主题：美国求学执教的见闻和感受（0） -- changshou

in classic physics, "up to" SR, we are all basically talking about 惯性参照系vs 惯性参照系 運動/movements, where in general we don't really have 加速度 in between 惯性参照系 per concept of 惯性参照系

if there is 加速度, it must be 引力, assuming a local 均匀引力場, meaning all 加速度 for all objects is same (such as 重力加速度为常数, and in a 保守力作功与路径无关) regardless of their 質量, _伽利略变换Galilean Transformation still holds, 低能条件 & local;

引力、慣性、狹義相對論及弱等效原理 wiki for math details

so, jumping out of brain box=basically jumping out of mind 重力場, using an analogy, regardless of where you are and what you are doing, or you would be torn down into "nothing (human does die) " by 保守力 in that particular 保守力場

to do the jumping, one obviously needs GR, or the 加速度 you buy will be a fake one, and you are still in a local 均匀引力場, your local 保守力場;

from there on, GR.