So a physicist, and engineer and a paleontologist walk into a bar. The physicist asks the engineer, “Why can’t The Flash fly?” The engineer takes a deep breath; the paleontologist gets out his notebook. Yes, this scenario is real, and yes, I was the paleontologist. My attempt is to now distill the mad dialogue between said physicist, played by Ben Tippett of previous zombie article fame, and Jacob Stump, engineer and blogger extraordinaire. The science here is real; I just don’t necessarily comprehend all of it. I will do my best.
First thoughts: No. The speed of The Flash moving through the air is enough to cause some wackiness to happen. Wackiness is not a scientific term, but it’s appropriate. At supersonic speeds, which we as comics fans know is nothing boy our boy, Barry (or Wally, or Jay, or Bart, or Max, ect…) the flash would be moving faster than the air’s ability to fill the space he was just in. This could create areas of super low pressure around and behind The Flash, areas with very few air molecules. With no air molecules even flapping his arms he’d be pushing against nothing. Like a swimmer in the International Space Station, it just doesn’t work. REAL LIFE EXAMPLE: Submarines can only go so fast in the water because even with a very fast propeller at a certain point the water undergoes supercavitation (air bubbles from the extreme forces created by the propeller acting against the water).
But what if…
As we all know The Flash’s suit protects him from the friction of air particles around him, but the particles themselves are experiencing friction with each other. Friction creates heat. When fluids warm their properties change. Most fluids get more viscous, hot syrup pours more quickly than cold syrup. AIR IS THE OPPOSITE! So if The Flash experienced drag from the air he’d experience more drag as the air around him was heated from him running through it an pushing it out of the way. At the speeds The Flash moves the air could be thought as tar-like. Problem is you can push against tar well enough, but if you think about a running motion your arms and legs are moving back and forth, meaning you don’t really get a net gain of force against the air in either direction. (BIO NOTE: Birds deal with this problem by pulling their wings into their bodies on the upstroke and shooting them straight up to get the maximum benefit from the downstroke, like a swimmer putting their arms above the water when moving them forward then putting them back in the water to get the thrust.) So this scenario wouldn’t be ideal for flying.
But what if…
He kicked against the air really hard? Hard is sort of the wrong word to use, because at this point The Flash’s speed determines his force so could he kick against the air fast enough to propel through it? If he was moving SLOW enough. Above Mach 1 (the speed of sound in air) the rules change. So if The Flash wanted to flutter kick his was around his feet would actually need to be below the speed of sound. He wouldn’t be very stable if his toes created sonic booms every time they reversed directions (even though that’d be AWESOME as a weapon). Ok, flutter kicking has some effect so why not just combine that with the most obvious solution to The Flash getting airborne: jumping. Dude can run near the speed of light, so he gets going fast enough and then jumps. This jump is going to carry him some distance. I'm not sure if his legs are strong enough to straight up catch him when he hits the ground so it'd be good if he had some way of controlling his descent. Otherwise he might need stitches. As soon as his falling with style slows down to under Mach 1 he could flutter kick his feet between Mach 0.52 and Mach 0.95 (Yes, Jacob and Ben were creating actual calculations, go read their blog posts!) to stay thrusting through the air. My brain translating this into the one thing I could relate to: Flash can double jump! That in and of itself should be listed as a superpower, I’m sure Josh Richardson can testify to this as our resident gamer guy.
There are your science options for Flash flight. The irony of it all is that if he could fly he’d have to be moving slower than if he just stayed on the ground. I guess this is why Barry hasn’t done it yet. He, as a fellow scientician, probably figured this out years ago and it just laughing at us while reading this in the crime lab. Quit reading at work, Barry!
At the end of this entire conversation I pointed out that The Flash just spins his arms really fast and make mini vortexes to keep him hovering. Duh. Sometimes these eggheads really miss the obvious answers.
Ryan Haupt hopes everyone learned something from this, both about the Flash, physics and how scientists like to waste their time with their brains. If you want to hear more brainy time-wasting listen to his show Science… sort of.