Bouyancy depends on the average density of the media surrounding the body. So air plus metallic particles can be made to be a little more dense than a persons body. Blow air through the particles and then the person can swim.-- Ling, Aug 29 2014 Fluidized sand. SmashLab http://www.discover...-fluidized-sand.htmSkip to 00:40 if pressed for time. [2 fries shy of a happy meal, Aug 29 2014] I wouldn't want to put my head under but would like to try it in a sensory deprivation chamber. A black sea.-- wjt, Aug 29 2014 Need a dust mask or better, to protect the lungs from this.-- Vernon, Aug 29 2014 No. Fluid dynamics indicates that the person will immediately sink to the bottom as they will exhibit dynamic density greater than air while the metal dust exhibited only partial fluid behavior.-- WcW, Aug 29 2014 Totally. [link]-- 2 fries shy of a happy meal, Aug 29 2014 I'm not so convinced... First of all, the video is showing partial submergence. That is expected, because, with possible exception of one guy, no one can walk on fluid without displacing an equal mass. Secondly, the only references I can find, on fluid dynamics in fluid beds, refers to small particles which behave differently. I still think that large objects will react according to equivalent bulk density, unless someone can point out any strange other behaviour.-- Ling, Sep 01 2014 random, halfbakery