Astronomy: Event Horizons

Astronomy: Event Horizons
Wikimedia Commons, CC BY-SA
Event Horizons In astrophysics, an event horizon is a boundary in spacetime beyond which no signal can ever reach a given observer. Wolfgang Rindler coined the term in the 1950s.

Commentary

Commentary

Event Horizons In astrophysics, an event horizon is a boundary in spacetime beyond which no signal can ever reach a given observer. Wolfgang Rindler coined the term in the 1950s. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive compact objects that even light cannot escape.

Commentary

Why Event Horizons matters: These foundational ideas and techniques are the tools ast ronomers use to measure, classify, and understand everything from nearby planets to the most distant galaxies. The Cauchy and Killing horizons. The photon spheres and ergospheres of the Kerr solution. Particle and cosmological horizons relevant to cosmology. Isolated and dynamical horizons, which are important in current black hole research.

Commentary

Deep dive: Event Horizons The Cauchy and Killing horizons. The ph oton spheres and ergospheres of the Kerr solution. Particle and cosmological horizons relevant to cosmology. Isolated and dynamical horizons, which are important in current black hole research. Source: https://en.wikipedia.org/wiki/Event_horizon (Wikipedia, CC BY-SA)