>>16711068
particulate matter is everywhere except (and sometimes even) cleanrooms
if something could magically detect the motion of a certain range of particulate sizes along maybe some sort of focus plane...
>>16711050 (OP)
In the absence of any detritus in the fluid or contrast with a fluid interface, seeing motion of water is just as hard as seeing motion of air.
>>16711135
No zoomer. Also not a fartmerican, so fuck you. As always, you have nothing of value to contribute, but you stay around to feel smart like a scientist. You are not.