Black Holes :: space black hole

Introduction Black holes are one of the more interesting topics in astrophysics. Even though they are commonly accepted as being real, their actual existence has yet to have been proven2. Black holes are objects that have such a concentration of mass that nothing can escape their gravitational pull once it crosses the black hole's event horizon or Schwarzschild radius. The Schwarzschild radius is the radius where, for anything inside, the escape velocity is greater than the speed of light. Since the speed of light is the maximum possible velocity, nothing escapes from a black hole. They are given their name from the fact that they do not emit any light, since light is also pulled into them. History The term "black hole" was first introduced in 1971 by John Archibald Wheeler1. The actual phenomena the term describes was theorized to exist back in 1916 by Karl Schwarzschild. Then, it was just a curiosity as a possible solution to Einstein's general theory of relativity which described gravity as a curvature of space-time2. It wasn't until 1939 that Oppenheimer and Snyder seriously considered the possibility that massive stars could collapse and become what is now called black holes at the end of their lives. Today, black holes are a commonly accepted theory that even the average person has some idea of what they are. There was even a recent Associated Press story about two black holes in the NGC6240 galaxy that scientists predict will someday merge. Properties Black holes have many interesting properties. The most obvious from their name is the fact that they can't be seen since no light is emitted from them. One of the ways they can be detected is by the x-rays given off by the matter being pulled into them before it crosses the Schwarzschild radius. As the matter is pulled in, it gains kinetic energy, heats up, ionizes, and when it reaches a few million Kelvin, emits x-rays3. Black holes can also be detected by the way nearby objects are affected by their immense gravity. As you get nearer to a black hole, light begins to be bent toward it. Black holes have a radius around them that forms what is called the photonsphere. At this point, photons of light can actually orbit the black hole4.

Compare and Contrast: Schools Essay

Choosing a college could be hard like if your choosing the University of Nevada, Las Vegas or University of California, Los Angleos. They have many similarities but there has to be something different about them that helps you choose a decision but you cant find it. Is it the environment that surrounds each of the schools. Maybe the different academics, does it have what I want to succeed in one day. Or what if it has the sports I love to play and watch and are they good at them. Choosing a college is a choice that is apart of your life forever. Its where one day you hopefully will get your degree and have the oppurtunities of a lifetime. Is the University of California, Los Angelos a better school then the University of Nevada, Las Vegas? The environment in Las Vegas is not as big and open as Los Angelos. They both have many simularites such as: the culture, opportunities, experiences, and walking distance in many places. But Las Vegas is known as sin city and if your for the partying, and having the fun its a great environment for you to be around. Like Los Angelos, Las Vegas is known to many big businesses. There are 20,000 people that attend this university which seems like a lot In contrast the University of California which is located in Los Angelos. When many people think Los Angelos they think gangs and violence but there is an up part to that. The University of California is one the highest known schools in the United States. The environment is a lot like Vegas but there are 40,000 people that attend the school and wheres there more people usually means more surroundings and a bigger space. It may have some of the same things like culture, opportunities , and experiences. Like UNLV, UCLA is a lot of walking distance from dorms to school, and many things in between those are things like food, gyms and etc. Vegas is a great place for learning; It has many things to offer just as well as Los Angelos. The environment is great but academics is the real reason you are going to college unless your the next Micheal Phelps, Lebron James , or another athletic star. In the University of Nevada they offer 220 undergraduate, masters , and doctoral degree program. It might offer less due to the smaller school. Unlv is based on a medical school. As for UCLA, it offers 5,000 courses that could end in 125 different majors. UCLA has a lot more to offer its not really based on just one thing. With the bigger classes it maybe a little crowed but the professors are there to help you. They may not care as much as they do it the classrooms but it would be your responsibility to go after to ask for help. Or even join tutoring which I’m sure is offered at both schools. With over 109 academic departments it would help you decided on what you want to do in life. Being Micheal Phelps, LeBron James, or even Alex Rodriguez, you would have to start somewhere in life. College is where everything hits the big time because the professional teams or even Olympics starts to really look at you. Both UNLV and UCLA have many sports to offer. The University of Nevada is the home of the red and silver Rebels. They offer the normal football , baseball, basketball, swim, golf, soccer,and etc. They do offer men cheer which not many schools do not offer. Although UCLA doesn’t offer male cheer it offers others things like track and field, mens volleyball, water polo, women gymnastics, women rowing,and women sand volleyball, otherwise it offers the same basic sports. UCLA is home of the blue and gold Bruns. They are very high in there division because of the level of talents they have on the field and/or courts. UCLA is a better school it offers a more experience environment that will prepare you more for the future, has a better verity of academics, and more sports to offer for the people who have dreams to become professional athletes. College is very stressful itself but finding one right for you is even harder. The University of Nevada in Las Vegas offers many things but; it isn’t just as big and have more opportunity then the University of California in Los Angelos. With the environment, academics, and sports its a bigger and better school. Some people might disagree but that’s what I think.

Graduation Speech Taking A Ged Test Essay - 870 Words

There was only a few of us that day, we all needed to take the GED test. We all seemed nervous. The nice lady who signed me in stood up front, she explained all the rules; no talking, no cheating, no getting up without your hand raised and acknowledged, and there are no bathroom breaks until you have finished each test. Before I took my seat I grabbed ear plugs took a last drink of my water and headed toward a seat up front. A little discouraged and nervous. Starting on only one test, then another. It was then time for me to take the last portion of the test. Normally, craving to write I really felt this was it, surely I was going to pass. Getting started, I began reading The rules: 60 timed minutes, 600 words or more, pick two Historical figures, Don’t forget to do your draft, revised draft and final. That’s when it hit me, wouldn’t I be writing about something I enjoyed? But, I was writing about something someone told me to write. Starting to tap and move my feet I couldn’t help it, overwhelmed and Tired. To add in more I scrolled down to find not only do I have to write, but having to read the excerpts of those characters and compare and contrast them. Now, with not finishing high school. Honestly, I had no clue what compare and contrast had meant. Or really how was I supposed to write this essay. The classroom was cold. My chair was squeaky and my ear plugs kept coming out. Breathing in and out, counting to ten and deciding to keep moving on. None the less I had 60Show MoreRelatedService For A Rock Solid Career Choice3315 Words   |  14 PagesTest day is here and you have been studying for weeks to take the test. Your moment of truth has finally arrived. Every new possible recruit must take and meet the minimum standards on the Armed Forces Vocational Aptitude Battery (ASAVB) Test. This test helps determine whether you have the mental aptitude to withstand the demands of the US Air Force and identifies your strengths to determine the careers best suited for your future success. Today is the day to make yourself proud and prove that allRead MoreAnalysis Of Jean Valjean s Les Miserables 7860 Words   |  32 Pagesabilities to obtain gainful employment and to pursue other endeavors after release and that PSE improves inmates self-esteem overall. Each of these perspectives w as offered at three of the four study sites (Hubbard, 2007). Finally, the college graduation ceremony was seen as a benefit (meaningful to the inmates) by stakeholders at two locations, as was PSE students being ‘looked up to’ and serving as role models for other inmates. Other cross-site responses included: time cuts (sentence reductions)Read MoreCase Studies13817 Words   |  56 Pagesassignment? * Should she order the T-shirts from a fair trade company? * Should she assume the Chinese company doesnt treat its workers fairly? CASE STUDY #4 Trust during the Dot-com Boom By Jessica Silliman Reyna Allen had her pick of jobs upon graduation as a communication major from Santa Clara University. She and her friends were graduating at what seemed like the perfect time-at the height of the dot-com boom. But Reynas professors had warned her about possible problems in the rose-colored jobRead MoreStephen P. Robbins Timothy A. Judge (2011) Organizational Behaviour 15th Edition New Jersey: Prentice Hall393164 Words   |  1573 Pagesresources in the classroom. Test Item File—Revised and updated to include questions that require students to apply the knowledge that they’ve read about in the text through Learning Objectives and Learning Outcomes. Questions are also tagged to reflect the AACSB Learning Standards. TestGen Test Generating Software—Test management software that contains all material from the Test Item File. This software is completely userfriendly and allows instructors to view, edit, and add test questions with just a