Friday, May 20, 2016

Introduction to Computer Graphics - David J. Eck


                Ebook Size : 4.8 MB

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The term “computer graphics” refers to anything involved in the creation or manipulation of images on computer, including animated images. It is a very broad field, and one in which changes and advances seem to come at a dizzying pace. It can be difficult for a beginner to know where to start. However, there is a core of fundamental ideas that are part of the foundation of most applications of computer graphics. This book attempts to cover those foundational ideas, or at least as many of them as will fit into a one-semester college-level course.
While it is not possible to cover the entire field in a first course—or even a large part of it—this should be a good place to start.
T he main focus of this book is three-dimensional (3D) graphics, where most of the work goes into producing a 3D model of a scene. But ultimately, in almost all cases, the end result of a computer graphics project is a two-dimensional image. And of course, the direct production and manipulation of 2D images is an important topic in its own right. Furthermore, a lot of ideas carry over from two dimensions to three. So, it makes sense to start with graphics in 2D. An image that is presented on the computer screen is made up of pixels. The screen consists of a rectangular grid of pixels, arranged in rows and columns.

The pixels are small enough that they are not easy to see individually. In fact, for many very high resolution displays, they become essentially invisible. At a given time, each pixel can show only one color. Most screens these days use 24-bit color, where a color can be specified by three 8-bit numbers, giving the levels of red, green, and blue in the color. Any color that can be shown on the screen is made up of some combination of these three “primary” colors. Other formats are possible, such as grayscale, where each pixel is some shade of gray and the pixel color is given by one number that specifies the level of gray on a black-to-white scale. Typically, 256 shades of gray are used. Early computer screens used indexed color , where only a small set of colors, usually 16 or 256, could be displayed. For an indexed color display, there is a numbered list of possible colors, and the color of a pixel is specified by an integer giving the position of the color in the list.

Wednesday, May 18, 2016

Sex at Dawn: The Prehistoric Origins of Modern Sexuality


           
                       Ebook Size :  2.7 MB

                       Download : Sex at Dawn by Christopher Ryan & Cacilda Jethá

 



We’ll show that human beings evolved in intimate groups where almost everything was shared— food, shelter, protection, child care, even sexual pleasure. We don’t argue that humans are natural born Marxist hippies. Nor do we hold that romantic love was unknown or unimportant in prehistoric communities. But we’ll demonstrate that contemporary culture misrepresents the link between love and sex. With and without love, a casual sexuality was the norm for our prehistoric ancestors.

Deep conflicts rage at the heart of modern sexuality. Our cultivated ignorance is devastating. The campaign to obscure the true nature of our species’ sexuality leaves half our marriages collapsing under an unstoppable tide of swirling sexual frustration, libido-killing boredom, impulsive betrayal, dysfunction, confusion, and shame. Serial monogamy stretches before (and behind) many of us like an archipelago of failure: isolated islands of transitory happiness in a cold, dark sea of disappointment. And how many of the couples who manage to stay together for the long haul have done so by resigning themselves to sacrificing their eroticism on the altar of three of life’s irreplaceable joys: family stability, companionship, and emotional, if not sexual, intimacy? Are those who innocently aspire to these joys cursed by nature to preside over the slow strangulation of their partner’s libido?

Forget what you’ve heard about human beings having descended from the apes. We didn’t descend from apes. We are apes. Metaphorically and factually, Homo sapiens is one of the five surviving species of great apes, along with chimpanzees, bonobos, gorillas, and orangutans (gibbons are considered a “lesser ape”). We shared a common ancestor with two of these apes—bonobos and chimps—just five million years ago. That’s “the day before yesterday” in evolutionary terms. The fine print distinguishing humans from the other great apes is regarded as “wholly artificial” by most primatologists these days.

Several types of evidence suggest our pre-agricultural (prehistoric) ancestors lived in groups where most mature individuals would have had several ongoing sexual relationships at any given time. Though often casual, these relationships were not random or meaningless. Quite the opposite: they reinforced crucial social ties holding these highly interdependent communities together.

Human beings and our hominid ancestors have spent almost all of the past few million years or so in small, intimate bands in which most adults had several sexual relationships at any given time. This approach to sexuality probably persisted until the rise of agriculture and private property no more than ten thousand years ago. In addition to voluminous scientific evidence, many explorers, missionaries, and anthropologists support this view, having penned accounts rich with tales of orgiastic rituals, unflinching mate sharing, and an open sexuality unencumbered by guilt or shame.

If you spend time with the primates closest to human beings, you’ll see female chimps having intercourse dozens of times per day, with most or all of the willing males, and rampant bonobo group sex that leaves everyone relaxed and maintains intricate social networks. Explore contemporary human beings’ lust for particular kinds of pornography or our notorious difficulties with long-term sexual monogamy and you’ll soon stumble over relics of our hypersexual ancestors.

Monday, May 16, 2016

COSMOS - Carl Sagan


                          Ebook Size : 1.1 MB

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The Cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us - there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, of falling from a height. We know we are approaching the greatest of mysteries.

The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explorations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe our future depends on how well we know this Cosmos in which we float like a mote of dust in the morning sky.

Those explorations required skepticism and imagination both. Imagination will often carry us to worlds that never were. But without it, we go nowhere. Skepticism enables us to distinguish fancy from fact, to test our speculations. The Cosmos is rich beyond measure - in elegant facts, in exquisite interrelationships, in the subtle machinery of awe.
  
In the summer and fall of 1976, as a member of the Viking Lander Imaging Flight Team, I was engaged, with a hundred of my scientific colleagues, in the exploration of the planet Mars. For the first time in human history we had landed two space vehicles on the surface of another world. The results, described more fully in Chapter 5, were spectacular, the historical significance of the mission utterly apparent. And yet the general public was learning almost nothing of these great happenings. The press was largely inattentive; television ignored the mission almost altogether.

When it became clear that a definitive answer on whether there is life on Mars would not be forthcoming, interest dwindled still further. There was little tolerance for ambiguity. When we found the sky of Mars to be a kind of pinkish-yellow rather than the blue which had erroneously first been reported, the announcement was greeted by a chorus of good-natured boos from the assembled reporters - they wanted Mars to be, even in this respect, like the Earth. They believed that their audiences would be progressively disinterested as Mars was revealed to be less and less like the Earth. And yet the Martian landscapes are staggering, the vistas breathtaking. I was positive from my own experience that an enormous global interest exists in the exploration of the planets and in many kindred scientific topics - the origin of life, the Earth, and the Cosmos, the search for extraterrestrial intelligence, our connection with the universe. And I was certain that this interest could be excited through that most powerful communications medium, television.

Saturday, May 14, 2016

The Martian - Andy Weir

 
  
                       Ebook Size:  1.2 MB

                       Download : The Martian - Andy Weir

Six days ago, astronaut Mark Watney became one of the first people to walk on Mars.

Now, he's sure he'll be the first person to die there.

After a dust storm nearly kills him and forces his crew to evacuate while thinking him dead, Mark finds himself stranded and completely alone with no way to even signal Earth that he’s alive—and even if he could get word out, his supplies would be gone long before a rescue could arrive.

Chances are, though, he won't have time to starve to death. The damaged machinery, unforgiving environment, or plain-old "human error" are much more likely to kill him first.

But Mark isn't ready to give up yet. Drawing on his ingenuity, his engineering skills—and a relentless, dogged refusal to quit—he steadfastly confronts one seemingly insurmountable obstacle after the next. Will his resourcefulness be enough to overcome the impossible odds against him?

Thursday, May 12, 2016

The Engineer - Follow Elon Musk on a journey from South Africa to Mars - Erik Nordeus


                     Ebook Size:  1.5 MB

                     Download : The Engineer - Erik Nordeus


This is a book about the beginning of a journey. Elon Musk is the main person in the journey through a roller-coaster life. His journey includes everything from Winston Churchill’s adventures in British colonies to demolished sports cars. From failed marriages to German scientists escaping from the Red Army. From the oil industry to the Burning Man festival.

Elon has been described as the Steve Jobs of heavy industry, as a modern version of the scientist Nikola Tesla, and as the Henry Ford of rockets. There’s a high probability that the British Secret Intelligence Service has a file on him. As the files of other James Bond villains, it describes secret rocket launches in the Pacific Ocean. But Elon doesn’t own a white cat - he’s more of a dog person. Maybe the most comparable persons are the great explorers who voyaged across the globe. They had an entrepreneurial spirit, were a little crazy, tried what no one else had tried, and thought what no one else had thought.

If you want to describe the companies Elon has founded with one theme, you can say that they improve the world with the help of innovative technologies. This is exactly what our world needs. The history of mankind begins about 50,000 years ago. We know little of the first 40,000 years, except at the end of them, we had learned to use the skins of animals. Then we emerged from our caves to construct other kinds of shelter. 5000 years ago, we learned how to write and how to use a cart with wheels. Now began the acceleration of technological progress. Within only a few hundred years, we invented the steam engine, electric lights, telephones, cars, and airplanes. In the last few years, we developed penicillin, television, and nuclear power.

Then something happened. Everyone forgot the larger problems and began to focus on the smaller problems. The computer in a modern phone is more powerful than the computer in the craft that landed on the Moon, but we are only using the power to fire birds against pigs and to watch pictures showing what our friends ate for breakfast. Was it that future we wanted? In a famous speech, the former US President John F. Kennedy said, “So it is not surprising that some would have us stay where we are a little longer to rest, to wait. But this city of Houston, this State of Texas, this country of the United States was not built by those who waited and rested and wished to look behind them.

This country was conquered by those who moved forward.” We are no longer moving forward with ever-greater speed, we are moving slower. The Concorde could fly across the Atlantic Ocean in three hours, and the commercial said, “The world is now a smaller place.” But with the decommissioning of the Concorde in 2003, the world is now a larger place. We’re not just flying slower, other modes of transportation are also moving slower. The US state of California ordered a bullet train that would be one of the slowest bullet trains in the world at the highest cost per mile.

The world has not just become a larger place; we are also destroying the world. One explanation to why we no longer are moving faster is because we are using expensive, dirty, and sometimes dangerous energy sources. We are not only using nuclear power plants, we are a world dependent on oil. The problem is that oil is a finite natural resource we are running out of, and we may begin to run out of it as soon as 2020. Unless we want to start using horses, we need to design technology that doesn’t rely on oil.

The question is why we are focusing on the smaller problems and forget the larger ones. One of the reasons might be that it’s complicated and more expensive to build an electric car, while it’s less expensive to build yet another Facebook clone. Another reason might be that we are satisfied with what we have. We don’t have to replace the world’s oil dependency today. But what happens when we need to? What if we need to leave the planet because something has happened or will happen to it. Then we have to trust that someone has the answers to these larger problems no one cares about today. But someone who cares about these larger problems is Elon. He knows how we can replace our dependency on oil.

He knows how we can colonize Mars and escape to the red planet if something happens to Earth. To yet again make the world a smaller place, he has designed an aircraft that’s faster than the Concorde. The difference between Elon and other pundits is that he realizes his ideas. To save the world from its oil dependency, he’s creating companies with exactly that purpose. To be able to escape to Mars, he has already begun building the rockets needed. To make the world a smaller place, he will release the technology for free. The rest of the world needs to just sit back and enjoy the ride.

Tuesday, May 10, 2016

The Hitchhiker's Guide to the Galaxy - Douglas Adams


                           Ebook Size : 432 KB

                           Download : The Hitchhiker's Guide to the Galaxy


Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose apedescended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea. This planet has - or rather had - a problem, which was this: most of the people on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movements of small green pieces of paper, which is odd because on the whole it wasn't the small green pieces of paper that were unhappy.

And so the problem remained; lots of the people were mean, and most of them were miserable, even the ones with digital watches. Many were increasingly of the opinion that they'd all made a big mistake in coming down from the trees in the first place. And some said that even the trees had been a bad move, and that no one should ever have left the oceans. And then, one Thursday, nearly two thousand years after one man had been nailed to a tree for saying how great it would be to be nice to people for a change, one girl sitting on her own in a small cafe in Rickmansworth suddenly realized what it was that had been going wrong all this time, and she finally knew how the world could be made a good and happy place. This time it was right, it would work, and no one would have to get nailed to anything.

Sadly, however, before she could get to a phone to tell anyone about it, a terribly stupid catastrophe occurred, and the idea was lost forever. This is not her story. But it is the story of that terrible stupid catastrophe and some of its consequences. It is also the story of a book, a book called The Hitch Hiker's Guide to the Galaxy - not an Earth book, never published on Earth, and until the terrible catastrophe occurred, never seen or heard of by any Earthman. Nevertheless, a wholly remarkable book. in fact it was probably the most remarkable book ever to come out of the great publishing houses of Ursa Minor - of which no Earthman had ever heard either. Not only is it a wholly remarkable book, it is also a highly successful one - more popular than the Celestial Home Care Omnibus, better selling than Fifty More Things to do in Zero Gravity, and more controversial than Oolon Colluphid's trilogy of philosophical blockbusters Where God Went Wrong, Some More of God's Greatest Mistakes and Who is this God Person Anyway? In many of the more relaxed civilizations on the Outer Eastern Rim of the Galaxy, the Hitch Hiker's Guide has already supplanted the great Encyclopedia Galactica as the standard repository of all knowledge and wisdom, for though it has many omissions and contains much that is apocryphal, or at least wildly inaccurate, it scores over the older, more pedestrian work in two important respects.

First, it is slightly cheaper; and secondly it has the words Don't Panic inscribed in large friendly letters on its cover. But the story of this terrible, stupid Thursday, the story of its extraordinary consequences, and the story of how these consequences are inextricably intertwined with this remarkable book begins very simply.

It begins with a house.