Twilight

Twilight is the illumination of the Earth's lower atmosphere when the Sun itself is not directly visible because it is below the horizon. Twilight is produced by sunlight scattering in the upper atmosphere, illuminating the lower atmosphere so that the surface of the Earth is neither completely lit nor completely dark. The word "twilight" is also used to denote the periods of time when this illumination occurs.

The further the Sun is below the horizon, the dimmer the twilight (other things such as atmospheric conditions being equal). When the Sun reaches 18 degrees below the horizon, the twilight's brightness is nearly zero, and evening twilight becomes nighttime. When the Sun again reaches 18 degrees below the horizon, nighttime becomes morning twilight. Owing to its distinctive quality, primarily the absence of shadows and the appearance of objects silhouetted against the bright sky, twilight has long been popular with photographers, who refer to it as 'sweet light', and painters, who refer to it as the blue hour, after the French expression: l'heure bleue.

Dave

Dave may refer to:

Film and television

Other entertainment:

Software

See also

David Gray

David Gray may refer to:

Screen Junkies

Screen Junkies is an online movie magazine and YouTube channel, owned and operated by Defy Media, that focuses on movies and television. It produces three main shows: The Screen Junkies Show, hosted by Hal Rudnick, consists mostly of interviews and film discussions; Honest Trailers is a series of trailers, narrated previously by Ptolemy Slocum and Gannon Nickell, and currently by Jon Bailey, that satirizes and parodies various films and television programs; and Movie Fights is a competition series, hosted by Andy Signore, where guests debate various issues related to film.

As of December 2015, Screen Junkies has over 5 million subscribers and over one billion video views.

Videos

Honest Trailers

Honest Trailers is a series of parody trailers of films, and occasionally TV shows, that are made to satirize the film. The videos are narrated by Jon Bailey.

Created by Andy Signore and Brett Weiner and shepherded by Break Media's Head of Programming Mitch Rotter, Honest Trailers debuted in February 2012 and by June 2014 had become the source of over 300 million views on the Screen Junkies YouTube channel. The series started when the creators saw that Star Wars Episode I: The Phantom Menace was being re-released in 3D and decided to make a parody trailer for it, continuing the series as a result of the positive reception the videos received.

New moon

In astronomy, new moon is the first phase of the Moon, when it orbits as seen from the Earth, the moment when the Moon and the Sun have the same ecliptical longitude. The Moon is not visible at this time except when it is seen in silhouette during a solar eclipse when it is illuminated by earthshine. See the article on phases of the Moon for further details.

A lunation or synodic month is the mean (average) time from one new moon to the next. In the J2000.0 epoch, the average length of a lunation is 29.530588 days (or 29 days, 12 hours, 44 minutes, and 3 seconds). However, the length of any one synodic month can vary from 29.26 to 29.80 days due to the perturbing effects of the Sun's gravity on the Moon's eccentric orbit. In a lunar calendar, each month corresponds to a lunation. Each lunar cycle can be assigned a unique Lunation Number to identify it.

Determining new moons: an approximate formula

The length of a lunation is about 29.53 days. Its precise duration is linked to many phenomena in nature, such as the variation between spring and neap tides (the extreme highest and lowest tides, respectively). An approximate formula to compute the mean moments of new moon (conjunction between Sun and Moon) for successive months is: