Yeah, sorry for the jargon. “System with a boost symmetry” = “relativistic system” as tailcalled was using it above.
Quoting tailcalled:
Stuff like relativity is fundamentally about symmetry. You want to say that if you have some trajectory τ which satisfies the laws of physics, and some symmetry σ (such as “have everything move in → direction at a speed of 5 m/s”), then στ must also satisfy the laws of physics.
A “boost” is a transformation of a physical trajectory (“trajectory” = complete history of things happening in the universe) that changes it by adding a fixed offset to everything’s velocity; or equivalently, by making everything in the universe move in some direction while keeping all their relative velocities the same.
Yeah, sorry for the jargon. “System with a boost symmetry” = “relativistic system” as tailcalled was using it above.
Quoting tailcalled:
A “boost” is a transformation of a physical trajectory (“trajectory” = complete history of things happening in the universe) that changes it by adding a fixed offset to everything’s velocity; or equivalently, by making everything in the universe move in some direction while keeping all their relative velocities the same.