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Neutron star

Neutron star
Neutron stars contain 500,000 times the mass of the Earth in a sphere with a diameter no larger than that of Brooklyn, United States A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Neutron stars are the densest and tiniest stars known to exist in the universe; although having only the diameter of about 10 km (6 mi), they may have a mass of several times that of the Sun. Neutron stars probably appear white to the naked eye. Neutron stars are the end points of stars whose inert core's mass after nuclear burning is greater than the Chandrasekhar limit for white dwarfs, but whose mass is not great enough to overcome the neutron degeneracy pressure to become black holes. Such stars are composed almost entirely of neutrons, which are subatomic particles without net electrical charge and with slightly larger mass than protons. Neutron star collision Formation[edit] Properties[edit]

Neutron Stars - Introduction Neutron stars are compact objects that are created in the cores of massive stars during supernova explosions. The core of the star collapses, and crushes together every proton with a corresponding electron turning each electron-proton pair into a neutron. The neutrons, however, can often stop the collapse and remain as a neutron star. Neutron stars are fascinating objects because they are the most dense objects known. Like their less massive counterparts, white dwarfs, the heavier a neutron star gets the smaller it gets. Neutron stars can be observed occasionally, as with Puppis A above, as an extremely small and hot star within a supernova remnant.

Einstein for Everyone Einstein for Everyone Nullarbor Press 2007revisions 2008, 2010, 2011, 2012, 2013 Copyright 2007, 2008, 2010, 2011, 2012, 2013 John D. Norton Published by Nullarbor Press, 500 Fifth Avenue, Pittsburgh, Pennsylvania 15260 with offices in Liberty Ave., Pittsburgh, Pennsylvania, 15222 All Rights Reserved John D. An advanced sequel is planned in this series:Einstein for Almost Everyone 2 4 6 8 9 7 5 3 1 ePrinted in the United States of America no trees were harmed web*bookTM This book is a continuing work in progress. January 1, 2015. Preface For over a decade I have taught an introductory, undergraduate class, "Einstein for Everyone," at the University of Pittsburgh to anyone interested enough to walk through door. With each new offering of the course, I had the chance to find out what content worked and which of my ever so clever pedagogical inventions were failures. At the same time, my lecture notes have evolved. This text owes a lot to many. i i i

String theory String theory was first studied in the late 1960s[3] as a theory of the strong nuclear force before being abandoned in favor of the theory of quantum chromodynamics. Subsequently, it was realized that the very properties that made string theory unsuitable as a theory of nuclear physics made it a promising candidate for a quantum theory of gravity. Five consistent versions of string theory were developed until it was realized in the mid-1990s that they were different limits of a conjectured single 11-dimensional theory now known as M-theory.[4] Many theoretical physicists, including Stephen Hawking, Edward Witten and Juan Maldacena, believe that string theory is a step towards the correct fundamental description of nature: it accommodates a consistent combination of quantum field theory and general relativity, agrees with insights in quantum gravity (such as the holographic principle and black hole thermodynamics) and has passed many non-trivial checks of its internal consistency.

Engineering The American Engineers' Council for Professional Development (ECPD, the predecessor of ABET)[1] has defined "engineering" as: The creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct or operate the same with full cognizance of their design; or to forecast their behavior under specific operating conditions; all as respects an intended function, economics of operation or safety to life and property.[2][3] One who practices engineering is called an engineer, and those licensed to do so may have more formal designations such as Professional Engineer, Designated Engineering Representative, Chartered Engineer, Incorporated Engineer, Ingenieur or European Engineer. History[edit] Engineering has existed since ancient times as humans devised fundamental inventions such as the pulley, lever, and wheel. Ancient era[edit] Renaissance era[edit] Modern era[edit]

Applied mathematics Applied mathematics is a branch of mathematics that deals with mathematical methods that find use in science, engineering, business, computer science, and industry. Thus, "applied mathematics" is a mathematical science with specialized knowledge. The term "applied mathematics" also describes the professional specialty in which mathematicians work on practical problems by formulating and studying mathematical models. In the past, practical applications have motivated the development of mathematical theories, which then became the subject of study in pure mathematics where abstract concepts are studied for their own sake. The activity of applied mathematics is thus intimately connected with research in pure mathematics. History[edit] Divisions[edit] Today, the term "applied mathematics" is used in a broader sense. There is no consensus as to what the various branches of applied mathematics are. Utility[edit] Status in academic departments[edit] Associated mathematical sciences[edit]

Nuclear technology A residential smoke detector is the most familiar piece of nuclear technology for some people Nuclear technology is technology that involves the reactions of atomic nuclei. Among the notable nuclear technologies are nuclear reactors, nuclear medicine and nuclear weapons. History and scientific background[edit] Discovery[edit] The vast majority of common, natural phenomena on Earth only involve gravity and electromagnetism, and not nuclear reactions. In 1896, Henri Becquerel was investigating phosphorescence in uranium salts when he discovered a new phenomenon which came to be called radioactivity.[1] He, Pierre Curie and Marie Curie began investigating the phenomenon. The new phenomenon of radioactivity was seized upon by the manufacturers of quack medicine (as had the discoveries of electricity and magnetism, earlier), and a number of patent medicines and treatments involving radioactivity were put forward. Fission[edit] Fusion[edit] Nuclear weapons[edit] Civilian uses[edit]

Creating your first iOS app If you already have Xcode, you can skip this step. If you want to develop apps for iOS, you need the SDK, which is provided with Xcode. Xcode only runs on Mac OS X (yes, Apple is doing that on purpose), so if you are running a windows (or linux, or pretty much any non-Mac OS X) operating system, you have a couple options: 1. 2. 3. Now that's settled, onto the IDE. iPadiPhone Course By Sarah Jane Keller Steve Fyffe Paul Hegarty teaches students how to program applications for iPads and iPhones in a free online course that's the most popular download on Stanford's iTunes U site, with more than 10 million views. Students may covet seats in Stanford's popular iPhone and iPad application development course, but you don't need to be in the classroom to take the course. Anyone with app dreams can follow along online. Stanford has just released the iOS 5 incarnation of iPhone Application Development on iTunes U, where the public can download course lectures and slides for free. When Stanford's first iPhone apps course appeared online in 2009, it made iTunes history by rocketing to a million downloads in just seven weeks. Alberto Martín is an engineer and independent iOS developer in Salamanca, Spain. He has created applications, now for sale in Apple's App Store, that organize your photos and make navigating while driving less distracting. L.A. Media Contact 126 Stumble

The Ultimate Teacher's Guide To Creating Educational Apps It’s no secret that students love their smartphones. Most were seemingly born with one in their hand. They use them to chat, talk with friends, get news, and to learn. Wait, learn?! That’s right, EduDemic is pleased to share with you some of the best ways teachers can make iPhone, iPad, and iPod Touch apps that will help students learn and feel a bit more engaged in class. We have tutorials for both tech experts and also teachers who are new to the tech game. Why Make An App? You may have decided to create an app simply so you would seem hip. A 24/7 learning store at your fingertips. Shop the App Store on iPhone and iPod touch to find apps for learning. Apps aplenty. Whether students need help defining a word, locating the lumbar spine, or practicing French vocabulary, there’s definitely an app for that. Wi-Fi wherever Voice Memos Record interviews, reading samples, study guides, or class lectures with Voice Memos — included on iPhone and iPod touch. VoiceOver Zoom White on Black Mono Audio

Optics Optics is the branch of physics which involves the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it.[1] Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties.[1] Some phenomena depend on the fact that light has both wave-like and particle-like properties. Explanation of these effects requires quantum mechanics. When considering light's particle-like properties, the light is modelled as a collection of particles called "photons". Optical science is relevant to and studied in many related disciplines including astronomy, various engineering fields, photography, and medicine (particularly ophthalmology and optometry). History[edit] Optics began with the development of lenses by the ancient Egyptians and Mesopotamians. . where and

100 Tools to Develop the Next Killer iOS or Android App <i><i><i><i><i><i><i><i><i>This post is #11 in DailyTekk’s famous Top 100 series which explores the best startups, gadgets, apps, websites and services in a given category. Total items listed: 113. Time to compile: 6+ hours. </i>*} There’s quite a list of people who are interested in creating iPhone/iPad and Android apps these days. There’s truly something for everyone here. 100+ Professional Social Media Business Tools for Brands and Marketers I’m sure there’s more than 100 awesome tools for creating awesome iPhone, iPad and Android apps out there so if I missed something good leave me a comment to let me know! Post Navigation Random + Noteworthy Tools DIY (No Coding) App Creation Tools Development, Analytics and Management Platforms Mockup and UI Design Tools Mobile Ads + Monetization Test, Refine and Get Feedback App Promotion & Marketing Enhance App Functionality Other and Miscellaneous Tapjoy - Drive more installs and boost your revenue. Vungle – Video trailers for your app. Back to top Footnotes

Software engineering Software Engineering is the study and application of engineering to the design, development, and maintenance of software.[1][2][3] Typical formal definitions of software engineering are: "the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software".[4]"an engineering discipline that is concerned with all aspects of software production"[5]"the establishment and use of sound engineering principles in order to economically obtain software that is reliable and works efficiently on real machines"[6] The term has been used less formally: History[edit] Programming languages started to appear in the 1950s and this was also another major step in abstraction. The term "Software Engineering" was first used in 1968 as a title for the world's first conference on Software Engineering, sponsored and facilitated by NATO. Barry W. Criticism[edit] A number of these phenomena have been bundled under the name "Software Engineering".

Artificial intelligence AI research is highly technical and specialized, and is deeply divided into subfields that often fail to communicate with each other.[5] Some of the division is due to social and cultural factors: subfields have grown up around particular institutions and the work of individual researchers. AI research is also divided by several technical issues. Some subfields focus on the solution of specific problems. Others focus on one of several possible approaches or on the use of a particular tool or towards the accomplishment of particular applications. The central problems (or goals) of AI research include reasoning, knowledge, planning, learning, natural language processing (communication), perception and the ability to move and manipulate objects.[6] General intelligence is still among the field's long-term goals.[7] Currently popular approaches include statistical methods, computational intelligence and traditional symbolic AI. History[edit] Research[edit] Goals[edit] Planning[edit] Logic-based

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