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 2 create a physics engine dedicated entirely to the animation of the female characters' breasts. "Dead or Alive 2" used the song "Exciter" by Bomb Factory in its opening sequence. Also used as a background track was "Deadly Silence Beach" and "Clumsy Bird". Both tracks can be found on the self-titled mini-album "Bomb Factory" and on the "Dead or Alive 2 Soundtrack". Two soundtrack CDs were released in 2000 by Wake Up in Japan: "Dead or Alive 2 Original Sound Trax" (KWCD-1001) and "Dead or Alive 2 Original Sound Trax" (KWCD-1004). Several Japanese guide books for the game were published by