The Leap of Faith, falling from huge heights on to your back in a cart full of hay, is a core part of Assassin's Creed, but just how far could you drop in real life?
That's where science comes in thanks to the University of Leicester and specifically Gregor McQuade, Michael Walker, Lee Garland and Thomas Bradley from the Department of Physics and Astronomy, along with their paper "A3_5 Falling into Straw."
Here's the abstract, describing the core idea behind the research:
The video game 'Assassin’s Creed' often depicts and encourages the player to leap off tall buildings into piles of straw/hay. This article looks into whether this is survivable, and finds the maximum height to which the depicted hay piles are safe to jump into to be about a 12-13m fall, and the max survivable fall height to be about 50m.
The science involves some pretty hardcore looking equations that mathematically calculate things like "the cushioning force provided by a pile of straw" (found by looking at the force required to compress it) and "the pressure applied by a falling object". They also look at things like impact velocity, deceleration, and the length of time the collision takes.
Using this, the team worked around the idea of an average human male's weight and the highest drop in the original game: the cathedral of the Holy Cross at Acre. They also stipulated the following, concerning what counts as "survivable":
"The maximum deceleration that a human can survive over instantaneous impact times, is roughly 100 times acceleration due to gravity. While not practical, (this acceleration would cause serious injury) this is a good upper bound for a survivable impact. A more comfortable impact deceleration is 25g."
Basically, what they found is that you'll survive most drops if, A) you're not bothered about being pretty any more, or, B) you really, really stack that hay up. Here's the conclusion from their paper:
The height of the piles of straw in the game 'Assassin’s Creed' is approximately 1.5m. Even using the most optimistic survivable impact accelerations, incurring severe injuries in the process, the leap off the cathedral in Acre requires a greater amount of cushioning than is depicted. The actual height the depicted amount of straw (1.5m) should correctly cushion was calculated to be a drop of 12-13m, giving a safe deceleration of 25g for a short duration of time. If the jumper is willing to suffer severe injuries (100g impact), the maximum jump height increases to 50m
[Journal of Physics Special Topics 1 A3_5 Falling into Straw - University of Leicester]