- A hypothetical, extremely dense form of matter composed entirely of strange quarks. These quarks are not grouped into separate particles (like the quarks bundled into protons and neutrons in atomic nuclei) but form a single undifferentiated mass. The material of which hypothetical quark stars are composed is thought to be strange matter; some evidence for strange matter has also been found in collisions in particle accelerators and in seismic events possibly triggered by the passing of strange matter through the Earth.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.