Pop Culture
Physics
Comics · Sci-Fi · Fantasy — All on the Same Lab Bench
Superheroes break bones and physics in equal measure. Starships ignore Einstein on a weekly basis. Dragons violate Galileo every time they take off. This is where we hold fiction accountable to the universe — not to ruin the fun, but to find the real science hiding underneath the spectacle. The question is never “is this realistic?” It is always “what would actually have to be true for this to work?”
Why Fiction Cares About Physics
Every story makes a deal with the laws of nature. The interesting question is which laws got renegotiated, and how much it cost the story.
The best fantastical fiction picks a small number of physical rules to break, and then enforces every other rule ruthlessly. The Hulk gets stronger when angry — fine, but he still has to obey conservation of momentum when he lands. Superman flies — fine, but air resistance still tears at his cape. The dragons in Game of Thrones breathe fire — fine, but they still cast shadows and pull air.
This series is not about debunking. It is about translation. Each piece of speculative fiction is a thought experiment dressed in narrative clothing, and underneath the costume there is usually real science worth knowing. Sometimes the science says the fiction is closer to plausible than you would expect. Sometimes it says the fiction needs orders of magnitude more energy than the visible universe contains. Both answers are interesting.
Three sections follow. Comics gets the most attention because it has the most violations per page. Sci-fi gets the most respect because its writers usually know they are cheating. Fantasy gets the most charity because it openly acknowledges its rules are made up — though even fantasy can’t escape the square-cube law.
Comic Book Physics
The genre with the highest violations-per-page rate. Also the one where the science is most interesting to recover.
Comics break physics on every page and the medium is honest about it. A character lifts a car. A punch sends someone through a wall. A villain shoots lightning from his hands. The story doesn’t pretend any of this is realistic — it pretends the consequences don’t matter. Real physics says they would. Recovering the consequences is where the fun is.
Most “comic physics” violations fall into three categories: energy that comes from nowhere (Superman’s flight, the Flash’s speed), materials that don’t behave like materials (Spider-Man’s webs, Cap’s shield), and biology that ignores its own scale (Hulk’s mass, Ant-Man’s whole career). Each of these has interesting answers if you take the question seriously.
The most common violation isn’t a single broken law — it’s the quiet violation: every superhero blow that doesn’t kill the bystanders nearby. Real shockwaves from a 100-mph punch would rupture eardrums for blocks. Comics solve this by simply not showing it.
Can Spider-Man’s webs actually hold a falling car?
Real spider silk has a tensile strength comparable to high-grade steel by weight — Darwin’s bark spider silk hits about 1.6 GPa. Scaled to the thickness Spider-Man uses, a single strand could theoretically arrest a falling sedan.
The problem isn’t the silk. The problem is what happens to Spider-Man. To decelerate a 4,000-lb car from 30 mph in a fraction of a second, the anchoring force at his end of the web has to match — and that force would tear his arms off.
The web could hold the car. Spider-Man could not hold the web.
How fast can the Flash run before friction kills him?
Sustained running at roughly the speed of sound (~770 mph at sea level) generates enough aerodynamic heating to start cooking the runner. Air molecules can’t move out of the way fast enough, so they compress and heat up against the leading edge.
At Mach 2 and higher, surface temperatures exceed 200°C. The comic-book solution is the Speed Force, which conveniently negates friction. Without it, the Flash is a very fast pile of ash.
The interesting part: real fighter pilots manage this by being inside a temperature-controlled cockpit. The Flash is the cockpit.
Where does Superman’s flight energy come from?
The canonical answer is “solar radiation absorbed by Kryptonian biology.” The actual numbers don’t cooperate. A 235-lb man hovering against gravity for one hour needs roughly 350,000 joules just to fight gravity.
The sun delivers about 1,360 W/m² at Earth’s orbit. Superman’s surface area is around 2 m². Even at 100% absorption, his maximum solar intake is about 2,720 W. That’s enough for a brisk jog. Not enough to lift continents.
He is either drawing energy from somewhere not on the diagram, or he is a portable cold-fusion reactor with a cape.
Could the Hulk’s mass actually exist?
Bruce Banner weighs about 130 pounds. The Hulk weighs up to 1,400 pounds. The transformation gains roughly 1,270 pounds of mass in about a second. Where does it come from?
The handwave is “extradimensional mass.” This is comic-speak for “we made it up.” Real biology can’t add mass that fast.
If you take the extradimensional explanation seriously, Banner is essentially a portal: matter is being pulled in from somewhere else when he transforms, and presumably sent back when he calms down. The interesting question is what that “somewhere else” looks like.
Could Cap’s shield really bounce like that?
This one is closer to plausible than people expect. Vibranium is fictional, but the bouncing behavior is consistent with a near-perfectly elastic collision. Real materials can approach this — silicon-nitride bearings retain over 95% of impact energy in elastic rebounds.
The shield’s geometry helps: a curved disc with weight concentrated near the rim is aerodynamically stable, like a frisbee. The trajectories Cap throws — angles, bank shots, ricochets — are mostly geometrically valid.
What is not realistic is Cap’s targeting. Hitting four moving enemies on three bank shots while running requires reflexes closer to a fighter jet’s targeting computer.
Why doesn’t Ant-Man have ant-mass problems?
When Ant-Man shrinks to the size of an ant, he keeps his full human mass. This is the “Pym Particle” handwave. But it should produce immediate, dramatic consequences he never has.
A 180-pound man compressed into ant volume would have a density roughly 10 million times that of normal tissue — denser than the core of a neutron star. He would not stand on a floor. He would fall through the planet.
The films sometimes flip this and have him gain mass when small — heavy enough to punch through metal. That version is more internally consistent.
Science Fiction Physics
The genre where the writers usually know they are cheating, and pick their cheats with care.
Sci-fi differs from comics in one important way: it tends to break physics on purpose, for narrative reasons, and to be transparent about the trade. Star Trek wanted ships that could reach other star systems within a single episode, so it invented warp drive. Star Wars wanted laser swords, so it invented plasma confined by an energy field. The Mass Effect games wanted FTL travel, so they invented mass effect fields. In each case, the writers know the cheat and structure the universe around it.
The result is that sci-fi physics is often closer to real physics than it looks. Warp drive borrows from Miguel Alcubierre’s actual 1994 paper. Star Trek transporters borrow vocabulary from quantum mechanics. Even sound in space, the most-violated rule, is a deliberate choice — Star Wars and Battlestar Galactica both made the conscious decision that silent space combat would be undramatic, and committed to the breach openly.
Why can’t there be sound in space (and why do movies pretend)?
Sound requires a medium — air, water, solid material. Vacuum has essentially no medium, so sound waves have nothing to propagate. This is solid 19th-century physics, confirmed by every spacecraft instrument that ever listened.
Movies show explosions and engine roars in space because human audiences process tension through sound. 2001: A Space Odyssey and Gravity are two of the rare films that committed to silent space — and notice how unnerving both feel.
The cheat is not science; it is dramaturgy. The writers know.
Is warp drive actually a real concept in physics?
Yes, surprisingly. Mexican physicist Miguel Alcubierre published a paper in 1994 describing a mathematical solution to Einstein’s field equations that would let a region of spacetime move faster than light — by contracting spacetime in front and expanding it behind, while the ship itself remains stationary inside the “bubble.”
The math works. The catch is the energy requirement. The original solution needed mass-energy larger than the observable universe in the form of “exotic matter” with negative energy density. Refinements have brought it down to about the mass of Jupiter, which is somehow worse, because it’s almost imaginable.
Warp drive is a real concept in general relativity. It just doesn’t have a known fuel source.
Would Star Trek transporters transport you?
The transporter scans your atomic state, disintegrates you, transmits the pattern, and reassembles you elsewhere. The question is whether the assembled person is you or a perfect copy.
The no-cloning theorem in quantum mechanics says you can’t perfectly duplicate an arbitrary quantum state. You can teleport a state — but only by destroying the original. Which is exactly what the transporter does. Quantum teleportation, in principle, is real.
What’s philosophically unresolved is whether the reassembled person experiences continuous consciousness — or whether the original dies and a new one is born with their memories. The franchise has had this argument with itself many times.
How does a lightsaber actually work?
Plasma confined by a magnetic field is a real thing — it’s what powers tokamak fusion reactors. The fictional version requires the magnetic field to extend exactly one meter from the hilt and then stop sharply, which real fields do not do.
The more interesting problem: a plasma blade hot enough to cut through doors would also be hot enough to set everything within several meters on fire just from radiant heat. Jedi should be wearing welding masks. They are not.
The franchise’s quiet solution is that “lightsaber blades emit no waste heat” — a convenient property no real plasma has. Once you accept that, the rest is just charged ions in a confined shape.
Fantasy Physics
The genre that openly admits its rules are invented — but still can’t escape the laws it didn’t think to invent around.
Fantasy gets the most charity in this series because it asks for the most. The setup is honest: “magic exists in this world.” Once you accept that premise, you’re not in the business of measuring against real physics anymore. You’re measuring against the story’s internal consistency.
Except — magic doesn’t actually exempt fantasy from physics. It exempts fantasy from specific physics. A dragon can still be too large to fly. A castle can still be too tall to stand. A sword can still be too heavy to swing. The interesting thing about good fantasy is which physical rules it leaves on, and which it disables.
Can a dragon actually fly?
The square-cube law was identified by Galileo in 1638 in his Discourses Concerning Two New Sciences. It says that when you scale up a creature, its volume (and mass) grows with the cube of the linear scale, but its cross-sectional area (and structural strength) grows only with the square. Translation: bigger animals get heavier faster than they get stronger.
The largest flying creature that ever existed — Quetzalcoatlus, a Cretaceous pterosaur — weighed about 550 pounds with a 33-foot wingspan. It is generally believed to have been at the upper limit of what powered flight allows on Earth. A movie dragon at 5 tons is roughly 18 times that mass.
The fictional escape valve is usually “magic.” If the dragon flies through arcane levitation rather than aerodynamic lift, the square-cube law doesn’t apply. This is fine — but it means the wings are decorative, and the dragon is essentially a magical platform shaped like a dragon. Which is, when you look at it that way, a fairly bold choice.
What would a dragon breathe to make fire?
Two candidates: a hypergolic two-stage system (two chemicals stored separately that ignite on contact, like rocket fuel) or methane plus an ignition source (similar to the bombardier beetle’s defense, scaled way up).
The hypergolic version is biologically plausible. Bombardier beetles already do this with hydroquinones and hydrogen peroxide, producing 100°C boiling liquid jets. Scale the chemistry up and you can plausibly reach napalm-equivalent temperatures.
The methane version requires the dragon to also be a chemical lighter. Several fictional treatments give dragons flint-like dental structures for this. Clever, but doesn’t quite escape the question of methane generation at industrial volumes.
Why would a fantasy giant be in constant pain?
Same square-cube law as the dragon, applied to bone. A 25-foot-tall giant proportioned like a human would weigh about 80,000 pounds. Their bones would need cross-sections roughly 10 times what their geometry could support before fracturing under their own weight.
Real-world giants (people with gigantism due to pituitary tumors) typically have severe joint problems, cardiac strain, and shortened lifespans. The tallest documented human, Robert Wadlow, died at 22 from foot infections he couldn’t feel because the nerves in his oversized feet were already failing.
If you scale a human to fantasy-giant proportions, the underlying biology would be brutal. Most stories quietly ignore this.
How tall can a fantasy tower actually stand?
For an unsupported stone tower without modern engineering, the practical limit is around 500-600 feet, set by the compressive strength of the stone at the base. Beyond that, the lower courses crush under the weight above.
This is why medieval cathedrals top out around 500 feet (Lincoln Cathedral was the tallest building in the world for over 200 years at 524 feet — until its spire collapsed in 1549). Modern steel-frame buildings cheat by using tension and triangulation; pre-industrial towers can’t.
Most fantasy “thousand-foot towers” are doing magic-as-rebar without acknowledging it.
Is Valyrian / mithril / damascus steel real?
Damascus steel is real, and it really was extraordinary. Historical Damascus blades had layered crystal structures (including, it turns out, carbon nanotubes — discovered in 2006 in samples from 17th-century swords) that gave them both flexibility and edge retention beyond what nominally identical steel could achieve.
The recipe was lost in the 18th century when the source ore (Wootz steel from India) ran out. Modern attempts have approximated it but never fully replicated the original microstructure.
Mithril and Valyrian steel are fantasy extrapolations of this real phenomenon. Tolkien knew about Damascus. Martin definitely knew about Tolkien knowing about Damascus.
Books That Hold Up
For anyone wanting to push deeper than this series goes. Each treats fictional physics with respect and rigor.
This series is a starting point. The authors below have spent careers on the questions this series only opens. Their books are the next step.
The Physics of Superheroes
The defining text in this micro-genre. Kakalios is a real physics professor at the University of Minnesota who built an undergraduate course around comic-book violations, and the book is the curriculum. Particularly strong on energy conservation, electromagnetism, and what would actually happen to bystanders in superhero fights.
The Physics of Star Trek
Krauss is a working theoretical physicist. The book is exactly what its title promises: a serious examination of warp drive, transporters, the holodeck, and time travel as they appear in Trek. Foreword by Stephen Hawking, which tells you the level of seriousness.
The Science of Interstellar
Thorne won the Nobel Prize in Physics in 2017 for his work on gravitational waves. He also served as scientific consultant on Christopher Nolan’s Interstellar, and wrote this companion book explaining which parts of the film are accurate, which are speculation, and which were knowingly bent for story.
Pterosaurs: Natural History, Evolution, Anatomy
Not specifically a “physics of fiction” book, but the definitive modern reference on real flying reptiles. Anyone interested in whether dragons could fly should read Witton’s treatment of Quetzalcoatlus first — it’s the upper bound of what powered flight allowed on Earth.
The Big Picture
Not about fiction at all, but worth reading because Carroll lays out what modern physics actually does and doesn’t allow, in plain language. After reading it, fictional violations become much sharper — you can tell the difference between “the writers don’t know any better” and “the writers are knowingly trading physics for story.”
What If? — Randall Munroe
Munroe was a NASA roboticist before he became a webcomic. The What If? column applies first-principles physics to absurd hypotheticals — “what would happen if you tried to hit a baseball pitched at 90% the speed of light?” — and the answers are rigorous and hilarious.
End of Volume 01. The Pop Culture Physics series continues with closer studies of specific franchises, specific powers, and specific creatures — wherever the questions get interesting and the math is willing to cooperate.
— TD