Atoms at negative Kelvin temperatures can exist in exotic high-energy states that are not normally stable at normal temperatures, and the transition between energy states happens very rapidly. When you add more energy to a system at negative temperature, it actually decreases the entropy in the system.
This potentially allows for the creation and study of new types of matter previously thought impossible or at least extremely difficult to create. This may include exotic matter with negative mass that exhibit properties akin to antigravity and/or Dark Energy. This may provide further insights for astrophysics and cosmology.
Game and Story Use
- Can be used as your justification for all sorts of super-science or alternative science, or a way to limit their availability within a setting. Also this provides some interesting flavor or description.
- Perhaps the warp drive in your sci-fi setting runs cold, not hot.
- Exotic matter may allow for the construction of a wormhole to other parts of the galaxy. However, it only works at negative temperatures, which are very damaging to organic tissues (I would assume). So you can teleport or send through time certain inorganic resources, but only those that are hardened or insulated against the extreme temperatures they will come into contact with along the way. You could send a Von Neumann Probe, metal ingots, or or maybe even freeze-dried protein item to another world in such a setting, but not a living human.
- The time machine or antigravity engine has a major temperature-related side-effect. Possibly either flash-freezing or even heating (see below) the area around it.
- Any of these devices might thus only be available in laboratory environments where super-cooling is a possibility. Which would mean you can have a time-machine, etc, but not a safely man-portable one.
- The wikipedia page on negative temperature makes some interesting statements about how negative temperature systems interact with positive temperature systems. Normally if you put a hot object and a cold object together, the hot one cools down and the cold one warms up until eventually they equalize. But apparently (I could be totally misunderstanding the science here) if you put a hot object and a negative temperature object together, the hot object actually gets hotter. Crazy, huh?
- Which means you can twist the players expectations, make the science feel more magical, etc.
- Disaster! A negative temperature experiment runs out of control, and threatens to either freeze or burn the entire planet.