Atomic, molecular, and optical physics the origin of the index of refraction treated an electron in an atomic system classically according to the model of Paul Drude and Hendrik Lorentz. The theory was developed to attempt to provide an origin for the wavelength-dependent refractive index "n" of a material. In this model, incident electromagnetic waves forced an electron bound to an atom to oscillate. The amplitude of the oscillation would then have a relationship to the frequency of the incident electromagnetic wave and the resonant frequencies of the oscillator. The superposition of these emitted waves from many oscillators would then lead to a wave which
Problem of why there is anything at all may necessarily exist. Particles can emerge from underlying quantum fields under the effects of quantum physics and possibly under other physical laws that may have existed at the start of the Big Bang. Problem of why there is anything at all The question "Why is there anything at all?", or, "Why is there something rather than nothing?" has been raised or commented on by philosophers including Gottfried Wilhelm Leibniz, Martin Heidegger − who called it the fundamental question of metaphysics − and Ludwig Wittgenstein. The question is general, rather than concerning the existence of anything specific such as the universe