Physics In My Traveller Universe
Traveller is a science fiction RPG. Therefore I don't restrict my universe to
what we know now (though I'm somewhat convinced that we currently have a reasonable handle on
all of the true laws of nature - I just hope I'm laughing at that comment in twenty years).
Thus in MTU there are several additional laws of nature (besides the forces that we're aware of now: gravity, electromagnitism, strong, and weak). I have not fully specified the additional laws, and I will always leave it a little open ended. However the scientists of the 3I are aware of twelve laws of nature and their associated forces and particles. The laws are grouped into four triplets. A triplet is a group of laws that behave in similar ways and on similar forms of matter. Gravity and electromagnitism and a third (unknown to Earth of 2003) law are grouped into the Natural triplet. These laws govern the things we see every day. I keep the third law of this triplet in my bag of GM tricks.
The strong force, the weak force, and a third (unknown to Earth of 2003) law are grouped into the Atomic triplet. These laws govern the behavior of the atom. This third law helps make the connection between classical physics and quantum mechanics more clear. Like the third Natural law, as a GM I do not qualify this law, but keep it available to get out of tight spots...
The remaining two triplets are entirely unknown to the scientists of Earth 2003. One of these triplets I keep unnamed, but one of the laws in this triplet governs the Invisiton and the Anti-invisiton particles. These two particles are sub-atomic particles and they are present in the nucleous of the atom. They were given their names by the scientists who first discovered them because they had remained invisible to physicists for so long (I'm not going to put a date on their discovery). These two particles are of opposite mass, and they are present in the nucleous in equal numbers (thus their mass is cancelled out, and not detectable to Earth 2003). I use the Invisitons to allow for entirely new forms of matter. However due to another law in the Invisitons triplet these forms of matter are not readily available on the Earth (though the particles are present in all atoms). In essence the Invisiton allows for a much larger Periodic Table.
The last triplet of laws are called Information laws. These laws govern the flow of information in the universe including the transmission of the fields of all laws. Once the Information triplet was discovered scientists realized that the speed of light was not absolute. Additionally, Psionics are governed by these laws. I keep these laws non-intuitive and non-specified to allow for a very wide range of psionic capabilities.
NOTE: What I've done here is to write myself a blank check. But that power wielded indiscriminately would spoil a game. Therefore I simply use these laws to explain things like grav-plates, psionics, and other such things, and to allow for some slightly more exotic Ancients artifacts.