The Clock Essay Example for Free

The Clock Essay A ‘clock’ is an instrument used to specify, record, and manage time. The word ‘clock’ comes from the French word â€Å"cloche† meaning bell, came into use when timekeepers were kept in bell towers in the Middle Ages. Historians do not who or when mankind â€Å"invented† a time-keeping device or a â€Å"clock†. Probably thousands of years ago when someone stuck a stick in the ground and saw a shadow of the sun move across the ground, known as the sundial. (Cummings, 1997-2012). After the Samarian culture left little knowledge behind, the Egyptians were next to divide their day in two parts. A vertical stick, or obelisk that is used to cast a shadow is known as a sundial. They were used as early as 3500 B.C.. Another shadow clock or sundial, possibly the first portable timepiece, came into use around 1500 B.C. to measure the passage of hours. As the sun moves from east to west, the shadows predict the time of the day. They also showed the years longest and shortest days when the shadow at noon was the shortest or longest of the year. The Greeks used a sundial called â€Å"pelekinon†. These sundials are marked to predict time accurately throughout the year. They built a more accurate sundial based on their knowledge of geometry. An ancient Egyptian sundial from the 8th century and a Greek sundial are still in existence today. Water clocks along with sundials are known to be the oldest time-measurements devices. The bowl-shaped outflow is the simplest form of a water clock and is known to have existed in Babylon and in Egypt around the 16th century BC. Other regions of the world, including India and China, also have early evidence of water clocks, but the earliest dates are less certain. Some authors, however, claim that water clocks appeared in China as early as 4000 BC. (Cowan, 1958) Ctesibius or Ktesibios or Tesibius (Greek: ΚτÎ ·ÃÆ'ÃŽ ¯ÃŽ ²ÃŽ ¹ÃŽ ¿Ãâ€š) (fl. 285–222 BC) was a Greek inventor and mathematician in Alexandria, Ptolemaic Egypt. (As of 2008, 1768–2010) He improved the clepsydra in the 3rd century by B.C. by which water that dripped into the container raised a float that carried a cursor to mark the hours. He attached a toothed rack with a float switch that when raised would turn a wheel where he installed mechanical signing birds and bells to signify certain hours of the day such as noon or midnight. In the 16th century A.D.  clepsydras were used by Galileo to time his experimental falling objects. A candle-timepiece is also of ancient origin. No one knows exactly when it originated. It was used to measure the transitory of time by marking intervals along the span of the candle. Ancient Egyptians used tallow, an animal substances to make candles. The Romans were the first to use a wick inside of a candle. Beeswax was used to make candles during the middle ages, however it was very expensive. It was said that the Romans and the Chinese would use candle-timepieces as alarm clocks. They would stick a nail in a certain point of the candle depending on the desired time. Whenever the candle wax melted down to the nail, the nail would then fall onto a tin pan and make a noise. An hourglass or sand clock was a commonly used time device. Its consist of two glass compartments connected by a narrow neck containing an certain amount of sand that slowly trickles from the bottom chamber to the lower in a set amount of time, often one hour or so. Hourglasses were very popular on board ships, as they were the most dependable measurement of time while at sea. Unlike the clepsydra, the motion of the ship while sailing did not affect the hourglass. The fact that the hourglass also used granular materials instead of liquids gave it more accurate measurements, as the clepsydra was prone to get condensation inside it during temperature changes. (Balmer, (Oct., 1978)). In the early-to-mid -14th century A.D., large mechanical clocks begin to appear in towers of several large Italian cities. These clocks were weight driven and very inaccurate. One of the first clocks to strike the hour was in Milan in around 1335 A.D. These clocks only had one hand, the hour hand. In 1510, a man by the name of Peter Henlein, a locksmith and clock maker of Nuremburg, Germany, invented the spring driven clock. He is often considered the inventor of the watch. (Dohrn-van Rossum Dunlap, 1996). In 1557, the minute hand was invented. However, it wasn’t until the invention of the pendulum in the late 1600’s that the minute hand became useful. As electricity was introduced, clocks began to use an electrical impulse to operate the dials of a master clock. The electrical current replaced the spring and weight as a power source. The piezoelectric effect given by the quartz crystals was discovered by the  Curie brothers, Pierre and Paul-Jacques Curie in 1880, but wasn’t applied into a clock until 1929. This effect exhibited by certain crystals generating a voltage when subject to an electric field, induced an electric potential to nearby conductors, therefore powering the clock. These clocks can have an accuracy of one second every 10 years. Along with these inventions, Charles Dowd introduces the idea of time zones in 1870 dividing the United States by meridians one hour, and 15 degrees apart using Greenwich, England as zero meridian. In 1883 the railroads adopt the four time zones for the continental United States. And in 1918 the United States Congress passes the ‘Standard Time Act’, authorizing The Interstate Commerce Commission to establish standard time zones within the United States, and establishing daylight saving times. Finally, In 1949 The National Institute of Standards and Technology built the first atomic clock, using ammonia. A second is formally defined as 9,192,631,770 vibrations of the cesium atom. Atomic clock NIST-7 has been the main atomic time standard for the United States, and is among the best time standards in the world.

The Wife of His Youth Essay -- Charles Chestnutt The Wife of His Youth

The Wife of His Youth In Charles Chestnutt’s â€Å"The Wife of His Youth,† Liza Jane is a woman who is determined to find her long lost husband, Sam Taylor. When he ran away from slavery and escaped up north, he left his wife behind. He changed his name to Mr. Ryder, to forget his past with slavery. Soon he became involved with a group called the Blue Veins, which were a group of people who believed in the preservation of light skinned blacks. In this group he was known as the dean. The Blue Vein society thought that dark skinned blacks were dirt and ignorant. Many years went by and Liza still felt that Sam was in love with her and that they would be back together. Liza was determined to find Sam. She searched for twenty-five years first going to many southern cities. Everywhere she wen...

Autism – General Overview of Autism

General Overview of Autism What is Autism? Autism is defined as a disorder of early development that causes severe problems in thinking, communicating with others, and feeling a part of the outside world (Autism 2009). A person diagnosed with autism has a brain abnormality that affects normal brain function (Nordquist 2009). Most diagnoses of autism are usually never the same, even though, the symptoms are generally similar. Autism must not be confused with childhood schizophrenia or mental retardation, though the actions of children with these circumstances are sometimes related to that of autistic children (Autism 2009).Autism prevents children from developing normal social relationships, even with their parents (Autism 2009). Infants and Autism Autism is generally not diagnosed until two or three years old, but there is an extremely controversial argument on whether or not it could be diagnosed in infants. According to Canadian researchers, they could already see signs and symptom s of autism in infants at approximately six months old (Boyles 2005). The researchers believe that the infant is already predisposed with abnormal brain development inside their mother’s womb.The infants that Canadian researchers experimented were only limited to families that already had an older child born with autism (Boyles 2005). According to research conducted in an article of Developmental Psychology, it is not possible to diagnose and infant with autism (Charman et al. ,1997). The researchers conducted a study on thirty eight boys, separated into three different groups: Autism Risk Group, Developmental Delay Group, and Normal Group. The studies were based upon four different criteria: Empathy, Pretend Play, Joint Attention, and Imitation (Charman et al. 1997). Based on their results, it was not evident t to say whether or not a child could be diagnosed with Autism. This based upon the findings that children in the autism group and children in the developmental delay g roup were indistinguishable and the scorings were far too similar (Charman et al. , 1997) In another study conducted by Dalery et al. , they compared young children and infants who were clinically diagnosed with autism or developmental delay (DD).The researchers were trying to differentiate whether the existence of symptoms of autism making it possible to be a different developmental disorder and whether or not the symptoms increase with age (Dalery et al. 2006). In the results from children under 26 months, the findings were insignificant and eerily similar to the experiment conducted by Chairman et al. They were unable to determine if the clear signs of developmental delay or autism were definite (Dalery et al. 2006). Symptoms of Autism Children diagnosed with Autism act differently from one another and no two autistic children have the same symptoms or act the same (CDC 2007).Children with Autism have severe impairments with social, emotional, and communication skills. Some have difficulty accomplishing everyday tasks and have to maintain a consistent day to day routine (CDC 2007). A symptom of autism that affects many autistic children is they have an intricate time holding a conversation. Thus, they tend to have a hard time making friends because of this impairment (CDC 2007). Another symptom of autism is repetitive behavior. This causes a stimulating effect on the child (CDC 2007). For example, a child may consistently rock back and forth, or flip the pages of a book over and over again.Autistic children have a difficult time managing in an everyday life. Once a child is diagnosed with autism, (usually between the ages of 2-4), it stays with them for the remainder of their lives (CDC 2007). With the various symptoms of autism, repetitive behavior seems to be the most consistent symptom that is distinguishable in almost all autistic patients (Gray et al. 1995). To determine whether or not this is true, research was conducted in Australia. The researchers wanted to determine if repetitive behavior was a distinguishable sign of autism in children less than 51 months.Since there are many different types of repetitive behavior, the different types were classified into two categories: higher and lower levels of repetitive behavior (Gray et al. 1995). According to Gray et al. , higher level repetitive behavior is highly consistent with autistic children under the age of 51 months. Low level repetitive behavior was not a direct diagnosis with autism. A significant number of children with other developmental delay disorders often demonstrated aspects of lower level repetitive behavior (Gray et al. 1995). Autism and Public SchoolingWhen a parents makes the decision to enroll their autistic child into public school, it is often a difficult decision. Sometimes the decision is made because the parent does not have the means to send their child to a school specialized for autistic children. Other times it is because many autistic designed school s only accept unique or extreme cases and their child do not meet the requirements (Rudy 2009). Even though a public school is required to give adequate education to a child with a learning disability, how does the parent know what is adequate to the teacher (Rudy 2009)?A positive aspect of public schools is that children with autism can interact with normal developing peers. Researchers argue that this type of interaction may â€Å"provide opportunities for building relationships and developing social and communicative behaviors, in response both to the demands made by mainstream peers and the modeling their behavior provides (Whitaker 2004). † In a study conducted by Whitaker, the mainstream peers developed a routine with the autistic children. The mainstream peers seemed to understand and learn the routines of the autistic peer.Whether or not the autistic child received any awareness or pleasure from this type of interaction was harder to detect, even though they appeared to be enjoying themselves (Whitaker 2004). Parents of Children with Autism It is devastating for a parent to learn that their child has a severe health problem or developmental disability (Parenting a Child with Autism 2007). The first question that arises is, â€Å"How can we cure it? †, but autism is not â€Å"curable†. In the beginning, parents often find some kind of support to help them cope with the discovery or having an autistic child.They also need to educate themselves as much as possible and decide what is best for the child (Parenting a Child with Autism 2007). D. E. Gray conducts a study to see how parents of autistic children cope with their child’s illness over time. Between 1988 and 1990, he begins his study and the sample included 28 parents of autistic children. In the beginning, parents used 51 different methods to cope with the discovery of their child’s illness. D. E. Gray followed-up with these parents 8-12 years later and the method s parents used decreased dramatically to 27.Parents learned to cope with their child’s autism throughout time. Maybe this was due to the fact that the child had become less disruptive and was more orderly in their habits (D. E. Gray 2006). It also may have been due to the fact that their children were enrolled in special schools (only one was enrolled in public schools). In the beginning, parents still had to adapt to the changes in their environment and with their child. As their emotional distress decreased, so did their need for emotional support (D. E. Gray 2006). ConclusionWhile the causes of autism remain a great mystery, one fact is certain: Autism affects every area of learning throughout the child‘s life. Until research on autism provides more information about how autism affects the human brain, children and their parents who are affected will be unable to understand and fully deal with this disability. It is only with more information that we will learn the b est approach to teach autistic children and tackle this disability head on.

The Existence Of God By Thomas Aquinas - 2218 Words

Kaitlyn Yinger 10-8-14 Robert Evans Intro to Philosophy The Existence of God Thomas Aquinas was a theologian that was a priest in the 1200’s and wanted to prove that God existed. He created many books and articles in his lifetime about God and things with the catholic religion, but, his more famous book Summa Thelogia gave five arguments that God exists in Articles II and III they are explained in detail. Below is my understanding of what he was saying the works of two other man that had comments on this man. Through the arguments of these three man I have came up with my own views and created an argument based on what they have to say. In Article II Aquinas states why people think that God doesn’t exist and goes on to destroy them piece by piece. The first argument in Article II against God states that God does not existence because it can not be demonstrated that he does in fact exist. He answers calmly and uses examples from the Bible to help him with the answer and then he states what he thinks. Based on what he stated in his example he went off of it and said that what he thinks. He states in Article II and I quote â€Å"I reply, therefore, that God’s existence, and those other things of this nature that can be known through natural reason concerning God, as is said in Rom. I., are not articles of faith, but preambles to these articles.† (Article II). He is saying that Faith is not a given thing you have to knowledge and understanding so that you can develop faithShow MoreRelatedThomas Aquinas And The Existence Of God849 Words   |  4 Pagestimes, the existence of God. Each philosopher ha s a varyingly different theory on how whether in fact God does exist, or that he does not exist. Evidently, God’s existence has not been settled and will continue to be deliberated until humans no longer exist, however, there are philosophers who are more successful at arguing for God’s existence than other theories do. Thomas Aquinas, a renowned philosopher and regarded as one of the greatest Christian theologians, wrote about God’s existence which isRead MoreSt. Thomas Aquinas On The Existence Of God1338 Words   |  6 Pagesphilosophers shifted their focus primarily to proving the existence of God, as well as other religious tenets they held. Two Saints of the Catholic Church, St. Anselm and St. Thomas Aquinas, developed their own respective proofs for the existence of God. These proofs have gained fame over the subsequent centuries and still face debate and comparison today. Although both St. Anselm and St. Thomas Aquinas both offer proofs for the existence of God, the proofs differ drastically due to the distinct argumentativeRead MoreSt. Thomas Aquinas On The Existence Of God1048 Words   |  5 PagesSt. Thomas Aquinas is considered to be one of the greatest minds of the western world as well as one of the greatest theologians. In his work Summa Theologica, which he revised many times over the course of his life, he explored the existence of God, and there are essentially five ways in which St. Thomas Aquinas argues the existence of God. The first way is the argument from change, the second way is the argument from causation, the third argument is the argument from possibility and necessity,Read MoreThomas Aquinas And His Views On The Existence Of God1527 Words   |  7 PagesThomas Aquinas was a famous philosopher and theologian from the 1200’s who dedicated his life to praising and explaining the existence of a higher being, God. Aquinas presents his evidence for the existence of a higher being through five distinct ways in the Summa Theologica. These ways give reason for God’s existence through the cause, existence and final cause of different events and objects. The two first ways made by Aquinas are the most influential sources I found that provide good evidenceRead More Thomas Aquinas Work to Prove the Existence of God Essays1013 Words   |  5 PagesChristian, Thomas Aquinas naturally believed in God, but he wanted to prove Gods existence to those who could not accept things on faith alone. As a result he made five proofs, which he claims, prove the existence of God. With each proof there is always a beginning, a starting point, Aquinas claims it must be God that is the beginning of each. The first proof does not do complete justice to Aquinas’s claim that God exist, while the fifth proof could be used alone to prove Gods existence. OneRead MoreSaint Thomas Aquinas On The Existence Of God Is Self Evident?941 Words   |  4 PagesSaint Thomas Aquinas was a Catholic Priest who is considered the most influential medieval scholar and philosopher. He studied under Albert the Great and received a master’s in philosophy and theology at the University of Paris. Disobeying his family he became a monk and was known for being a chasing off a prostitute with a hot iron and for being a large slow moving man. Saint Thomas Aquinas has a specific writing style. He typically states a topic, writes a question about the topic after whichRead More Saint Thomas Aquinas Five Proofs for the Existence of God Essay1914 Words   |  8 PagesSaint Thomas Aquinas Five Proofs for the Existence of God   Ã‚  Ã‚  Ã‚  Ã‚  Scientific reasoning has brought humanity to incredibly high levels of sophistication in all realms of knowledge. For Saint Thomas Aquinas, his passion involved the scientific reasoning of God. The existence, simplicity and will of God are simply a few topics which Aquinas explores in the Summa Theologica. Through arguments entailing these particular topics, Aquinas forms an argument that God has the ability of knowing and willingRead MoreSir Thomas Aquinas And William Paley s Argument On The Existence Of God1176 Words   |  5 PagesSir Thomas Aquinas and William Paley present two arguments for the existence of God. Aquinas defines God as omnibenevolent (all good) for his argument, and he continues in â€Å"The Five Ways† to present arguments to prove God’s existence (Rosen et al. 11). Paley, on the other hand, primarily defines God as a designer worthy of our admiration for his work (Rosen et al. 27). During class discussion, defining God involved three major qualities: omnipotence, omniscience, and omnibenevolence. Both AquinasRead MoreThe Existence Of God s Existence1339 Words   |  6 Pagesidea of God. The existence of God is one of the most sought out topic that is frequently inquired. Is there really a God or is God merely a concept humans created to explain the unexplainable? And if God does exist, what makes him different from the rest of us? A well-known philosopher, St. Thomas Aquinas, introduced five proofs including the Cosmological Arguments of God’s existence, as well as explained some divine qualities that are associated with God. The nature of God’s existence is oftenRead MoreSt. Thomas Aquinas Essay823 Words   |  4 PagesSt. Thomas Aquinas, was a Dominican monk, who generally one of the greatest Scholastic writers of all times. He used ancient philosophy to prove religious propositions. One of the ancient philosophers that St. Thomas Aquinas used to prove religious facts was Aristotle. One of the greatest works that Aristotle did was to prove that god really exists. St. Thomas Aquinas used the forms that Aristotle and Plato used to prove the same philosophical question, does god really exist? St. Thomas Aquinas