Question

I have a spectrometer which outputs a dataset of Irradiance (Watt per meter² per nanometer) in the vertical axis vs. wavelength (nanometer) in the horizontal axis.

The fact that it is per nanometer means that a plot of this dataset is not a scatter plot, but a histogram.

Now, suppose I see in the newspaper a histogram that depicts the age distribution in a city; you might see the number of people in the city between age 10-20 years, a 20-25 years old bin, a 25-35 years old bin, a 35-55 years old bin etc. The vertical axis in this case is simply number of people, not number of people per unit of age in years.

My question is why the developer of the spectrometer outputs the radiation power per wavelength unit, and not a simple data set of radiation power in each wavelength - a series of heights.

The only thing I can think of is that wavelength (the independent variable in the former case) is a continuous variable. And age is not continuous (at least, not in the case of counting number of people in a specfic age). Is it correct?

Answer 1

The developer of the spectrometer outputs the radiation power per wavelength unit because wavelength is a continuous variable. Different parts of the electromagnetic spectrum are typically specified using different units, such as frequencies for radio waves and wavelengths for visible light. This convention allows the spectrometer to accurately analyze the light source and provide valuable information about its characteristics.

Step-by-step explanation:

The developer of the spectrometer outputs the radiation power per wavelength unit because wavelength is a continuous variable. In contrast, age is not continuous when counting the number of people in a specific age range. By expressing the radiation power per wavelength unit, the spectrometer can represent the intensity of radiation at different frequencies or wavelengths accurately and provide valuable information about the light source.

Additionally, different parts of the electromagnetic spectrum are typically specified using different units, such as frequencies for radio waves and wavelengths for visible light. This convention is based on convenience and historical legacies.

Overall, the use of a dataset of radiation power per wavelength unit allows the spectrometer to analyze the light source accurately and provide valuable information about its characteristics.