Do You Know How to Do a Dye as It Ink Doughnut?

Scientists used vortex rings blasters to shoot dye in the same direction. The experiment was done once, but it seemed not repeatable. If you don't take all these steps to know why it worked, then even if you got it right, you'd still be in the same boat that you were in with the old video. David: Why hasn't this been reproduced in the last 21 years? Because it's hard.