Thursday, 27 August 2015

PHP - The Right Way by Josh Lockhart and Phil Sturgeon


                Ebook Size: 562 KB

                Download : PHP - The Right Way

PHP was created to write web applications, but is also useful for scripting command line interface (CLI) programs. Command line PHP programs can help automate common tasks like testing, deployment, and application administrivia.
CLI PHP programs are powerful because you can use your app’s code directly without having to create and secure a web GUI for it. Just be sure not to put your CLI PHP scripts in your public web root!

If you are getting started with PHP, start with the current stable release of PHP 5.61. PHP has added powerful new features over the last few years. Though the incremental version number difference between 5.2 and 5.6 is small, it represents major improvements. If you are looking for a function or its usage, the documentation on the php.net2 website will have the answer.

Please help Phil Sturgeon and Josh Lockhart by spreading the word about this book on Twitter! The suggested hashtag for this book is #phptherightway.

Tuesday, 25 August 2015

Hubble 25: A Quarter-Century of Discovery with the Hubble Space Telescope!


                 Ebook Size : 189 MB

                 Download : Hubble 25: The Hubble Space Telescope

On April 24, 1990, NASA’s Space Shuttle Discovery blasted off from the Florida coast carrying precious cargo that was destined to revolutionize the way humans see the cosmos. The Hubble Space Telescope had been decades in the making, the dream of astronomers who yearned to study the universe with a clear view unhindered by the distorting influence of Earth’s atmosphere. A day after launch, Discovery’s astronauts fulfilled that dream by releasing Hubble into orbit hundreds of miles above the ground, and more importantly, above the bulk of our planet’s atmosphere.

Hubble was not the first telescope launched into space, nor is it the largest telescope at astronomers’ disposal. Hubble’s exceptional and ongoing capacity to help unveil the secrets of the universe comes not just from its position beyond Earth’s atmosphere and, as a result, its exquisite image quality, but also its ability to be upgraded with new science instruments — a unique feature among space-based telescopes. After Hubble’s launch, shuttle astronauts returned to the telescope five times to install new cameras, detectors, and other equipment built with ever-more advanced technology, keeping Hubble on the leading edge of astronomy. Hubble’s suite of instruments also allows the observatory to record wavelengths of light not just in the visible range but in ultraviolet and near-infrared wavelengths (which are not visible to our eyes), including some wavelength ranges that cannot be observed from the ground.

The Hubble Space Telescope is an instrument of science — one of the most productive in history. Thousands of astronomers from around the world have used Hubble to explore nearly every facet of the universe, publishing more than 11,000 scientific papers in the process. Still, the magnificent images Hubble  takes have proven time and again their power to capture the hearts and minds of scientists and non-scientists alike. The majestic scenes fire the imagination and inspire awe for the astonishing vastness of the cosmos and all the wonders it contains. To celebrate Hubble’s 25th anniversary, this book presents 25 of the most remarkable images Hubble has acquired so far. They are ordered according to distance from Earth, highlighting Hubble’s great range, from observing planets in our own solar system to the stars and galaxies born when the universe was still young. Each chapter in this book introduces one of Hubble’s images and points out some of the features that Hubble’s exceptional vision reveals. It also describes a sample of the related scientific research or discoveries achieved with Hubble. Supplemental images and videos provide more context and help bring the subject to life.


Now 25 years into its trailblazing mission, Hubble’s greatest accomplishments to date include helping to uncover black holes in the centers of galaxies, observing changes on planets in our solar system, investigating the atmospheres of planets around stars other than the Sun, seeing disks that are possibly forming new solar systems, and hunting down nascent galaxies in the very early universe. Astronomers have also used Hubble to follow up on the work done almost a century ago by the telescope’s namesake, the astronomer Edwin Hubble, whose observations of galaxies revealed that the universe was expanding. Observing with the Hubble telescope, astronomers have refined their calculation for the universe’s expansion rate and discovered the existence of a force called dark energy, which is causing the universe to expand faster and faster as time goes on.

Hubble’s work is far from finished, though. Astronomers are continuing to use the orbiting observatory to extend their view and understanding of the cosmos ever farther. In 2009, during Hubble’s final servicing mission, astronauts installed new science instruments, batteries, computers, gyroscopes, and other equipment that will keep the observatory hot on the trail of the most pressing celestial mysteries for years to come.

Monday, 24 August 2015

Mathematics for Computer Science - Eric Lehman, F. Thomson Leighton, Albert R. Meyer

                      Ebook Size : 1.6MB

                      Download :  Mathematics for Computer Science

This book covers elementary discrete mathematics for computer science and engineering. It emphasizes mathematical definitions and proofs as well as applicable methods. Topics include formal logic notation, proof methods; induction, well-ordering; sets, relations; elementary graph theory; integer congruences; asymptotic notation and growth of functions; permutations and combinations, counting principles; discrete probability. Further selected topics may also be covered, such as recursive definition and structural induction; state machines and invariants; recurrences; generating functions.