We have holograms that are in 'open' space. The problem is they aren't particularly fast, safe, or interestingly- quiet. The ones I know of converge multiple b

We have holograms that are in 'open' space. The problem is they aren't particularly fast, safe, or interestingly- quiet. The ones I know of converge multiple beams at a point; this results in a Bloom (https://en.m.wikipedia.org/wiki/Thermal_blooming https://en.m.wikipedia.org/wiki/Thermal_blooming). Not sure how they aim the beams. (Voice coil and mirrors, digital mirror device aka DLP. Both valid options with pros and cons)