Is the electromagnetic spectrum infinite?

That's a hazardous word. Let's just say that the wavelength can be as long as twice the diameter of the universe or as short as the Planck length. read more

The electromagnetic spectrum is a human abstraction to order the various wavelengths of electromagnetic radiation. The wavelength can run from zero to a blazillion times the size of the Universe. Of course, you only use the range in the spectrum that serves your needs, which varies from case to case. read more

The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from below one hertz to above 10 25 hertz, corresponding to wavelengths from thousands of kilometers down to a fraction of the size of an atomic nucleus. read more