From eye-popping and mouth-watering street food displays to one-trick stunts, the reality is we live in an era of viral videos, where one impressive stunt or feat can amass thousands or even hundreds of thousands of views within only a few days.
Still, some stand out more than others. This is definitely the case of one video that has been circulating. It shows a man passing his hands through molten metal, and with no signs of any injury. First, he removes his work glove, and after a round of “See, audience, no tricks up my sleeve” gestures, he makes 5 swipes of his right hand. His hand seems to simply bounce off of the hot metal.
However, before we all begin hatching theories about pain-transcending meditation and launching Google searches with the phrase "biological anomalies in villages", in all probability the man is able to pull off the trick thanks to the Leidenfrost effect. The simplest way to think of it is to imagine the little droplets of water that you sometimes see dancing on a hot pan. At the time of contact, a protective layer is formed between the two due to a combination of evaporation and a resulting slow down of heat transfer.
In a tongue-in-cheek demonstration of the Leidenfrost effect, Cleveland State University Physics Professor Jearl Walker dips his hand into a pot of molten lead, explaining, "When I go in[to the water with my hand], the water will immediately vaporize and set up a gas layer on my fingers, keeping the molten lead away from me."
In our favorite experiment demonstrating how the Leidenfrost effect works, a team of scientists from the University of Bath was able to make water flow uphill : in other words, levitating water! They conducted a study to determine whether they could create a thermostat that required no moving parts, free of temperature-maintaining switches. The findings were published in a paper, titled “A Leidenfrost Thermostat”, which appeared in The American Society of Mechanical Engineers in March 2015.
Study co-author Kei Takashina said of the achievement: “The Leidenfrost effect has traditionally been viewed as a problem in the world of heat transfer systems, but we’ve harnessed this phenomenon to make a thermostat. This is the first time we’ve demonstrated negative feedback using the Leidenfrost effect. Our proof-of-principle device demonstrates that temperature can be controlled and stabilised using the Leidenfrost effect, but as it has no mechanical moving parts except for the water, it could potentially be more reliable than other thermostats.”
Check out the video below detailing their research:
The video of the man passing his hands through the molten metal or the man who is able to use his hands as skewers to fish fried chicken out of bubbling hot oil represent stunts in which the people seem to know the possible risks and act anyway. However, for some others who don't understand the true seriousness of necessity of the often used disclaimer "Don't try this at home," accidents are bound to occur.