What are the amplitudes called for blue visible light, and microwaves?

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Discussion Overview

The discussion revolves around the terminology used to describe the amplitudes of blue visible light and microwaves, comparing it to the amplitude of sound waves. Participants explore the appropriate terms and concepts related to amplitude in different contexts, including sound, radio frequency, and light.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that the amplitude of blue visible light is referred to as brightness, while questioning the terminology for microwaves.
  • Another participant mentions that intensity and amplitude are terms used interchangeably, indicating a more dictionary-like approach to the question.
  • A third participant clarifies that blue light and microwaves are different frequencies, not amplitudes, but agrees with the previous participant that the terminology remains consistent across contexts.
  • A minority viewpoint introduces a more nuanced discussion about how different fields measure amplitude, noting that sound professionals use sound pressure level (SPL) while RF professionals measure field strength in volts per meter. This participant highlights the differences in measurement approaches between sound, radio waves, and light, emphasizing the role of quantum efficiency in light measurement.

Areas of Agreement / Disagreement

Participants express differing views on the terminology and measurement of amplitude across different types of waves. There is no consensus on a single term or approach, and the discussion remains unresolved regarding the best terminology to use.

Contextual Notes

The discussion highlights the limitations of terminology across different fields and the dependence on context, such as frequency ranges and measurement techniques. The differences in scale and measurement methods for sound, microwaves, and light are acknowledged but not resolved.

FisherDude
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The amplitude of sound waves is commonly referred to as volume. What about for blue visible light, and microwaves? I'm guessing for the first one it's brightness. Btw I'm looking for a word answer, not the magnitude of the amplitude (not a numerical amplitude)

Thanks for reading.
 
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Intensity. Amplitude. The question sounds more like a dictionary rather than a physics question.
 
Btw, blue light and microwaves are different frequencies, not amplitudes. But mathman is right - the terminology is the same.
 
Minority viewpoint: there is an interesting question behind this. Professional sound folks measure SPL ... sound pressure level ... to assess the amplitude or volume of sound. RF people measure 'Volts Per Meter' from a Field Strength meter as a measure of the E field of a source, and call it field strenth or intensity. By the time you get to light we don't measure the peak of the electric field, we measure the intensity, the average energy delivered, and we do that with detectors that have a 'quantum efficiency'.

So on the one hand, they are all the same thing: amplitude is amplitude. On the other hand, the huge change (sound at kilohertz to light at 100's of terrahertz) in scale allows us to use comfortable classical concepts for sound and radio waves, while light is better handed with photon and quantum efficiencies.

If you think this doesn't matter, consider the difference in output from a sound transducer, which outputs a waveform proportional to the pressure field, and the output from a photodiode, which outputs a current proportional to the incident light energy (# electrons proportioanl to # photons).
 

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