"Google accidentally made computer science history last week. In recent years the company has been part of an intensifying competition with rivals such as IBM and Intel to develop quantum computers, which promise immense power on some problems by tapping into quantum physics. The search company has attempted to stand out by claiming its prototype quantum processors were close to demonstrating “quantum supremacy,” an evocative phrase referring to an experiment in which a quantum computer outperforms a classical one. One of Google’s lead researchers predicted the company would reach that milestone in 2017."