event horizon

noun

: the surface of a black hole : the boundary of a black hole beyond which nothing can escape from within it

Examples of event horizon in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
That led physicists to believe that the event horizon was a physical singularity. Steve Nadis, Quanta Magazine, 31 May 2024 To preclude the increase of entropy, this process would have to break the entanglement between the particle pairs across the event horizon. Ahmed Almheiri, Scientific American, 1 Sep. 2022 Now, the white dwarf might be orbiting within millions of miles of the black hole’s event horizon—the point beyond which no matter or light can escape. Sara Hashemi, Smithsonian Magazine, 14 Jan. 2025 The event horizon is the point around every black hole at which gravity becomes so strong not even light is fast enough to escape. Robert Lea, Space.com, 13 Jan. 2025 See all Example Sentences for event horizon 

Word History

First Known Use

1956, in the meaning defined above

Time Traveler
The first known use of event horizon was in 1956

Dictionary Entries Near event horizon

Cite this Entry

“Event horizon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/event%20horizon. Accessed 11 Feb. 2025.

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!