Long before the Earth was.
what does an electromagnetic spectrum consist of
The entire electromagnetic spectrum frequencies, from the lowest to the highest frequencies, are collectively called the electromagnetic spectrum.
The visible spectrum is a tiny, almost negligible slice of the electromagnetic spectrum. 'Sonar' has no place in this discussion. It's not even electromagnetic.
Electromagnetic waves were predicted, by calculations, by James Clerk Maxwell. Later, different parts of the electromagnetic spectrum were either discovered or confirmed to be electromagnetic waves by various scientists.
The electromagnetic spectrum includes electromagnetic waves with a continuous flow of the wavelength.
X-rays were not invented, they were discovered. They are part of the electromagnetic spectrum and a natural phenomena.
Radio waves have the longest wavelength in the electromagnetic spectrum.
Visible light is a small section in the electromagnetic spectrum.
Radio waves have the lowest energy in the electromagnetic spectrum.
I think in the ultraviolet region of the electromagnetic spectrum.
It lies in infrared region of electromagnetic spectrum.
Light is classified in the electromagnetic spectrum as a form of electromagnetic radiation that falls within the visible spectrum, which is the range of wavelengths that can be detected by the human eye.