NASA scientist creates a video of a liquid sand hot tub

A former NASA engineer has created a hot tub with a difference, filled with liquid sand that acts the same way as water, allowing him to float and splash around. Mark Rober, 37, from Orange County, California, is known for his quirky science based videos on YouTube. And for his latest post, he decided to customize a hot tub so he could experience the sensation of floating in liquid sand, known in science as a fluidized air bed. Experiment: During the video, Mark reveals how he created'liquified sand' using an old hot tub, copper pipes and pressurized air'I am sitting in a hot tub filled to the brim with solid sand. This is one of the coolest things ever,' Mark told the camera as he sat in his creation.