The Life and Death of a Star

Stars last a long time, but eventually they will die. The energy that makes up stars, some of the largest objects we ever study, comes from the interaction of individual atoms. So, to understand the largest and most powerful objects in the universe, we must understand the most basic. Then, as the stars life ends, those basic principles once again come into play to describe what will happen to the star next. Astronomers study various aspects of stars to determine how old they are as well as their other characteristics. That helps them also understand the life and death processes they experience. The Birth of a Star The stars took a long time to form, as gas drifting in the universe was drawn together by the force of gravity. This gas is mostly hydrogen, because its the most basic and abundant element in the universe, although some of the gas might consist of some other elements. Enough of this gas begins gathering together under gravity and each atom is pulling on all of the other atoms. This gravitational pull is enough to force the atoms to collide with each other, which in turn generates heat. In fact, as the atoms are colliding with each other, theyre vibrating and moving more quickly (that is, after all, what heat energy really is: atomic motion). Eventually, they get so hot, and the individual atoms have so much kinetic energy, that when they collide with another atom (which also has a lot of kinetic energy) they dont just bounce off each other. With enough energy, the two atoms collide and the nucleus of these atoms fuse together. Remember, this is mostly hydrogen, which means that each atom contains a nucleus with only one proton. When these nuclei fuse together (a process known, appropriately enough, as nuclear fusion) the resulting nucleus has two protons, which means that the new atom created is helium. Stars may also fuse heavier atoms, such as helium, together to make even larger atomic nuclei. (This process, called nucleosynthesis, is believed to be how many of the elements in our universe were formed.) The Burning of a Star So the atoms (often the element hydrogen) inside the star collide together, going through a process of nuclear fusion, which generates heat, electromagnetic radiation (including visible light), and energy in other forms, such as high-energy particles. This period of atomic burning is what most of us think of as the life of a star, and its in this phase that we see most stars up in the heavens. This heat generates a pressure - much like heating air inside a balloon creates pressure on the surface of the balloon (rough analogy) - which pushes the atoms apart. But remember that gravitys trying to pull them together. Eventually, the star reaches an equilibrium where the attraction of gravity and the repulsive pressure are balanced out, and during this period the star burns in a relatively stable way. Until it runs out of fuel, that is. The Cooling of a Star As the hydrogen fuel in a star gets converted to helium, and to some heavier elements, it takes more and more heat to cause the nuclear fusion. The mass of a star plays a role in how long it takes to burn through the fuel. More massive stars use their fuel faster because it takes more energy to counteract the larger gravitational force. (Or, put another way, the larger gravitational force causes the atoms to collide together more rapidly.) While our sun will probably last for about 5 thousand million years, more massive stars may last as little as 1 hundred million years before using up their fuel. As the stars fuel begins to run out, the star begins to generate less heat. Without the heat to counteract the gravitational pull, the star begins to contract. All is not lost, however! Remember that these atoms are made up of protons, neutrons, and electrons, which are fermions. One of the rules governing fermions is called the Pauli Exclusion Principle, which states that no two fermions can occupy the same state, which is a fancy way of saying that there cant be more than one identical one in the same place doing the same thing. (Bosons, on the other hand, dont run into this problem, which is part of the reason photon-based lasers work.) The result of this is that the Pauli Exclusion Principle creates yet another slight repulsive force between electrons, which can help counteract the collapse of a star, turning it into a white dwarf. This was discovered by the Indian physicist Subrahmanyan Chandrasekhar in 1928. Another type of star, the neutron star, come into being when a star collapses and the neutron-to-neutron repulsion counteracts the gravitational collapse. However, not all stars become white dwarf stars or even neutron stars. Chandrasekhar realized that some stars would have very different fates. The Death of a Star Chandrasekhar determined any star more massive than about 1.4 times our sun (a mass called the Chandrasekhar limit) wouldnt be able to support itself against its own gravity and would collapse into a white dwarf. Stars ranging up to about 3 times our sun would become neutron stars. Beyond that, though, theres just too much mass for the star to counteract the gravitational pull through the exclusion principle. Its possible that when the star is dying it might go through a supernova, expelling enough mass out into the universe that it drops below these limits and becomes one of these types of stars ... but if not, then what happens? Well, in that case, the mass continues to collapse under gravitational forces until a black hole is formed. And that  is what you call the death of a star.

What Are the Reasons of the Teenagers in Smoking - 1469 Words

CHAPTER 1 Introduction Tobacco contains nicotine, a highly addictive drug, smokers are aware in this. Even people who haven’t been addicted to smoking at all, why do they take up smoking? What are the reasons? Why they engaged there selves to this kind of habit? Curiousness convinced me to study this problem. One of my objectives in this study is to know how important that reasons of smokers why they used to link and addicted in this habit. It seems obvious that smoking is very bad, and people tell us not to smoke. Yet in everyday life, there are people, especially the teenagers now who scattered everywhere that you see they’re smoking. Nowadays, teenagers have their own way just to please their satisfaction. They’re just aware in the†¦show more content†¦Next time, I’m going for quality over price because if I’m going to inhale toxic fumes into my lungs, it better be delicious tasting. So far, cigarette reviews on YouTube seem to be the best source of information regarding strength, flavour and smell. Related Literature (Foreign) Cigarettes Are Evil†¦and delicious JULY 6, 2012 Or should I say deliciously evil†¦ I write this after having numerous smoking dreams last night. It must have been an alternate universe but in the dream I was outside smoking with my co-workers before school started. This would never happen, ever. Many of my co-workers are, however, closet smokers or former smokers that occasionally indulge. Today, in between tackling my massive to-do list I contemplated buying some cigarettes. I haven’t bought cigarettes for myself in a very long time. There something about cigarette smoking that is so much more alluring than the other types of tobacco smoking I also enjoy. Both pipe and cigar smoke is more flavourful and pleasant tasting. I get a pleasant buzz from doing all three but I think what it comes down to is inhaling. I know some people can inhale pipe or cigar smoke†¦ but I am not one of those people. Cigarettes are designed to make it easy for you to inhale thus making them far more efficient at delivering the drug. I think my boyfriend gets my attraction to smoking. He offered me cigars last night and I turned them down. He turned to me and said, â€Å"You just want a cigarette, don’tShow MoreRelatedTeenage Smoking In Teenagers886 Words   |  4 PagesSmoking in teenagers has been a topic of conversion for years. Should it be legal, illegal? Should there be an age requirement? Teenagers do what they want, and smoking is part of that. Most teenagers have taken in the consequences of smoking and its effects. Smoking isn’t a problem with teenagers anymore because most of them have had classes about smoking, the price has risen, and it has horrible effects to your body. The first reason why smoking isn’t a problem among teens is they care aboutRead MoreEssay on Smoking Trends Among Teenagers1066 Words   |  5 Pages Cigarette smoking is a habit that kills approximately million of people per year. It is surprisingly being picked up by myriad amount of children every day. Smoking becomes a growing trend in the youth community. The number of young smokers have been increased in most American middle schools and high schools. Both girls and boys are smoking because they think it is cool. The four reasons that cause many teenagers to start smoking are peer-pressure, image projection, rebellion, and adult aspirationsRead MoreWhy do teenagers indulge in alcoholism and smoking?873 Words   |  4 Pages 1 October 2013 Why do teenagers indulge in alcoholism and smoking? In today’s society many teenagers are introduced to new ideas every day. Teenage years often include adjusting to new people, and experimenting and trying out many unfamiliar ideas. 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Nowadays smoking becomes a trend like a social media, and especially teenagers, are participating in this as well. Although smoking makes you a person feel relaxed from the stress, it harms the body of the smokers in the long run. We have known that smoking can kill us from past 50-60 years, and according to the World Health OrganizationRead MoreCauses of Smoking Habit Among Teenagers1621 Words   |  7 PagesCauses of Smoking habit among Teenagers Regina Jane A. Ancheta Math11FA1 Prof. Dangla Hypothesis: Chapter 1: Introduction Each year a great amount of money are being wasted in smoking. Although it is quite obvious that smoking habit is dangerous and injurious to health but still a larger number of people especially teenagers attracting and getting involved in smoking habit day by day. Some reasons of this addiction are obvious such as influence of friends or community member as teenageRead MoreRestricted Teens950 Words   |  4 Pagesabout teenagers attending rated R movies, past president Bill Clinton said, â€Å"One can value the 1st amendment right to free speech and at the same time care for and act with restraint†. Clinton was the one who proposed that all people under 17 would have to be accompanied by an adult to a rated R (Restricted) movie. Although some people believe that teens should be able to go to see these movies alone, they do not have enough maturity and good judgment to have this right. Kids and teenagers should

To Learn English as an English Teacher Free Essays

Omar Alfaro Reyes ADVANTAGES AND DISADVANTAGES TO LEARN ENGLISH AS A SECOND LANGUAGE Why learning English as a second language? Nowadays learning another language is important because it is the most common language in the world, almost 60% people in the world use English regularly. Sometimes people think that learning English is difficult because most of the students can have different difficulties and problems in learning another language for example they make mistakes in their pronunciations, grammar, spelling and vocabulary usage. However it is worth for the wealth of information and the opportunity to open up for a person, for instance, the use of information and communication by internet or traveling abroad the world, they are two advantages for learning English. We will write a custom essay sample on To Learn English as an English Teacher or any similar topic only for you Order Now Also most of the students think to learn English is difficult because they speak English as speak Spanish or because students have lack vocabulary and they are two disadvantages to learn English as a second language. The ability to speak English fluently opens up a world of information and communication for a person. Information and communication by internet is a good idea for people or students that can surf in the web sites for looking examples or exercises about grammar for studying more in English. This is the best way for people can study another language, for instance the use of internet will allow them to chat with people from all over the world in chat-room. The second advantage is traveling abroad the world. English is often spoken in other country as a universal language for example Trinidad y Tobago, Puerto Rico and other ones. Knowing English is a great advantage to learn English because they can improve their knowledge in a real way. A much more serious problem for learners of English is the extent of the vocabulary. People think they can speak English as speak Spanish, this is the reason for a lot of misunderstandings happen when two non-English people talk with each other in English. Sometimes is confused because the people do not practice a lot and they are think that is really difficult. Second problem is that people have lack vocabulary, also for people are really difficult to learn English because they want to communicate but all the time is stressful for do not have a lot of vocabulary. 0% of people in Mexico think that English is really difficult to learn for instances because they do not have feeling for learning English and this are big disadvantages to learn English. In conclusion, the most important thing to do in this situation is to maximize your opportunities: to speak English, and not only speak English also try to practice a lot and try to understand in class and use English whenever possible out side the class. If you follow these rules, you will not have problems to learn a second language. How to cite To Learn English as an English Teacher, Papers

Ahhh...The Test free essay sample

Do you ever feel sweat coming from your hands? If you say yes, I bet I know why your hands are sweating†¦ it’s the test, isn’t it? I know it’s creepy, but here are ways to help you get good grades on everything you get. You don’t cheat, you practice, and you let your brain do the work, these are the advice I would give you, if you follow them, I hope that you should get a higher grade on your test. The following paragraphs will show you why you should follow my advices. My first advice is you don’t cheat. For example if you cheat, it’s called cheating, and that won’t help you pass the test, you might pass it, but what is it worth for? You will not understand anything they teach you, so re you cheating them, or are you really cheating yourself? Cheating is bad, because once in a while you’ll get caught by the teacher. We will write a custom essay sample on AhhhThe Test or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Another advice is you practice. For example if you practice you’ll get smarter. And then you can do the test like it is a piece of cake. Have you ever heard the phrase â€Å"Practice makes perfect†? Well believe in that phrase. It has proved very useful. I strongly believe in that phrase, because if you keep practicing, you will eventually find what kind of mistakes your making, and then you’ll learn to avoid all those mistakes. The last advice is you let your brain do the work. For example since you’ve practiced so hard for it, relax, I mean be nervous a little, but don’t worry too much, relax and have faith in yourself, say this in your head â€Å"I’m going to ace this test!†. Your brain will speed through the questions as if they were nothing much than a bug. In conclusion don’t cheat, because it’s going to get you nowhere.(except maybe the principle’s office.) Practice, Practice, Practice, because if you don’t you’ll regret it. And let your brain do all the work, because your brain has all the facts you need. Follow these advices, and there will be unlimited possibilities for your future. TRUST ME, when I used all these methods, I got the highest score on the 5th grade math test. And remember this is a secret between you and me†¦ don’t tell a soul. Good luck on your test†¦ oh wait, you don’t need luck you have skills on your side, so go ace that test!