Infrared Light

What do night vision goggles, land mine detectors, and studies of the universe have in common? In some way, all of them are connected to a small range of light sandwiched between visible light and microwaves on the electromagnetic spectrum—infrared light.

Feynman Diagrams: The science of doodling

Every popular explanation of particle physics is liberally illustrated with cartoon-like pictures of straight and wiggly lines representing electrons, photons, and quarks, interacting with one another. These so-called Feynman diagrams were introduced by Richard Feynman in the journal Physical Review in 1949, and they quickly became an essential tool for particle physicists.

Optical Tweezers

Unwind a chromosome to see how it’s put together? Sort cells with a light beam? Make a model of a molecular motor? All these and more—welcome to the world of optical tweezers, where cells and even individual molecules are manipulated with laser light.

Through a Lens Darkly

What limits the sharpness of an image? The answer has to do with the wave nature of light.

Slow Light

Suppose you and a friend tried to measure the speed of light. You have a powerful flashlight and a stopwatch, and your friend has a mirror. You walk away until the two of you are 100 m apart. You aim the flashlight at the mirror, turn the light on, and wait to see the reflection. How long do you have before the light gets back?

Matters of State

We know about solids, liquids, gases, and plasmas —these are the well-known states of matter. But now there’s another, called the Bose-Einstein condensate (BEC), and it’s been predicted for a long time.

Deep Impact

Comets are relics from the origin of the solar system, carrying material about 4.5 billion years old.

Seeing Atoms

What does it mean to see an atom? Suppose you tried to use the world’s strongest optical microscope to see an atom. What would happen?

Sound, Lights, Action!

Sonoluminescence is a way to turn sound energy into light. When intense sound waves are created in a flask of water, a tiny air bubble in the water can give off flashes of light.

Solar Flares

You may have seen the “northern lights” in the fall of 2003, even if you live as far south as Texas or Italy.

Laser Cooling and Trapping

Absolute zero, as cold as it gets, resides at the very bottom of the temperature scale.

Do You See What Eye See?

It’s been hard to miss the publicity for LASIK, the laser surgery that reshapes the cornea to improve the eye’s ability to focus.