The science behind superheroes

Super powers abound in comic books but not so much in the real world. So, how does the science of superheroes stack up when it’s put under the microscope? Tim Dean takes a look.

A Superman comic book from the 1930s. The superhero genre is an extension of science fiction. – Hulton Archive/Getty Images

We've all heard it before: a scientist, working in a secret laboratory buried deep in the heart of an extinct volcano, suffers an unfortunate mishap and is doused in radioactive chemicals/gamma rays/mutagenic DNA. Next thing you know, he is transformed into a crime-fighting guardian of justice.

Oddly, the physical appearance of these accident-prone super-brains is always the polar opposite of a stereotypical scientist – extraordinarily buffed and good looking even before their transformations – leading to malicious speculation about why these fit, handsome, intelligent people aren’t out clubbing with all the other chick magnets.

Possible social phobias and personality disorders aside, stories about the exploits of these super-powered heroes have littered our daily newspapers for decades but, despite their sensational character, they never appear on the front pages.

Instead, they’re found towards the back, just before the commonplace exploits of our sporting heroes, typically – and some would say unfairly – sandwiched between the hard-drinking English everyman Andy Capp and the sarcastic, lasagne loving Garfield.

Science has always played a leading role in our superhero myths, from the cosmic rays that turned a team of space pioneers into the Fantastic Four, to the alien roots of Superman.

A rare first issue of The Amazing Spider-Man comic book – Mario Tama/Getty Images

AS MUCH AS WE’D all love to believe that a random mishap involving an irradiated arachnid could turn us into a crusader for truth, justice and whatever way we please, science tells us that the world is a lot more temperate when it comes to doling out super powers. So, how does the science of superheroes stack up when it’s put under the microscope?

It’s no accident that many superheroes themselves are scientists, including Bruce Banner (aka the Incredible Hulk) and Reed Richards (aka Mr Fantastic, the plastic man from the Fantastic Four - it’s pure modesty that he’s called Mister and not Doctor). It’s also no accident that science plays a significant part in the origins of many superheroes and their stories. After all, superhero stories are really just an extension of science fiction as a genre.

The first superhero stories, led by Superman himself in Amazing Stories #1, published in 1938, were originally an offshoot of the pulp-fiction magazines and comic strips popular throughout the 1930s. These were stories of adventure, heroism, strange worlds and magical powers – whether it was Flash Gordon battling Ming the Merciless on the planet Mungo, or Conan the Barbarian wrestling dark demons in forgotten temples.

The 1930s was a time when the Great Depression gripped the globe, and this had a particularly poignant effect on the people of the United States. The country that had promised the great American dream was now a land of unemployment, poverty, suffering and a failing free-market economy. People needed heroes, and newspaper comic strips and pulp-fiction magazines provided them in spades.

THE EARLY 20TH CENTURY also had scientific and technological breakthroughs regularly reaching the front pages of the newspapers, from Albert Einstein and his revolutionary (if counter-intuitive) perspective on the nature of the universe, to the pioneering activities of the first airmen and women shrinking the world. These developments held the lingering promise that science and technology could answer humanity’s troubles – to bring it out of the Depression and into a better world.

But science was, for the most part, an unknown quantity for the common person.

The rate of technological and scientific progress over the latter half of the 19th century and first half of the 20th century was startling. Those who now benefited from electric lights and rail transport also had all-too-vivid memories of mustard gas attacks in World War I or the soulless, polluted neighbourhoods that sprang up as a result of the industrial revolution.

This led to wild speculation about where science was taking us: towards a utopian paradise, or into a world where humans were enslaved by the very technology that tempted them with salvation? Science fiction explored both the utopian and dystopian visions: the alien invasions of H.G. Wells and the fantastic voyages of Jules Verne.

Enter now the superhero. Epitomising the heroic character, many of the first superheroes came with pseudoscientific backgrounds, but were also just as often based on the same rich mysticism that permeated other pulp magazines of the time. With their great powers came great responsibilities. They promoted a utopian worldview, where good was good, and evil was to be battled tirelessly in defence of the common man.

Even their costumes, with bright, often almost flourescent colours, and bold symbols, reflected their reassuringly simplistic view of the world.

Superheroes gained popularity in World War II. Names we know and love, such as Superman, Batman, The Flash, Wonder Woman and Captain America graced the covers of publications such as Amazing Comics, Detective Comics, Amazing Fantasy and All-Star Comics. This was the Golden Age.

However, after the war, superheroes fell from favour as more traditional war, Western and crime comics took the fore. It wasn’t until the mid 1950s that superheroes began to make a comeback, in the period that’s become known as the Silver Age among comic-book aficionados.

THE WORLD WAS BUSY rebuilding in the 1950s. The US was largely untouched by the ravages of war and now with an unprecedented industrial capacity, began to surge ahead of the rest of the planet in science and technology. Once again, science was being seen to offer a panacea for the world’s problems, and was providing new and previously undreamed of luxuries to homes across the US and the world.

However, the 1950s was also the time when the spectre of nuclear war cast a shadow over the future of the human race. Never before had humanity possessed the capability to extinguish all life on the planet, and never before had two sovereign nations faced each other off to the brink of destruction on quite such a global scale.

In this environment, heroes were needed – heroes who could reassure the world that good would ultimately triumph over evil, and that science would not be allowed to hurtle forward unshackled by humanitarian concerns. Against this background the panoply of superheroes changed. Their origins reflected the concerns of the day, such as the radiation and gamma rays emitted from atomic bombs, or the cosmic rays recently discovered on man’s first forays into space.

The Incredible Hulk joins Marvel's stable. – Mario Tama/Getty Images

Many of the superheroes from the Golden Age were reinvented, with new back-stories that involved a greater quantity of hard (or semi-hard) science. The new tales also learned from contemporary science fiction novels by giants of the genre such as Arthur C. Clarke and Isaac Asimov, with plots involving aliens, weather control, doomsday devices and the evil machinations of a spectrum of mad scientists.

For every one of the superheroes who consciously called science to their aid in attempting to bring justice to an unjust world, there were even more villains who used its weapons to further their nefarious purposes. Lex Luthor, Dr Doom and Dr Octopus were a few of the wicked and nefarious villains threatening to destroy the world and our brave superheroes but who were also, nonetheless, supposedly intelligent men of letters.

Despite tacit acknowledgement of the science going on behind the heroic scenes, there’s no question that laws were being broken and theories bent. It may not be possible for anyone to lift a car over their head in humdrum reality, but much of the science of superheroes is still interesting and well worthy of closer examination.

One thing we haven’t attempted to explain is why superheroes tend to wear their underwear on the outside. We’ll leave that for you to contemplate.


PERHAPS THE MOST easily recognised of all superheroes is the very first – Superman himself. Back in 1938 his creators, Jerry Siegel and Joe Shuster, provided a science fiction back-story, and it has evolved ever since.

In most versions, Superman was born Kal-El, son of Jor-El and Lara Lor-Van, on the planet Krypton, which circled a giant red sun. When Jor-El realised Krypton was doomed to explode, he sent his baby son in a rocket to Earth to save him. Earth has much lower gravity than Krypton, and is bathed in the high-energy light of a yellow sun, which lends Superman his super powers.

An organism drawing energy from sunlight is hardly strange – it’s the basis of photosynthesis in plants. But Superman’s cells must be substantially more efficient at converting light into energy than the chemical reactions that take place in the cells of plants. Given the energy that Superman must expend in order to lift a building or an ocean liner, let alone fly at many times the speed of sound, his cells may even be based around some kind of nuclear reaction, such as cold fusion, which requires light to trigger the reaction. That would make his a truly alien biology.

It’s said Superman’s great strength comes from the gravity difference between Krypton and Earth. That strength has been estimated as enabling him to lift between 100 tonnes and 800,000 tonnes. Let’s take a conservative estimate of 1,000 tonnes and run the numbers. Your average buff mid-20s male can bench-press about 100 kilograms. That means Superman can lift 10,000 times more than our Average Joe.

Assuming that 1,000 tonnes on Earth is equivalent to 100 kg on Krypton, the gravity on Krypton must be 10,000 times more intense. That’s one dense planet! So dense, in fact, that its surface gravity (assuming a similar diameter to Earth) would be 370 times even that of the Sun. A box of Krypton Corn Flakes would crush poor old Average Joe.

Then we have kryptonite, the mythical element that was created at the explosion of Krypton, whose green variety can be lethal to our favourite man of steel. In the Superman tales, kryptonite is described as an element, although the suffix ‘-ite’ is often reserved for compounds of two or more elements. As such, it has been suggested that kryptonite could be a compound of krypton and something else. But krypton is a noble gas, is very unreactive and doesn’t form compounds easily.

IF KRYPTONITE IS AN element, it should appear on Mendeleev’s periodic table. But the periodic table is already populated by more than 100 elements, and no two can share the same spot on the table, which doesn’t leave much room for kryptonite.

There are a number of openings among the very heavy elements, with atomic numbers of above 118, although all elements in this range are unstable and have half-lives of, at best, only a few seconds. It also means kryptonite would be very radioactive, and deadly both to Superman and us common folk.

This fits with its ability to rob Superman of his powers, with symptoms akin to radiation sickness, although Superman has never lost his slick black hair due to kryptonite exposure.

The science is hazier still about his flight. Some theories say Superman can fly by willpower alone. But, if it was only a matter of willpower, there’d surely be no shortage of children, resplendent with tea towels about their necks, hurtling into the skies fuelled by wishful thinking. We’ll have to chalk flight up to fantasy, and set science aside.

Ultimately, it must be very useful indeed to be so many thousands of times stronger than Average Joe, but the world around you is still frustratingly fragile. Perhaps one of Superman’s more remarkable feats is his ability to lift delicate objects such as tanker trucks without having them twist and buckle in his grip – gravity may be a harsh mistress, but inertia can truly mess up your bid to throw a truck across the road.

And then there’s the matter of the fallibility of our mere Earth soil. Superman’s feet are no larger than Average Joe’s, so having several tonnes pressing down on to an area of about 600 cm2 would drive him into most surfaces up to his knees. We can only imagine that Superman’s wardrobe includes some very potent and nimble soles.


“WITH GREAT POWER comes great responsibility.” No, it’s not the motto of a suddenly sage inhabitant of the White House, but the wise words spoken to the fledgling webbed wonder by his Uncle Ben. Spider-Man is an interesting superhero: he’s not as black and white as many of his fellow superheroes in the DC Comics family, such as Superman and Wonder Woman (although, granted, he still wears primary colours).

Spider-Man is naught but a geeky teenager, Peter Parker, with a penchant for science, who was accidentally bitten by a radioactive spider. These factors combine to make a compelling story line, which is as much about the trials and tribulations of being a teenager as it is dealing with villains and criminal masterminds as a superhero.

Spider-Man has always had scientific overtones, from Peter Parker’s preferred subjects at school, to the premise of a man-animal fusion instead of magical or alien powers. Having said that, it’s worth noting that there have been no recorded cases of radioactive spider bites causing anything other than irritation and mild inflammation in humans.

At a stretch, it’s just about possible to imagine the radiation that bombarded the spider changed its DNA in such a way that when its venom was injected into poor Peter, it managed to penetrate his cells and fuse with his own DNA. This could have started a series of mutations in Peter, giving him some of the characteristics of a spider.

Among Spider-Man’s slender but impressive range of powers is his super grip, which is ideal for clinging to walls, ceilings and beer cans in high-wind situations. Some spiders, like some insects, have specialised hairs at the base of their feet that can find their way around the microscopic bumps and crevices in most surfaces.

Creepy crawlies are also assisted by the fact they are very small compared to people, which means the ratio of body mass to surface area in contact with the wall is favourable. Things would be a little tougher for Spider-Man though, because when you double an organism’s size, you square its mass. This means Spidey’s extremities must have incredible adhesive power (that is, very hairy palms – eew).

SPIDER-MAN ALSO POSESSES the strength and agility of a spider, proportionally magnified into human scale. And although spiders lack the relative strength of ants or other insects, any organism that is as small as a spider will appear to be super strong at its scale, when compared to a human being. This is for a similar reason to the scale issue we have already examined.

A spider can seemingly effortlessly lift itself and an enwebbed victim up a thread of web because its mass is relatively small compared to the density of its muscle mass.

Assuming Spidey’s strength has been proportionally boosted, it’s plausible he would be able to lift several tonnes. This strength would also enable him to jump great distances, which brings us to his other trademark power: web-slinging.

Spider silk is known as being a remarkable substance, with a tensile strength similar to steel, yet having around one fifth the density. There’s no question that a thread of spider silk of appropriate thickness could support the weight of a human, although it’s a little less likely that the adhesive bond securing said human to nearby office building would be up to the task.

Peter must have also stumbled across some aspect of molecular science that has escaped our best minds so far, as the materials industry would surely love a substance that is strong, yet stretches, and is stored in liquid form but solidifies almost immediately on contact with air.

And that’s not all. Regarding Spider-Man’s last remaining, and possibly most remarkable power, his spider sense, things become somewhat hazier still. Spiders do have specialised hairs, called setae, which are connected directly to the spider’s nervous system and provide the arachnid with a detailed picture of anything it touches.

It’s conceivable that Spider-Man’s equivalent of these hairs could be sensitive enough to detect subtle compression waves in the air, perhaps something akin to super-sensitive hearing with directional abilities.

However, when it comes down to being able to detect the cool aim and deadly intention of an evil-doing sniper on the top of an office building several hundred metres away, well, hairs ain’t going to help Spidey too much there.


GAMMA RAYS are not to be trifled with. It’s a lesson learned early in the career of most nuclear scientists, but one sadly lost on Dr Bruce Banner. Gamma rays are from the high-energy end of the electromagnetic spectrum, and are lethal in high enough doses. Banner was accidentally exposed to gamma rays when testing a gamma bomb, triggering an unusual transformation in the scientist.

Different tellings give different reasons for the transformation, ranging from his father, Brian Banner, passing Bruce mutant DNA due to Brian’s previous exposure to radiation at Los Alamos, where the first atom bombs were developed.

The most recent movie version places an interesting and contemporary twist on matters. In the film, Bruce’s father is experimenting with genetics, and modifies his own DNA, which is then passed down to Bruce. Then Bruce’s own experiments with nanotechnology go haywire after a massive dose of gamma radiation. Needless to say, the gamma rays that serve as a catalyst in all versions are lethal in reality.

The Hulk’s powers themselves are relatively straightforward: the Hulk is enormous and built like a brick outhouse, and as such possesses prodigious strength, stamina and durability. The real science-bending factor is his transformation to and from the meek Bruce Banner.

While it’s common for individual organisms to grow to great size during their lifetimes, trebling in size and cubing in body mass in a matter of seconds would be a tricky manoeuvre.

Even if the cells were built for such replication, the energy required would be immense – matter doesn’t just pop out of nowhere, after all. Perhaps the growth is powered to the latent lingering traces of gamma rays? If so, you’d not want to stand next to Bruce Banner in a lift without being separated by a few centimetres of lead, at least.


WITH HER TIGHT, bright, red-and-blue outfit, golden headband, bulletproof bracelets and magic lasso, Wonder Woman has served as a bold and powerful representation of femininity in world largely populated by musclebound supermen.

Another of the DC’s earliest superheroes, Wonder Woman made her debut in 1940 and, although her powers may have been granted by the ancient Greek gods, there is nonetheless a surprisingly scientific story behind Wonder Woman’s powers.

Wonder Woman was created by William Moulton Marston, a psychologist and feminist theorist. Marston was also the inventor of an early lie detector, which provided the thinking behind Wonder Woman’s magic lasso.

Marston’s lie detector used blood-pressure monitors to look for changes in the subject’s physiology under the hypothesis that an individual undergoes subconscious and autonomic physiological changes if they tell a lie. When answering a question, a rise in blood pressure indicated that the subject was lying. Blood-pressure monitoring became one of the elements involved in the more complex polygraph test, which also includes skin conductivity, heart rate and several other factors.

While it’s highly unlikely that Wonder Woman had a polygraph machine attached to her lasso, the principle that she could detect physiological changes in a subject through the lasso is plausible enough. However, Wonder Woman’s lasso also did something that a polygraph test never could, which is to force the bound subject to tell the truth. Imagine if the CIA had a hold of her lasso.


IT ALL STARTED predictably enough, with a cocktail certain either to create a superhero, or make a terrible mess: a lightning strike, a cabinet full of chemicals, and one plain old, garden variety human being. And the result: Flash, the fastest man alive.

After his accident, Flash discovered that he was capable of incredible speed, both when running and also in terms of lightning fast reflexes. At least, we’d hope that Flash had pretty quick reflexes, because it only takes a split second of diverted attention when running at several thousand kilometres an hour to ruin your day by colliding with a wall or a tree.

Even assuming there is some hitherto unknown reaction possible between certain chemicals and vast amounts of electricity that might endow a human with blinding speed, there are still a few physical barriers to be overcome before Flash could become reality. The first is at once both the bane and the boon of any fast-moving object: friction.

In a world without friction, not only would you not be able to stand up, you’d not be able to move around, if you were already moving, you wouldn’t be able to slow down without colliding with something. Friction with the ground makes walking and turning a possibility, while friction with the air serves to slow you down when moving quickly.

An object moving at Flash-like speeds in the Earth’s atmosphere would somewhat resemble a meteor, generating tremendous amounts of heat through friction with the atmosphere.

FLASH HAS A convenient loophole in this regard. The authors of the Flash comics appreciated the conundrum that friction posed to our swift hero, so explained his unhindered movement care of an aura that reduces friction when he runs. While the mechanism remains unexplained, the concept itself is actually quite canny.

If Flash was somehow able to displace the air in front of him and pass it around his body without coming into contact with it, then that would alleviate many of his meteoric tendencies. However – and with superheroes there’s always a “however” – it would also remove his ability to grip the ground, and leave him there like Wile E. Coyote, legs spinning, but not getting anywhere fast.

Another of Flash’s remarkable powers is the ability to move so fast that his individual molecules can slip past those of other solid objects around him, effectively making him intangible.

This is especially handy when it comes to passing through walls, or having objects such as bullets pass harmlessly through him. Intangibility as a concept is not as strange as it might sound, in fact some interpretations of quantum theory allow for an element of intangibility in all solid objects. However the probabilities involved in one large object passing through another without any collisions occurring between their constituent molecules are slim.

6. X-MEN

IT TOOK BILLIONS OF YEARS to evolve from single-celled organisms into mere slimes, and millions more to evolve legs, arms and brains, eventually leading to humans and monster trucks. Yet, in the world of Marvel Comics’ X-Men, it took only a few generations for humans to go through a process of rapid mutation that spawned hundreds of individuals with unique abilities and powers. Evolution is, evidently, a funny game.

There’s long been a debate over whether evolution is a slow and steady process of gradual change, as Darwin proposed, or whether it is punctuated by bursts of mutation that radically change various species, as suggested by Niles Eldridge and Stephen Jay Gould. If Eldridge and Gould are correct, then this theory could explain the rampant mutations that affect the X-Men in such a short time, evolutionarily speaking.

Mutation is a pivotal tenet of the theory of evolution. All organisms have the potential to undergo random mutations with each new individual. Many such mutations will be benign or damaging to the organism, but occasionally a mutation gives an organism a clear competitive advantage over the rest of its species. If the organism proves more successful at breeding, and the mutation is passed down to its offspring, the mutation can become a new feature of the species, or even branch off into a new species all together.

In the X-Men, the mutants are even given their own scientific name, Homo superior, instead of Homo sapiens, but it would be incongruous to consider all the various and diverse mutations as belonging to a single new species. Furthermore, if the mutants can interbreed with Homo sapiens, then they shouldn’t be considered a new species at all. Rather, they could be considered to belong to a subspecies, such as Homo sapiens superior, or a range of subspecies.

Some mutations seen in the X-Men are quite plausible; others, such as innate weather control or shooting energy beams from one’s eyes, stretch the science textbook substantially further.

One of the more plausible mutants is Beast, who is himself a scientist specialising in biophysics. While Beast has no superpowers beyond his physique – which resembles that of an oversized blue gorilla – his feet are as nimble as his hands, and his agility is much like that of a smaller tree-swinging primate. He is also gifted with a powerful intellect, which along with his extensive education, set him apart from humanity, but not from scientific plausibility.

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