaces 2.85 Breakfast cereal pulling together 2.86 Sandcastles 2.87 Appearance of bad coffee 2.88 Tears of wine and other liquid surface play 2.89 Tia Maria worm-like patterns 2.90 Patterns in hot coffee and other fluids 2.91 Patterns in coffee stains 2.92 Breath figures 2.93 The lotus effect 2.94 Aphids and liquid marbles 2.95 Paintbrushes, wet hair, and dunking cookies 2.96 Deep-fat frying of potatoes 2.97 Ducks stay dry 2.98 Cut potatoes, bird droppings, and a car 2.99 Catapulting mushroom spores 2.100 Waves on a falling stream 2.101 Water bells, sheets, and chains 2.102 Stepping on a wet beach and into quicksand 2.103 Collapse of buildings and a freeway 2.104 SHORT STORY: Quicksand effect with grain 2.105 Pedestrian flow and escape panic 2.106 Sandpiles and self-organizing flow 2.107 Flows in hourglasses and silos 2.108 Brazil-nut effect and oscillating powders 2.109 Avalanche balloon 2.110 and ripples and movement 2.111 Sand dunes 2.112 Yardangs and other sand cuttings 2.113 Snow fences and wind deposits 2.114 Snow avalanches 2.115 Long-runout landslides 2.116 Rockfalls 2.117 Fluttering flags and ribbons 2.118 Fluttering fountains and pounding waterfalls 2.119 Pulsating fountains 2.120 Pouring: inverted glass, yard-of-ale 2.121 Dripping 2.122 Soap bubble shapes 2.123 Bubble paths 2.124 Antibubbles 2.125 Lifting rice with a rod 2.126 Throwing a discus 2.127 Javelin throw 2.128 Two boats drawn together 2.129 Aerodynamics of cables and lines 2.130 Surf skimmer 2.131 Buoyancy while turning a corner 2.132 Wave reflection by sandbars 2.133 Rain and waves 2.134 A salt oscillator 2.135 Salt fingers and a salt fountain 2.136 Lifting water through tall trees 2.137 Windrows on water 2.138 Cloud streets and forest-fire strips 2.139 Packing M&Ms 2.140 A pile of apples 2.141 Powder patterns 2.142 A hydraulic oscillator 2.143 Oil blobs moving through glycerin 2.144 Ball in an airstream 2.145 Flettner's ship 2.146 Strait of Gibraltar. Strait of Messina. Strait of Sicily 2.147 Granular splashing 2.148 Slight ridge on moving water 2.149 Meandering thin streams 2.150 Shaver clippings and camphor boats on water 2.151 Oil stains on a road 2.152 Patterns of water drops onto glycerin 2.153 Olive-oil fingers on talc-covered water 2.154 Chicken-fat oscillator

### CHAPTER 3: Hiding under the Covers, Listening for the Monsters (SOUND)

3.1 Howling of the wind 3.2 Singing of telephone wires and pine needles 3.3 Whistles and whistling 3.4 Speaking and singing 3.5 Speaking with helium 3.6 Throat singing 3.7 Snoring 3.8 Purring and roaring 3.9 SHORT STORY: Sound from a Parasaurolophus dinosaur 3.10 Sounds of tigers and elephants 3.11 Bullfrog croaking 3.12 Crickets and spiny lobsters 3.13 Frog playing a tree; cricket playing a burrow 3.14 Attack of the Australian cicadas 3.15 Penguin voices 3.16 Whale clicks 3.17 Reflection tone 3.18 Long-distance sound 3.19 Acoustic shadows 3.20 Hearing the Soviet subs 3.21 Cheerleader's horn. foghorns 3.22 Direction of a whisper 3.23 Doppler shift 3.24 Bat finding an insect 3.25 Bat finding a flower 3.26 Hearing underwater 3.27 Cocktail party effect 3.28 Sound emitted by the ears 3.29 Music in your head 3.30 Noise-induced hearing loss 3.31 Sound enhanced by noise 3.32 Stethoscopes and respiratory sounds 3.33 Tightening guitar strings and rubber bands 3.34 Bowing a violin 3.35 Flashing brilliance of a violin 3.36 Conch shells 3.37 Didgeridoo 3.38 Silo quaking and honking 3.39 Singing corrugated tubes 3.40 Coffee mug acoustics 3.41 Bottle resonance 3.42 Fingers on a chalkboard 3.43 Rubbing wineglasses 3.44 Shattering wineglasses with voice 3.45 Murmuring brooks and rain noise 3.46 Jar and beaker resonance 3.47 Rumbling from plumbing 3.48 Knuckle cracking 3.49 Korotkoff sounds 3.50 Attack of the killer shrimp 3.51 Sounds of boiling water 3.52 Food-crushing sounds 3.53 Snap, crackle, and pop 3.54 Sonic booms from aircraft and bullets 3.55 Sonic booms from train tunnels 3.56 Thunder 3.57 Brontides-mysterious booms from the sky 3.58 Rockfall and tree downing 3.59 Popping bullwhips and wet towels 3.60 Coughing and sneezing 3.61 Acoustics of rooms and concert halls 3.62 Whispering galleries in various enclosures 3.63 Whispering gallery in St. Paul's Cathedral 3.64 Echoes from walls, corners, and forest groves 3.65 Musical echoes from stairs and fences 3.66 SHORT STORY: Acoustics of ancient structures 3.67 Singing in the shower 3.68 Noisy upstairs neighbor 3.69 Booming sand and squeaking sand 3.70 Cracking ice and bergy seltzer 3.71 Audibility through snow 3.72 Sounds of walking in snow 3.73 "Can you hear the shape of a drum?" 3.74 Infrasound 3.75 Sounds of corn growing 3.76 Snapping cloth sounds 3.77 Culvert whistlers 3.78 Slinky whistlers 3.79 Rifle-shot noises in permafrost regions 3.80 Hearing auroras and fireballs 3.81 Australian bullroarer

### CHAPTER 4: Striking at the Heat in the Night (THERMAL PROCESSES)

4.1 Dead rattlesnakes 4.2 Fire-detecting beetles 4.3 Bees kill hornet 4.4 Huddling animals 4.5 Space walking without a spacesuit 4.6 Drops on a hot skillet, fingers in molten lead 4.7 SHORT STORY: A rather dreadful swallow 4.8 Walking over hot coals 4.9 SHORT STORY: Fire-walking accounts 4.10 Freezing and supercooling water 4.11 Eating sea ice 4.12 Cooling rates of initially hot and warm water 4.13 Water frozen by the sky 4.14 Saving the stored vegetables with a tub of water 4.15 Spraying an orchard to prevent freezing 4.16 Throwing hot water into very cold air 4.17 Icicles 4.18 Ice dams at eaves 4.19 Rime ice and glaze ice on cables 4.20 Ice spikes and other ice formations 4.21 Cloudy ice cubes 4.22 Figures inside melting ice 4.23 Freezing of ponds and lakes 4.24 Freezing carbonated drinks 4.25 Bursting pipes 4.26 Touching or licking a cold pipe 4.27 Bumps in winter, pingos in permafrost 4.28 Arctic ice polygons 4.29 Growing stones in a garden, patterned ground 4.30 Ploughing boulders 4.31 SHORT STORY: Dead-cat bomb and a frozen disappearance 4.32 Snowflake formation 4.33 Skiing 4.34 Ice-skating and making a snowball 4.35 Ice walking 4.36 Igloos 4.37 Snowrollers 4.38 Snow avalanche 4.39 Patterns formed by melting snow 4.40 Salting icy sidewalks 4.41 Homemade ice cream 4.42 Drinking hot coffee, eating hot pizza 4.43 Boiling water 4.44 Boiling an egg 4.45 Cooking in a stove or over flames 4.46 Campfire cooking 4.47 Cooking pizza 4.48 Heating in a microwave oven 4.49 Popping popcorn 4.50 Cooking scrambled eggs 4.51 Geysers and coffee percolators 4.52 Toy putt-putt boat 4.53 Thermal effects on lengths 4.54 Collapse of railroad storage tank 4.55 Drying of hanging laundry 4.56 Warm coats 4.57 Warm plants 4.58 Polar-bear hairs 4.59 Black robes and black sheep in the desert 4.60 Cooling rate of a cup of coffee 4.61 Cool water from porous pottery 4.62 Dunking bird 4.63 SHORT STORY: Large dunking birds 4.64 Heat pipes and potato stickers 4.65 Foggy mirrors 4.66 Condensation on eyeglasses 4.67 Water collection in arid regions 4.68 Mud cracks 4.69 Inflating juice containers on airplanes 4.70 Inflating bubbles and balloons 4.71 Making cakes at high altitudes 4.72 Champagne in a tunnel 4.73 SHORT STORY: Stuck in a bottle 4.74 Wintertime thunder 4.75 Stack plume 4.76 Smoke signals and mushroom clouds 4.77 Fire in a fireplace 4.78 A candle flame 4.79 Spraying a fire 4.80 Cooking-oil fires 4.81 Brush fires and forest fires 4.82 Firestorms 4.83 Temperature regulation in mounds and buildings 4.84 Warmth of greenhouses and closed cars 4.85 Heat islands 4.86 Rubber-band thermodynamics 4.87 The foehn and the chinook 4.88 The boiling-water ordeal 4.89 Energy in a heated room 4.90 Icehouse orientation 4.91 A radiometer toy and its reversal 4.92 Water wells and storms 4.93 Insect and shrimp plumes

### CHAPTER 5: Ducking First a Roar and Then a Flash (ELECTRICITY AND MAGNETISM)

5.1 Lightning 5.2 Lightning: people, cows, and sheep 5.3 Lightning: vehicles 5.4 Lightning: trees, towers, and ground 5.5 Bead and ball lightning 5.6 Sprites 5.7 Lightning rods 5.8 Sweaters, playground slides, and surgery rooms 5.9 Cars, fuel pumps, and pit stops 5.10 SHORT STORY: Shocking exchange of gum 5.11 Danger of powder floating in the air 5.12 Danger of aerosol cans 5.13 Danger of spraying water 5.14 Ski glow 5.15 Hindenburg disaster 5.16 A gurney fire 5.17 Glow in peeling adhesive tape 5.18 Parsley, sage, rosemary, and thyme 5.19 Wintergreen glow in the closet 5.20 Earthquake lights 5.21 St. Elmo's fire and Andes glow 5.22 High-voltage lines 5.23 Current, voltage, and people 5.24 SHORT STORY: An act of indiscretion 5.25 Use of current in surgery 5.26 Surgical fires and explosions 5.27 Lemon battery, tingling of teeth fillings 5.28 Electric fish and eels 5.29 Charging by blown dust, sand, and snow 5.30 Lightning-like discharges above a volcano 5.31 Bacterial contamination in surgery 5.32 Bees and pollination 5.33 SHORT STORY: Fire ants and electrical equipment 5.34 Plastic food wrap 5.35 Flies on ceilings, geckos on walls 5.36 Meringue pie 5.37 Sauce bearnaise 5.38 Lodestones 5.39 Earth's magnetic field and archaeology 5.40 MRI complications 5.41 SHORT STORY: Magnetic search for the Garfield bullet 5.42 Magnets, tattoos, and body jewelry 5.43 Breakfast and cow magnetism 5.44 Electric guitars 5.45 Electric-guitar amplifiers 5.46 Auroras 5.47 Solar eruptions and power outages 5.48 Levitating frogs 5.49 Fizzing sound from a magnet 5.50 Currents in you at a train station

### CHAPTER 6: Splashing Colors Everywhere, Like a Rainbow (OPTICS)

6.1 Rainbows 6.2 Strange rainbows 6.3 Artificial rainbows 6.4 The daytime sky is not dark 6.5 Colors of the sky 6.6 Blue mountains, white mountains, and red clouds 6.7 Sailor's warning 6.8 Sunsets and volcanoes 6.9 Bishop's ring 6.10 Cloud-contrast bow 6.11 Sky colors during a solar eclipse 6.12 When the sky turns green, head for the cellar 6.13 Enhancement of overhead blue 6.14 Dark patch and rosy border during sunset 6.15 Bright and dark shafts across the sky 6.16 Blue haze, red haze, brown haze 6.17 Lights of a distant city 6.18 How far is the horizon? 6.19 Color of overcast sky 6.20 Maps in the sky 6.21 Brighter when it snows 6.22 The end of a searchlight beam 6.23 SHORT STORY: Newgrange winter-solstice sunbeam 6.24 The green flash 6.25 Distortions of the low Sun 6.26 Red Moon during lunar eclipse 6.27 Crown flash 6.28 Oasis mirage 6.29 Wall mirage 6.30 Water monsters, mermen, and large-scale mirage 6.31 A ghost among the flowers 6.32 Shimmy and twinkling stars 6.33 Shadow bands 6.34 The 22° halo and sun dogs 6.35 A sky full of halos, arcs, and spots 6.36 Mountain shadows 6.37 Disappearing cloud shadows 6.38 Colors of the ocean 6.39 Reflection glitter of Sun and Moon 6.40 Rings of light 6.41 Shadows and colors in water 6.42 Color of your shadow 6.43 Seeing the dark part of the Moon 6.44 Heiligenschein and opposition brightening 6.45 Grain field waves 6.46 Glory 6.47 Corona 6.48 Frosty glass corona 6.49 Iridescent clouds 6.50 Blue moon 6.51 Yellow fog lights 6.52 Dark when wet 6.53 Colors of snow and ice 6.54 Firnspiegel and snow sparkles 6.55 Whiteouts and snowblindness 6.56 Yellow ski glasses 6.57 When the ice grows dark 6.58 Bright clouds, dark clouds 6.59 Noctilucent clouds 6.60 You in a looking glass 6.61 Reflections off water and a stage mirror 6.62 Pepper's ghost and the bodiless head 6.63 Tilt of windows for air traffic controllers 6.64 Images in two or three mirrors 6.65 Kaleidoscopes 6.66 Mirror labyrinths 6.67 A sideshow laser shoot 6.68 Dark triangles among the decorations 6.69 Shiny turns to black: blacker than black 6.70 Retroreflectors 6.71 SHORT STORY: Landing in the dark behind enemy lines 6.72 One-way mirror 6.73 Rearview mirror 6.74 Sideview mirror 6.75 A Bar at the Folies-Bergère 6.76 Renaissance art and optical projectors 6.77 Anamorphic art 6.78 The bright and dark of street lamps 6.79 Multiple images from double-pane windows 6.80 World's most powerful searchlight 6.81 Archimedes' death ray 6.82 SHORT STORY: Illuminating a referee 6.83 Spooky lights in a graveyard 6.84 What a fisherman sees of a fish 6.85 What a fish sees of the fisherman 6.86 Reading through a sealed envelope 6.87 SHORT STORY: Sword swallowing and esophagoscopy 6.88 Shower-door optics 6.89 Magic of refraction 6.90 The invisible man and transparent animals 6.91 A road made crooked by refraction 6.92 Watering plants in sunlight 6.93 Starting a fire with ice 6.94 Diamonds 6.95 Opals 6.96 Alexandrite effect 6.97 Star sapphire 6.98 Patterns from a glass of wine, a window, and a drop of water 6.99 Shadows with bright borders and bands 6.100 Bright and dark bands over the wing 6.101 SHORT STORY: Shock waves from the Thrust SSC car 6.102 Pinhole and pinspeck cameras 6.103 Solar images beneath a tree 6.104 Lights through a screen, lines between fingers 6.105 Bright scratches and colorful webs 6.106 Bright streaks in a car windshield 6.107 Reflections from a phonograph record 6.108 Colors on finely grooved items 6.109 Anticounterfeiting: Optically variable devices 6.110 Colored rings from a misty or dusty mirror 6.111 Color of milk in water 6.112 Color of campfire smoke 6.113 Ouzo effect 6.114 Colors of oil slicks, soap films, and metal cooking pots 6.115 Structural colors of insects, fish, birds, and monkey butts 6.116 Pearls 6.117 Protuberances on insect eyes and stealth aircraft 6.118 Iridescent plants 6.119 Anticounterfeiting: Color-shifting inks 6.120 Color saturation in flower petals 6.121 Yellow brilliance of aspen trees 6.122 Colors of eyes 6.123 So cold I turned blue 6.124 Speckle patterns 6.125 Colors in fluorescent light 6.126 Polarizing sunglasses 6.127 Sky polarization 6.128 Ant navigation 6.129 Colors and spots and polarization 6.130 Colorless foam and ground powder 6.131 Glossy black velvet, glossy varnish 6.132 Colors of green glass and green velvet 6.133 Peachy skin and apparent softness 6.134 Twinkies and Vaseline parties 6.135 The colors of meat 6.136 A short beer 6.137 "Whiter than white" 6.138 Disappearing coin 6.139 Sunglasses and smog 6.140 Brightness of the ocean 6.141 Blue ribbon on sea horizon 6.142 Darkness falls with a bang 6.143 Colorful contrail 6.144 Nacreous clouds 6.145 Twilight purple light 6.146 Ripples in the sky 6.147 Line across distant rain 6.148 Bright nights 6.149 Zodiacal light, gegenschein, and other nocturnal lights 6.150 Reflections from sea horizon 6.151 Using a solid metal ball to focus light 6.152 A fast spin in a curved mirror 6.153 Color of cigarette smoke 6.154 If you could see in the UV 6.155 Diffracted alphabet 6.156 A game of reflection

### CHAPTER 7: Armadillos Dancing Against a Swollen Moon (VISION)

7.1 Enlarging the Moon 7.2 Shape of the sky 7.3 Decapitation with the blind spot 7.4 Gray networks in the morning, dashing specks in the daylight 7.5 Floaters and other spots in your eye 7.6 Streetlight halos, candle glow, star images 7.7 Phosphenes—psychedelic displays 7.8 Humming becomes a stroboscope 7.9 Keeping your eye on the baseball 7.10 Impressionism 7.11 Pointillistic paintings 7.12 Moiré patterns 7.13 Op art 7.14 Depth in oil paintings 7.15 Reading in the dark 7.16 Trailing ghost light 7.17 Reflecting eyes 7.18 Underwater vision of humans, penguins, and crocodiles 7.19 Underwater vision of "four-eyed fish" 7.20 Cheshire cat effect 7.21 Rhino-optical effect 7.22 Flying clouds and Blue Meanies 7.23 Pulfrich illusion 7.24 Streetlight delay sequence 7.25 Mach bands 7.26 An upside-down world 7.27 Inverted shadows, the blister effect 7.28 Peculiar reflection from a Christmas tree ball 7.29 Rotated random-dot patterns 7.30 Patterns in television "snow" 7.31 Mona Lisa's smile 7.32 Floating, ghostly images of a television screen 7.33 Reading through pinholes 7.34 Finger colors 7.35 Stars seen through a shaft during the daytime 7.36 A stargazer's eye sweep 7.37 Resolution of Earth objects by astronauts 7.38 Honeybees, desert ants, and polarized light 7.39 Haidinger's brush 7.40 Colors of shadows 7.41 Safety of sunglasses 7.42 Fish lens 7.43 Depth in red and blue signs 7.44 Purkinje's blue arcs 7.45 Maxwell's spot 7.46 Visual sensations from radiation 7.47 Red light for control boards 7.48 Superman's x-ray vision 7.49 Fireworks illusion 7.50 Looking at the ceiling