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The Physics of Superheroes by James Kakalios
Introduction
P6
Golden Age of Comics (1940s)
-less science
Silver age of Comics (late 1950s-60s)
-more science
P7
newspaper rivalry in 1890s between Joseph Pulitzer and William Randolph Hearst
-printed comic strips in papers
-comics appealed to immigrants with limited English skills
P8
Superman rejected by papers
P9
Superman first appeared in Action Comics #1 (June 1938) for 10 cents
P10 1940s Green Lantern
-made ring and received powers from mysterious Chinese lantern
-not powerful against wood
P10 Green Lantern reinvented in 1959
-lantern and ring (and powers) from outer space
-chemical impurity in ring left him vulnerable to yellow
P10 Spiderman created in 1962
-bite from radioactive spider
P10 Spiderman reinvented in 2000 (comics) and 2002 (film)
-bite from genetically engineered spider
P10 heroes reinvented with the current cultural settings and fears
P11 Comics Code Authority (CCA)
-self regulation to avoid government interference
-could not show: gore, lewdness, drug use, zombies, vampires
P12 Marvel no longer belongs to CCA regulations
-self regulates using a system similar to movies
P14 comic book writers used to be pulp science fiction writers who were paid by the
word
-include facts and trivial information to increase number of words
-give educational value to keep government away
Section 1: Mechanics
Chapter 1: Up, up, and away-Forces and Motion
P21 Superman’s powers on Earth due to Krypton having a stronger gravity
P22 flight, heat and x-ray vision, super-hearing, super-breath, super-hypnotism
-can’t be explained with gravity
P22 Action Comics #262: powers now explained by fact that Krypton had a red sun
and Earth has a yellow sun
-surface temperature and atmosphere it is viewed through affect color
P22 sky is blue because blue light is scattered
P24 kryptonite’s effects on Superman introduced so radio actor could go on vacation
-different actor could just moan into microphone
P24
P24
P25
P26
P28
P30
P32
P32
leap a tall building
-660 feet (Superman #1)
Newton’s 3 Laws of Motion
F=ma
Why can’t an astronaut pick up Space Station?
-it has a large mass (even if weightless)
force pairs
-Superman jumping: legs push down on ground; ground pushes up on his legs
Superman must jump at 140 mph to leap a tall building (660 ft)
5,600 lbs. of force needed to jump building
gravity on Krypton 15X larger than on Earth
Chapter 2: Deconstructing Krypton-Newton’s Law of Gravity
P33 Newton’s Law of Gravity
mm
F  G 12 2
r
P34 Superman’s mass = 100 kg
P34 acceleration of gravity:
m
g G 2
d
P34-35
tie a string to a bucket and swing in a horizontal circle
-tension of string not acting in direction that bucket is moving
-tension in string can only change direction, not speed
P35 if there was no gravity, moon would fly past Earth in a straight line
P35 if there was gravity but the moon was stationary, the moon would be pulled into
the Earth
P35-36
Large bodies can only be spheres because of gravity
-spherical shape separates planets from asteroids which have odd shapes
-Kakalios implies he would group Pluto with the planets
P36 Bizarro’s home planet (cubical) must be small
-radius from center to any side face must be  300 miles
-too small to hold an atmosphere
g Krypton
 R
P36
 15  K K
g Earth
 E RE
P37 Krypton unlikely to be 15X denser than Earth
P37 size of atom analogy to explain why 15X as dense as Earth is unlikely
-nucleus is size of a marble (1 cm)
-electron 100 yards away
P38 Earth density  E  5 g/cm3 (densest planet)
15X greater = 75 g/cm3
(no normal matter is this dense)
P38
P39
P39
P39
P40
P40
P40
P40-41
P41
if Krypton has the same density as Earth, it would need to have a radius 15X
larger than Earth’s to have the gravity it does
-Jupiter is 11X larger than Earth
-if Jupiter were 10X larger, it would be same size as sun
large planets will be gas because they need a lot of atoms and most of universe is
gas: the universe is 73% H by mass and 25% He by mass
large planets are far from sun: if they weren’t, the gases would boil off
Krypton can’t be made of normal matter
nuclei up to Fe created in stars
elements up to U created as star collapses in a supernova
neutron stars-remnant of really large stars
A sphere of r = 600 m of neutron star material at core of Earth-sized planet would
give g = 150 m/s2
this would make the planet unstable
-would explode like Krypton did!
Chapter 3: The Day Gwen Stacey Died – Impulse and Momentum
P43 DC comics had the Justice League of America (Wonder Woman, Flash, Green
Lantern, Aquaman, Martian Manhunter, etc.)
-Marvel did not have superheroes
P43 Stan Lee created the Fantastic Four for Marvel (1961)
-heroes complained about their powers
P44 Spider-Man debut in Amazing Fantasy #15
-bit by radioactive spider
-able to lift several times his weight
-made web shooters for wrists
-2002 movie had webs shoot from within his wrists
P45 “with great power there must also come great responsibility”-Uncle Ben
P45 Peter Parker’s girlfriend Gwen Stacey dies in Amazing Spider-Man #121 (1973)
P45 Green Goblin debuted in Amazing Spider-Man #14
P45 Green Goblin drops Gwen Stacey from top of tower on George Washington
Bridge
-Spider-Man catches her with a web near bottom
-pulls her up and finds her dead
-Green Goblin stated, “She was dead before your webbing reached her! A fall
from that height would kill anyone-before they struck the ground!”
P48 How large is the force supplied by Spider-Man’s webbing when stopping the
falling Gwen Stacey?
P48 assume she fell 300 feet before the webbing caught her
-her velocity at this point would be 95 mph
P49
Ft  mv
P49 air bags
-increase impact time to lower force
-increase area of impact
P49 boxer rolling with punch
P50
P50
P51
assume Gwen is 50 kg
Time to stop 0.5 seconds
Then stopping force will be: F = 970 pounds (~10 Gs!)
Therefore, the rapid deceleration from Spider-Man’s web broke her neck!
Col. John Stapp (1954) rode a rocket sled at 40 Gs during deceleration and lived
2002 Spider-Man movie
-Green Goblin drops Mary Jane from Queensboro Bridge
-Spider-Man catches up to Mary Jane before shooting a web to swing away
Chapter 4: Can He Swing from a Thread?-Centripetal Acceleration
P53 a force can only produce an acceleration in the direction it acts
P54 webbing has to supply 2 forces
1) Spider-Man’s weight
2) a force to cause parabolic motion
v2
P55
for circular motion
a
R
P55 web must supply these 2 forces:
1) mg
v2
2) m
R
P55 if Spider-Man’s web is 200 feet long, swinging at 50 mph, then the centripetal
acceleration would be a = 27 ft/s2, and g = 32 ft/s2
-assume his mass is 73 kg (160 lbs)
-Fc = 135 lbs
-total force on web = 160 lbs + 135 lbs = 195 lbs
P55 a spider’s dragline silk webbing is 5X stronger per pound than steel cable and
more elastic than nylon
P55 spider webs filled with fluid to distribute tensile force
-control tensile force by varying chemical composition of web
P55-56
Spider web making genes spliced into goats
-goats’ milk will contain webbing to collect
-has run into problems (unspecified)
P56 success with injecting it into viruses, E. coli, plants
P56 webbing can withstand impact 5X stronger than Kevlar
P56 real webs can support 20,000 lbs/cm2
Chapter 5: Flash Facts-Friction, Drag, and Sound
P57 police scientist Barry Allen exposed to lightning and chemicals-became the Flash
P58 ran up side of office building in Showcase #4
P58 action-reaction forces for walking
P59 Captain Cold would use his “freeze ray” gun to create ice in front of the Flash
-couldn’t move
P59 friction first addressed scientifically in early 1500s by Leonardo Da Vinci
P59 atomic physics of 1920s lead to fundamental understanding of friction
P59
P59
P60
P61
P61
P61
P61
P61-62
P62
2 ways for matter to be arranged:
1) crystalline structure
2) random, amorphous grouping
friction like flipping Rocky Mountains upside down on Himalayas and dragging
across them
when Flash ran up the side of a building, none of his weight was perpendicular to
the wall
-frictional force should have been zero
-shouldn’t have been able to run up wall
when running/walking, your foot pushes at an angle with the ground
-propels up and forward
if Flash bounces up 2 cm with each step, then he is in the air for 1/8 of a second
if Flash runs at 3,600 mph, then in 1/8 s, he moves about 1/8 mile forward
between steps (660 feet…like Superman’s building)
-in this way, he doesn’t have to touch building to “run” up it
must tolerate acceleration needed to change direction from horizontal to vertical
Flash can run across water because viscosity increases with density and velocity
(page 64 has an exception: Ketchup-hit the bottom of bottle and viscosity actually
decreases with increased velocity)
speed of sound/shock wave-when trying to move faster than air molecules, they
can’t get out of way fast enough and pile up in front
P62-63
P63
P64
P64
Flash used this principle to stop the Weather Wizard (Flash #110)
-knocked him over with the pressure of the piled up air
running at over 100 mph, water molecules can’t move out of the way fast enough
and form a shock front (meaning you can run on water if you do so at 100 mph)
-water skiers
region behind Flash becomes partial vacuum as he pushes air out of the way
-air rushes in from sides and back
-supplies forward force
whenever Flash runs  750 mph, he outruns sound waves approaching him
-can’t communicate with sound
P66-67
Doppler Effect-for frequency detected by the Flash to be 20,000 Hz (if 100 Hz
was emitted), he’d have to run 150,000 mph (0.02 % speed of light)
P67-68
Flash stops bullets by moving his hand at same speed (1,000 mph) as bulletrelative velocity is zero-so he can grab bullet (Flash #124)
Chapter 6: Like a Flash of Lightning-Special Relativity
P69 Flash is running faster than sound
-Flash is running at you from a distance of 10 miles
-he yells “Flash”
-when 5 miles away, he yells “Rules”
-you’ll hear “Rules Flash”
P70
P70
P71
P72
P73
Flash is running at the speed of sound, and does everything as above
-you’d hear both words at the same time
In Flash #202 (vol 2) he blew out windows from his sonic boom caused by his
super speed
Special Theory of Relativity
1) can’t travel faster than light (186,000 miles/second)
2) laws of physics same for everyone everywhere
Flash running toward you near the speed of light
1) he appears thinner to you
2) time slows down for him
3) he makes same observations about you
can’t exceed speed of light
-force of feet on ground is constant
-if acceleration doesn’t keep increasing, then mass must increase (F=ma)
-JLA #89 (near light speed travel increased his mass)
-mass only increases while moving
Chapter 7: If This Be My Density-Properties of Matter
P75 Dr. Henry Pym…Ant-Man-was a biochemist
-taunted by other scientists for not doing practical research
-worked on shrinking potion
P75 his 1st exposure to his potion led him to an adventure in an ant hill
P79 miniaturization is physically impossible because of the atom-to make something
smaller requires:
1) making atoms smaller
2) removing a large % of atoms
3) pushing atoms closer together
P79 size of atom ~1/3 of a nanometer
-all atoms same size to within factor of 3
P80 size of atom determined by:
1) mass of electron
2) charge of electron
3) # of protons in nucleus
4) Planck’s constant, h
-these are all constants, so you can’t change the size of an atom
P81 2nd option to shrink-remove atoms
-to go from 6 ft to 6 inches (and corresponding reduction in width and thickness)
would require only keeping 1 of every 1,729 atoms (keep 1, remove 1,728)
P81 it is a myth that humans only use 10% of their brains
-if true, it would be a huge evolutionary waste of space
P81 brain neuron has a width of 1/1,000 cm (ant or human)
P81 humans have ~400,000 times more neurons than ants
P82 remove a large % of these and we’d lose a lot of intelligence
P82
3rd option to shrink-push atoms closer together
-electrons repel the electrons in other atoms (difficult to keep close together)
-rigid, like marbles
-can’t compress smaller without crushing atoms
Chapter 8: Can Ant-Man Punch His Way Out of a Paper Bag?-Torque and
Rotation
P84 Ant-Man rode on carpenter ants so he could travel faster
-implies his mass decreased with his size
P84 built spring-loaded catapult to launch himself across town
-called upon insects to break his landing
P85 Ant-Man punched his way out of a vacuum cleaner bag in Tales to Astonish #37
(had strength of a normal human)
-could he do this?
P86 human strength comes from muscles and skeleton structure by way of levers
-teeter-totter: balance torques, not forces
P87 try closing a door by pushing near hinges, then try closing by pushing near handle
-will be easier to close by handle
-same as a wrench
-longer lever arm
P87 example of lifting a rock in your hand
-bicep compresses which forces part of forearm closest to elbow down
-this raises the end furthest from elbow (hand goes up)
P87 muscles only contract and pull (do not push)
P87-88
Fulcrum of forearm is at elbow
-like a fishing rod
P88 bicep pulls 2 inches in front of elbow (forearm ~14 inches long)
-factor of 7 to 1
-to lift 2 lbs requires 14 pounds of lifting force from the bicep
P88 likewise, when the bicep contracts 2 inches, your hand raises 14 inches
P88 hand displacement of 12 inches occurs in about 0.1 s (7 mph)
P88 from evolutionary point of view: able to throw rocks/spears at animals much
faster than if we didn’t have this reverse lever (requires more force to lift, but
increases speed)
P89 force of muscles depends on cross-sectional area
P89 if Ant-Man is 0.01X his normal height, his muscles have a cross-section of
(0.01)2=0.0001
-if he can punch with 200 lbs when full size, then scaled down force is 0.02 lbs
-assume Ant-Man’s hand is 1 mm wide (0.0005 in2)
-pressure of punch would be 40 lbs/in2 as Ant-Man
-as full-sized Henry Pym, pressure of punch would be: 200 lbs/5 in2 = 40 lbs/in2
as well
P89 Ant-Man can punch out of a paper bag
Why being bitten by a radioactive spider isn’t all its cracked up to be
P89 if a spider can jump 1 m (500X its body height), then Spider-Man should have
been able to jump 3,000 ft
P90
v 2  2 gh (jumping height does NOT depend on mass)
P90 acceleration needed to jump up (and hence v) does depend on mass (F=ma)
P90-91
Insects: small force but a small mass
Humans: large force but a large mass
-same effect
Chapter 9: Is Ant-Man Deaf, Dumb, and Blind?-Simple Harmonic Motion
P92 all shrunken superheroes would have difficulty communicating with nonshrunken people
P92 as Ant-Man shrinks, his voice becomes higher pitched
-will be at upper range of normal-sized human hearing
-he will also only be able to hear higher frequencies
P92 his vision will be blurry
P94-95
Pendulums
-shrinking length of pendulum decreases period or increases frequency
P95 Henry Pym shrinks 300 times
-increases frequency 17 times ( 300 )
P95 normal human speech is ~200 cycles/second
-Ant-Man would be 17X this (3,400 cycles/s)
-normal range is 20 to 20,000 cycles/s
P96 resonant frequency of eardrum rises as its diameter shrinks
P96 since lowest pitch a normal human can hear is 20 cycles/s, at 17X larger, it is 340
cycles/s for Ant-Man
-normal speaking is below this at 200 cycles/s
-Ant-Man can’t hear this speech
P96-97
Because of shrinking, Ant-Man’s voice will not forcefully move air
-the volume of his speech will be low
-conversely, normal sounds for a human would be too loud for him to distinguish
P97 Ant-Man’s vision will be blurry
-visible light ~500 nm
-normal pupil 5 cm (10,000X larger than light)
-Ant-Man’s pupil 300X smaller (30X larger than light)
-light will diffract (like water waves diffracting between docks)
-vision will be blurry (out of focus) as a result
P99 smell is least sensitive sense, and least affected by shrinking
Chapter 10: Does Size Matter?-The Cube-Square Law
P101 Henry Pym developed a growth potion and became Giant-Man (Goliath) in Tales
to Astonish #49
P102 being larger means more light could enter larger pupils and you’d have to wear
protective goggles
P102 also, can only be a certain size because of strength of bones
P103 sometimes scientists have to make simplifications in order to understand nature
P104 assume Giant-Man is a cube (cylinder is a more accurate approximation, but the
math is more complicated)
-each side has length, L
P104 doubling each side makes the volume 8X larger
-sides 10X longer makes volume 1,000X larger
P104 to keep same density as he grows, mass must increase by same factor as his
volume (NOT length)
-get too large, and his bones will break
P104 ability to withstand being pulled apart or crushed is tensile strength
-depends on cross-sectional area
P105 think of fishing line rated at 20 lbs
-more length will not lift more weight
-only a thicker line will lift more weight
P105 apple trees (and other trees) make use of this for reproduction
-apple becomes too heavy
-stem breaks and apple falls to ground
-eaten by animals and seeds then taken to new locations
P105 this limits how far Mr. Fantastic (Reed Richards) of the Fantastic Four can stretch
-cannot extend length of body beyond 500 yards (Fantastic Four Annual #1)
P105-106
Mr. Fantastic’s muscles become weaker the further he stretches
-consider a 6 ft 2x4 board supported at each end: it won’t sag much in the middle
-however, a 60 ft 2x4 board supported at each end would sag a lot in the middle
-my note to self: like my “Strong-Man Demo” with a brick on a string
P106 As Henry Pym grows into Giant-Man, his volume increases faster than his crosssectional area
-volume and mass increase as the cube of the growth factor
-cross-sectional area (and bone strength) only grows as the square of the growth
factor
P106 assume Henry Pym is 6ft tall and 185 lbs
-femur can support 18,000 lbs
-vertebrae can support 800 lbs
-femurs of elephants and dinosaurs thicker and denser than human femurs
P106 at 60 ft tall, Giant-Man’s growth factor is 10
-weight and volume would be 1,000X greater (185,000 lbs)
-cross-section of bones would be 100X greater
-femur can support 1,800,000 lbs but vertebrae could only support 80,000 lbs
-since his weight would be greater than the breaking strength of his neck, his neck
would break!
P107-108
Cube-square law applies to bubbles rising in a fluid like Coke
-volume (and buoyant force) depends on r3
-resistance depends on surface area which depends on r2
-bubble would accelerate to top of liquid
-if glass was tall enough, bubble would reach terminal velocity
Section 2: Energy-Heat and Light
Chapter 11: The Central City Diet Plan-Conservation of Energy
P111 How often does the Flash need to eat?
P112 ‘”energy” is a measure of the ability to cause motion’
P113 Conservation of Energy
-pendulum example
P114 as a car travels 1 mile, it must move 1 ton of air out of the way
P115 the smaller the surface area of a car, the greater its fuel efficiency if the mass is
the same
P115 all the energy of the universe was present at the Big Bang
-volume was smaller than an electron
P115 within the first second after the big Bang, energy density had dropped enough for
matter to form (E=mc2)
-protons and electrons
-like cooling water forming crystals
P116 in 1997, scientists collided high-energy gamma rays and created electron/positron
pairs
P116 nobody really knows what energy is or where it came from
P116 work is performed when a force acts on an object over a certain distance
-changes kinetic energy
P116 for a falling mass, work=mgh
P118 in Flash #106, the Flash needed to stop chasing an object moving at 500 mph
-stops in 15 feet
-W=Fx
-F=80,000 lbs!
1
P119 KE= mv 2
2
-the Flash’s caloric requirements increase as the square of his velocity
P119 if the Flash’s mass is 70 kg and he runs at 1% of the speed of light (not near his
top speed)
-75 trillion calories
P120 to a physicist, 1 calorie is defined as the energy needed to raise the temperature of
1 gram of water by 10 C
P120 the food calorie = 1,000 physics calories
-divide the Flash’s 75 trillion calories by 1,000
-still needs 75 billion Food Calories
-would need to eat 150 million cheeseburgers (probably twice as much as ½ our
caloric intake goes into maintaining metabolic functions)
P120 if the Flash stops running, and wants to go this fast again, he needs to eat this
amount again!
P123 the helium nucleus weighs 99.3% of the mass of 2 deuterium nuclei (proton +
neutron) [E=mc2]
-if it was 99.2%: too much energy would be released
-all protons in the early universe would have formed He nuclei and no fuel
would have been left for stars
-if it was 99.4%: deuterium would not form
-fusing of He could not proceed; stars would shine too dimly to synthesize
elements or form supernova explosions to produce and spread heavy
elements
P124 oxygen needed to release energy in food
P124 for elite runners: 70 cm3 of O2 per kilogram of runner mass is used per minute at a
pace of 6 minutes per mile
-if Flash is 70 kg, he uses 30 liters of O2 per mile
-would have to run 10 m/s for 500 billion years to use up O2 in Earth’s
atmosphere
P125 the Flash carries a bubble of air around him
-“no-slip zone” in fluid mechanics
P125-126
Laminar flow in pipes (all fluid moving in same direction)
-ring closet to pipe wall slowest; fastest in middle
Chapter 12: The Case of the Missing Work-The Three Laws of Thermodynamics
P129-130
Ray Palmer, a physicist, became The Atom when he discovered a chunk of white
dwarf star
-can shrink to smaller than an electron
-can independently change size and mass (density not constant)
P130 The Atom was normally 180 lbs. (82 kg) and 6 ft tall
-if he reduces to 6 inches, he is 12 times smaller
-his volume decreases 1,728 times (12x12x12)
-if he had constant density, mass would be 47 grams (however, he is able to keep
is full weight by using a control on his belt)
P131-132
Could reduce mass to be carried by hot air currents
P133 ‘”heat” describes any exchange of energy without the system performing work’
P133 First Law of Thermodynamics-‘any change in the energy of an object can only
come about by either a transfer of heat or the performance of work’
P134-135
In the comic Atom #2, the Atom is pushed upward and warmed by the hot, rising
air from a fire
-‘net change in the Atom’s total energy is the sum of the heat flow and the work
done on him’
P138 entropy describes the number of different ways a system can arrange itself
-a new deck of cards, arranged in numerical order by suit has low entropy
-thoroughly shuffled deck has high entropy (hard to know which card is next)
P138-139
2 rooms-one filled with air, and the other a vacuum with the door between them
closed
-some air pushes on door; if door unlocked, air will push door open into the
vacuum room
P140 car engine-only exploding gasoline molecules headed toward the top of the piston
will move it and do useful work
-other molecules are wasted energy and do no work
-this is the Second Law of Thermodynamics
P140 2nd Law of Thermodynamics-no process can be 100% efficient
P140-141
Blowing on your hot coffee blows off most energetic molecules so that the
average KE decreases (temperature drops)
-evaporative cooling
P143 the Third Law of Thermodynamics-the entropy is zero only when the temperature
is zero
-no atomic vibrations at zero degrees Kelvin
-temperatures above zero give the atoms KE so they can arrange themselves in
many ways
P143 only way to beat 2nd Law of Thermodynamics is to use systems with zero entropy
-only occurs at zero degrees Kelvin
-but at zero Kelvin, no heat flows to power engines; therefore, there is no way to
get around 2nd Law of Thermodynamics
P144 Brownian Motion (Robert Brown)-pollen grain darted back and forth in a water
drop
-Einstein explained in his 1905 PhD dissertation paper
-related to temperature of the medium
P145 random motion of air on your eardrums produces deflections at the threshold of
hearing
-can hear air bombarding your eardrums if in a very quiet room
Chapter 13: Mutant Meteorology-Conduction and Convection
P146 Bobby Drake appeared as Iceman in X-Men #1
P146-147
Iceman lowered his body temperature to below 320 F so water condensed on him
and froze
-heat he subtracts from surroundings when water freezes must be deposited
somewhere…where does it go in his case?
P147 refrigerators remove heat from inside and dump it out the back
-warm up room by leaving refrigerator door open: struggles to cool down so
motor will work harder and dump more heat out the back and into the kitchen,
warming the air
P147 when water vapor condenses, it warms the surrounding air
-this less dense, warmer air keeps clouds afloat
P148 water molecules will form a hexagon with each other
P148 conduction is when molecules diffuse from a high temperature region
P148-149
Water molecules in cloud display Brownian motion
-random walk
-outer edges of snowflake grow faster than inner region because they are closer to
other water molecules
P149 Iceman traveled by creating unsupported ice slides
-not physically possible; would collapse once he went beyond center of mass
P150 to see this, slide a book to edge of table
-all on table: ok
-some hanging over, but most on table: ok
-up to midpoint: ok
-more of book overhanging than is on the table: torque rotates book and it falls
P151 original 1960-1970 X-Men not very successful
P151-152
All New, All Different X-Men created in 1975 introduced Ororo Munroe (Storm),
Logan (Wolverine), Peter Rasputin (Colossus), and Kurt Wagner (Nightcrawler)
was popular
P153 cold air sinks because it has low KE and is pulled to the ground by gravity
P153 hot air rises because it has a high KE and can scatter off of other molecules into
the region vacated by the cool air
P154 this is convection
P154 convection is efficient at transferring energy
P154 double-paned windows prevent convection rolls in a room
P154-155
cold air is dense and therefore has less room to hold water molecules
P155 if Storm can control the local temperature, she could control pressure and
humidity as a result
-rain or snow, even lightning
Chapter 14: How the Monstrous Menace of the Mysterious Melter makes Dinner
Preparation a Breeze-Phase Transitions
P158 Iron Man (Tony Stark) debuted in Tales of Suspense #39
P159 Bruno Horgan (The Melter) had a melting ray he tried to use on Iron Man
P161 the Flash could escape being entombed in ice from Captain Cold by vibrating
back and forth-imparts KE to ice
-100,000 times/second over a distance of ½ inch gives 35 million Joules of energy
1
(kg m2/s2) because of mv 2
2
-melting ice requires 336 J/kg (Flash can melt 100 kg of ice)
P161-162
electrons in atoms may not be perfectly distributed around it
-charge imbalance allows an external electric field to influence it
P162 atoms will line up with this field
-switching field back and forth 1800 causes all atoms to rotate
-heats whole material more efficiently than conduction
P162 microwave emitters (magnetrons) were developed for radar use in WWII
P162 engineer Percy L. Spencer discovered its cooking application in 1945 when a
candy bar in his pocket melted near a magnetron
P162 make an “ice cup” and fill it with water
-place in microwave
-can boil water inside while cup stays frozen
-demonstrates that liquids are more easily vibrated and rotated than solids
P164 new weapons tuned to the resonant frequency of water are being used for crowd
control
-heat makes people want to move away from area
P164 you can put metal in a microwave oven
-electrons in metal will flow
-charge builds up at sharp edges
-creates new electric field in object
-if field is > 12,000 volts/cm, spark can result
Chapter 15: Electro’s Clinging Ways-Electrostatics
P166 almost all forces we experience, other than gravity, are electrostatic
P166-167
Examples of electrical forces:
-force of muscles
-force of chair pushing you up (support)
-force of hot gases in car cylinder
P168 Max Dillon became the villain Electro in Amazing Spider-Man #9
-struck by lightning
-could store and discharge electrical energy
P168-169
had to recharge at city power stations
-he was a rechargeable taser gun
P170 attractive force between protons and electrons roughly cancels out repulsive force
between electrons in atoms
-uranium about same size as carbon
P170 Coulomb’s Law
- F=k[(charge 1)x(charge 2)]/(distance)2
-17th Century French scientist Charles Coulomb
P171 k is much larger than G
P171 proton and electron have same magnitude of charge but proton about 2,000 times
more massive
-force of electrostatic attraction actually 10 thousand trillion trillion trillion times
stronger than gravity (1x1040)
P171 at this time, we only know of positive mass and attractive gravity
-some astronomical observations point to ‘antigravity’ and ‘dark energy’ although
this is controversial
P172 if a second electron is brought near an electron orbiting a proton, the second
electron will reach a point where it has no net force acting on it (attraction to
proton cancelled by repulsion of electrons)
-this is analogous to the idea of gravitational levitation except there is only one
type of mass (positive)
P172 the Flash should pick up a lot of electrons when he runs
P172 walk across the carpet in dry conditions and you pick up electrons
-spread across whole body
-they repel each other and look for a way to leave
P172-173
driving a car picks up charge and then discharges when you touch the door handle
-is painful because the surface area of your finger is small (current/area is large)
-better to touch with forearm or elbow
-fingertips have a lot of nerve endings
P173-174
Swiss engineer George de Mestral investigated why burrs clung to his pants on
hikes
-invented Velcro
P174 geckos can climb walls and ceilings because of millions of microscopic hairs on
its toes called setae
-static cling
-charge fluctuations in setae induce opposite charge in wall
-van der Waals force
-each hair supplies a small force
P174 2002 movie Spider-Man showed Peter Parker had microscopic barbs growing
from his fingers
P174 University of Manchester in England has developed ‘gecko tape’
-millions of tiny fibers
-fibers must be small to maximize surface area to volume since only outer surface
contributes to force
Chapter 16: Superman Schools Spider-Man – Electrical Currents
P176 the pull exerted on electrons in a wire is called voltage
P177 electric field greater than 12,000 volts/cm needed to make electrons jump gap in
air
P177 an object will not discharge if all the surrounding objects have the same charge
P178 electrons will not flow through a wire with a voltage across it unless it is
connected to something
-think of a brick held over your head: keeps its potential energy stored until you
let go and it can fall
P178 2 points must have different electrical potential for current to flow and there must
be a ground
-water will flow between 2 faucets connected by a hose as long as they have
different water pressures and the lower pressure faucet can dump its excess water
down a drain (ground)
P178-179
Superman #1 got it right
-birds on 1 wire are safe (same potential)
-touch 1 wire and a pole or 2 wires at different potential and you will get shocked
P180 Amazing Spider-Man #9 got it wrong
-chair thrown over Electro’s head will not attract his lightning bolts like the comic
showed
-chair not connected to anything so a current can’t flow
P180 Amazing Spider-Man #1 has Spider-Man tying a metal wire to his ankle before
fighting Electro
-this grounds Spider-Man
-allows current to flow through him: bad idea!!!
P183 in Amazing Spider-Man #9, Spider-Man douses Electro with water
-tap water has ions
-ions conduct electricity
-allows charge to drain off Electro
Chapter 17: How Electro Becomes Magneto when he Runs-Ampere’s Law
P184 in Amazing Spider-Man #9, Electro climbed up a building by creating magnetic
fields in pipes
P184-185
This is the Ampere Effect
-discovered by Hans Christian Oersted
-named after Andre-Marie Ampere
P185 a charge either attracts or repels other charges: there is a ‘”zone of force”’ around
a charge
-called electric field
P185 a charge in motion creates a magnetic field
-wire with a current deflects a compass needle
-discovered by Oersted
P185 2 current carrying wires will attract or repel
P186 the charges must be in relative motion for the magnetic effect to be observed
P186 2 charges moving in same direction at same speed:
-no relative motion: just electrostatic force present
-for a stationary observer in the lab, there is relative motion: observer sees
magnetism as well as electrostatic force
P186-187
Special Theory of Relativity explains why magnetism results from moving
charges:
-imagine 2 parallel train tracks: one is + and the other is –
-a + test charge placed between the tracks will experience no net force
-tracks now move at the same speed in opposite directions and the + test charge
moves in the same direction and with the same speed as the + track: magnetism
results
-from the test charge’s point of view, the spacing between the – charges in the
other track is length contracted so the distance between the + and – charges in the
tracks are not the same: a net force results (we call this magnetism)
P187 Flash should build up a large charge (because of friction) as he runs at high speed,
and therefore a large magnetic field, but he doesn’t because of an ‘aura’ around
him that the extradimensional imp Mopee gave him
P188 magnetic field created by a moving charge = (electric field)/(speed of light)
P188-190
In Superboy #1, Superboy wrapped miles of wire around a train locomotive, ran a
current through it, and used it as a giant electromagnet to capture crooks who
were driving around in army tanks
Chapter 18: How Magneto Becomes Electro When he Runs-Magnetism and
Faraday’s Law
P191 the first villain the X-Men encounter is Magneto in X-Men #1
P191 Special Theory of Relativity is also responsible for magnetism of a stationary
chunk of iron
P191-192
Quantum Mechanics is responsible for the intrinsic magnetic field of sub atomic
particles
-the Relativistic version of Quantum Mechanics
P193 Hematite (Fe2O3) is nonmagnetic
Magnetite (Fe3O4) is magnetic
-both forms of rust
P193-194
only a small fraction of your blood (hemoglobin) is magnetic
-in the movie X-Men 2: X-Men United, Magneto escaped from his plastic jail cell
when his accomplice Mystique injected a magnetic metal in the guard’s blood
P195 iron can be nonmagnetic
-domains-regions where the atoms’ magnetic fields point in same direction
-entropy dictates that the domains should be pointing in different directions
-heat up iron (thermal energy allows atoms to rotate) and then place it in a strong
external magnetic field-the iron domains will align with the external field and
leave the iron as a permanent magnet
-hitting the iron can randomize the domains and make it nonmagnetic
P195-196
Ferromagnetic-domains line up in same direction
-iron
Paramagnetic-atoms will align in a strong magnetic field, but will randomize at
room temperature when the field is removed
-molecular oxygen
-gaseous nitric oxide
-aluminum
Diamagnetic-atoms line up opposite to an external field and tend to cancel out the
external field
-water molecules (and humans since we’re composed of a lot of water)
P196 if Magneto supplies a field to a person that is 200,000 times greater than the
Earth’s magnetic field (100 times larger than a refrigerator magnet’s field), then
the diamagnetic water molecules in a person will line up opposite to Magneto’s
field and the opposite magnetic poles will repel (levitation!)
P196 High Field Magnetic Laboratory at the University of Nijmegen in the Netherlands
has movies/pictures on its website (http://www.hfml.ru.nl/) of floating frogs,
grasshoppers, tomatoes, etc.
P197 only 3 elements are magnetic at room temperature: Fe, Co, Ni
-limits Magneto’s powers unless he wants to use an incredible amount of effort to
affect paramagnetic and diamagnetic metals
P197 Magneto has easier control over electric currents than doing the above
P197 relative motion causes magnetic fields to create electrical currents
P197-198
Move a magnet toward a stationary wire with no current flowing through it
(hence, no magnetic field)
-however, from the magnet’s point of view, the wire is moving toward it
-since the charges are now in relative motion, they create a magnetic field that
will interact with the magnet’s field
-this creates forces on the charges, and they move (a current has been created!)
P199 Faraday’s Law-when a magnetic field passing through the plane of a coil of wire
is changed, a current is induced in the wire (Michael Faraday)
-induced current travels in a direction so that its magnetic field opposes the
changing external field (Conservation of Energy)
P200-201
all sources of power (coal, oil, nuclear, or bio-mass) except hydropower and
geothermal can be traced back to the sun or stars (photosynthesis and the creation
of heavy, radioactive elements)
-(I’d argue that geothermal is related to the stars as well because of the heat
coming from radioactive decay in the Earth’s interior)
-writers of Superman did change his power source from Krypton’s strong gravity
to the light from our sun
Chapter 19: Electro and Magneto Do the Wave-Electromagnetism and Light
P202-203
In 1862, Scottish physicist James Clerk Maxwell linked electricity and magnetism
-Maxwell’s Equations (combined the laws of Coulomb, Gauss, Ampere, and
Faraday)
P203 voltage = (current)x(resistance) : Ohm’s Law
-car jumper cables are short and thick so current from the one battery is not
wasted by resistance by the time it reaches the 2nd battery
P204 consider a charge swinging at the end of a pendulum
-this is a current with changing speed
-creates a magnetic field that also changes in magnitude
-this changing magnetic field creates an electric field in phase with it
-pendulum will slow down since the waves created carry away energy
-oscillating electric and magnetic fields are called light
P205 at room temperature, atoms and their electrons vibrate at 1 trillion cycles per
second-infrared radiation
P205 atoms in a lightbulb filament must be vibrating at a thousand trillion cycles per
second to emit visible light
P205-206
Sun burns 600 million tons of hydrogen each second
-part of the released energy goes into the KE energy of the resulting He nuclei
-He nuclei emit electromagnetic radiation as they accelerate
-sun is so dense it takes 40,000 years for light from the core to reach the surface
as it random walks
P207 nerve cells process information by transmitting and altering electrical currents
with ions of Ca, Na, and K
-an accumulation of ions in one part of the brain produces an electrical field that
causes other ions to move
-these moving ions create a magnetic field
P207 researchers have placed sensitive electrodes in the brain and have detected the
electric fields produced by the flow of ions
P208 very low frequency and weak (over 1 billion times less power than the radio
waves that surround us) electromagnetic waves travel outward from the brain
whenever electrical activity happens
-can only be detected if a probe is directly placed on the head
P208 Magneto wears a metal helmet to shield ingoing and outgoing electromagnetic
waves so his thoughts can’t be detected or altered
P209 Prof. X uses an amplifier called Cerebro to magnify the signals he is sending if
trying to reach a distant X-Men member
-like radio stations broadcasting in megawatts
P210-211
Prof. X possibly communicates as described in X-Men comics because it is
similar to radio or TV broadcasts
Section 3: Modern Physics
Chapter 20: Journey into the Microverse-Atomic Physics
P215 Victor von Doom was expelled from college when one of his science experiments
went wrong, blew up the lab, and scarred his face (Reed Richards, aka Mr.
Fantastic, attended same college during this time)
-became Dr. Doom
P216 actually did not receive his PhD yet called himself Dr. Doom
P216 became the dictator of a small European country called Latveria
P216 Dr. Doom often ended up lost in space, trapped in other dimensions, or stuck in
time
P216 in Fantastic Four #10, Doom was shrunk to nothingness
-in Fantastic Four #16, the Fantastic Four learns Doom entered a “micro-world-a
world that might fit on the head of a pin”
In Fantastic Four #76, Reed, Ben, and Johnny traveled to the microverse (a stain
on a microscope slide in Reed’s lab)
P216 the diameter of this world would be ~ 1mm
(Earth’s diameter is 13,000 km): this is 13 billion times smaller than Earth
P217 microworld would have to be white-dwarf-star matter, but the fact that the
characters walked around on it without difficulty refutes this
-microworld not realistic
P217 the Atom found a world within an atom in Atom #5
-smaller than an electron
-can’t explain this
P218 ‘”matter waves”’ associated with the electron’s motion are within the atom
P218-219
In the 1800s, scientists made these 2 observations about light emitted from hot
objects:
1) the amount of light emitted at a certain wavelength only depends on the
temperature
2) the total amount of light emitted was finite and only depended on the
temperature
-this led to the development of Quantum Mechanics
P219 Conservation of Energy explains why light from a hot object only depends on its
temperature
-“If two objects made of different materials at the same temperature emitted
different radiation spectra, there would be a way to have a net transfer of energy
between them and hence useful work, without any heat flow.”
-would violate 2nd Law of Thermodynamics
P219 we use the fact that the emitted light spectrum only depends on temperature to
measure the temperature of the sun (11,0000 F) and the microwave background
radiation of the Big Bang (3 K)
P219 Maxwell’s Equations correctly predicted the amount of light emitted at low
frequency, but failed at high frequency
-the “ultraviolet catastrophe”: predicted infinite intensity at high frequency-would
violate Conservation of Energy
P220 Maxwell’s Equations had worked well every other time, so scientists weren’t
concerned; just thought problem was in how they applied his equations to
vibrating atoms in a glowing object
P220 in 1900, Max Planck determined the mathematical equation that matched the
experimental data
-then tried to find a physical basis for it
-only explanation was to put restrictions on the energy of atoms
-electrons could only have certain energies
-called theory Quantum Mechanics from the Latin word for “how much”
-separation between adjacent energy levels is less than 1 million trillionth of a
Joule
P220 Planck introduced the constant “h” into his formula
-energies could only be E=nhf where n is an integer and f is the frequency
P221 Planck didn’t like his “h” constant, so he tried making it zero, but when he did, he
obtained the same infinite energy result others had
- h = 660 trillionth trillionth trillionth kg(m2/s) {Js}
-too small to affect large objects
P221 imagine if h were larger:
-we could drive a car at only 40, 50, 60 mph, etc., but no speeds in between!
-this would require instantaneous, HUGE accelerations!
-great harm to passengers
-this is how bizarre Quantum Mechanics is!
P221-222
We can understand why only certain energies are allowed if we accept that “there
is a wave associated with the motion of any matter, and the greater the momentum
of the object, the shorter the wavelength of this wave.”
P222 in 1924 Louis de Broglie proposed “matter-waves”
-  depends on momentum
-called “wave function” by physicists
-not a physical wave
-can interfere
-physicists not sure what they are
-unless moving near the speed of light, momentum can be calculated by the
formula: (mass)(velocity)
P223 momentum represented by “p” (Kakalios doesn’t know why it’s p either)
P223 matter-waves experimentally verified in 1926 by Clinton Davisson and Lester
Germer
P223 p  h
P223 a baseball moving at 100 mph has a p = 6 kg(m/s), and a   1 trillionth trillionth
the width of an atom
P223 the matter-wave of an electron is about the size of an atom
P223-224
when the Atom shrunk to the size of an atom, he was smaller than visible light
wavelengths so his normal vision could not work
P224 matter-wave of electron must fit completely around the atom
-because  is related to p, p can therefore only have certain values
p2
-p is related to KE ( KE 
), so therefore only certain energies are allowed 
2m
P225 when an electron makes a transition from a higher energy level to a lower energy
level, it makes a “quantum jump” and the energy must be given off
-a photon
-concept of photon introduced by Einstein in 1905
-name not given until 1926 by Gilbert Lewis
P226-227
when matter-waves of 2 atoms interact, a new lower energy wave can form and a
chemical bond results
P227 idea of orbits can’t be correct because the electrons would accelerate in their
curved paths and therefore radiate away energy
-would spiral into nucleus in < 1 trillionth of a second and no atoms would exist
Chapter 21: Not a Dream! Not a Hoax! Not an Imaginary Tale! – Quantum
Mechanics
P229 in Showcase #4, Barry Allen was reading Flash Comics #13 (Golden Age FlashJay Garrick) before he was struck by lightning and became the Silver Age Flash
-Golden Age Flash was just a comic book character in Barry Allen’s reality
-this changed in September 1961 in The Flash #123
P229-230
In this issue, titled “Flash of Two Worlds”, it was disclosed that both the Golden
and Silver Age Flashes were real, but existed on parallel Earth’s, separated by a
“vibrational barrier”
P230 Barry Allen vibrated at super-speed at exact frequency needed to cross barrier
-said 2 objects could occupy same space at same time if they vibrated differently
P230-231
This was wrong
-no 2 objects can occupy same space at same time
-however, massless objects like photons can be in same place at same time
P231 Silver Age Earth was Earth-1; Golden Age Earth was Earth-2
-comic book readers’ world was Earth-Prime
-comic book characters were all fictional to readers
P232 there were so many cross-overs and universes, it became too difficult to follow
P232 in 1985, DC launched Crisis on Infinite Earths to rid themselves of unpopular
ones on Earth-1
-killed off the Silver Age Flash Barry Allen and Supergirl
-Superboy removed from Superman’s history
P232-233
Some scientists believe in parallel universes
-a slight change in a person’s history leads to a divergent world that can’t be
visited
P233 classical mechanics-if you know all the forces on an object, then you can predict
the stable configuration of an object (ladder leaning against a wall) and its motion
-F=ma
-For large objects: gravity, friction, and electrostatics
P233 for electrons and atoms, F=ma doesn’t work
-Quantum Mechanics needed
P233 after about 25 years of trying to tweak Newton’s 2nd Law to work with atoms,
Werner Heisenberg and Erwin Schrödinger almost simultaneously developed
the correct form of F=ma for atoms
P234 Heisenberg used linear algebra (matrices) and Schrödinger used complex partial
differential equations
P236 Schrödinger Equation describes how matter-waves evolve in space and time
-could understand interaction of atoms with light
P236 things made possible by the Schrödinger Equation:
1) transistor 2) laser 3) nuclear fission (atomic bombs and nuclear reactors)
4) nuclear fusion (hydrogen bombs) 5) CD player 6) personal computer
7) cell phone 8) DVD player
P237 Schrödinger Equation:
2  2


 V ( x , t )   i
2
2m x
t
P238 if you know the potential energy of an electron, V, then you can calculate the
probability per volume  2 of finding the electron at a certain point in space and
time
-then you can calculate the average location and momentum
P239 Why does the wavelength nature of particles limit us to averages?
-imagine a vibrating violin string that is vibrating so fast we can’t see it
-we can determine it is vibrating by touching the string
-but touching it will change its vibrational frequency
-holding finger close to string will feel vibrating air, but the air will bounce from
your fingertip back to the string and alter it
-holding finger far from string will lead to a faint detection of the vibration so you
won’t have the best measurement of it
P240-241
Schrödinger’s Cat thought experiment:
-cat in a box with a poison that will be released when a radioactive isotope decays
(half life of 1 hour)
-after 1 hour when you look in the box, the cat is either alive or dead
-before looking inside, the cat is an average of alive and dead
-once you look, the wave function collapses and you see either a live or a dead cat
-experiments suggest this occurs as described
P241 in 1957 Hugh Everett III proposed the Many Worlds Interpretation of Quantum
Mechanics
-each time a quantum process has 2 or more possible outcomes, the universe splits
that many times and they evolve separately
P241-242
Therefore, Earth-2 and Earth-1 and so forth are possible, but no communication
between them is possible
P242 few physicists like the Many Worlds Interpretation
-however, string theorists like it
P243 Quantum Electro-Dynamics (QED)-describes how electron’s wave function
interacts with electric and magnetic fields
Quantum Chromo-Dynamics (QCD)-describes how the wave function of quarks
behave
Don’t have a theory of how matter-waves interact with gravity
P243 closet we have come to a quantum theory of gravity is string theory
-strings are the fundamental building blocks
-mass is a vibration of a string
P243 many physicists aren’t convinced string theory is correct
-equations only work in 11 dimensions (10 space and 1 time)
-string theorists argue that 7 space dimensions curl up into little balls with
diameters < 1 billionth trillionth of a cm (Planck length)
-such small scales require large energies to probe (nothing current or planned can
reach these energies)
-can’t be verified
P244 Many Worlds Interpretation used to resolve conflicts with time travel
-so you can’t go back in time and kill your grandparent-if you could travel back in
time, you’d travel into a parallel universe
P244-246
in Superman #146, Superman travels at great speed to break the “time barrier”
and save Atlantis
p244-246
in a 1961 Superman comic, he travels through time to save Lincoln, Custer, etc.,
but returning to Earth, finds the history books are unchanged
Chapter 22: Through a Wall Lightly – Tunneling Phenomena
P249 Schrödinger Equation predicts matter can pass through barriers
-Kitty Pryde of the X-Men
-Flash vibrating through walls
P249 picture 2 handball courts-fenced on 3 sides each and sharing a concrete wall
between them-you’re in court 1
-high probability of being in court 1
-small probability of being in court 2 (not zero, so it is possible)
P250 this process is called tunneling
-no hole is created
P251 higher velocity increases probability of tunneling
-might be how Flash tunnels through walls
P251 2 metals separated by a vacuum
-electron in one metal has a small but nonzero probability of being found in the
2nd metal
-electron does not jump gap or have enough KE to leave 1st metal
-the electron wave function extends into the gap and decreases in magnitude the
further it extends
-small occurrence: maybe 10,000 out of 1 million
P252 electrons in a solid vibrate at 1 thousand trillion times per second
-have 1 thousand trillion chances to tunnel
-send enough electrons toward a barrier and if it isn’t too high or too wide, a
number of electrons get through
-principle behind Scanning Tunneling Microscope
P253 metal tip placed close to atoms so the electron clouds of the atoms overlap with
the tip
-electrons tunnel into tip
-current is detected
-by mapping the current, you map the locations of the atoms
P253-254
Graphite has carbon bonded into hexagons
-lays in sheets that slide past each other
-if it had 4 bonds (like diamond) it would peel off easily onto paper
P254 transistors-amplify and regulate the flow of current
-2 conductors separated by an insulating layer
-apply voltage across barrier to change the ‘height’ of the barrier
-tunneling occurs
-solid-state devices including cell phones use transistors
P254 Kitty Pryde mass 50 kg: would take longer than the age of the universe to tunnel
through wall
P255 why doesn’t Kitty Pryde fall through the floor when tunneling?
-in X-Men #141 it was stated she doesn’t actually touch the floor
-but question remains how a partially material foot can follow her through the
wall
-quantum mechanical tunneling gives answer: energy is conserved-must have
same amount on both sides of the barrier
-can’t fall through the floor-would increase energy
-can’t slow down-would lose energy
Chapter 23: Sock it to Shellhead – Solid-State Physics
P257 the basis of Iron Man’s powers is the transistor
P257 transistor initially replicated role of vacuum tubes, but were lighter and more
efficient
-ability to do mathematical calculations lead to development of computers
P257-258
An alien Green Lantern crashed on Earth in Showcase #22, his power ring found
Hal Jordan to take his place
-Fantastic Four created in 1961 when a scientist, his girlfriend, her younger
brother, and a former fighter pilot took an unauthorized space flight and were
Exposed to cosmic rays
-Hulk created when Dr. Robert Bruce Banner’s assistant (a Communist) didn’t
stop the countdown on a bomb test and Dr. Banner was exposed to gamma
radiation
P258 Iron Man (industrialist Tony Stark) introduced in Tales of Suspense #39
-used his knowledge of transistors to build weapons for the US to beat the
Communists in Indochina
P258-259
Tony Stark travels to Vietnam to witness how well his weapons work
-a boobytrap leaves shrapnel in his chest close to his heart
-captured by Wong-Chu (Communist guerilla)
-Wong-Chu offers him life-saving surgery if he’ll develop weapons for him
-Tony develops a metal chestplate and suit of armor containing transistors
-offensive and defensive weapon
-chestplate keeps shrapnel from entering his heart
-defeats his captures and returns to US
P259 Iron Man continually battled Communism
P259 Tony Stark maintained Iron Man was his bodyguard
P260 transistor developed by 3 physicists at Bell Labs in New Jersey in 1947
P260 Iron Man’s suit was originally gray (Tales of Suspense #39)
-changed to gold in next issue (Tony thought it would attract women)
-within a year, it was the familiar red and yellow
P261-262
How much does Iron Man’s suit weigh?
-assume 1/8 inch thick suit and the density of Fe (8 g/cm3)
-assume arms, legs, trunk, and head are cylinders
-assume Tony is 6 ft tall and wears a size 50 suit jacket
-surface area ~ 26,200 cm2
-volume ~ 8,400 cm3
-weight ~ 68,000 grams (148 lbs)
P262 since Iron Man’s total weight is about 330 lbs (148 lbs + 180 lbs), his jet boots
must supply 330 lbs of thrust just to hover
P262 Tony often flew from Stark Industries in Long Island to Avengers Mansion in
Manhattan (50 miles away) in 10 minutes
-300 mph
-1.37 million kg (m2/s2) =1.37 million Joules
An average person uses 8 million J during a whole day
P263 Iron Man often used motorized roller skates built into his boots
-could recharge batteries when he decelerated by using an alternator (like hybrid
cars)
P263 in 1970s, Iron Man put solar cells in his suit
-in US, average energy from the sun is 200 J/s over an area of 1 m2
-solar energy hitting his suit per second is 262 J
-even if his solar cells are 50% efficient (most are only 10% efficient), he’d need
3 hours of sunlight to charge batteries for his 1 trip (ignores air conditioning and
repulsor rays)
P263-264
Writers of Iron Man were aware of Conservation of Energy
-in Iron Man #132, he totally drained all the energy from his suit when he
knocked out the Incredible Hulk
-couldn’t move and eye and mouth openings on mask closed (would suffocate if
they stayed closed)
-Ant-Man had to crawl into Iron Man’s suit and open faceplate coverings from the
inside
P266 the magnetic repulsor rays of Iron Man would only work if the object he was
trying to deflect had a magnetic field, and if that field had its south pole pointing
at his north pole, or vise versa
P266-267
Iron Man’s repulsor rays would work against diamagnetic materials
-by putting the rays in his gloves and using servo motors in the arms of his suit, he
is able to handle the large recoil force the rays produce
P267 pulsed energy weapons under consideration by military
P269 electrons can only absorb energy if there is an empty state at higher energy
P269 metals are good conductors because they have many available higher levels
P269 insulators do not have higher available spots
P270 if the temperature of an insulator is raised, some electrons gain enough energy to
rise to a higher energy level
-also if it absorbs light
P270 when the electron returns to its lower energy level, it can give off light or cause
vibrations (heat)
P270 windows (insulators) are transparent because the energy separation between the
highest filled level and the lowest unfilled level is in the ultraviolet part of the
spectrum
-visible light (lower energy) passes through
P270 metals always have available empty levels
-can always absorb light
-give the light back when electrons return to lower level
-makes metals shiny
P270 a semiconductor is an insulator with a small energy gap between the filled level
and the closest empty one
P270-271
Because of this small energy gap, a certain amount of electrons will jump to the
higher level because of the room temperature
-promoted electrons can conduct electricity
-electrons leave behind a “hole”-a positive charge: can also conduct current
P271 when some semiconductors absorb light, enough electrons get excited to higher
levels (and in turn “holes” are created) that it becomes a good conductor
-called photoconductors
-used as light sensors
-used in some smoke detectors, TV remotes, automatic door openers in grocery
stores
P271 semiconductors made of Si because its energy gap is just below the range of
visible light
-Germanium or gallium arsenide added to improve performance
P271 Iron Man’s and the military’s night-vision goggles are semiconductors with
photoconducting properties in the IR portion of the spectrum
P271 human’s emit 100 W of IR radiation
P272 semiconductors in night-vision goggles detect IR radiation
-this creates a photocurrent
-photocurrent directed to adjacent material which gives off visible light when the
photoexcited electrons and their holes recombine
P272 all objects give off same intensity of light if they are at the same temperature
-why these goggles only work at night when the surroundings are cooler
P272-273
Sue Storm (Susan Richards)-the Invisible Woman-became transparent by being
able to increase the energy gap of all the molecules in her body into the UV part
of the spectrum
-visible light will be ignored and pass through
-like the lens of your eye
P273 Sue still absorbs and reflects UV light, but we can’t see it
-Dr. Doom used UV-vision goggles built into his mask to detect her
P273 when invisible, the Invisible Woman can detect (see) UV light scattered off
objects
-windows will appear as dark spaces to her while walls will appear transparent
P273 Fantastic Four #62, vol. 3 (Dec 2002), the 491st issue dating back to 1961, tells us
Sue sees by detecting scattered cosmic rays
-wrong source of illumination
-cosmic rays are high speed protons that strike atoms in upper atmosphere
-causes shower of electrons, gamma rays, and muons (related to electrons) and
other particles
P274 flux of cosmic rays at ground level is a million trillion times less than visible light
P274 transistors change ability to conduct electricity by a factor of 1 million
P274 material with excess electrons next to material with excess holes
-solar cell
-add a third layer with excess electrons and you have a transistor
P274-275
Stained glass-impurities added so different colors absorbed
-manganese atoms vibrate and remove all wavelengths except violet which passes
through
-cobalt-blue
-selenium-red
P275 n type semiconductor-chemical impurities donate electrons
p type semiconductor-impurities accept electrons (positive holes left)
P275 put an n type next to a p type:
-electrons and holes recombine
-the charged impurities remain behind and create an electric field that points in
one direction
-an applied current can only move in direction of the field
-called a diode in the dark and a solar cell in the light
-one of the few ways to create a current without turning a wire in a magnetic field
P276-277
Before transistors, vacuum tubes were used
-heated wires (eject electrons)
-accelerated by a positive voltage toward a metal plate
-applying a current to a grid/screen between the wire and the plate affects the
current that is collected (acts as a valve)
-tubes were large and used a lot of power and took time to warm up
-transistors are small, low power devices that are instantly on
P277-278
Small input current will give a small output current (called number zero ‘0’)
Large input current produces a large output current (called one ‘1’)
-combine millions of these and use Boolean logic to build computers
Section 4: What Have We Learned?
Chapter 24: Me Am Bizarro! – Superhero Bloopers
P281-282
Scott Summers (Cyclops) was the first mutant recruited to join the X-Men by
Prof. X
-beams of pure force were emitted from his eyes
-could punch through a concrete wall or stop a falling 2 ton rock
-2 things immune to his blast: his skin, and ruby quartz
P282 glass-disordered silicon dioxide
Quartz-ordered silicon dioxide
P282 X-Men comics and films never show Cyclops’ head recoiling backward after an
eye blast
P283 eye blast at least 4,000 lbs (stopping 2 ton rock); body mass 80 kg
-F=ma yields an acceleration of > 20 times gravity
-must have strong neck muscles
P283 in Action Comics #1, Superman lifted a car over his head
-assume car is 3,000 lbs
-Krypton’s gravity 15 times greater means car seems like 200 lbs! 
P284-285
Lifting an office building or an ocean liner is unrealistic because these objects are
designed to be supported all along their undersides
-any slight variation from vertical would introduce torques
P287 Dr. Octopus should topple over if one of his arms isn’t anchoring him to the
ground
P287 in JLA #58, Superman, Wonder Woman, and Green Lantern pulled the moon into
Earth’s atmosphere to defeat invading Martians
P289 by the late 1990s, Superman was revealed to be able to lift 8 billion pounds
P289 assume Wonder Woman and Green Lantern are also able to pull with 8 billion
pounds each
-total pulling force on moon is therefore 24 billion pounds
-heroes nullify effect of gravity
-mass of moon: 70 billion trillion kg
-F=ma: a=5 billionths ft/s2
-distance of moon: 240,000 miles
-time to pull moon into Earth’s atmosphere: 735 years!
P290 birds and planes fly because of Newton’s 3rd Law, not the Bernoulli effect
-planes couldn’t fly upside down if Bernoulli effect was responsible for flightwould be pushed into the ground
P290-291
Warren Worthington III of the X-Men must supply at least 150 lbs of downforce
with his wings in order to fly (if he weighs 150 lbs/68 kg)
-his wings grew out of his back
-a force of 200 lbs would impart an acceleration of 11 ft/s2 (0-60 mph in 8
seconds)
P291 birds have 1) keeled sternum bone 2) 2 large muscles: supercorocoiderus and
pectorals
-Warren would need enormous muscles
P292 birds replace every oxygen molecule after every 2 breaths because their muscles
need a lot of oxygen
P294 in The Power of the Atom #12, the Atom and a friend shrank to a size smaller
than an atom
-friend asked how they could breathe since oxygen molecules are larger than them
P294-296
In Showcase #34, the Atom shrinks himself and sends himself through the phone
line to a criminal’s house
-information sent over phone lines by electromagnetic waves, not electrons
physically moving from point A to point B
-greater than normal electron density repels itself and expands into next region
-this bulge propagates down the line at ~ 1/3 the speed of light
-time lag between 2 points 12 inches apart is < billionth of a second
-the Atom would have to jump from one group of electrons to the next at greater
than the speed of light if he hopes to ride the wave
-“average speed that an electron moves along a wire in response to an external
electric field is less than a millimeter/sec.”
P296-298
Physics professor Ray Palmer became the Atom when he discovered a chunk of
white dwarf material
-density is 3 million grams/cm3
-light from supernova type Ia events might be the result of 2 colliding white dwarf
stars (12 per year detected)
P298 white dwarfs are degenerate matter
-electrons all in the same quantum state so atoms can compress, making it denser
P298 chunk of white dwarf star Ray Palmer picked up had a radius of roughly 6 inches
4
-volume is r 3 = 905 in3 = 15,000 cm3
3
-mass = 45 billion grams = 45 million kg! = 100 million pounds!
Afterward – Lo, There Should be an Ending!
P301 goal of science is 2-fold:
1) discover new rules
2) understand situations in which the old rules don’t apply
p303 Niels Bohr – “Knowledge is in itself the basis of civilization.”
Ask Dr. K
P305 Most Realistic Superhero? – Batman
Most Unrealistic Superhero? – Superman
P306-307
Most Unlikely yet Physically Accurate Superhero Feat? – Thor swinging his
hammer
-jumps at the instant he throws his hammer
P307 Who is Faster: Superman or the Flash? – The Flash
Additional Reading
1) Discovering the Natural Laws: The Experimental Basis of Physics by Milton A.
Rothman (Dover 1989)
2) Mad About Physics: Braintwisters, Paradoxes, and Curiosities by Christopher P.
Jargodzski and Franklin Potter (John Wiley and Sons, 2000)
3) Back of the Envelope Physics by Clifford Swartz (John Hopkins University Press,
2003)