In a reference frame attached to the flame front, the flame spreading rate becomes an eigenvalue for the flame spreading over a rod fuel. 当参考坐标系团结在火焰前锋上时,该火焰传播问题成为一准稳态问题,燃料以一固定速度供给火焰。
Two events that occur at the same moment if observed from one reference frame may occur at different moments if viewed from another. 从某个参考坐标系来看,同时发生的两个事件,对于另一坐标系而言,可能就发生于不同的时刻。