PHIL 110 Lecture Notes - Lecture 46: Metal Forces, Electromagnetic Radiation, Electric Field
Document Summary
Electromagnetic waves: made up of vibrating electric and magnetic fields. Electromagnetic wave velocity: em waves moving in free space (vacuum) never change speed. If waves slow down it would cause reduction in electric field induction which would reduce magnetic fields indu(cid:272)tio(cid:374), a(cid:374)d so o(cid:374) . Result is speed limit of em wave. Electrons or molecules in the glass are forced into vibration. Energy is momentarily absorbed and vibrates the electrons in the glass. This vi(cid:271)rati(cid:374)g ele(cid:272)tro(cid:374) either e(cid:373)its a photo(cid:374) (cid:894)a (cid:862)parti(cid:272)le(cid:863)(cid:895) Opaque materials: most things around us are opaque they absorb light without re-emitting it. Vibrations given by light to their atoms and molecules are turned into random kinetic energy into internal energy. Metals = light shining on metal forces free electrons in the metal into vibrations that emit their own light as a reflection. Dry surfaces bounce directly to your eye.
