acceleration
This term carries a clinical, precise energy associated with physics and engineering. It describes the sensation of being pushed back into a seat or the sudden surge of speed that transforms a slow state into a fast one. It is the active transition of momentum rather than the speed itself. In a broader social or economic sense, the word evokes a feeling of urgency and compression. When applied to "digital acceleration" or "cultural acceleration," it suggests a pace of change that is becoming so rapid it may feel uncontrollable or overwhelming to the human experience.
Countable when referring to a specific instance of speeding up, such as the acceleration of a rocket during takeoff. Uncountable when referring to the general physical concept or the mathematical property of motion.