Negative massIn theoretical physics, negative mass is a hypothetical type of exotic matter whose mass is of opposite sign to the mass of normal matter, e.g. −1 kg. Such matter would violate one or more energy conditions and show some strange properties such as the oppositely oriented acceleration for an applied force orientation. It is used in certain speculative hypothetical technologies, such as time travel to the past and future, construction of traversable artificial wormholes, which may also allow for time travel, Krasnikov tubes, the Alcubierre drive, and potentially other types of faster-than-light warp drives.
Negative energyNegative energy is a concept used in physics to explain the nature of certain fields, including the gravitational field and various quantum field effects. Gravitational energy Gravitational energy, or gravitational potential energy, is the potential energy a massive object has because it is within a gravitational field. In classical mechanics, two or more masses always have a gravitational potential. Conservation of energy requires that this gravitational field energy is always negative, so that it is zero when the objects are infinitely far apart.
Alcubierre driveThe Alcubierre drive (alkuˈβjere) is a speculative warp drive idea according to which a spacecraft could achieve apparent faster-than-light travel by contracting space in front of it and expanding space behind it, under the assumption that a configurable energy-density field lower than that of vacuum (that is, negative mass) could be created. Proposed by theoretical physicist Miguel Alcubierre in 1994, the Alcubierre drive is based on a solution of Einstein's field equations.
StarshipA starship, starcraft, or interstellar spacecraft is a theoretical spacecraft designed for traveling between planetary systems. The term is mostly found in science fiction. Reference to a "star-ship" appears as early as 1882 in Oahspe: A New Bible. While NASA's Voyager and Pioneer probes have traveled into local interstellar space, the purpose of these uncrewed craft was specifically interplanetary, and they are not predicted to reach another star system; Voyager 1 probe and Gliese 445 will pass one another within 1.
Exotic matterThere 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.
