Wigner's friend and continuous time evolution of the state of a closed system and the probabilistic, discontinuous collapse of the state of a system upon measurement. Wigner's friend is therefore directly linked to the measurement problem in quantum mechanics with its famous Schrödinger's cat paradox. The thought experiment posits a friend of Wigner in a laboratory and lets him perform a quantum measurement on a physical system (this could be a spin system or also Schrödinger's cat). This system is assumed to be in a superposition of two distinct states, say, state 0 and state 1 (or "dead" and "alive", in the
Dead or Alive 5 Ultimate Dead or Alive 5 Ultimate Dead or Alive 5 Ultimate (abbreviated to "DOA5 Ultimate" or just "DOA5U") is a fighting game in the "Dead or Alive" series, developed by Team Ninja, and released by Tecmo Koei for the PlayStation 3 and Xbox 360 in September 2013. It was followed by an arcade edition later in 2013. It is the first arcade game to be released by Koei Tecmo since "Dead or Alive 2 Millenium" in 2000. "DOA5 Ultimate" is an expanded edition of 2012's "Dead or Alive 5", incorporating some features from the PlayStation Vita's "Dead or Alive 5 Plus"