If spin classes were housed in pseudo-planetariums like this art installation by Bruce Munro, I’d probably sign up for them. Well, I’d sign up for them and then feel guilty for not attending, but that is beside the point.
Called Star Turn, the interactive exhibit uses absolutely no electricity what so ever. T-light candles fly through the air on a mechanical armature which is spun by pedal-power. The candles, mounted on metal brackets, are encased in borosilicate sleeves to protect them (and the cyclist) as they spin.