Post created by: Anna
Anyone who has read or watched The Lord of the Rings or The Hobbit, is easily able to grasp just how valuable the Mirkwood elf Legolas is. The success of the Ring-bearer Frodo’s quest is very much due to him joining the cause. Not only is Legolas skilled in combat, but he requires little to no sleep, is immortal, and has a heightened sense of sight and hearing. Another, potentially lesser-known perk of being Legolas is that he can defy gravity. One particular scene of The Hobbit (which he ought to have been left out of) demonstrates this skill quite explicitly. After crushing an orc’s head, Legolas leaps from brick-to-brick along a falling stone bridge, gliding seamlessly over the chasm lying beneath him as the rock formation crumbles away. Cue Tolkein rolling over in his grave.
How this happens, only the filmmakers can be sure of. But the question remains, is it feasible, even for eleven standards? To begin, we must consider Middle-Earth’s gravitational field. Tolkien wrote that Middle-Earth is located on Earth, so we can assume that the acceleration of gravity is 9.8 m/s². Orlando Bloom is 1.8 meters tall so it is safe to assume that Legolas also shares this height. Using Tracker Video Analysis, Allain Rhett, Associate Professor of Physics at Southeastern Louisiana University, found that three of the falling stones in the scene are of the following vertical accelerations: -1.122 m/s2, -2.792 m/s2, and -2.46 m/s2. The only viable way in which this data could be wrong is if Legolas had a much larger mass. Because the stones would also be much larger, their acceleration would be greater. The scene has to have been conducted in slow motion (Allain).
The notion of running on falling blocks is still in question, however. In theory, the possibility is real. In analyzing a free body diagram of Legolas and the stones’ movement, Legolas’ landing and subsequent push off upon the blocks, in addition to gravity, causes a change in the block’s momentum. Legolas does not contribute much in terms of changing the blocks’ momentum since the stones’ have such a large mass. It is the timing, however, of Legolas’ feat that is truly remarkable. As Allain indicates quite clearly, “If the block is falling, Legolas won’t have much time to push on this block to push himself up.” As the distance the blocks fall increases, the less time there is for Legolas to push up off of them. Legolas would only have 0.05 seconds to land on a stone after it had fallen just half a meter. In assuming that he jumps 0.5 meters upward to get to the next block, and Legolas has a mass of 60 kg, Rhett calculated that he must jump with a force of 7,788 Newtons. Then there is also the horizontal component of Legolas’ movement to consider. If the blocks were each 0.5 meters in length, his horizontal velocity would be (0.5 meters)/(0.05 seconds) = 10 m/s or 22 mph (Allain).
That’s quick but still doesn’t seem totally impossible given all that elves are capable of. If we are to impose what we now know in analyzing the actual scene itself, we would see some inconsistencies with the physics. In looking at a graph outlining the vertical motion of Legolas, we can see that the blocks Legolas pushes off of are about one meter below the bridge, which doesn’t bode well in providing Legolas with sufficient landing time. And until Legolas reaches the opposite side of the bridge from where he set out, all of the bricks he lands on have fallen at least a meter below their initial placement when the bridge was intact. In this scenario, Legolas would have to jump higher and push harder than what we assumed he could do in the above calculations, since he would have an initial downward velocity of roughly 4.5 m/s (Allain). I think it’s safe to say that Legolas had some help from the movie crew in performing such a stunt. Sometimes the things that appear “seemingly impossible,’’ are actually impossible.
Picture and Information from…
Allain, Rhett. “The Laws of Physics Do Not Apply to Legolas.” Wired, 08 Apr. 2015, https://www.wired.com/2015/04/laws-physics-not-apply-legolas/.
Comments