Physics in Action
Dark Matter
In 2006, an investigation of the Bullet cluster, which is composed of two colliding clusters of galaxies, provided important evidence for the existence of dark matter.
Our Very Own Black Hole
The Milky Way is a vast spiral, similar to our neighbor the Andromeda galaxy.
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.
Planet Pluto Goes Poof
Pluto—now reclassified as a "dwarf planet"—was discovered after American astronomer Percival Lowell predicted that a "Planet X" was perturbing the orbits of Uranus and Neptune.
Quark-Gluon Plasma
A millionth of a second after the Big Bang, the universe was an incredibly dense plasma, so hot that no nuclei nor even nuclear particles could exist.