Some of these examples use glass or slats to partially enclose the staircase while keeping the airy feel. Others have a railing so there's at least a handhold should one feel wobbly. And finally, for the truly hardcore (and sure-footed), there are completely exposed steps.
Could you handle it? Where do you stand on floating stairs?
6. Lawrence Architecture via Homedit
7. Mark Koehler Architects via Plastolux.
8. Elite Metalcraft Co. via Houzz
9. Bates Masi Architects via Onekindesign
10. Ong and Ong Architects via Arch Daily
(Images: as linked above)