Quantum superposition the eigenvector corresponding to the measured eigenvalue. It is natural to ask why ordinary everyday objects and events do not seem to display quantum mechanical features such as superposition. Indeed, this is sometimes regarded as "mysterious", for instance by Richard Feynman. In 1935, Erwin Schrödinger devised a well-known thought experiment, now known as Schrödinger's cat, which highlighted this dissonance between quantum mechanics and classical physics. One modern view is that this mystery is explained by quantum decoherence. A macroscopic system (such as a cat) may evolve over time into a superposition of classically distinct quantum states (such as "alive" and
Dead or Alive 5 as several new stages and fighters (including "Ninja Gaiden"s Rachel and Momiji, and "Virtua Fighter"'s Jacky Bryant, as well as the return of "Dead or Alive 2" characters Leon and Hayate's amnesiac karateka identity, Ein), and all-new features such as two-on-two online multiplayer tag team battles, among many other changes. Three new female characters: Marie Rose, Phase-4 and Nyotengu, joined the game's roster in 2014. A free digital version, titled "Dead or Alive 5 Ultimate: Core Fighters", which features four playable characters and the online mode, with additional characters and story mode content available as purchasable downloadable content, was released