825.3 consequences of Einsteins postulates Event 1: emission of the pulse MOTION 0,y1=0,x1=0,t1=0 Event 2 reflection of Event 1 even the pul x2=v/2,y2=l0, z,=0,t,=τ/2 Event 3: detection of T 2 +(vT/2)2 the pulse 3=vz,y3=0, 2L/c z3=0,t53= =n22= 8 25.3 consequences of Einsteins postulates Conclusions: the moving clock has a greater time interval between its ticks than the clock that is at rest a moving clock runs slow. This is called time dilation Time intervals in relativity are not absolute or universal but depend on whether the clock is moving or not: we say time is a relative not an absolute quantity. The proper time interval is the shortest Time dilation has been confirmed by many experiments13 Event 1: emission of the pulse x1 = 0, y1 = 0,z1 = 0,t1 = 0 Event 2: reflection of the pulse 0, 2 2, , 2 2 2 2 0 τ τ = = = = z t x v y l Event 3: detection of the pulse τ τ = = = = 3 3 3 3 0, , 0, z t x v y s τ vτ 0l c l v 2 2 0 ( 2) 2 τ + τ = 2 2 0 2 2 0 1 1 2 v c v c l c − = − = τ τ §25.3 consequences of Einstein’s postulates Conclusions: the moving clock has a greater time interval between its ticks than the clock that is at rest ; a moving clock runs slow. This is called time dilation. Time intervals in relativity are not absolute or universal but depend on whether the clock is moving or not: we say time is a relative not an absolute quantity. Time dilation has been confirmed by many experiments: §25.3 consequences of Einstein’s postulates The proper time interval is the shortest