النسبية الغاليلية والنسبية الخاصة
دبلومة البكالوريا الدولية · IB Diploma · Physics · HL الموضوع 5 4:09 سرد باللغة الإنجليزية · ترجمة مدمجة بالإنجليزية + الصينية
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النص الصوتي
Two observers can assign different times between the same events.
两个观察者可以为同一事件分配不同的时间。
A clock reading has meaning only when the frame and events are specified.
只有指定了参考系和事件，时钟读数才有意义。
In special relativity, inertial observers measure the same vacuum light speed.
在狭义相对论中，惯性观测者测量到相同的真空光速。
Time dilation compares proper time measured where two events occur at one place with the interval in another inertial frame.
时间膨胀比较固有时间与另一惯性参考系中的时间间隔。
Proper time is the time between events measured at one location in a frame.
固有时间是指在某一参考系中同一位置测得的两个事件之间的时间。
An inertial frame is a frame in which a free body moves at constant velocity.
惯性参考系是指自由物体以恒定速度运动的参考系。
The Lorentz factor is 1 divided by the square root of 1 minus speed squared over light speed squared.
洛伦兹因子等于1除以根号下1减去速度平方除以光速平方。
Galilean velocity addition is an approximation for speeds much smaller than light speed.
伽利略速度叠加公式是适用于远小于光速的速度的近似。
In the lab: Label which frame measures proper time or proper length before substituting.
在实验室中，代入数据前请标明哪个参考系测量的是固有时或固有长度。
Use event coordinates consistently.
事件坐标的使用须保持一致。
Do not combine lengths from one frame with time intervals from another without transformation.
未经变换，切勿将某一参考系的长度与另一参考系的时间间隔混合使用。
Known: v equals 0.60 c, and proper time is 4.0 microseconds.
已知：v = 0.60c，固有时为 4.0 微秒。
Gamma equals 1 divided by the square root of 1 minus v squared over c squared, which equals 1 divided by the square root of 1 minus 0.60 squared, which equals 1.25.
γ = 1/√(1-v²/c²) = 1/√(1-0.60²) = 1.25。
Delta t equals gamma times delta t sub 0, which equals 1.25 times 4.0, which equals 5.0 microseconds in the stated second frame.
Δt = γΔt₀ = 1.25 × 4.0 = 5.0 微秒（在所述第二参考系中）。
Your turn: A proper interval is 8 microseconds and gamma is 1.25.
轮到你了。 固有时为八微秒，伽马因子为1.25。
Find the other-frame interval.
求另一参考系中的时间间隔。
Pause the video and work it out.
请暂停视频，自己算一算。
Check: gamma times the proper interval, 1.25 times 8, is 10 microseconds.
核对：γ 乘以固有时间，1.25 × 8，得 10 微秒。
Time dilation is not an instrument fault.
时间膨胀并非仪器故障。
Proper length is measured in the object rest frame. A contracted length is measured in a frame where it moves.
固有长度在物体静止参考系中测量；收缩长度在物体运动的参考系中测量。
Not true: All inertial observers must measure the same time interval between any two events.
并非如此。 所有惯性观察者必须测量任意两个事件之间的相同时间间隔。
Simultaneity and duration are frame-dependent: inertial observers in relative motion generally measure different time intervals between the same two events.
同时性和持续时间依赖于参考系。 处于相对运动中的惯性观察者通常测量同一对事件之间的不同时间间隔。
Only the proper interval, measured in the rest frame of the events, is shared.
只有固有间隔，即在事件静止参考系中测量的间隔，才是共享的。
In special relativity, inertial observers measure the same vacuum light speed.
在狭义相对论中，惯性观测者测量到的真空光速相同。
The Lorentz factor is 1 divided by the square root of 1 minus speed squared over light speed squared.
洛伦兹因子等于1除以根号下1减去速度平方除以光速平方。
Watch for: time dilation is not an instrument fault.
请注意：时间膨胀并非仪器故障。
A proper interval is 12 microseconds and gamma is 1.5.
固有时为12微秒，洛伦兹因子γ为1.5。
Find the interval in the other frame.
求另一参考系中的时间间隔。
Inertial observers need not agree on the duration.
惯性观察者对持续时间未必一致。
The result is a dilated interval of 18 microseconds.
结果是膨胀后的时间间隔为18微秒。
The proper time is measured by a clock at rest relative to the events, 4 microseconds.
固有时由相对于事件静止的钟测得，为4微秒。
An observer moving relative to it measures a longer interval, 5 microseconds, so the Lorentz factor is 1.25.
相对运动的观察者测得更长的时间间隔，5微秒，所以洛伦兹因子为1.25。
At v equal to 0.60 c, the lab lifetime is 10 microseconds.
当 v 等于 0.60c 时，实验室中测得的寿命为 10 微秒。
Find the proper lifetime and the lab travel distance. Identify the proper clock.
求固有寿命和实验室中的飞行距离，并指出哪个是固有时钟。
Gamma is 1.25, so the proper lifetime is 8 microseconds.
γ 等于 1.25，所以固有寿命为 8 微秒。
The lab distance is 0.60 times 3 times 10 to the 8, times 10 to the minus 5, which is 1,800 m.
实验室中的距离等于 0.60 乘以 3×10⁸ 再乘以 10⁻⁵，即 1800 米。
Birth and decay occur at the same particle-frame location.
粒子的产生和衰变发生在粒子参考系中的同一位置。
Pause and check yourself. Explain each point on screen in your own words, then change one number in the last example and say which assumption must still hold.
暂停一下，自我检查：用自己的话解释屏幕上的每个要点，再改动最后一个例子中的一个数字，说明哪个假设仍然必须成立。