Physics doesn't lie, kids. It's bad news for fans of the Dark Knight: four physics students have proven that while the construction of the bat cape would allow Batman to glide from tall buildings, unfortunately it would do little to slow his rapid descent and eventually drop him on the pavement like a ton of bricks.
Frankly, I expected more from Bruce Wayne Industries.
In a paper titled "Trajectory of a falling Batman," David Marshall, Tom Hands, Ian Griffiths and Gareth Douglas studied the wingspan, height of descent and velocity representative of Batman's cape during one of his flights. As part of their research they exposed the bat cape's fatal flaws.
We know from the films that the bat cape is constructed not unlike a glider. Most of the time the dashing cape hangs loose, allowing for unfettered movement on the ground. Other times, when needed to scare the pants off a henchman or swoop down from a lofty perch, the Bat's arms outstretch and an electric current travels through the cape's "memory cloth," causing it to become rigid for flight.
While this is enough to support a glide of sorts, according to the team's calculations, the essential accessory falls short. The 15.4-foot wingspan is only half of a hang glider. If Batman launched himself off one of Gotham's average 492-foot high towers he could glide successfully for approximately 1,150 feet.
The problem is the caped crusader's velocity would peak somewhere around 68 mph before leveling off at 50 mph — enough speed to cause Batman to take a permanent dirt nap upon "landing."
As with all things in physics there are variables — the cape could be made bigger or Batman could leap from a taller building to change the glide slope and rate of descent. The team admits these are all things that could very well lead to a gentler landing, though with Batman's weight unknown I'm sure no physicist-to-be would want to commit to anything without crunching the numbers.
Because physicists are the solution-oriented types, the team came up with a few additional suggestions that would change the unfortunate outcome. Things such as parachutes and/or jet propulsion would allow for a more controlled and less death provoking descent.
One team member, 22-year-old David Marshall suggested that "If he really wanted to stick with tradition (of a glide) he could follow the method of Gary Connery, who recently became the first person to glide to the ground from a helicopter using only a wingsuit, although he only made it down safely using a large number of cardboard boxes."
Frankly, a padded landing (cardboard or otherwise) is far less badass than jets, so the memo to Bruce Wayne Industries re: Improvement of Batman's Cape Design is likely to have the more fearsome, fire-breathing option at the top.
The superhero certainly owes a debt of gratitude to the four creative physicists to be. They chose to focus on the Dark Knight's costuming problem as part of a fourth year Masters program Physics Special Topics module at the University of Leicester that encourages applying physics in an "outside of the box" situation.
The 'Trajectory of a falling Batman' certainly fits that bill. Well done, gentlemen, and I'm sure that if it were up to Bruce Wayne you'd all be wearing diamond-studded Rolexes and be invited to some fancy costume party thrown by the Mayor of Gotham as a thank you.
If you want to read the paper and get geeky with the calculations, you can check it out in the Journal of Physics Special Topics.