TODAY'S ASTRONOMY OF THE DAY
· #210

Astronomy: Event Horizons

Concepts & Techniques
Astronomy: Event Horizons
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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.

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Source: Wikipedia (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. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive compact objects that even light cannot escape.

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Why Event Horizons matters: These foundational ideas and techniques are the tools astronomers 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.

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Source: Internal
Deep dive: Event Horizons 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. Source: https://en.wikipedia.org/wiki/Event_horizon (Wikipedia, CC BY-SA)