Superman! He is a super man, man. Well, not really, he’s actually an alien called Kal-El. Though his name may sounds like an unknown keyboard shortcut his powers are near infamous, ranging from the awesome (flight, X-ray vision) to the absurd (turning back time ).
It’s pretty much common knowledge that Clark Kent (a.k.a. Superman) grew up in Smallville, a sleepy little town which (depending on who was writing the comics at the time) was often located in rural Kansas. I think we can all agree that Kansas is undeniably located right here on planet Earth, and not to sound too much like Nigel Farage, but if Superman is waltzing around the very world that you and I live in, then surely he has to abide to our laws of physics?
Now I could sit here and nit-pick all the factual anomalies surrounding Superman, such as his ability to travel faster than the speed of light, or the fact a 70kg-plus man pushing people out of the way of a 10 gram speeding bullet with his immense power probably does them more harm than good. But this is all stuff that has been gone over a million times before and frankly is too kill-joy-like, even for me.
What’s far more interesting is exploring physics to find an explanation for Superman’s powers, the most intriguing of which is flight.
I spoke with Dr Jonathan Pearson, an ex-theoretical cosmologist, who laid out two plausible physical explanations as to why Superman can fly. Please note, the word ‘plausible’ is surrounded by inverted commas the size of ol' Clark's home planet Krypton.
Not only are these elusive waves highly topical at the moment, but they may also have the ability to make people fly… sort of. Gravitational waves are a by-product of mass moving through space-time and while everything emits them, they are so unfathomably tiny you simply cannot detect them. For example, it took two huge black holes colliding for astronomers to get a minuscule whiff of a gravitational wave, and even that required ridiculously hyper-tuned equipment.
So, in order to fly using gravitational waves Superman would have to act as a source of said waves and essentially surf them through space-time.
For the purposes of this explanation, imagine yourself floating in the middle of a calm lake, and then casually dropping a stone right in front of you. This would cause ripples (tiny waves) to radiate away from you. The heavier the stone, the larger the ripples, meaning a heavy enough stone could create waves large enough for you to surf on.
Apply this logic to space-time and our Kryptonian hero could disturb the ‘lake’ of space-time by rapidly oscillating a mass of some kind between his head and his toes, creating waves large enough to move him.
How heavy would this mass have to be exactly? Turns out it’s quite a lot, roughly 100 times the weight of our entire galaxy, and that’s just enough to float 1m off the ground for a minute, let alone fly around the world a couple of hundred times a second.
The energy required just to synthesise that mass alone is more than the sun has kicked out in its entire lifetime, and there are also one or two other niggles that go along with generating gravitational waves strong enough to lift a 70kg man.
For starters, the very waves Superman is surfing around on would obliterate everything in their path, and by obliterate I mean tear apart every single atom they touch. Not particularly useful when you’re trying to catch someone falling to their death.
Then there’s the issue of stopping. If Superman were to grind to a halt the sheer amount of mass decelerating in such a short time would actually create a black hole. Which is one way of stopping Lex Luthor I guess.
So gravitational waves may not be the best mechanism for flight but thankfully there is another means by which the cape-donning alien can soar through the skies like a bird and/or plane.
Anti-Gravity / Gravity Repulsion
Much like if you were to place two north-ends of a magnet next to each other, a blob of anti-gravity would repel a blob of gravity. Surprisingly, anti-gravity is everywhere in the form of dark energy, which is said to make up 70 per cent of the universe. However dark energy is incredibly sparse. Whereas a metre cubed of air weighs 1kg, a metre cubed of dark energy theoretically weighs a meagre 10-27kg. That's the equivalent of 0.
In theory, you could get as much dark energy as you want from the entire body of the universe, condense it into one space, and you would be able to repel gravity... (again, in theory).
However, if you wanted to float on Earth you would need enough dark energy to overcome its gravitational pull of 9.81m/s2, caused by its mass of 6x1024kg. So if you just get one Earth’s mass worth of dark energy in one place you could fly. Simple!
Using the Schwarzschild radius, you could make the blob of anti-gravity (with the mass of the Earth) about the size of a 2cm marble. Any smaller than that and you would have so much mass in one place you would have accidentally created a black hole. To get one Earth’s mass worth of dark energy (of density 10-27 kg/m3) you would need a volume roughly 300 trillion times the size of the largest visible star in our sky (VY Canis Majoris), and that’s only enough to MATCH Earth’s gravitational pull - you would need more to overcome it.
So apart from the small drawback of needing a volume of more than 300,000,000,000,000 VY Canis Majoris’ there are even more clauses to this flight method. While anti-gravity/gravity repulsion would allow Superman to fly, he could only do so in one direction, which would be directly away from the blob of anti-gravity.
And he would also never be able to stop floating either.
Oh, and the dark energy blob would also displace the Earth from its orbit in the opposite direction from Superman. So depending on where he is standing on the planet, he would either fry or freeze us by permanently expelling us from the habitable zone of our solar system. Nice going, Clark.
So, No Chance Then?
Did you really expect any different? While there is actual physics that gives an explanation as to why Superman can fly, not only are the real world applications of these theories damn near impossible, the side-effects are unfortunately pretty shitty. If Superman were to harness the physics required to fly at will his options are 1) fly and destroy everything in his path or 2) fly, just once, in one direction, for all eternity and condemn the planet he loves so dearly to a fiery fate or icy doomsday. Perhaps it’s best to just assume Superman can fly because he’s, well, super.