For the time being, classical technology can manage any task thrown at a quantum computer. Quantum supremacy describes the ability of a quantum computer to outperform their classical counterparts. Some companies, such as IBM and Google, claim we might be close, as they continue to cram more qubits together and build more accurate devices. Not everybody is convinced that quantum computers are worth the effort. Some mathematicians believe there are obstacles that are practically impossible to overcome, putting quantum computing forever out of reach. Time will tell who is right.