In mathematics, an open set is a generalization of an open interval in the real line.
Gravitational lensing has been used for the first time to detect and measure an inactive black hole. The door is now open to study the largest black holes in the universe. "Gravitational lensing events are rare, but are most prevalent in the most massive galaxies, that host the largest black holes."
The Dark Triad (Narcissists, Psychopaths, & Machiavellians) use unique combinations of breakup strategies when ending romantic relationships, new study (N=722) finds. For instance, narcissists using open confrontation, whereas psychopaths use manipulation, cost escalation, and distant communication.