How did Louis Essen measure the speed of light? (1 Viewer)

[Thundermaster123]

I need help in understanding how Louis Essen measured the speed of light. It would be great if someone could explain the method.

 

[Life'sHard]

If I'm not mistaken isn't this out of syllabus?

 

[amdspotter]

If I'm not mistaken isn't this out of syllabus?

Nah it comes under this dot point if I'm not mistaken:
conduct mvestigations of historical and contemporary methods used to determine the speed of light and its current relationship to the measurement of time and distance (ACSPH082)

 

[vishnay]

If I'm not mistaken isn't this out of syllabus?

syllabus is vague enough that this can technically be counted as part of syllabus but i highly doubt this would ever be explicitly tested in hsc

 

[wizzkids]

Essen paved the way for the modern definition of the second, so he is significant. Essen's method of measuring the speed of light was a bold departure from optical methods. He used a microwave cavity resonator, with interior dimensions known to within a few micrometres. The resonant modes of the cavity resonator were fixed by the interior dimensions. He knew the precise frequency of his wave generator from his experience with atomic clocks. He used the fundamental wave equation, v = f x lambda to come up with a value for "c" of 299,792 kms-1