C14 dating video i know

c 14 dating video i know

Carbon dating is used to determine the age of biological artifacts up to 50,000 years old. This technique is widely used on recent artifacts, but teachers should note that this technique will not work on older fossils (like those of the dinosaurs which are over 65 million years old). This technique is not restricted to bones; it can also be used on cloth, wood and plant fibers. Carbon-14 dating has been used successfully on the Dead Sea Scrolls, Minoan ruins and tombs of the pharohs among other things.

Carbon-14 is a radioactive isotope of carbon. Its has a half-life of about 5,730 years. The short half-life of carbon-14 means its cannot be used to date extremely old fossils. Levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 remains undecayed).

Carbon-14 is created from nitrogen-14 in the upper atmosphere of the earth. Radiation from the sun collides with atoms in the atmosphere. These collisions create secondary cosmic rays in the form of energentic neutrons. When these neutrons collide with nitrogen-14 in the atmosphere carbon-14 can be created. Nitrogen normally occurs in a seven proton, seven nuetron, nitrogen-14 state. When it collides with an energetic neutron it becomes carbon-14, with six protons and eight neutrons and gives off a hydrogen atom with one proton and zero neutrons.

Most of the carbon on Earth exists as carbon-12. Carbon-14 is an isotope of carbon, which exists only is small amounts in the environment (1 in one trillion carbon atoms is carbon-14). The ratio of carbon-14 to carbon-12 in the atmosphere and on earth is nearly constant, although there has been some change in carbon-14 concentration over the last 10,000 years.

Carbon-14 formed in the atmosphere can combine with oxygen to form carbon dioxide (CO2). This carbon-14 labeled carbon dioxide is taken up by plants in their normal process of photosynthesis. Animals and people that eat these plants take the carbon-14 into their bodies as well.

Carbon-14 in the bodies of animals and plants is constantly decaying. However, the decaying carbon-14 is constantly being replaced as the plant or animal consumes more carbon-14 from the air or through its food. At any given moment all living plants and animals have approximately the same percentage of carbon-14 in their bodies.

When a plant or animal dies it stops bringing in new carbon-14. However, the carbon-14 already in the organism's body continues to decay at a constant rate. Therefore, the amount of carbon-14 in an artifact decreases at a predictable rate while the amount of carbon-12 remains constant. By comparing the ratio of carbon-14 to carbon-12 in an artifact to the ratio of carbon-14 to carbon-12 in living organisms scientists can determine the age of an artifact.

For example, say a fossil is found that has 35% carbon 14 compared to the living sample.  How old is the fossil? 
We can use a formula for carbon 14 dating to find the answer.

Where t 1/2  is the half-life of the isotope carbon 14, t is the age of the fossil (or the date of death) and ln() is the natural logarithm function.  If the fossil has 35% of its carbon 14 still, then we can substitute values into our equation.

Dating is a stage of romantic and/or sexual relationships in humans whereby two or more people meet socially, possibly as friends or with the aim of each assessing the other's suitability as a partner in a more committed intimate relationship or marriage . It can be a form of courtship consisting of social activities done by the couple. The protocols and practices of dating, and the terms used to describe it, vary considerably from country to country and over time. While the term has several meanings, the most frequent usage refers to two or more people exploring whether they are romantically and/or sexually compatible by participating in dates with the other. With the use of modern technology, people can date via telephone or computer or meet in person.

This term may also refer to two or more people who have already decided they share romantic and/or sexual feelings toward each other. These people will have dates on a regular basis, and they may or may not be having sexual relations . This period of courtship is sometimes seen as a precursor to engagement or marriage . [1] [2] Some cultures require people to wait until a certain age to begin dating, which has been a source of controversy.

Dating as an institution is a relatively recent phenomenon which has mainly emerged in the last few centuries. From the standpoint of anthropology and sociology , dating is linked with other institutions such as marriage and the family which have also been changing rapidly and which have been subject to many forces, including advances in technology and medicine. As humans have evolved from hunter-gatherers into civilized societies and more recently into modern societies, there have been substantial changes in the relationship between men and women, with perhaps one of a few remaining biological constants being that both adult women and men must have sexual intercourse for human procreation to happen. [3]

Generally, during much of recorded history of humans in civilization, and into the Middle Ages in Europe , weddings were seen as business arrangements between families, while romance was something that happened outside of marriage discreetly, such as covert meetings. [7] The 12th-century book The Art of Courtly Love advised that "True love can have no place between husband and wife." [7] According to one view, clandestine meetings between men and women, generally outside of marriage or before marriage, were the precursors to today's dating. [7]

One of the main purposes of dating is for two or more people to evaluate one another’s suitability as a long term companion or spouse. Often physical characteristics, personality, financial status, and other aspects of the involved persons are judged and as a result feelings can be hurt, and confidence shaken. Because of the uncertainty of the whole situation, the desire to be acceptable to the other person, and the possibility of rejection, dating can be very stressful for all parties involved. Some studies have shown that dating tends to be extremely difficult for people with social anxiety disorder . [21]

There are now more than 500 businesses worldwide that offer dating coach services—with almost 350 of those operating in the U.S. And the number of these businesses has surged since 2005 [37] Frequency of dating varies by person and situation; among singles actively seeking partners, 36% had been on no dates in the past three months, 13% had one date, 22% had two to four dates and 25% had five or more dates, according to a 2005 U.S. survey. [38]

The copulatory gaze, looking lengthily at a new possible partner, brings you straight into a sparring scenario; you will stare for two to three seconds when you first spy each other, then look down or away before bringing your eyes in sync again. This may be combined with displacement gestures, small repetitive fiddles that signal a desire to speed things up and make contact. When approaching a stranger you want to impress, exude confidence in your stance, even if you're on edge. Pull up to your full height in a subtle chest-thrust pose, which arches your back, puffs out your upper body and pushes out your buttocks. Roll your shoulders back and down and relax your facial expression.



How Carbon-14 Dating Works | HowStuffWorks

For example, say a fossil is found that has 35% carbon 14 compared to the living sample.  How old is the fossil? 
We can use a formula for carbon 14 dating to find the answer.

Where t 1/2  is the half-life of the isotope carbon 14, t is the age of the fossil (or the date of death) and ln() is the natural logarithm function.  If the fossil has 35% of its carbon 14 still, then we can substitute values into our equation.