unstable

Over tens of millions of years, this pocket of warm, unstable rock slowly migrated to its current position at a pace of about 20 km per million years.

Walk around it, and the shifting, light-reflective and -absorbent white forms create an uncanny illusion of the pillar in jumpy, unstable motion.

But he says that Peru's unstable national governments make change difficult.

A further challenge to testing for 7-OH, specifically, is that the compound is “incredibly unstable,” she said.

They wanted one that would address the trauma of an unstable childhood they felt was driving his angry, impulsive behavior.