Everything we see around us, from the ground beneath our feet to the most remote galaxies, is made of matter. For scientists, that has long posed a problem: According to physicists’ best current ...

The molecular hydrogen ion H₂⁺ is the simplest molecule. This simplicity makes it a perfect study object for physicists, as its properties—for example, its energy levels—can be calculated precisely.

The pulse of an atom's magnetic heart as it ticks back and forth between quantum states has been timed in a laboratory. Physicists used a scanning tunneling microscope to observe electrons as they ...

Forget about turtles; for all practical purposes, it’s really particles all the way down. Consider the seemingly simple matter of their size, the very thing that makes them so alien. We’re typically ...