Is Carbon Dating Accurate essays

Is Carbon Dating Accurate essays Carbon dating, used since 1948, is currently the main method of testing artifacts for age. My objective through this essay is to disprove the accuracy of the Carbon 14 dating method. William Libby invented carbon dating in 1948. It works on the principle that the carbon 14-C, is radioactive. It decays at a known rate called a half-life. This is balanced by the fact that 14-C is constantly produced in atmospheric reactions. Because of this, 14-C and its breakdown product 12-C, typically stay in balance. Carbon is passed between the ocean, atmosphere, and living things in the Carbon Cycle. When an animal dies it is taken out of the carbon cycle. After this, the proportion of 14-C to 12-C steadily declines. This supposedly allows one to date an object by the proportion of 14-C to 12-C. The problems of Carbon 14 dating are endless. A test in Science (vol. 141, page 636, August 16, 1963) showed the shell from a living mollusk to be dead for 3,000 years! Tests of Hawaiian lava flows known to be less than 200 years old have been dated up to 3 billion years old! The truth is, the time range for 14-C is unknown1! That is, the scientists themselves do not know the effective range for 14-C. Also, All carbon dates have a plus-minus probable error range. The older the item, the bigger the error range. An additional problem is that the true half-life of 14-C is unknown2! Scientists are drawing logical conclusions from an assumption of 14-Cs half-life!. Surrounding soil, water, vegetation and/or animal matter can even contaminate samples! When this contamination occurs, it mixes the date for the item with the date of the contaminant. Exacerbating this effect, non-living items cannot be dated! There is also the human subjectivity in carbon-14 dating. For instance, if someone found a 9.5 million year old human in an area where there was a ...

The Meanings and Variations of Sister

The Meanings and Variations of Sister The Meanings and Variations of Sister The Meanings and Variations of Sister By Mark Nichol Sister, from the Old English word sweoster and cognate with the Latin term soror, means not only â€Å"a female with one or more parents in common† but has also come, by extension, to refer to a woman with whom one has a bond or a common interest. It also applies to national or racial commonality, as in the term â€Å"soul sister,† which in American English describes a black female. In addition, it can refer loosely to a female relative or a girl or woman with whom one has an affinity, including among feminists; it is also slang for referring to a female in general. In religious contexts, it denotes a female member of a religious order. Because nuns often served as nurses, in British English, sister is still synonymous with nurse. Sis is an informal abbreviation, often used in direct address by a sibling, as is sissy, though this term acquired the pejorative connotation of an effeminate man. The quality of being a sister, literally or figuratively, is sisterhood; the term also applies to a society of sisters, such as a religious community of women. Sister-german is a technical legal term pertaining to the default definition of sister- â€Å"a woman or girl who has both of the same parents as a given person,† as opposed to a half sister, who shares only one parent, or a stepsister, the daughter of a stepparent. (The term german, from the Latin word germanus, means â€Å"having the same parents† and is unrelated to the proper noun referring to a person from Germany.) A blood sister is literally a sister by birth or figuratively someone with whom one shares a bond of loyalty; this term, inspired by â€Å"blood brother,† alludes to the ceremonial exchange of blood between two men, often by mingling blood at the point of a slight self-inflicted wound. â€Å"Big sister† refers to one’s older female sibling or to a woman who mentors a girl to whom she is not related. Phrases that include the word include â€Å"sister act,† a term from vaudeville describing a variety act consisting of two or more sisters, and â€Å"sob sister,† slang for an advice columnist or a writer of sentimental stories supposed to appeal primarily to women, alluding to the emotional reaction expected of female readers when reading such material. â€Å"Weak sister† is an allusion to the supposed inferiority of women that refers to an ineffectual, unreliable, or weak person in a group. Meanwhile, a sister language is one in the same language family, such as Spanish as compared to Portuguese and vice versa, while a sister city is a municipality that has established a cultural-exchange connection with a city in another country. In construction, to sister is to strengthen a structural element by attaching a similar component to it. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Vocabulary category, check our popular posts, or choose a related post below:Spelling Test 150 Diminutive Suffixes (and a Cute Little Prefix)One "L" or Two?