As science experiments go, this was one of the more spectacular.
At a special Harry Potter-themed event at a museum in Arkansas, the lead demonstrator asked visitors what they thought would happen if they combined liquid nitrogen with hot water.
The answer, it turned out, was this.
As two demonstrators dumped buckets of hot water into the specially constructed nitrogen container, a huge cloud erupted, shooting as high as the ceiling and, according to one onlooker, soaking the front row of people looking on at the Museum of Discovery in Little Rock.
It wasn’t just the audience who were taken by surprise – the museum’s educators were too.
Sara from Little Rock, who took the video, told the Press Association: “Both of their face shields were blown off, the assistant wasn’t wearing an apron or as much covering as he was, and they were both looking up at the ceiling with surprise afterwards.”
The experiment took place at a special evening event, open only to adults, called Science After Dark: Wizards, Muggles and Science.
Both Sara and the museum confirmed nobody was hurt, even if the experiment didn’t go quite to plan.
Kelley Bass, the museum’s chief executive officer, told the Press Association: “The hot water hitting the very cold liquid nitrogen causes a rapid phase change. The expanding gas is forced upward, creating the large ‘cloud’.
“In this case, the innermost of the three plastic vessels shattered and the force of the reaction between the liquid nitrogen and hot water propelled it upward.
“The middle vessel also broke but remained contained in the larger white vessel that surrounded the inner two vessels.”
Bass, who said the museum had done the experiment “dozens if not hundreds of times”, added that the outer vessel was there as a safety measure to protect visitors and that it “worked just as it was supposed to, absorbing the shock and directing everything upward”.
The incident didn’t seem to diminish the enjoyment of the visitors in attendance one bit.
Sara, who was there with her husband, said: “People were having a good time and enjoyed the show. I didn’t get the indication that anyone was hurt or afraid by any means.
“The Museum of Discovery is supported and adored by the locals.”
As for why the inner container shattered, Bass said it was down to “thermal shock”.
Bass added: “We believe the innermost trash can failed due to thermal shock from the liquid nitrogen sitting in the bottom end of that vessel while our educators donned their safety gear.
“The best news here is that the precautions with the demo protected the museum guests and no-one was injured.”
He said that the museum would review its safety protocols and “share this experience with other science museums here in Arkansas and nationwide”.