Have online speculators cracked Dynamo's levitation trick? David Penn, one of the country's leading illusionists, said the trick would have been months in the making. To present that illusion in a urban environment like that is incredibly challenging, especially on the side of a moving bus. It really pushes the boundaries," he said. It was excellent. It was probably incredibly dangerous, he's got a lot of guts. James Anthony, a member of Manchester's Magic Circle, said the "result speaks for itself." It's completely different, no one's ever done it off the side of a bus. It's completely original," he said. Both magicians refused to give away the secrets of the stunt, but speculation online is rife. Here are the three leading theories... Prosthetic limb Theory: Throughout the stunt Dynamo's right arm - the one touching the bus - remains at a perfect right angle to his body, leading some to suggest it's fake. According to this theory his real right arm is tucked beneath his clothes, while a prosthetic arm is bolted to the bus and specially designed to support his weight. Potential flaws: The arm does look remarkably lifelike. And wouldn't the people on the bus's top deck have notice his hidden real arm? Secret platform Theory: The arm is a distraction - while it's there for support, the real secret is in a hidden platform. The most likely candidate, according to this line of speculation, is a thin wire that Dynamo can balance on. He does appear to move from foot to foot in videos. Potential flaws: If it's a platform strong enough to stand on, surely it would have been spotted on camera? Camera trickery Theory: It wasn't that long ago that the levitation of another magician - David Blaine - had the country chattering. His Channel 4 program would show the shocked reaction of the public as he levitated on the street. According to online magic blogs the key to this trick was positioning the audience, thereby hiding the means of support. Could Dynamo have pulled off a similar feat? Potential flaws: Given how open Dynamo was, traveling on a bus with 360-degree exposure, he had almost no control over the audience's eyeline. How do you think he did it?