Visuals

Animations

Cesium Clock: The ability to make precision measurements in a short amount of time has jumped enormously.

Evaporative Cooling: When Zwierlein applies a certain radio frequency to the trapped atoms, it shaves off the hotter atoms and leaves the cooler ones.

Frequency of Cesium Atoms: Cesium atoms run at a frequency of around 10 billion cycles per second, which corresponds to a microwave frequency.

Laser Cooling 1: The key to laser cooling is that in the process of absorbing a photon, an atom receives a small push in the direction away from the source of light.

Laser Cooling 2: As atoms continuously absorb photons coming from one direction, and re-emit photons in random directions, the net result is a loss of momentum.

Laser Cooling 3: The cooling inside the chamber takes place in several steps. The ultimate temperature they can reach is limited and they will need to be cooled further.

Mercury Trap: Removing the electron gives the ion an electrical charge, so it can be suspended in a trap by electric forces.

Photon as Electromagnetic Wave: A photon, a particle of light, can be thought of as an electromagnetic wave with a particular oscillation frequency.

Photon Frequency and Excitement of Atoms: The probability that the atoms will be excited out of their ground state reaches a peak when the photons are tuned to exactly the right frequency.

Photographs

1997 Nobel Prize Winners: Recipients of the 1997 Nobel Prize, for laser cooling and trapping of atoms.

Atoms in a MOT: Atoms trapped in a magneto-optical trap.

Atoms in an Optical Lattice: Neutral rubidium atoms in an optical lattice trap.

g-2 Experiment: Gerald Gabrielse (left) is shown with the apparatus he used to make some of the most precise measurements of a single electron.

Heisenberg and Schrödinger: Left: Werner Heisenberg; right: Erwin Schrödinger.

Industrial Furnace: This furnace for melting glass is nearly an ideal blackbody radiation source.

Next-Generation Clock: The heart of a next-generation optical clock.

Planck, Max: Max Planck solved the blackbody problem by introducing quanta of energy.

Rabi, Isidor Isaac: Isidor Isaac Rabi pioneered atomic physics in the U.S. during the 1930s, invented magnetic resonance, and first suggested the possibility of an atomic clock.

Ripples on a Pond: A circular wave created by tossing a pebble in a pond.

Single and Two-Slit Interference: Diffraction of laser light through one (top) and two (bottom) small slits.

Trapped Ions: Thirty-two ions, fluorescing under illumination by laser light in an electrodynamic trap.

Uncertainty in a Baseball: The effect of quantum mechanical jitter on a pitcher, fortunately, is too small to be observable.

Graphics

Atomic Fountain: Schematic diagram of an atomic fountain clock.

Black Hole Jet: This VLBI image of jets from a black hole could not have been produced without atomic clocks.

Bohr's Model of the Atom: Model of the atom by Niels Bohr.

Cosmic Microwave Background Spectrum: Spectrum of the cosmic microwave background radiation.

Diffraction of Atoms: This diffraction pattern appeared when a beam of sodium molecules encountered a series of small slits, showing their wave-like nature.

Doppler Cooling: Red-detuned lasers don't affect an atom at rest (left) but will slow an atom moving towards the light source (right).

Electromagnetic Spectrum: The electromagnetic spectrum from radio waves to gamma rays.

Electron Interference: An interference pattern builds up as individual electrons pass through two slits.

Harmonic Oscillator: A simple harmonic oscillator (bottom) and its energy diagram (top).

Harmonic Oscillator Energy Levels: Low-lying energy levels of a harmonic oscillator.

Harmonic Oscillator, n=40: The wavefunction (left) and probability distribution (right) of a harmonic oscillator in the state n = 40.

Hydrogen Atom: The size of a hydrogen atom is determined by the uncertainty principle.

Hydrogen Spectrum: The spectrum of atomic hydrogen.

NIST F1 Clock: This apparatus houses the NIST F1 cesium fountain clock, which is the primary time and frequency standard of the United States.

Optical Lattice: Atoms trapped in an optical lattice.

Particle in a Box: The first three allowed de Broglie wave modes for a particle in a box.

Single-Slit Interference: Ripple tank picture of plane waves incident on a slit that is about two wavelengths wide.

Standing Waves: Standing waves on a string between two fixed endpoints.

Temperature Scale: Temperature scale in physics.

Two-Wave Interference: Two waves interfere as they cross paths.

Various Interference Effects: The two-slit interference pattern depends on the distance between the slits.

Wavefunction and Probability Distribution: The ground state wavefunction of a harmonic oscillator (left) and the corresponding probability distribution (right).

Wavefunctions: (a)-(d) Some wavefunctions for a particle in a box. Curve (e) is the sum of curves (a-d).