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night sky. We know that celestial bodies are in reality, fixed in their positions. The reason for their dramatic movement in the night is because of the rotation of the |
earth. This is the same reason why the Sun and the Moon seem to rise and set. For the longest time, this motion caused many philosophers and astronomers to assume |
that the Earth was the center of the Universe. Fortunately later astronomers like Copernicus were able to discern the true movements of the Earth, Moon, and Sun helping to explain |
their movements. The time that it takes for a star, planet or other fixed celestial body to ascend and descend in the night sky is also called sidereal period. Coincidentally |
this time corresponds to the time it takes for the Earth to rotate one revolution which is just under 24 hours. Sidereal time is not like solar time which is |
measured by the movement of the sun. Or the lunar cycles which take about 28 days. It is the relative angle of a celestial object to the prime meridian of |
the vernal equinox of the earth. IF these terms are confusing, here is what they mean. In cartography, the Earth is bisected by two major lines of longitude and latitude. |
These lines are the 0 degree points on the globe. The 0 degree point for the latitude is the Equator the point where the Earth is perfectly bisected. It cut |
through South America and Africa. The 0 degree point for the longitude is the prime meridian. It exact location is Greenwich, UK. The Equinoxes are essentially the times of the |
year when the sun rise and sets at the exact same point of the horizon at the equator. This means that these are the only times the solar day is |
equally divided into 12 hours of day and 12 hours of night. The hour angle for a celestial object relative to this meridian is what we call sidereal time.This angle |
changes with the rotation of the Earth creating a pattern of ascension and descent for celestial bodies in the Earth’s sky. With the knowledge of sidereal time astronomers can predict |
the positions of stars. The values for the sidereal time of celestial objects is compile in a table or start chart called an ephemeris. With this guide to sidereal time |
astronomers can find a celestial object regardless of the change in their position over the year. There are also some great resources on the net. The U.S. Naval observatory has |
Tell me about the International Dark-Sky Association—how did it start, what's the mission? IDA’s mission is to preserve and protect the nighttime environment and our heritage of dark skies through environmentally responsible outdoor lighting. IDA was founded in 1988 by a professional astronomer working at the Kitt Peak... |
increasing sky glow over Tucson was interfering with nighttime observations. Their message is simple, clear, and effective, and their efforts were fundamental in getting light pollution recognized around the world as an unwelcome and detrimental environmental condition. What are some of the effects of light pollution o... |
There are four main types of light pollution: sky glow (that strange orange dome over urban areas), glare (overly bright, unshielded points of light), light trespass (unwanted light intruding onto private property), and clutter (groupings of light sources). Animals and even plants are affected by sky glow and light tre... |
from year to year, many species rely on light cues to tell them when to shed leaves, mate, and reproduce. When outdoor lighting artificially prolongs the day, the instinctive rhythms of many species are affected. Many species behave unnaturally in the presence of artificial light—for example, light at night decreases a... |
to attract a mate. Sea turtles and migratory birds use starlight to orient themselves, so light pollution has devastated their internal navigation systems. Some birds will crash into tall buildings, or fixate on a light source, circling around it until they are exhausted and unable to fly. Glare from unshielded light s... |
glare from poor outdoor lighting are a primary reason that the American Medical Association unanimously adopted Resolution 516 to support light pollution and glare reduction efforts last June. Depending on the severity, glare can cause discomfort or temporary night blindness. On the roadway, glares can interfere with v... |
as people age and gradually lose their ability to adjust to changing light levels. Exposure to excessive light at night has been found to alter the circadian rhythm, interfere with sleep patterns, and suppress the sleep hormone melatonin. The amount of light needed to affect sleep patterns is not known, but sleeping in... |
CDC and the NIH as a way to promote a regular circadian rhythm. What is International Dark-Sky Association doing to combat light pollution? How are you measuring the effectiveness of these campaigns? As an environmental educational 501(c)(3) non-profit, IDA has enacted dynamic programs in the areas of technology, conse... |
sky glow by establishing “dark sky-friendly” criteria for outdoor light fixtures. Currently in the spotlight is our International Dark Sky Places (IDSPlaces) program, a conservation curriculum established to protect urban and rural starscapes. The IDS Communities and Dark Sky Developments of Distinction designations re... |
lighting requirements through retrofits and legislation and have undertaken outreach efforts to educate the public about the importance of natural night. Many designees are successfully incorporating astronomy and stargazing into their local attractions, hosting festivals or sky watching events known as “star parties.”... |
for free on the IDA website. We also participate in industry meetings and technology expos, and actively collaborate with non-profit interest groups. Do you see differences regionally? How bad is the East Coast in terms of light pollution? Several New England states have taken great strides to protect their skies. The ... |
because it is more densely populated, not because the lighting is necessarily worse. We don’t see a huge difference regionally so much as from city to city. Rural and urban areas across the world have enacted dark sky ordinances or are undertaking retrofits in public lighting (usually as part of an energy saving endeav... |
thoughtful, more aesthetically pleasing, and more efficient than cities or townships that have not. What can you tell me about any legislation concerning light pollution, particularly on the East Coast? In New York? IDA’s newly opened public policy office in Washington, DC is creating a lot of opportunities for collabo... |
energy agencies and congressional leaders, but any national action is a long way off. Many of these accomplishments have been spurred by Leo Smith, IDA’s Regional Director for New England Sections. Connecticut is the furthest along in terms of addressing light pollution, with three state laws, one state building code r... |
a new streetlight rate for streetlights that are programmed to turn off at midnight are on the books. The New Hampshire law, signed in July, also requires utility regulators to adopt a rate for streetlights that are turned off at midnight, as well as requiring shielded streetlights. Maine and Rhode Island both require ... |
yet, though night lighting has been addressed in several regions, namely the municipalities of Tully, East Hampton, Southampton, Tuxedo Park, Riverhead, and Brookhaven. IDA conducts third-party certification of light fixtures— how successful has this program been, how many certified fixtures are currently on the market... |
lighting industry since its inception. Good quality light at night is necessary for safety, security, and recreation, but outdoor light is the main cause of light pollution. Some members of the lighting community have been very apt to address this, and have worked to create products that minimize light pollution by dir... |
instead of to the sky, where it becomes a wasteful nuisance. IDA is fortunate to have support from these companies, because they provide the technology to make our mission effective. The Fixture Seal of Approval program was started in 2005 to recognize lighting manufacturers who integrated the concept of full shielding... |
of dark sky-friendly products. Any approved fixture must be fully shielded to emit no light above a 90 degree angle. This program has been wildly successful for both IDA and the lighting manufacturers who join. The IDA seal is gaining worldwide recognition and becoming a selling point for manufacturers and vendors alik... |
expanding as companies strive to design sleek, stylish, and efficient fixtures. Over 100 manufacturers have joined the FSA program to date, featuring approximately 300 fixture models. What can consumers do to combat light pollution? And then, what can architects, builders, planners do to combat light pollution? Shield ... |
fixture makes a huge difference in directing light where you want it to go. If you install dark sky-friendly fixtures outside your home or business, you’ve already made a difference. Look for the IDA Fixture Seal of Approval or purchase a fully-shielded or full-cutoff product. Those who want to learn more or work towar... |
local IDA Section (information at darksky.org) or contact a local astronomy club. Architects and builders interested in sustainability can achieve LEED Credit 8, which specifically addresses outdoor lighting. Again, purchasing and installing fully shielded fixtures in any new development is all it takes. The market now... |
sent into the sky costs the U.S. approximately $2.2 billion every year. As energy efficiency becomes imperative, city planners must consider improvements in public lighting as a long term way to reduce energy and conserve public funds. Most streets can dramatically lessen their lighting without compromising driver resp... |
for consumers to swap their traditional outdoor lighting to a Dark Sky fixture, and how are you getting that message out? The dark skies movement will resonate with anyone who recognizes the profound effect light has on a space, indoor or outdoor. Seriously, what other small change can you make that affects wildlife, e... |
neighborhood? In addition to the personal benefits you receive in terms of reduced energy use and a more pleasant personal space, a shift to dark sky-friendly lighting shows an awareness of the environment at large and a respect for the place you live. The dark sky message usually sells itself, once people become aware... |
a phenomenal job in spreading enthusiasm for the cause. Their interest in creating a sustainable, beautiful nighttime environment and their dedication to action is what drives the success this campaign. Thanks to the hard work of IDA volunteers worldwide, cities in the Americas, Europe, Asia, and even Australia are see... |
v.: to dismantle or otherwise redistribute the composite parts of a whole, as with an automobile, motorcycle, or computer system, according to the respective practical or monetary value of each. |
n./adj.: used to denote or describe an item whose original purpose or function as a whole is no longer viable, but whose constituent parts retain some individual practical or monetary |
value, as with a "yard out" motorcycle (often hyphenated: "yard-out"), also called a "parts machine". Context: The parting out of automobiles, motorcycles, electronic computer systems, industrial and agricultural machinery, electrical |
appliances, medical apparatuses, nautical and aeronautical equipment and other mechanical devices and instrumentation is done as an economical and, incidentally, ecological means of recycling (see recycle) and reusing various components |
that may otherwise be more expensive or difficult to obtain. See also: part out; part it out; dismantle; parts queen, junk wagon. "Patrick had me yard out a Zenith carburetor |
Martin Luther King, Jr.? Reviews for Who Was Martin Luther King, Jr.? An Excerpt from Who Was Martin Luther King, Jr.? Dr. Martin Luther King, Jr. was only 25 when he helped organize the Montgomery Bus Boycott and was soon |
organizing black people across the country in support of the right to vote, desegregation, and other basic civil rights. Maintaining nonviolent and peaceful tactics even when his life was threatened, King was also an advocate for the poor and spoke |
out against racial and economic injustice until his death—from an assassin’s bullet—in 1968. With clearly written text that explains this tumultuous time in history and 80 black-and-white illustrations, this Who Was…? celebrates the vision and the legacy of a remarkable |
Such was the condition in Kansas at the opening of the presidential year of 1856, and it became one of the leading issues of the campaign. The whole country was aroused over reports from Kansas, and it was impossible that such a question remain long out of the halls of Congress, notwithstanding the claim of Douglas tha... |
question from national politics. In May, 1856, Senator Sumner made a powerful speech on "The Crime against Kansas." The speech was a fearful arraignment of the slave power. But the speaker went out of his way to abuse certain senators whom he did not like, especially Senator Butler of South Carolina, who was then absen... |
personal attack on Sumner. Charles Sumner, with all his learning, was a narrow-minded man. He was opinionated, egotistical, and incapable of giving credit to another for an honest difference of opinion. But he was sincerely honest and courageous.¹ His espousal of the cause of the slave when that cause was very unpopula... |
Butler was occasioned by the indignation expressed by the latter at the audacity of the Topeka convention in applying for statehood. But Sumner suffered severely for his extravagance. Two days after making this speech, as he sat at his desk writing, after the Senate had adjourned, he was assaulted with a cane by Presto... |
Senator Butler. Brooks rained blows on Sumner's head with great ferocity. Sumner sat so near his desk that he had no chance to defend himself; but at length he rose, wrenching the desk from its fastenings. Brooks then grappled with him and continued his blows until Sumner fell bleeding and unconscious to the floor. So ... |
he did not fully recover for four years; and indeed, never after this assault was he the powerful, robust athlete that he had been before. No incident in many years revealed more vividly the vast gulf between the North and the South than did the different manner of their receiving the news of this assault on Sumner² Th... |
as a cowardly outrage, unworthy of any but a bully and a thug. At the South, where Sumner was hated above all men, the verdict was that he received only the punishment he deserved. Brooks was hailed as a champion and a hero, and was presented with many canes. He resigned his seat in the House because of a majority vote... |
thirds--for his expulsion; but he was immediately reëlected by his district.³ Meantime matters were growing worse on the plains of Kansas. On the day that intervened between the closing of Sumner's speech and the assault by Brooks the town of Lawrence was sacked by a mob. The House of Representatives sent a committee o... |
composed of William A. Howard of Michigan, John Sherman of Ohio, and Mordecai Oliver of Missouri, after examining several hundred witnesses, reported in July. Howard and Sherman reported favorably to the free-state party, but agreed that the election of Reeder to Congress, as that of Whitfield, was illegal. Oliver made... |
War in Kansas may be said to have begun. Soon after this occurred the massacre of Pottawatomie, the leader of which was John Brown. Brown had come from the East to join his sons, who had been among the early settlers of Kansas. He was an ascetic and a fanatic. He had come to Kansas to make it a free state at any hazard... |
He regarded slavery with a mortal hatred, and while his courage was unlimited and his intentions upright, his soul was too utterly narrow to see a thing in its true light. He believed that the only way to free the slaves was to kill the slaveholders. "Without the shedding of blood, there is no remission of sins," said ... |
one of whom was a neighbor of Brown, had been killed by the opposite party, and Brown determined that an equal number of them should suffer death to expiate the crime. He organized a night raid--his sons and a few others--and started on his bloody errand. They called at one farmhouse after another and slew the men in c... |
if they were guilty of not guilty; enough if they belonged to the opposite party. One man was dragged from the presence of a sick wife. Her pleadings that he be spared were not heeded. He was murdered in cold blood in the road before his house. Before the end of that bloody night raid Brown's party had put six or seven... |
death--for no crime except that they belonged to the opposite party and had made threats--an offense of which Brown's party were equally guilty. When the news of this ghastly work was flashed over the country, the people in general refused to believe it; and to the credit of the free-state people in Kansas, they repudi... |
speech, in which he attacked Senator Douglas also without mercy, the latter said to a friend: "Do you hear that man? He may be a fool, but I tell you that he has pluck." Poore's "Reminiscences," Vol. I, p. 461. ²Rhodes, Vol. II, p. 143 ³Brooks died the following January, and Butler in May of the same year. |
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A modem self-test in which data from the keyboard or an internal test pattern |
is sent to the modem's transmitter, turned into analog form, looped back to the receiver, and converted back into digital form. A variety of signals and wavelengths that can be transmitted over communications lines such as the sound of a |
voice over the phone line. The mode used by your modem when answering an incoming call from an originating modem. The transmit/receive frequencies are the reverse of the originating modem, which is in originate mode. A computer program designed to |
perform a specific task or set of tasks. Examples include word processing and spreadsheet applications. Automatic Repeat reQuest. A function that allows your modem to detect flawed data and request that it be retransmitted. See MNP and V.42. American Standard |
Code for Information Interchange. A code used to represent letters, numbers, and special characters such as $, !, and /. Data transmission in which the length of time between transmitted characters may vary. Because characters may not be transmitted at |
set intervals, start/stop bits are used to mark the beginning and end of each character. Sets the modem to pick up the phone line when it detects a certain number of rings. See S-register S0 in the Technical Reference section |
of this guide. A process where your modem dials a call for you. The dialing process is initiated by sending an ATDT (dial tone) or ATDP (dial pulse) command followed by the telephone number. Auto-dial is used to dial voice |
numbers. See basic data command Dn in the Technical Reference section of this guide. A term used to measure the speed of an analog transmission from one point to another. Although not technically accurate, baud rate is commonly used to |
mean bit rate. A 0 or 1, reflecting the use of the binary numbering system. Used because the computer recognizes either of two states, OFF or ON. Shortened form of binary digit is bit. Also referred to as transmission rate. |
The number of binary digits, or bits, transmitted per second (bps). Communications channels using analog modems are established at set bit rates, commonly 2400, 4800, 9600, 14,400, 28,800, 33,600, and higher. bits per second (bps) The bits (binary digits) per |
second rate. Thousands of bits per second are expressed as kilobits per second (Kbps). A temporary memory area used as storage during input and output operations. An example is the modem's command buffer. A group of binary digits stored and |
operated upon as a unit. Most often the term refers to 8-bit units or characters. One kilobyte (KB) is equal to 1,024 bytes or characters; 640 KB is equal to 655,360 bytes or characters. The basic signal altered or modulated |
by the modem in order to carry information. A representation, coded in binary digits, of a letter, number, or other symbol. characters per second (cps) A data transfer rate generally estimated from the bit rate and the character length. For |
example, at 2400 bps, 8-bit characters with start/stop bits (for a total of ten bits per character) will be transmitted at a rate of approximately 240 characters per second (cps). Some protocols, such as error-control protocols, employ advanced techniques such |
as longer transmission frames and data compression to increase cps. class 1 and 2.0 International standards used by fax application programs and faxmodems for sending and receiving faxes. cyclic redundancy checking (CRC) An error-detection technique consisting of a test performed |
on each block or frame of data by both sending and receiving modems. The sending modem inserts the results of its tests in each data block in the form of a CRC code. The receiving modem compares its results with |
the received CRC code and responds with either a positive or negative acknowledgment. The transmission or sharing of data between computers via an electronic medium. data compression table A table containing values assigned for each character during a call under |
MNP5 data compression. Default values in the table are continually altered and built during each call: The longer the table, the more efficient throughput gained. Mode used by a modem when sending and receiving data files. Data Communications (or Circuit-Terminating) |
Equipment, such as dial-up modems that establish and control the data link via the telephone network. Any setting assumed, at startup or reset, by the computer's software and attached devices. The computer or software will use these settings until changed |
by the user or other software. A test that checks the modem's RS-232 interface and the cable that connects the terminal or computer and the modem. The modem receives data (in the form of digital signals) from the computer or |
terminal and immediately returns the data to the screen for verification. Discrete, uniform signals. In this guide, the term refers to the binary digits 0 and 1. Data Terminal (or Terminating) Equipment. A computer that generates or is the final |
destination of data. Indicates a communications channel capable of carrying signals in both directions. See half-duplex, full-duplex. Electronic Industries Association (EIA) Group which defines electronic standards in the U.S. Various techniques that check the reliability of characters (parity) or blocks |
of data. V.42 and MNP error-control protocols use error detection (CRC) and retransmission of flawed frames (ARQ). A method for transmitting the image on a page from one point to another. Commonly referred to as fax. The mode used by |
a modem to send and receive data in facsimile format. See definitions for V.17, V.27 ter, V.29. A mechanism that compensates for differences in the flow of data into and out of a modem or other device. See extended data |
commands &Hn, &In, &Rn in the Technical Reference section of this guide. A data communications term for a block of data with header and trailer information attached. The added information usually includes a frame number, block size data, error-check codes, |
and Start/End indicators. Signals can flow in both directions at the same time over one line. In microcomputer communications, this may refer to the suppression of the online local echo. Signals can flow in both directions, but only one way |
at a time. In microcomputer communications, may refer to activation of the online local echo, which causes the modem to send a copy of the transmitted data to the screen of the sending computer. Hertz, a frequency measurement unit used |
internationally to indicate cycles per second. An electronic communications network that connects computer networks and organizational computer facilities around the world. Internet Service Provider (ISP) A company that provides dial-up (modem) access to the Internet for a fee. An international |
organization that defines standards for telegraphic and telephone equipment. For example, the Bell 212A standard for 1200-bps communication in North America is observed internationally as ITU-T V.22. For 2400-bps communication, most U.S. manufacturers observe V.22 bis. Link Access Procedure for |
Modems. An error-control protocol defined in ITU-T recommendation V.42. Like the MNP protocols, LAPM uses cyclic redundancy checking (CRC) and retransmission of corrupted data (ARQ) to ensure data reliability. A modem feature that enables the modem to display keyboard commands |
and transmitted data on the screen. See basic data command En in the Technical Reference section of this guide. Microcom Networking Protocol, an error-control protocol developed by Microcom, Inc., and now in the public domain. There are several different MNP |
protocols, but the most commonly used one ensures error-free transmission through error detection (CRC) and retransmission of flawed frames. A device that transmits/receives computer data through a communications channel such as radio or telephone lines. It also changes signals received |
from the phone line back to digital signals before passing them to the receiving computer. nonvolatile memory (NVRAM) User-programmable random access memory whose data is retained when power is turned off. On the USRobotics modem, it includes four stored phone |
numbers and the modem settings. Modem operations that are the equivalent of manually lifting a phone receiver (taking it off-hook) and replacing it (going on-hook). online fall back/fall forward A feature that allows high-speed, error-control modems to monitor line quality |
and fall back to the next lower speed in a defined range if line quality diminishes. As line conditions improve, the modems switch up to the next higher speed. The mode used by your modem when initiating an outgoing call |
to a destination modem. The transmit/receive frequencies are the reverse of the called modem, which is in answer mode. A simple error-detection method that checks the validity of a transmitted character. Character checking has been surpassed by more reliable and |
efficient forms of error checking, including V.42 and MNP 2-4 protocols. Either the same type of parity must be used by two communicating computers, or both may omit parity. A system of rules and procedures governing communications between two or |
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