electromagnetic radiation - Is there an infinite amount of wavelengths of light? Is the EM spectrum continuous?

The electromagnetic spectrum is a continuum of wavelengths of light, and we have labels for some ranges of these and numerical measurements for many.

Question: Is the EM spectrum continuous such that between two given wavelengths (e.g. 200nm and 201nm) there is an infinite number of distincts wavelengths of light? Or is there some cut-off of precision with which light might exist (e.g. can light only have wavelengths of whole number when measured in nanometers, etc.)?

Answer

In general the frequency spectrum for Electromagnetic (e.g light, radio, etc) is continuous and thus between any two frequencies there are an uncountable infinity of possible frequencies (just as there are an uncountable number of numbers between 1 and 2).

1. 
   

   There are situations in which the only relevant frequencies are discrete (such as the modes in a cavity).

   
   


2. 
   

   For any given experimental measurement you will always have a finite precision or bandwidth with which you can measure, and so although light at 200nm and 200.01nm is in principle different, you might not be able to tell in practice.