Different colors of LED light illuminate a small corked test tube with no reaction. Ultraviolet light causes an explosion that shoots the cork across the room.
3 cm microwaves and prisms made of plastic beads demonstrate total internal reflection in one prism, and coupling of the evanescent wave to a second prism. An audio signal corresponds to the one kiloHertz modulation of the microwaves.
In quantum mechanics, it is possible for a particle to tunnel through a potential barrier because its wave function has a small but finite value in the classically forbidden region. Here we use FTIR as an optical analog of this quantum...
In the Heisenberg uncertainty relation, the momentum of a particle cannot be known with any greater accuracy than h/∆x where h is Planck's constant and ∆x is the uncertainty in spatial position. The more you localize its spatial position...
A pulse-modulated electromagnetic signal is simultaneously displayed in the time domain (on an oscilloscope) and in the frequency domain (on a spectrum analyzer). Using ∆n for the frequency spread (uncertainty in frequency) and ∆t for the...
Louis de Broglie predicted that matter under certain circumstances would exhibit wave-like properties. A proof of this is the repeat of X-ray diffraction experiments using electrons, whose de Broglie wavelengths at high accelerating...
The photoemission of electrons from a metal surface depends on the energy of the incident radiation and not on its intensity. Knowing the energy of the emitted photoelectrons and the frequency of the incident light, you can calculate a...
A direct observation that the photoelectric effect is color (i.e. frequency) dependent and not intensity dependent. We discharge an electroscope using UV radiation after all attempts to discharge it with light of a longer wavelength has...
An accelerated electric charge radiates energy. So according to classical physics, an electron in orbit about an atomic nucleus should emit electromagnetic radiation by virtue of its orbital motion. As it radiates energy, the radius of its...
Black body radiators in thermal equilibrium should emit the same spectrum of radiation; inside a muffle furnace at high temperature, objects should appear the same color, whatever their material.
