Index.php
From Eu3
Maya concepts of time
With the development of the place-notational Long Count calendar (believed to have been inherited from other Mesoamerican cultures), the Maya had an elegant system with which events could be recorded in a linear relationship to one another, and also with respect to the calendar ("linear time") itself. In theory, this system could readily be extended to delineate any length of time desired, by simply adding to the number of higher-order place markers used (and thereby generating an ever-increasing sequence of day-multiples, each day in the sequence uniquely identified by its Long Count number). In practice, most Maya Long Count inscriptions confine themselves to noting only the first five coefficients in this system (a b'ak'tun-count), since this was more than adequate to express any historical or current date (20 b'ak'tuns cover 7,885 solar years). Even so, example inscriptions exist which noted or implied lengthier sequences, indicating that the Maya well understood a linear (past-present-future) conception of time.
However, and in common with other Mesoamerican societies, the repetition of the various calendric cycles, the natural cycles of observable phenomena, and the recurrence and renewal of death-rebirth imagery in their mythological traditions were important influences upon Maya societies. This conceptual view, in which the "cyclical nature" of time is highlighted, was a pre-eminent one, and many rituals were concerned with the completion and re-occurrences of various cycles. As the particular calendric configurations were once again repeated, so too were the "supernatural" influences with which they were associated. Thus it was held that particular calendar configurations had a specific "character" to them, which would influence events on days exhibiting that configuration. Divinations could then be made from the auguries associated with a certain configuration, since events taking place on some future date would be subject to the same influences as its corresponding previous cycle dates. Events and ceremonies would be timed to coincide with auspicious dates, and avoid inauspicious ones.[10]
The completion of significant calendar cycles ("period endings"), such as a k'atun-cycle, were often marked by the erection and dedication of specific monuments (mostly stela inscriptions, but sometimes twin-pyramid complexes such as those in Tikal and Yaxha), commemorating the completion, accompanied by dedicatory ceremonies.
A cyclical interpretation is also noted in Maya creation accounts, in which the present world and the humans in it were preceded by other worlds (one to five others, depending on the tradition) which were fashioned in various forms by the gods, but subsequently destroyed. The present world also had a tenuous existence, requiring the supplication and offerings of periodic sacrifice to maintain the balance of continuing existence. Similar themes are found in the creation accounts of other Mesoamerican societies.
Are you tired of laying wires through your house
Are you tired of laying wires through your house,, creeping through small places just to get the right sound effect? Wireless speakers are the answer to your headaches. With wireless speakers you gain the freedom to move your music to where you want it to be without the hassles of cables. Planning to have a party outside? Don't move your whole entertainment system outside while you can make use of outdoor wireless speakers which can move right along with the party.
Want to have hi-fi quality sound through your laptop computer? Why should you be tied to wires while using a portable computer? Make use of wireless speakers to give you the freedom to work or play on your computer where you want to,, while having the high fidelity sound you deserve.Here are a few examples of how you can use wireless speakers to improve your way of living.
?Listen to your favorite music collection while taking a bath.
?Have a BBQ or party outside without having to move your whole stereo system.
?You can store all your favorite music on your computer and listen to it anywhere in your home.
?Listen to music while working in the garden.
?When your computer is doing certain time consuming tasks,, have it play a sound when it is done with the task or when there is an error and have your wireless speaker notify you while you are lying next to the pool.
?Get the perfect surround sound effect by having the freedom to move the speakers to exactly the right spots without getting tangled in wires.
?Let your computer notify you of upcoming tasks or appointments by playing a sound through your outdoor wireless speakers, while you are washing your car.
?Let your wireless speaker notify you discretely of intruders by connecting it to your alarm system.
?Use you wireless speakers as a portable intercom system.
There are however a few things you need to watch out for when shopping for wireless speakers. Some are listed here:
Interference
Some wireless speakers may interfere with other wireless devices in your house like cordless phones. A good wireless speaker system will allow you to tune it to a different frequency to overcome these interferences.
Battery life
Battery life is not always too great on wireless speakers, as it consumes power to drive the speakers,, internal amplifier and RF receiver. So, if you want to use your wireless speakers for extended periods of time, it may be wise to make use of the AC power adaptor. Now this may not always be practical - the whole idea of wireless speakers is to get rid of the wires. Rechargeable batteries might be the answer and some of the models even come with rechargeable batteries -something to consider when you need total freedom, even from power outlets.
Range
Most wireless speakers can work fine within a range of 150 to 300 feet from the transmitter. (Which would be located at the source of sound i.e. your hi-fi or computer) The RF frequency is high enough for it to work through walls and furniture. You do not need a line of sight, but bear in mind that obstacles weakens the signal,, and the more obstacles between the transmitter and receiver,, the shorter the range will become.
Weatherproof
Outdoor wireless speakers are claimed to be weatherproof,, but if you do not need to use your speakers outside all the time,, rather store them inside. This will definitely extend the life of your valuable outdoor wireless speakers. If you really need to leave it outside all the time,, try to find a spot where it can be hidden from the most harsh weather conditions.
Stereo
Not all wireless speaker systems include two speakers to give you a stereo experience. Especially the outdoor wireless speakers are sold as single units. This can easily be overcome by purchasing two speakers,, obviously doubling the price.
Legislation
Wireless speakers use RF signals which may interfere with other RF devices. Make sure that the frequency range is legal in your country. If it is sold by a reputable dealer in your country, this should not be a problem.Wireless speakers are till a fairly new technology and some still have issues to be sorted out. So you have to do your shopping wisely.
Arno Esterhuizen
webmaster@wireless-speakers-guide
[返回上一页] [打 印]Related articles：
design the most painful thing children is valid and not map did not finish the design changed ; do design most painful thing is valid and is to map finally finished the whole change program ; design by far the most painful thing is Han know that not done is the diagram of the dog days of the customers ran ; 5 to do the design of the most most most painful thing is valid and not that the customer is back in Figure not to delete
