Hi, recently I saw a great video about some scientists levitating small objects in mid air by trapping them in overlapping 180 degrees out of phase sine waveforms. It is easy to see that air is the medium through which sound can travel and sounditself being the vibration of air traps these objects placed at the way of these waves. just to be sure everyone gets my idea here , here is the video about the sound. So could such principle be used if I had plasma as a medium, like in a chamber of plasma and I wanted to float an object or some charges like electrons in the middle of it , assuming electrons becauce they are lighter than ions, protons and would probably respond for such external manipulation. I read that the plasma has it's specific frequency under wich it acts like a typical conductor and reflects the em wave and above which the em wave can penetrate the plasma, I assume this boundary is different for different plasmas depending on the density of the plasma and temperature am I correct here ? So if I would have my plasma of whatever shape and I wanted to float an object inside of it , could I use the em waves at and above the specific frequency to achieve something similar to this in what they achieved with audio waves? I am asking this from a theoretical standpoint , so doesnt matter if objects cannot be in a plasma because of the heat and other factors dont play a role here.