According to our teacher, the electromagnetic spectrum comprises "Cosmic rays", Gamma rays, X-rays, UV rays, Visible light, Infrared rays, Microwave rays, and Radio waves/rays. I didn't really like the "Cosmic rays" in the whole equation, all because it's not a EM (ElectroMagnetic) radiation, since:
- It consists of mostly protons, and a little alpha particles, with traces of beta-particles and heavier elements.
- They do not propagate at the speed of light, a charecteristic property of EM radiation.
- They aren't made of photons; the signature content of an EM ray.
- Unlike EM rays, they are modulated by the earth's magnetic field and solar factors.
- Many interactions with earth's atmosphere wouldn't be observed if cosmic rays were to be EM rays
Cosmic rays are blasts of ionizing radiation of extrasolar (at times solar) origins. These rays aren't composed of photons, as mentioned afore, but of protons (at around 90%), alpha particles (9%), beta particles (1%) and traces of elements which mass to range all the way to iron nuclei. Since it's consitiuents haarbor mass, relativity forbid's there propagation at the speed of light. However, it may propagate at relativistic velocities, with unignorable effects like time dilation, lorentz contraction, and so on.
Cosmic radiation comprises particles with extremely high energies (extremes peaking at 50J/particle!!), and are highly ionizing (i.e capable of stripping electrons off the atom's vicinity). Ionizing rays are charecterized by high energies per particle, instead of an intense flood of particles. Gamma rays and X-rays are relatively less ionizing, but have considerable penetrating power, which makes X-rays ideal for certain medical imaging mechanisms.
Cosmic rays may interact with earth's upper atmosphere to generate unstable mesons, and suvh particles, which are to instantaneously decay into X-rays and other forms of particle radiation. Whatever may it be, they're NOT EM rays, and are not included in the EM spectrum.
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