Monthly Archives: July 2016
iPhoneOgraphy – 31 Jul 2016 (Day 213/366)
A memory card or flash card is an electronic flash memory data storage device used for storing digital information. These are commonly used in portable electronic devices, such as digital cameras, mobile phones, laptop computers, tablets, MP3 players and video game consoles.
PC Cards (PCMCIA) were the first commercial memory card formats (type I cards) to come out, but are now mainly used in industrial applications and to connect I/O devices such as modems. Since 1994, a number of memory card formats smaller than the PC Card arrived, the first one was Compact Flash later Smart Media and Miniature Card. The desire for smaller cards for cell-phones, PDAs, and compact digital cameras drove a trend that left the previous generation of “compact” cards looking big. In digital cameras SmartMedia and CompactFlash had been very successful. In 2001, SM alone captured 50% of the digital camera market and CF had captured the professional digital camera market. By 2005 however, SD/MMC had nearly taken over SmartMedia’s spot, though not to the same level and with stiff competition coming from Memory Stick variants, as well CompactFlash. In industrial and embedded fields, even the venerable PC card (PCMCIA) memory cards still manage to maintain a niche, while in mobile phones and PDAs, the memory card has become smaller.
Since 2010, new products of Sony (previously only using Memory Stick) and Olympus (previously only using XD-Card) have been offered with an additional SD-Card slot. Effectively the format war has turned in SD-Card’s favor.
iPhoneOgraphy – 30 Jul 2016 (Day 212/366)
Chopsticks are shaped pairs of equal length sticks that have been used as the traditional ancient kitchen and eating utensils in virtually all of East Asia for over six thousand years. Chopsticks were first used by the Chinese and later spread to countries, through cultural influence or through Chinese immigrant communities, such as Japan, Korea, Vietnam, Singapore, Malaysia, Laos, Myanmar, Thailand and Nepal as well as in areas of the United States, especially California, New York, Hawaii, and cities in Canada and Australia with Chinese communities. Chopsticks are smoothed and frequently tapered, and are commonly made of bamboo, plastic, wood, or stainless steel. They are less commonly made from gold, silver, porcelain, jade, or ivory. Chopsticks are held in the dominant hand, between the thumb and fingers, and used to pick up pieces of food.
The English word “chopstick” may have derived from Chinese Pidgin English, in which “chop chop” meant “quickly”. According to the Oxford English Dictionary, the earliest published use of the word is in the 1699 book Voyages and descriptions by William Dampier: “They are called by the English seamen Chopsticks”.
The Chinese term for chopsticks is kuaizi (Chinese: 筷子). The first character (筷) is a sematic-phonetic compound with a phonetic part meaning “quick” (快), and a semantic part meaning “bamboo” (竹).
In ancient written Chinese, the character for chopsticks was zhu (箸; Middle Chinese reconstruction: d̪jwo-). Although it may have been widely used in ancient spoken Chinese, its use was eventually replaced by the pronunciation for the character kuai (快), meaning “quick”. The original character, though still used in writing, is rarely used in modern spoken Chinese. It, however, is preserved in Chinese dialects such as Hokkien and Teochew.
For written semantic differentiation between the “fast” (快) versus “chopsticks”, a new character was created for “chopsticks” (筷) by adding the “bamboo” (竹) radical (⺮) to it.
In Japanese, chopsticks are called hashi (箸). They are also known as otemoto (おてもと), a phrase commonly printed on the wrappers of disposable chopsticks. Te means hand and moto means the area under or around something. The preceding o is used for politeness.
In Korean, 저 (箸, jeo) is used in the compound jeotgarak, which is composed of jeo”chopsticks” and garak “stick”. Jeo cannot be used alone, but can be found in other compounds such as sujeo, meaning “spoon and chopsticks”.
In Vietnamese, chopsticks are called “đũa”, which is written as 𥮊 with 竹 trúc (bamboo) as the semantic, and 杜 đỗ as the phonetic part. It is an archaic borrowing of the older Chinese term for chopsticks, 箸.
Chopsticks were invented in ancient China as early as the Shang dynasty (1766-1122 BCE) and possibly even earlier during the Xia dynasty. The earliest evidence were six chopsticks, made of bronze, 26 cm (10 inches) long and 1.1 to 1.3 cm (0.43 to 0.51 inches) wide, excavated from the Ruins of Yin near Anyang (Henan) and dated roughly to 1200 BCE; those were supposed to be used for cooking. The earliest known extant textual reference to the use of chopsticks comes from the Han Feizi, a philosophical text written by Han Fei (c. 280-233 BCE) in the 3rd century BCE.
The first chopsticks were probably used for cooking, stirring the fire, serving or seizing bits of food, and not as eating utensils. Chopsticks began to be used as eating utensils during the Han dynasty. Chopsticks were considered more lacquerware friendly than other sharp eating utensils. It was not until the Ming dynasty that chopsticks came into normal use for both serving and eating. They then acquired the name kuaizi and the present shape.
iPhoneOgraphy – 29 Jul 2016 (Day 211/366)
A bandsaw uses a blade consisting of a continuous band of toothed metal rotating on opposing wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, but may cut a variety of materials. Advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band and its kerf. Most bandsaws have two wheels connected by a belt or chain rotating in the same plane, one of which is powered, although some may have three or four to distribute the load.
The idea of the band saw dates back to at least 1809, when William Newberry received a British patent for the idea, but band saws remained impractical largely because of the inability to produce accurate and durable blades using the technology of the day. Constant flexing of the blade over the wheels caused either the material or the joint welding it into a loop to fail.
Nearly 40 years passed before Frenchwoman Anne Paulin Crepin devised a welding technique overcoming this hurdle. She applied for a patent in 1846, and soon afterward sold the right to employ it to manufacturer A. Perin & Company of Paris. Combining this method with new steel alloys and advanced tempering techniques allowed Perin to create the first modern band saw blade.
The first American band saw patent was granted to Benjamin Barker of Ellsworth, Maine, in January of 1836. The first factory produced and commercially available band saw in the U.S. was by a design of Paul Prybil.
Power hacksaws (with reciprocating blades) were once common in the metalworking industries, but bandsaws and cold saws have mostly displaced them.
iPhoneOgraphy – 28 Jul 2016 (Day 210/366)
A pencil sharpener (also referred to in Ireland as a parer or topper) is a device for sharpening a pencil’s writing point by shaving away its worn surface. Pencil sharpeners may be operated manually or by an electric motor.
Before the development of dedicated pencil sharpeners, a pencil was sharpened by whittling it with a knife. Pencil sharpeners made this task much easier and gave a more uniform result. Some specialized types of pencils, such as carpenter’s pencils are still usually sharpened with a knife, due to their flat shape, though since the 2000s a fixed-blade device with a rotatable collar has become available.
French mathematician Bernard Lassimonne applied for the first patent (French patent #2444) on pencil sharpeners in 1828, but it was not until 1847 that the pencil sharpener in its recognisable modern form was invented by fellow Frenchman Thierry des Estivaux. The first American pencil sharpener was patented by Walter K. Foster of Bangor, Maine in 1855. Electric pencil sharpeners for offices have been made since at least 1917.
They now come in a wide array of colors and shapes. It is common for traditional sharpeners to have a case around them to collect the shavings. It can be removed for emptying the shavings into a compost bin.
In May 2011, tourism officials in Logan, Ohio put on display, in its regional welcome center, hundreds of pencil sharpeners which had been collected by Rev. Paul Johnson, an Ohio minister who died in 2010. Johnson, a World War II veteran, had kept his collection of more than 3,400 sharpeners in a small shed, outside his home in Carbon Hill in southeast Ohio. He had started collecting after his wife gave him a few pencil sharpeners as a gift in the late 1980s. He kept them organized into categories, including cats, Christmas, and Disneyland. The oldest was 105 years old.
So-called “prism” sharpeners, also called “manual” or “pocket” sharpeners in the United States, have no moving parts and are typically the smallest and cheapest commonly used “pencil sharpener” on the market. The most simple common variety is a small and rectangular prism or block, only about 1 × 5/8 × 7/16 inch (2.5 × 1.7 × 1.1 cm) in size. The block-shaped sharpener consists of a combined point-shaping cone that is aligned to the cylindrical pencil alignment guide hole, into which the pencil is inserted. A sharp blade is mounted so that its sharp edge just enters the shaping cone. The pencil is inserted into the sharpener and rotated while the sharpener is held motionless. The body of the sharpener is often contoured, ridged or grooved to make the small block easier to firmly grip.
The blade inside the sharpener shaves the wood and graphite tip of the pencil, while the shavings emerge through a slot along the blade edge. It is important that the cylindrical alignment hole closely fit the diameter of the pencil to keep the pencil from wobbling; causing stepped or lurching cut-depths and point breakage. Another important feature is a larger clearance hole at the end of the cone allowing sections of the pencil lead which break away to be removed with only minor inconvenience. Prism sharpeners can be bare or enclosed in a container to collect the shavings. Enclosed sharpeners can be harder to clear in the event of a blockage. The base of such a sharpener is typically made of aluminium or hard plastic.
Moderate care is needed to not break the tip of the pencil being sharpened, losing the result of work immediately. However, because pencils may have different standard diameters in different nations, imported sharpeners may have non-standard-sized alignment guide-holes, — if it’s too-small the pencil cannot be inserted, while too-big (or missing,) and the tip of the pencil constantly breaks off,— making sharpening attempts futile. A few prism sharpeners are hand-cranked, as in the photo above. Prism sharpeners may be right- or left-handed, requiring clockwise or counter-clockwise rotation of the pencil being sharpened.
iPhoneOgraphy – 27 Jul 2016 (Day 209/366)
A nail clipper (also called a nail trimmer or nail cutter) is a hand tool used to trim fingernails, toenails and hangnails.
Nail clippers are usually made of stainless steel but can also be made of plastic and aluminium. Two common varieties are the plier type and the compound lever type. Most nail clippers usually come with another tool attached, which is used to clean dirt out from under nails. A nail clipper often has a miniature file fixed to it to allow rough edges of nails to be manicured. A nail file allows for removal of any excess nail that is jagged or has been missed. Nail clippers occasionally come with a pocket knife or a nail catcher. The nail clipper consists of a head which may be concave or convex. Specialized nail clippers which have convex clipping ends are intended for trimming toenails, while concave clipping ends are for fingernails. The cutting head may be manufactured to be parallel or perpendicular to the principal axis of the cutter. Cutting heads which are parallel to the principal axis are made to address accessibility issues involved with cutting toenails.
The inventor of the nail clipper is not exactly known, but the first United States patent for an improvement in a finger-nail clipper (implying such a device already existed) seems to be in 1875 by Valentine Fogerty. Other patents for an improvement in finger-nail clippers are in 1876, William C. Edge, and in 1878, John H. Hollman. Filings for complete finger-nail clippers (not merely improvements) include, in 1881, Eugene Heim and Celestin Matz, in 1885, George H. Coates (for a finger-nail cutter), and, in 1905, Chapel S. Carter (son of a Connecticut Baptist church deacon) patented a finger-nail clipper with a later patent in 1922. Around 1913, Carter was secretary of the H. C. Cook Company of Ansonia, Connecticut, which was incorporated in 1903 as the H. C. Cook Machine Company by Henry C. Cook, Lewis I. Cook, and Chapel S. Carter. Around 1928, Carter was president of the company when, he claimed, about 1896, the “Gem”-brand finger nail clipper made its first appearance.
Around 1906, the L.T.Snow company manufactured nail cutters. Around 1908 (or 1911), the King Klip Company of New York manufactured nail cutters.
In 1947, William E. Bassett (who started the W. E. Bassett Company in 1939) developed the “Trim”-brand nail clipper, the first made using modern (at the time) manufacturing methods using the superior jaw-style design that had been around since the 19th century, but adding two nibs near the base of the file to prevent lateral movement, replacing the pinned rivet with a notched rivet, and adding a thumb-swerve in the lever.
iPhoneOgraphy – 26 Jul 2016 (Day 208/366)
Sewing is the craft of fastening or attaching objects using stitches made with a needle and thread. Sewing is one of the oldest of the textile arts, arising in the Paleolithic era. Before the invention of spinning yarn or weaving fabric, archaeologists believe Stone Age people across Europe and Asia sewed fur and skin clothing using bone, antler or ivory needles and “thread” made of various animal body parts including sinew, catgut, and veins.
For thousands of years, all sewing was done by hand. The invention of the sewing machine in the 19th century and the rise of computerization in the 20th century led to mass production and export of sewn objects, but hand sewing is still practised around the world. Fine hand sewing is a characteristic of high-quality tailoring, haute couture fashion, and custom dressmaking, and is pursued by both textile artists and hobbyists as a means of creative expression.
The first known use of the word sewing was in the 14th century.
Sewing has an ancient history estimated to begin during the Paleolithic Age. Sewing was used to stitch together animal hides for clothing and for shelter. The Inuit, for example, used sinew from caribou for thread and needles made of bone; the indigenous peoples of the American Plains and Canadian Prairies used sophisticated sewing methods to assemble tipi shelters. Sewing was combined with the weaving of plant leaves in Africa to create baskets, such as those made by Zulu weavers, who used thin strips of palm leaf as “thread” to stitch wider strips of palm leaf that had been woven into a coil. The weaving of cloth from natural fibres originated in the Middle East around 4000 BCE, and perhaps earlier during the Neolithic Age, and the sewing of cloth accompanied this development.
During the Middle Ages, Europeans who could afford it employed seamstresses and tailors. Sewing for the most part was a woman’s occupation, and most sewing before the 19th century was practical. Clothing was an expensive investment for most people, and women had an important role in extending the longevity of items of clothing. Sewing was used for mending. Clothing that was faded would be turned inside-out so that it could continue to be worn, and sometimes had to be taken apart and reassembled in order to suit this purpose. Once clothing became worn or torn, it would be taken apart and the reusable cloth sewn together into new items of clothing, made into quilts, or otherwise put to practical use. The many steps involved in making clothing from scratch (weaving, pattern making, cutting, alterations, and so forth) meant that women often bartered their expertise in a particular skill with one another. Decorative needlework such as embroidery was a valued skill, and young women with the time and means would practise to build their skill in this area. From the Middle Ages to the 17th century, sewing tools such as needles, pins and pincushions were included in the trousseaus of many European brides.
Decorative embroidery was valued in many cultures worldwide. Although most embroidery stitches in the Western repertoire are traditionally British, Irish or Western European in origin, stitches originating in different cultures are known throughout the world today. Some examples are the Cretan Open Filling stitch, Romanian Couching or Oriental Couching, and the Japanese stitch. The stitches associated with embroidery spread by way of the trade routes that were active during the Middle Ages. The Silk Road brought Chinese embroidery techniques to Western Asia and Eastern Europe, while techniques originating in the Middle East spread to Southern and Western Europe through Morocco and Spain. European imperial settlements also spread embroidery and sewing techniques worldwide. However, there are instances of sewing techniques indigenous to cultures in distant locations from one another, where cross-cultural communication would have been historically unlikely. For example, a method of reverse appliqué known to areas of South America is also known to Southeast Asia.
iPhoneOgraphy – 25 Jul 2016 (Day 207/366)
The chicken or the egg causality dilemma is commonly stated as “which came first, the chicken or the egg?” To ancient philosophers, the question about the first chicken or egg also evoked the questions of how life and the universe in general began.
Aristotle (384–322 BC) was puzzled by the idea that there could be a first bird or egg and concluded that both the bird and egg must have always existed:
“If there has been a first man he must have been born without father or mother – which is repugnant to nature. For there could not have been a first egg to give a beginning to birds, or there should have been a first bird which gave a beginning to eggs; for a bird comes from an egg.”
The same he held good for all species, believing, with Plato, “that everything before it appeared on earth had first its being in spirit.”
A dialectical answer (that of Hegel and Marx) is that the egg and chicken exist in a dialectical relationship; the problem, it says, is that we are approaching an organic/dialectical relationship with the mindset of formal logic, i.e., linear cause-and-effect. Using this mindset, we reach a paradox, for we only see it in terms of ‘this caused that.’ To reach the true nature of this relationship, we have to admit the fact that the egg creates the chicken just as much as the chicken creates the egg. Hegel uses an analogy of a bud:
“The bud disappears when the blossom breaks through, and we might say that the former is refuted by the latter; in the same way when the fruit comes, the blossom may be explained to be a false form of the plant’s existence, for the fruit appears as its true nature in place of the blossom. These stages are not merely differentiated; they supplant one another as being incompatible with one another. But the ceaseless activity of their own inherent nature makes them, at the same time, moments of an organic unity, where they not merely do not contradict one another, but where one is as necessary as the other; and this equal necessity of all moments constitutes alone and thereby the life of the whole.”
According to Popular Science, dinosaurs were laying eggs before there were any birds, and the ancestors of chickens were chicken-like birds which laid eggs. Thus eggs came first.
According to evolutionary biologist and popular science writer, Richard Dawkins, the question is moot. In his book The Magic of Reality, Dawkins discusses the origins of humanity, and presumably any other species, in a chapter titled “Who was the First Person”. When addressing the question, he writes that “there never was a first person – because every person had to have parents, and those parents had to be people too!” In order to explain this, Dawkins employs a thought experiment. In the thought experiment, you start off with a picture of yourself. Then, you stack a photo of your father on top of your photo. Then, he asks the reader to consider continuing this process indefinitely, or until he or she finally encounter the common ancestor of all life on Earth. Now that the reader has this incredible genealogical record of himself or herself, or a chicken, the reader can then begin pulling out pictures from the stack. Dawkins says that, at each generation, the immediately preceding photographs will look only slightly different from the generation before or after, not distinguishable as separate species from their forebears. In other words, no matter where the reader decides to pull a photo from their stack of ancestors, they will definitely be recognizable as the parents of the generation after himself, and a child of his parents’ generation. But take photos from thousands of generations apart, and the ancestor will be nearly unrecognizable from their eventual progeny.
iPhoneOgraphy – 24 Jul 2016 (Day 206/366)
Excavators (Hydraulic Excavators) are heavy construction equipment consisting of a boom, dipper (or stick), bucket and cab on a rotating platform known as the “house”. The house sits atop an undercarriage with tracks or wheels. They are a natural progression from the steam shovels and often mistakenly called power shovels. All movement and functions of a hydraulic excavator are accomplished through the use of hydraulic fluid, with hydraulic cylinders and hydraulic motors. Due to the linear actuation of hydraulic cylinders, their mode of operation is fundamentally different from cable-operated excavators which uses winches and steel ropes to accomplish the movements.
Excavators are also called diggers, JCBs (a proprietary name, in an example of a generic trademark), mechanical shovels, or 360-degree excavators (sometimes abbreviated simply to 360). Tracked excavators are sometimes called “trackhoes” by analogy to the backhoe. In the UK, wheeled excavators are sometimes known as “rubber ducks.”
Hydraulic excavator capabilities have expanded far beyond excavation tasks with buckets. With the advent of hydraulic-powered attachments such as a breaker, a grapple or an auger, the excavator is frequently used in many applications other than excavation. Many excavators feature a quick coupler for simplified attachment mounting, increasing the machine’s utilization on the jobsite. Excavators are usually employed together with loaders and bulldozers. Most wheeled, compact and some medium-sized (11 to 18-tonne) excavators have a backfill (or dozer) blade. This is a horizontal bulldozer-like blade attached to the undercarriage and is used for levelling and pushing removed material back into a hole.
iPhoneOgraphy – 23 Jul 2016 (Day 205/366)
Children’s literature or juvenile literature includes stories, books, magazines, and poems that are enjoyed by children. Modern children’s literature is classified in two different ways: genre or the intended age of the reader.
Children’s literature can be traced to stories and songs, part of a wider oral tradition, that adults shared with children before publishing existed. The development of early children’s literature, before printing was invented, is difficult to trace. Even after printing became widespread, many classic “children’s” tales were originally created for adults and later adapted for a younger audience. Since the 15th century, a large quantity of literature, often with a moral or religious message, has been aimed specifically at children. The late nineteenth and early twentieth centuries became known as the “Golden Age of Children’s Literature” as this period included the publication of many books acknowledged today as classics.
Early children’s literature consisted of spoken stories, songs, and poems that were used to educate, instruct, and entertain children. It was only in the 18th century, with the development of the concept of childhood, that a separate genre of children’s literature began to emerge, with its own divisions, expectations, and canon.
French historian Philippe Ariés argues in his 1962 book Centuries of Childhood that the modern concept of childhood only emerged in recent times. He explains that children were in the past not considered as greatly different from adults and were not given significantly different treatment. As evidence for this position, he notes that, apart from instructional and didactic texts for children written by clerics like the Venerable Bede and Ælfric of Eynsham, there was a lack of any genuine literature aimed specifically at children before the 18th century.
Other scholars have qualified this viewpoint by noting that there was a literature designed to convey the values, attitudes, and information necessary for children within their cultures, such as the Play of Daniel from the 12th century. Pre-modern children’s literature, therefore, tended to be of a didactic and moralistic nature, with the purpose of conveying conduct-related, educational and religious lessons.
During the 17th century, the concept of childhood began to emerge in Europe. Adults saw children as separate beings, innocent and in need of protection and training by the adults around them. The English philosopher John Locke developed his theory of the tabula rasa in his 1690 An Essay Concerning Human Understanding. In Locke’s philosophy, tabula rasa was the theory that the (human) mind is at birth a “blank slate” without rules for processing data, and that data is added and rules for processing are formed solely by one’s sensory experiences. A corollary of this doctrine was that the mind of the child was born blank, and that it was the duty of the parents to imbue the child with correct notions. Locke himself emphasized the importance of providing children with “easy pleasant books” to develop their minds rather than using force to compel them; “children may be cozen’d into a knowledge of the letters; be taught to read, without perceiving it to be anything but a sport, and play themselves into that which others are whipp’d for.” He also suggested that picture books be created for children.
Another influence on this shift in attitudes came from Puritanism, which stressed the importance of individual salvation. Puritans were concerned with the spiritual welfare of their children, and there was a large growth in the publication of “good godly books” aimed squarely at children. Some of the most popular works were by James Janeway, but the most enduring book from this movement, still widely read today, was The Pilgrim’s Progress (1678) by John Bunyan.
In 1634, the Pentamerone from Italy became the first major published collection of European folk tales. Charles Perrault began recording fairy tales in France, publishing his first collection in 1697. They were not well received among the French literary society, who saw them as only fit for old people and children. In 1658, Jan Ámos Comenius in Bohemia published the informative illustrated Orbis Pictus, for children under six learning to read. It is considered to be the first picture book produced specifically for children.
The first Danish children’s book was The Child’s Mirror by Niels Bredal in 1568, an adaptation of a Courtesy book by the Dutch priest Erasmus. A Pretty and Splendid Maiden’s Mirror, an adaptation of a German book for young women, became the first Swedish children’s book upon its 1591 publication. Sweden published fables and a children’s magazine by 1766.
In Italy, Giovanni Francesco Straparola released The Facetious Nights of Straparola in the 1550s. Called the first European storybook to contain fairy-tales, it eventually had 75 separate stories and written for an adult audience. Giulio Cesare Croce also borrowed from stories children enjoyed for his books.
Russia’s earliest children’s books, primers, appeared in the late 16th century. An early example is ABC-Book, an alphabet book published by Ivan Fyodorov in 1571. The first picture book published in Russia, Karion Istomin’s The Illustrated Primer, appeared in 1694. Peter the Great’s interest in modernizing his country through Westernization helped Western children’s literature dominate the field through the 18th century. Catherine the Great wrote allegories for children, and during her reign, Nikolai Novikov started the first juvenile magazine in Russia.
iPhoneOgraphy – 22 Jul 2016 (Day 204/366)
Moths comprise a group of insects related to butterflies, belonging to the order Lepidoptera. Most lepidopterans are moths; and there are thought to be approximately 160,000 species of moth, many of which are yet to be described. Most species of moth are nocturnal, but there are also crepuscular and diurnal species.
The modern English word “moth” comes from Old English “moððe” (cf. Northumbrian “mohðe”) from Common Germanic (compare Old Norse “motti”, Dutch “mot”, and German “motte” all meaning “moth”). Its origins are possibly related to the Old English “maða” meaning “maggot” or from the root of “midge” which until the sixteenth century was used mostly to indicate the larva, usually in reference to devouring clothes.
Moths evolved long before butterflies, fossils having been found that may be 190 million years old. Both types of lepidoptera are thought to have evolved along with flowering plants, mainly because most modern species feed on flowering plants, both as adults and larvae. One of the earliest species thought to be a moth-ancestor is Archaeolepis mane, whose fossil fragments show scaled wings similar to caddisflies in their veining.
Moths frequently appear to circle artificial lights, although the reason for this behavior remains unknown. One hypothesis to explain this behavior is that moths use a technique of celestial navigation called transverse orientation. By maintaining a constant angular relationship to a bright celestial light, such as the moon, they can fly in a straight line. Celestial objects are so far away, that even after travelling great distances, the change in angle between the moth and the light source is negligible; further, the moon will always be in the upper part of the visual field, or on the horizon. When a moth encounters a much closer artificial light and uses it for navigation, the angle changes noticeably after only a short distance, in addition to being often below the horizon. The moth instinctively attempts to correct by turning toward the light, thereby causing airborne moths to come plummeting downward, and resulting in a spiral flight path that gets closer and closer to the light source.