Search results
Results from the WOW.Com Content Network
The curvature of the horizon is easily seen in this 2008 photograph, taken from a Space Shuttle at an altitude of 226 km (140 mi). The horizon is the apparent curve that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This curve divides all ...
An event horizon is a bed that marks a geological event, such as an earthquake or a meteorite impact. It is the basic unit used in event stratigraphy. [5] It is related to the marker horizons in that event horizons can be used as a marker horizon, though they are not always the same.
In archaeology, the general meaning of horizon is a distinctive type of sediment, artefact, style, or other cultural trait that is found across a large geographical area from a limited time period. [ 1 ] [ 2 ] [ 3 ] The term derives from similar ones in geology , horizon or marker horizon , but where these have natural causes, archaeological ...
Topologically, the event horizon is defined from the causal structure as the past null cone of future conformal timelike infinity. A black hole event horizon is teleological in nature, meaning that it is determined by future causes.
The particle horizon, also called the cosmological horizon, the comoving horizon, or the cosmic light horizon, is the maximum distance from which light from particles could have traveled to the observer in the age of the universe. It represents the boundary between the observable and the unobservable regions of the universe, so its distance at ...
Horizon scanning is "the systematic examination of potential threats, opportunities and likely future developments which are at the margins of current thinking and planning’ and, continuing, horizon scanning ‘may explore novel and unexpected issues, as well as persistent problems or trends."
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Diagram showing the relationship between the zenith, the nadir, and different types of horizon. The zenith (UK: / ˈ z ɛ n ɪ θ /, US: / ˈ z iː n ɪ θ /) [1] is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction opposite to the gravity direction at that location . The ...