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Cosmic ray visual phenomena, or light flashes (LF), also known as Astronaut's Eye, are spontaneous flashes of light visually perceived by some astronauts outside the magnetosphere of the Earth, such as during the Apollo program.
Another possibility is a composite group, in which successive groups in the period have different numbers of flashes, e.g. "Fl. (2+1)" indicates a group of two flashes, followed by one flash. A specific case sometimes used [2] is when the flashes are longer than two seconds. Such a light is sometimes denoted "long flashing" with the ...
On September 8, 2017, many people reported such sightings in Mexico City after a 8.2 magnitude earthquake with epicenter 740 km (460 mi) away, near Pijijiapan in the state of Chiapas. [16] Appearances of the earthquake light seem to occur when the quakes have a high magnitude, generally 5 or higher on the Richter scale. [14]
Chamberlain, LiftMaster, and Craftsman have interchangeable parts, primarily the gear and circuit boards. The greatest difference between the brands is that Chamberlain and Craftsman operate on a square shaped split-rail system, while LiftMaster consists of one single solid piece of inverted t-shaped rail.
The shape properties of the light waveform (e.g. sinusoidal, rectangular pulse and its duty cycle); see Figure 1; The average light level of the light source and its contrast with the background light level within the environment; The viewing angle and changes in direction of view by the observer; Physiological factors such as age and fatigue.
In addition to being able to detect gamma rays, X-rays, and neutrons, the satellite also contained two silicon solid-state bhangmeter sensors that could detect the dual light flashes associated with an atmospheric nuclear explosion: the initial brief, intense flash, followed by a second, longer flash. [8]
An Ottoman heliograph crew using a A Blinkgerät (left) Begbie signalling oil lamp, 1918 Signal lamps were pioneered by the Royal Navy in the late 19th century. They were the second generation of signalling in the Royal Navy, after the flag signals most famously used to spread Nelson's rallying-cry, "England expects that every man will do his duty", before the Battle of Trafalgar.
Flicker vertigo, sometimes called the Bucha effect, is "an imbalance in brain-cell activity caused by exposure to low-frequency flickering (or flashing) of a relatively bright light." [ 1 ] It is a disorientation -, vertigo -, and nausea -inducing effect of a strobe light flashing at 1 Hz to 20 Hz, approximately the frequency of human brainwaves .