Exotic matter
There are several proposed types of exotic matter: Hypothetical particles and states of matter that have "exotic" physical properties that would violate known laws of physics, such as a particle having a negative mass. Hypothetical particles and states of matter that have not yet been encountered, but whose properties would be within the realm of mainstream physics if found to exist. Several particles whose existence has been experimentally confirmed that are conjectured to be exotic hadrons and within the Standard Model. States of matter that are not commonly encountered, such as Bose–Einstein condensates, fermionic condensates, nuclear matter, quantum spin liquid, string-net liquid, supercritical fluid, color-glass condensate, quark–gluon plasma, Rydberg matter, Rydberg polaron, photonic matter, and time crystal but whose properties are entirely within the realm of mainstream physics. Forms of matter that are poorly understood, such as dark matter and mirror matter. Ordinary matter placed under high pressure, which may result in dramatic changes in its physical or chemical properties. Degenerate matter Exotic atoms Negative mass Negative mass would possess some strange properties, such as accelerating in the direction opposite of applied force. Despite being inconsistent with the expected behavior of "normal" matter, negative mass is mathematically consistent and introduces