The paper by Matthew P. A. Fisher explores the possibility of a new thermodynamic phase in the mixed state of bulk, disordered, type-II superconductors, termed a "vortex-glass superconductor." This phase lacks conventional off-diagonal long-range order but is argued to be a true superconductor with zero dc resistance. The author discusses the role of disorder in pinning vortex lines, leading to metastable currents that decay as $(\ln r)^{-1/\mu}$ with $\mu \leq 1$. The relevance of this phase to experiments on bulk high-$T_c$ oxides is also discussed. Fisher uses a Ginzburg-Landau Hamiltonian and a dual representation of the mixed state to analyze the system, showing that a vortex-glass phase exists in 3D but not in 2D. The phase is characterized by a nonzero Edwards-Anderson order parameter but lacks conventional off-diagonal long-range order. The paper also explores the dynamics of the vortex-glass phase, predicting a nonlinear voltage response and vanishing linear dc resistance.The paper by Matthew P. A. Fisher explores the possibility of a new thermodynamic phase in the mixed state of bulk, disordered, type-II superconductors, termed a "vortex-glass superconductor." This phase lacks conventional off-diagonal long-range order but is argued to be a true superconductor with zero dc resistance. The author discusses the role of disorder in pinning vortex lines, leading to metastable currents that decay as $(\ln r)^{-1/\mu}$ with $\mu \leq 1$. The relevance of this phase to experiments on bulk high-$T_c$ oxides is also discussed. Fisher uses a Ginzburg-Landau Hamiltonian and a dual representation of the mixed state to analyze the system, showing that a vortex-glass phase exists in 3D but not in 2D. The phase is characterized by a nonzero Edwards-Anderson order parameter but lacks conventional off-diagonal long-range order. The paper also explores the dynamics of the vortex-glass phase, predicting a nonlinear voltage response and vanishing linear dc resistance.