Dan Grayber’s machine-like sculptures resemble elaborate apparatuses from a futuristic science lab. In actuality, though, the three dimensional compositions of metallic rods, joints, pulleys, and levers are designed solely for the purpose of keeping themselves in place. Each leg of the spidery sculptures holds it weight to form a perfect balance that keeps the others up — but that’s all. Grayber’s work comments on how human life is beautiful and intricate yet is ultimately self-indulgent and pointless. He’s currently showing work at Johansson Projects (2300 Telegraph Ave., Oakland) in the show Maintanence, through August 27. Alongside, Craig Dorety presents Gradient, in which he uses his mastery of LED light displays to mimic the rising and setting of the sun. Dorety’s work investigates perception in relationship to light through geometric wooden sculptures that glow with shifting, colored illumination. Together, the works present a sci-fi collection of works made with technical prowess.