ScienceJuly 16, 2026

antimatter

/ˈæntimætər/

Definition

A form of matter composed of antiparticles that have the same mass as ordinary matter but opposite electrical charges; when it contacts matter, both are annihilated into pure energy.

Etymology

The word is a hybrid construction combining the Greek prefix 'anti-' meaning 'against' or 'opposite to' and the Latin 'materia' meaning 'substance' or 'matter'. It emerged in 20th-century physics to describe the theoretical and eventually discovered mirror-image of atomic particles.

In the news

In this article, antimatter is discussed as the mysterious counterpart to matter that largely disappeared from the early universe. Scientists are studying radioactive molecules to find the physical asymmetry that explains why our current universe is dominated by matter.

Cold radioactive molecules prepped and readied for physics discoveries

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EurekAlert!

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