One of the most well-known characters in comic book history, Superman is also one of the oldest. Created by writer Jerry Siegel and artist Joe Shuster, Superman first appeared in Action Comics # 1 – all the way back in June of 1938, setting the stage for countless superheroes that followed in the next seventy-eight years (and counting). While certain elements of Superman’s backstory and powers remain the same nearly eight decades later, different writers and artists also brought with them changes to the hero’s mythology. Some carried forward, adding to Superman canon, while others were set aside and abandoned when they were no longer needed.
While there is not one “official” Superman, though fans will likely have their favorites, DC Comics has attempted to refine the Man of Steel over the years – delving deeper and deeper into why the Kryptonian hero can do the various “super” things he does. Superman’s powers are no secret but how, exactly, science (albeit science fiction) contributes to Kal-El’s super-human abilities is less well-known. This might be review for the biggest Superman lovers but, for fans who want to know more about the Big Blue Boy Scout, we’re digging into the god-like biology of Earth’s iconic Kryptonian.
Super Fuel
Originally, the reason for Superman's abilities was not explicitly detailed – other than stating Superman is an alien. However, as the Superman character developed over the years, DC writers attempted to provide real world explanations for the hero's super powers, settling on the idea that Superman receives his abilities from stored-up solar energy - via Earth's yellow sun. Where Kryptonians lived under the harsh conditions of a red sun, known as Rao, Superman's body is able to metabolize energy from Earth’s yellow sun (similar to how humans metabolize energy from their food) - then uses that energy to fuel his various super powers. Like most life forms, Superman can also store excess energy for later use – which is then used to fuel many of Kal-El’s powers
However, the hero’s solar-powered abilities also come with drawbacks. Should the Kryptonian over-use his super powers, without a chance to recharge, he can exhaust all of his reserve energy - becoming weakened and even vulnerable to injury. Red sunlight has a similar effect - blocking Kal-El’s ability to absorb yellow sun and, consequently, suppressing his superhuman abilities. Of course, the opposite can be true as well. In certain situations, Superman can even choose to over-charge his cells with solar energy, granting him enhanced healing and additional abilities. In particular, "The Death of Superman" saw Kal-El's critically injured body returned to the Fortress of Solitude and placed inside the regeneration matrix to be rejuvenated - a feat that required both the hero's inherent solar regeneration and advanced Kryptonian technology.
Super Strength, Speed, and Perception
Initially described as "more powerful than a locomotive" and "faster than a speeding bullet," Kal-El's super abilities have increased significantly over the years. Yet, Superman's strength, endurance, and speed, are derived from stored solar energy - providing fuel to his inherently dense molecular structure - allowing Kal-El to move with superhuman force (all without injury to himself). For that reason, Superman's raw power is incalculable - because his strength and speed are not a uniform benchmark and can be diminished or amplified by other conditions and external factors (especially the amount of solar energy he has stored). That energy also affords the Kryptonian enhanced reflexes and a relative perception of time - making him a dangerous hand-to-hand combatant. This means that the Man of Steel can quickly react to the actions of others as well as assess his environment much quicker than humans.
This isn't to say that Superman necessarily slows time or perceives normal time differently than humans by default but, at the very least, the hero is capable of heightened in-the-moment focus, allowing him to rapidly process and react to external stimuli.
One of Superman's most iconic super powers, freeze breath might seem like an exception to Kal-El’s solar-powered skill set; yet, the super breath is actually an extension of the hero’s strength - thanks to the real-life Joule–Thomson effect. The effect shows that compressed air, speedily pushed through a restricted opening rapidly reduces the overall temperature of the burst. This means Superman, who can forcefully exhale at high velocity and pressure, could turn the burst into an arctic blast - by intentionally directing the air through pursed lips.
Bio-Electric Aura
Kal-El has only been shown to possess telekinetic abilities on a few isolated occasions; however, it is largely accepted that Superman’s store of solar energy also affords him a bio-electric aura that allows him to manipulate electromagnetic fields – an ability that has come to be known as “tactile telekinesis.” Tactile telekinesis attempts to explain why Superman can pick up a jetliner by the nose without the entire airplane buckling from the pull of gravity on the tail-end (for example) - asserting that the hero was surrounded by a solar-powered telekinetic aura that engulfed anything he touched - resulting in both physical and electromagnetic field manipulation to evenly distribute force across an object through only one point of contact.
Superman's "flight" was, originally, an extension of his strength - as the super-strong hero could just leap higher and farther than humans. However, viewers who watched Zack Snyder’s Man of Steel will see that jumping alone isn't enough to keep Superman airborne (at least in the modern movie universe); instead, Superman is shown lifting and spinning ice particles before erupting into the sky - implying that he isn't just pushing off or jumping, he's consciously using his bioelectric aura to manipulate surrounding gravitational forces – tactile telekinesis in practice. In the film’s final fight, Zod is also shown to levitate debris and other items when he learns to fly – indicating that when Kryptonians take flight, that flight unleashes energy onto the surrounding area and objects. As a result, the levitation seen in Man of Steel is an example of a complex gravitational field manipulation that allows Kryptonians on Earth to outright defy gravity, hover above the ground, and even lift heavy objects into the sky – all thanks to repurposing of solar energy.
Invulnerability
Certain versions of Superman also credit his "bio-electric aura" as a contributor to the hero’s invulnerability – as the bio-electric aura also surrounds objects and organisms in Superman's immediate vicinity, making it possible for Kal-El to protect Lois Lane, for example, from a deadly explosion without having to cover every square inch of her body. The strength and range of Superman's bio-electric aura varies but, in an extreme case, even enabled the hero to survive a supernova.
Yet, though justifications for Kryptonian invulnerability can vary, most have one thing in common: solar energy. As previously detailed, Krypton's red sun caused the kryptonians to evolve under extremely harsh conditions, in comparison to Earth, affording the extra-terrestrial race with an extremely dense molecular structure - including near-unbreakable cellular bonds. For that reason, the Man of Steel is invulnerable to injury on Earth - be it piercing, puncture, impact, and incineration. Though, absorbing yellow sun is necessary for Superman to maintain this invulnerability - as metabolized solar energy fuels and strengthens those near-unbreakable cellular bonds. If Kal-El depletes his solar stores or is exposed to kryptonite materials, he becomes increasingly vulnerable to attack and injury as well.
Heat Vision
Since Superman's powers are derived by absorbing and metabolizing solar energy then using that energy to fuel super strength, speed, and other enhanced abilities, one of the more literal examples of this process is Superman's heat vision - which allows the hero to emit stored solar energy as directed beams of focused heat through his eyes. The beams have varied in precision and strength throughout the years but have been shown to reach objects over a hundred feet away and, conversely, feature surgical accuracy - down to microscopic levels. Depending on the situation and intensity of the emission, Superman's heat vision can be invisible to the naked eye - allowing the hero to use the power, albeit sparingly, even when disguised as Clark Kent.
As indicated, Superman can also over-charge with solar power, and in modern versions of the character, a new evolution of heat vision was introduced: the "super flare." Using the same mechanics as heat vision, Superman can unleash a devastating attack on his surrounding environment - by venting the stored solar energy in every single one of his cells. The super flare is possibly the hero's most powerful ability but comes with a downside - expelling all of his stored up solar energy leaves Kal-El vulnerable and without powers, essentially human, for nearly 24 hours (the time it takes him to recharge those solar stores).
Conclusion
Even though we didn’t cover all of Superman’s powers here, it’s safe to say that many of the hero’s stranger abilities can also be explained by solar-power absorption. X-Ray vision? A further manipulation of Superman’s bio-electric aura that allows him to perceive cosmic radiation bouncing off objects in his surrounding environment. Genius level intellect? Yellow sun has further enhanced the Man of Steel's extra-terrestrial biology to process information faster than his Kryptonian ancestors (and much faster than humans).
No doubt, comic book writers have presented other explanations for Superman’s abilities; yet few offer such a convincing package. Now, if only there was one definitive answer for how the Man of Steel can shave his beard?
NEXT: Batman V Superman Ending Explained
Batman V Superman: Dawn of Justice is now playing, followed by Suicide Squad on August 5th, 2016; Wonder Woman on June 23rd, 2017; Justice League Part One on November 17th, 2017; The Flash on March 16th, 2018; Aquaman on July 27th, 2018; Shazam on April 5th, 2019; Justice League Part Two on June 14th, 2019; Cyborg on April 3rd, 2020; and Green Lantern Corps. on June 19th, 2020.