Friday, October 9, 2009

Fall Lunar Equinox

My neighbor called a little while ago and said that her broom was standing on its own in the middle of the room due to the Lunar Equinox. She told me to get my broom and try it. It worked, This is my broom standing on its own.
Myths, Facts and Fables.....
One effect of equinoctial periods is the temporary disruption of
communications satellites. For all geostationary satellites, there are a few days near the equinox when the sun goes directly behind the satellite relative to Earth (i.e. within the beamwidth of the groundstation antenna) for a short period each day. The Sun's immense power and broad radiation spectrum overload the Earth station's reception circuits with noise and, depending on antenna size and other factors, temporarily disrupt or degrade the circuit. The duration of those effects varies but can range from a few minutes to an hour. (For a given frequency band, a larger antenna has a narrower beamwidth, hence experiences shorter duration "Sun outage" windows).
A modern
urban legend[clarification needed] claims that on the March equinox day (some may also include the September equinox day rather than leaving it out), one can balance an egg on its point.[7][8] However, one can balance an egg on its point any day of the year...if one has enough patience.[9]
Although the word equinox is often understood to mean "equal [day and] night," as is noted elsewhere, this is not strictly true. For most locations on earth, there are two distinct identifiable days per year when the length of day and night are closest to being equal; those days are commonly referred to as the "equiluxes" to distinguish them from the equinoxes. Equinoxes are points in time, but equiluxes are days. By convention, equiluxes are the days where sunrise and sunset are closest to being exactly 12 hours apart. This way, you can refer to a single date as being the equilux, when in reality, it spans from sunset on one day to sunset the next, sunrise on one to sunrise the next or lunchtime on one day to lunchtime on the next.
What is true about the equinoxes is that two observers at the same distance north and south of the equator will experience nights of equal length.
The equilux counts times when some direct sunlight could be visible, rather than all hours of usable daylight (which is any time when there is enough natural light to do outdoor activities without needing artificial light). This is due to twilight; a particular type of twilight which is officially defined as
civil twilight. This amount of twilight can result in more than 12 hours of usable daylight up to a few weeks before the spring equinox, and up to a few weeks after the fall equinox.
In a contrary vein, the daylight which is useful for illuminating houses and buildings during the daytime and is needed to produce the full psychological benefit of daylight, is shorter than the nominal time between sunrise and sunset. So in that sense, "useful" daylight is present for 12 hours only after the vernal equinox and before the autumnal equinox, because the intensity of light near sunrise and sunset, even with the sun slightly above the horizon, is considerably less than when the sun is high in the sky.
It is perhaps valuable for people in the Americas and Asia to know that the equinoxes listed as occurring on March 21, which occurred frequently in the 20th century and which will occur occasionally in the 21st century, are presented as such using
UTC, which is at least four hours in advance of any clock in the Americas and as much as twelve hours behind Asian clocks. Thus, there will be no spring equinox later than March 20 in the Americas in the coming century.

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