A ten-week series that focuses on the future of humanity.

Type: Documentary

Languages: English

Status: Ended

Runtime: 8 minutes

Premier: 2015-10-06

## Beyond the Horizon - Horizon - Netflix

The horizon or skyline is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting intersection of earth and sky is called the visible horizon. When looking at a sea from a shore, the part of the sea closest to the horizon is called the offing. The word horizon derives from the Greek “ὁρίζων κύκλος” horizōn kyklos, “separating circle”, from the verb ὁρίζω horizō, “to divide”, “to separate”, and that from “ὅρος” (oros), “boundary, landmark”.

## Beyond the Horizon - Curvature of the horizon - Netflix

κ = ( 1 + h R ) 2 − 1 . {\displaystyle \kappa ={\sqrt {\left(1+{\frac {h}{R}}\right)^{2}-1}}\ .}

κ {\displaystyle \kappa } , the altitude h {\displaystyle h} , and the Earth's radius R {\displaystyle R} , . It is

From a point above the surface the horizon appears slightly bent (it is a circle). There is a basic geometrical relationship between this visual curvature

The curvature is the reciprocal of the curvature angular radius in radians. A curvature of 1 appears as a circle of an angular radius of 57.3° corresponding to an altitude of approximately 2640 km above the Earth's surface. At an altitude of 10 km (33,000 ft, the typical cruising altitude of an airliner) the mathematical curvature of the horizon is about 0.056, the same curvature of the rim of circle with a radius of 10 m that is viewed from 56 cm directly above the center of the circle. However, the apparent curvature is less than that due to refraction of light in the atmosphere and because the horizon is often masked by high cloud layers that reduce the altitude above the visual surface.

## Beyond the Horizon - References - Netflix

- [https://web.archive.org/web/20110605182059/http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=o(/ros](https://web.archive.org/web/20110605182059/http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=o(/ros)
- https://web.archive.org/web/20170329060451/https://books.google.com/books?id=KS8_AAAAYAAJ&pg=PA73
- [http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry%3Do(ri/zw](http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry%3Do(ri/zw)
- https://web.archive.org/web/20031018020513/http://mintaka.sdsu.edu/GF/explain/atmos_refr/horizon.html
- http://dispenser.info.tm/~dispenser/cgi-bin/dab_solver.py?page=Horizon&editintro=Template:Disambiguation_needed/editintro&client=Template:Dn
- [http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry%3Do(/ros](http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry%3Do(/ros)
- [https://web.archive.org/web/20110605181946/http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=o(ri/zwn](https://web.archive.org/web/20110605181946/http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=o(ri/zwn)
- https://www.netflixtvshows.com
- http://doi.org/10.1364%2FJOSA.28.000327
- http://mintaka.sdsu.edu/GF/explain/atmos_refr/horizon.html
- https://web.archive.org/web/20170329050848/http://blogs.discovermagazine.com/badastronomy/2009/01/15/how-far-away-is-the-horizon/#.WNp_MGczVEY
- http://mintaka.sdsu.edu/GF/explain/atmos_refr/dip.html
- https://books.google.com/books?id=KS8_AAAAYAAJ&pg=PA73
- http://upload.wikimedia.org/wikipedia/commons/4/44/Horizon_distance_graphs.svg