This is sort of SF in the sense that it's not scientifically accepted or reviewed. The "idea" comes from other people and it is that a usually round light beam of a certain diameter, like 30-50-100-similar cm diameter, extends slowly and even stops midair. It's flat at the end. Like a straight cylinder of semi transparent colored light with a perfectly straight 90 degree bottom end. It's the physically possible? How? PS: might be accompanied with various physical effects such as appearing to be solid or semi solid in nature, not blinding, no heat.