In a reference frame attached to the flame front, the flame spreading rate becomes an eigenvalue for the flame spreading over a rod fuel. 當參考坐標系團結在火焰前鋒上時(shí)，該火焰傳播問(wèn)題成為一準穩態(tài)問(wèn)題，燃料以一固定速度供給火焰。
Two events that occur at the same moment if observed from one reference frame may occur at different moments if viewed from another. 從某個(gè)參考坐標系來(lái)看，同時(shí)發(fā)生的兩個(gè)事件，對于另一坐標系而言，可能就發(fā)生于不同的時(shí)刻。
