Download PDF WIZARDS, ALIENS, AND STARSHIPS Physics And Math In Fantasy And Science Fiction by Charles L. Adler

Sinopsis

When I was young, back in the 1970s and 80s, I read a lot of science fiction.I read a lot of other stu􀏱, as well, but science 􀏧ction (and fantasy) 􀏧lled a need that other literature simply didn’t. I tended to read “hard” science 􀏧ction, that is, stories plotted around hard science: physics, astrophysics, giant engineering projects, and the like. The worlds these stories portrayed, where space travel was common, human problems such as poverty were nearly eliminated, and con􀏩icts centered on larger-than-life issues, always seemed to me more compelling than human dramas that revolved around why someone didn’t love someone else.

My tastes have changed since then, but the initial thrill of these stories has never really left me. I am a scientist because of my initial love of these tales. A chill still runs down my spine whenever I look at a Hubble Telescope photo or learn of a new exoplanet discovered. I live in hope that I will be alive when life on other planets is discovered. I still want to take a vacation to the Moon or to an orbiting satellite. These thrills are tempered by my adult realization that much of what goes into science 􀏧ction is quite unrealistic. This book is written for my 􀏧fteen-year-old self, and other readers like him, who would like to know which parts of science 􀏧ction are based on real science, and therefore in some way plausible, and which parts are unrealistic. This is the book I would have wanted to read when I was young. Just as for Niven’s correspondent, my interest in science 􀏧ction was mostly in the strange environments, the new worlds, the alien life, the superscience it portrayed. I wanted to know which parts were (potentially) real and which weren’t. To a large extent, that is why I eventually became a physicist.

Almost any science 􀏧ction story has a lot of incorrect science. This doesn’t make the story bad or invalid. Some authors, like Larry Niven, are almost obsessive in trying to get the science right; most are more lackadaisical about it. However, the standards for the profession are pretty high: no science 􀏧ction writer can be really esteemed accomplished unless he or she has a thorough knowledge of basic physics, chemistry, biology, astrophysics, history (ancient and modern), sociology, and military tactics; and besides all this, must possess a certain something in their air and manner of writing, or their profession will be but half-deserved. (Improvement of their minds by extensive reading goes without saying.) Science 􀏧ction writers do not have the same opportunities as research scientists do to stay up-to-date in their research 􀏧elds, and writing science 􀏧ction involves a lot more 􀏧elds than most research scientists can keep up with.

This book is one physicist’s attempt to discuss the science, particularly the physics and mathematics, that goes into writing hard science 􀏧ction. As an added bonus, I also take a look at physics in fantasy writing: there’s more in it than meets the eye. This is not an attempt to predict the future: as G. K. Chesterton pointed out, most of the fun in predicting the future comes from burying the people who attempt to do it [50]. Rather, I stick to the science used in crafting the stories. There are many books dedicated to the literary criticism of science 􀏧ction; this book is devoted to its scientific critique. As such, my choice of which literature to use is dictated both by my own reading and by the needs of the book. I tend to avoid writers who don’t make much use of science in their stories, except occasionally to comment on their errors. I also tend to stick to literature, that is, novels and short stories, although I occasionally comment on science 􀏧ction movies or television shows as well.

Content

1. PLAYING THE GAME
2. POTTER PHYSICS
3. HARRY POTTER AND THE GREAT CONSERVATION LAWS
4. WHY HOGWARTS IS SO DARK
5. FANTASTIC BEASTS AND HOW TO DISPROVE THEM
6. SPACE TRAVEL
7. WHY COMPUTERS GET BETTER AND CARS CAN’T (MUCH)
8. VACATIONS IN SPACE
9. SPACE COLONIES
10. THE SPACE ELEVATOR
11. MANNED INTERPLANETARY TRAVEL
12. ADVANCED PROPULSION SYSTEMS
13. SPECULATIVE PROPULSION SYSTEMS
14. INTERSTELLAR TRAVEL AND RELATIVITY
15. FASTER-THAN-LIGHT TRAVEL AND TIME TRAVEL
16. WORLDS AND ALIENS
17. DESIGNING A HABITABLE PLANET
18. THE SCIENTIFIC SEARCH FOR SPOCK
19. THE MATHEMATICS OF TALKING WITH ALIENS
20. YEAR GOOGOL
21. THE SHORT-TERM SURVIVAL OF HUMANITY
22. WORLD-BUILDING
23. DYSON SPHERES AND RINGWORLDS
24. ADVANCED CIVILIZATIONS AND THE KARDASHEV SCALE
25. A GOOGOL YEARS

Click here to download

Read more »

Download PDF Asteroids, Comets, and Meteorites Cosmic Invaders of the Earth by Jon erickson

Sinopsis

The science of meteoritics deals with the study of meteorites and their impacts on Earth. Meteorite craters on the Moon, the inner planets, and the moons of the outer planets are quite evident and numerous. Several remnants of ancient meteorite craters remain on Earth, suggesting it was just as heavily bombarded as the rest of the solar system. Meteorite impacts have produced many strikingly circular features in the crust scattered throughout the world. They are testimony to disasters in the past caused by major meteorite impacts. In the future, many more craters will be found, painting a clear picture of what transpired long ago.The evidence hints that impact cratering is an ongoing process, and the planet can expect another major meteorite impact at any time.

Large meteorite impacts had a major effect on the history of life since the very beginning. Throughout geologic history, asteroids and comets have repeatedly bombarded Earth, implying such events are a continuing process. Sometimes asteroids the size of mountains struck the planet, extinguishing large numbers of species.The most celebrated extinction was the death of the dinosaurs and many other species.The dinosaur killer left its footprints all over the world.

Content

1. Origin of the Solar System: Formation of the sun and planets
2. The Formation of Earth: planetary origins
3. Cratering Events: Historic meteorite impacts
4. Planetary Impacts: Exploring Meteorite Craters
5. Asteroids: Wandering rock fragments
6. Comets: cosmic ice debris
7. Meteorite Craters: formation of impact structures
8. Impact Effects: the global changes
9. Death Star: impact extinction of species 
10. Cosmic Collisions: Asteroid and comet bombardment

Click here to download

Read more »

Download PDF Lego Space Building The Future by Peter Reid

Sinopsis

In October 1957, an elite group of Soviet scientists made history. The world’s first man-made orbital satellite,

Sputnik, launched from the Tyuratam Complex in Kazakh. The event marked the dawn of the Space Age. After blasting free from Earth’s gravity, Sputnik settled into its planned orbit and began transmitting information back to Earth. The scientists were jubilant as they established radio contact with the world’s first artificial satellite.

The compact sphere made a complete orbit every 96.2 minutes, transmitting a continuous pattern of beeps to radio operators across the globe. Sputnik exceeded its creators’ expectations, dispatching information for 22 days before losing battery power. A valuable component of these signals was environmental telemetry, including atmospheric temperature and pressure readings. A decaying orbit drew the satellite slowly back to

Earth, and after three months in space, Sputnik burned up as it reentered the atmosphere.

Content

1. THE SPACE AGE
2. THE FEDERATION
3. SHIPS OF THE FEDERATION
4. Inhospitable Climate Engineers
5. New Frontiers
6. Realm of Shadows
7. Army of Darkness 
8. Star Justice
9. Infiltration
10. Across the Universe

Click here to download

Read more »

Download PDF Wireless Networks and Security Issues, Challenges and Research Trends by Shafiullah Khan

Sinopsis

Computer programs that radio amateurs use in their digital networks give various opportunities for checking user authentication before allowing access to sensitive parts of communication systems. Those systems include not only email servers that handle amateur radio messaging and file exchange, but also include radio-relay networks of digital repeaters that operate in big cities, or in rural and remote locations. This chapter summarizes results of experiments performed in real amateur packet radio networks as well as those provided by simulations with amateur radio software in local area networks. Our intention was to test security in accessing e-mail servers and radio relay systems within the average amateur radio digital infrastructure. This study suggests various methods which aim is to bridge the gap between the improved safety, and eventual discomfort in regular end-user’s and system administrator's activities. We focused our work to the following challenges: user authentication in amateur radio email servers; key management, i.e. obtaining, installing, and renewing secret documents (‘keys’) in between end-users and system administrators; encryption of email content and user passwords; attacks, epidemics, and appropriate countermeasures; and other protective actions that increase the security and satisfaction in average network participants. Described methods will help practitioners, students and teachers in computer science and communication technologies in implementing exciting amateur radio wireless opportunities within educational computer networks, as well as in planning new telecommunication systems.

Compared to security challenges we face to in our daily Internet-related activities, the amateur radio community does not suffer so much from exposures to known and unknown dangers that may come from their own wireless networks. For such positive situation we can thank to the global and local laws and regulations that require from all amateur radio candidates to pass written and oral, technical and regulatory tests, as well as to pass a basic security background check – before obtaining a license for transmitting radio signals. However, that does mean that the amateur radio digital infrastructure is completely secured and safe for every day’s use. Luckily, there are many opportunities in available safety measures, which support the integrity of both user's rights and system administrator's privileges. Personal computers that most of our schools, workplaces and homes are equipped with nowadays are capable to include security features in existing amateur radio programs or to become additionally enhanced with add-on software. Valuable information about available safety features can be easily obtained in regular amateur radio correspondence with peers, or by using dedicated information channels such as various ‘doc’ folders in email servers’ file repositories. For those who are likely to experiment in an isolated local area network (LAN), consisting of at least two or three machines, there are opportunities to replicate some of the experiments in this chapter.

As described in available sources on the amateur radio simulations [1], a simplest testing scenario might be in a LAN with at least two computers, which is a suitable situation for simulating radio traffic between two different amateur radio facilities, such as digital amateur radio-relay systems - commonly called digipeaters (a short of 'digital repeaters'), or BBS ('Bulletin Board Systems'; i.e., email servers). By simulating amateur radio traffic, we learn technologies and protocols used in real amateur radio frequency (RF) networks that include thousands radio-relay stations worldwide, as well as radio email servers and various home or work communicating solutions. For those of you who already have experience in dealing with ‘ham’ (=amateur radio) high frequency (HF), VHF or UHF communications, these homemade simulations will provide useful information on available solutions that are going to improve security of a wireless system that you might be responsible for.

One of the frequently asked questions during author’s amateur radio presentations at technical conferences and similar events – is how to ensure the safe access to the end-user email accounts – where the radio waves are the only media for transmitting information. In fact, due to the international regulations, the amateur radio traffic must travel as the open, no ciphered text, which means that all radio amateurs on a frequency are capable to ‘read’ everything that flows through the channel, by just simple activating his or her antenna, receiver, modem, and appropriate computer software [2]. The same rules also restrict what types of topics and discussions are acceptable in ham radio or not. For example, it is completely common to communicate the following themes: installation of antenna systems, power supply and grounding facilities; building amateur radio receivers and transmitters; programming amateur radio hardware and software; fixing small technical problems with computers and amateur radio stations, etc. That does not mean that general educational topics are not interesting for the local radio amateur community. Discussions about preparing technical conferences, papers and tutorials, or incoming technical expeditions and interesting school projects as well as non-classified details of scientific research or master and doctoral studies are completely suitable for distributing via amateur radio wireless networks. In opposite, it is not acceptable to discuss on things that include political, racial, national, social, sexual, business and similar potentially provocative themes. On the other side, there is a not a strict distinction between more or less priorities in the amateur radio communications. It is obvious that, according to the laws, emergency cases have priority, particularly when it comes to save human's lives or proprieties. But, in any occasion, one can be sure that amateur radio conversations are as 'private' as the talks in, say, public transportation systems, which actually means that there is not much 'privacy' there – if any. As mentioned, every user of a local amateur radio email server should be aware that unknown amateurs could easily read the text of his or her messages – either during an exchange of content with the email server, or during the exchange of content between those 'store & forward' systems, i.e. email servers. In such a relatively open environment, most countries have allowed the amateur radio communications primarily for an exchange of results of radio- and computer-related experiments that do not include commercial discussions, such as advertisements related to selling computers, other home appliances or any other goods. In the other words, the amateur radio laws support the major goal, which is to establish an ordinary '2-way' communication link between two or more wireless enthusiasts who might be the local school's students or teachers, as well as their parents, friends and other relatives. The basic idea is to increase the popularity of engineering and technology in young generations and to motivate them to continue education in technical professions such as electronics, electrical and mechanical engineering, computer science, hardware production, software development, etc. To summarize, when we come to commercial or other topics that are not appropriate for the amateur radio channels, it is the right time for all of us to switch from the amateur radio to commercial email service providers or similar public communicating systems.

Content

1. Security in Amateur Packet Radio Networks
2. Security Issues in Mobile Ad Hoc Network
3. Secure AODV Routing Protocol Based on Trust Mechanism 
4. Security and Privacy in Vehicular Ad-Hoc Networks: Survey and the Road Ahead.
5. Security Issues and Approaches onWireless M2M Systems 
6. Security and Privacy in Wireless Body Area Networks for Health Care Applications
7. Security and Privacy Issues in Wireless Mesh Networks: A Survey
8. Trust Establishment Techniques in VANET
9. Improving the Security of Wireless Sensor Networks by Protecting the Sensor Nodes against Side Channel Attacks
10. Intrusion Detection in Wireless Sensor Networks: Issues, Challenges and Approaches
11. Network Coding for Security in Wireless Reconfigurable Networks
12. A Secure Intragroup Time Synchronization Technique to Improve the Security and Performance of Group-Based Wireless Sensor Networks
13. Capacity-Approaching Channel Codes for Discrete Variable Quantum Key Distribution (QKD) Applications
14. A Comparative Study on Security Implementation in EPS/LTE and WLAN/802.11

Click here to download

Read more »

Download PDF ASTRONOMY A Self Teaching Guide Seventh Edition by Dinah L. Moché

Sinopsis

On a clear night in a place where the sky is really dark, you can see about 2000 stars with your unaided eye. You can look trillions of kilometers into space and peer thousands of years back into the distant past.

As you gaze at the stars you may wonder: What is the pattern or meaning of the starry heavens? What is my place in the vast cosmos? You are not alone in asking these questions. The beauty and mystery of space have always fascinated people.

Astronomy is the oldest science—and the newest. Exciting discoveries are being made today with the most sophisticated tools and techniques ever available. Yet dedicated amateurs can still make important contributions.

This book will teach you the basic concepts of astronomy and space exploration. You will more fully enjoy observing the stars as your knowledge and understanding grow. You will be better able to surf the Web and to read more on topics that intrigue you, from ancient astronomy to the latest astrophysical theories and spaceflights.

Content

1. Chapter 1 Understanding the Starry Sky 
2. Chapter 2 Light and Telescopes 
3. Chapter 3 The Stars 
4. Chapter 4 The Sun 
5. Chapter 5 Stellar Evolution 
6. Chapter 6 Galaxies 
7. Chapter 7 The Universe 
8. Chapter 8 Exploring the Solar System 
9. Chapter 9 The Planets 
10. Chapter 10 The Moon 
11. Chapter 11 Comets, Meteors, and Meteorites 
12. Chapter 12 Life on Other Worlds?

Click here to download

Read more »

Download PDF Astronomy Principles And Practice by A. E. Roy & D Clarke

Sinopsis

The etymology of the word ‘Astronomy’ implies that it was the discipline involved in ‘the arranging of the stars’. Today we might say that astronomy is our attempt to study and understand celestial phenomena, part of the never-ending urge to discover order in nature. We do not know who were the first astronomers—what we do know is that the science of astronomy was well advanced in parts of Europe by the middle of the third millennium BC and that the Chinese people had astronomical schools as early as 2000 BC. In all ages, from the burgeoning of man’s intelligence, there have been people fascinated by the heavens and their changing aspect and these people, as far as their cultural environment has allowed them, have tried to formulate cosmologies. We are no different today. Nowadays, the word ‘Astrophysics’ is also used to describe the study of the celestial bodies. In fact, many astronomers use both terms quite generally and it is not infrequent to find Departments of Astronomy and Astrophysics within educational establishments. The question may well be asked ‘What is the difference between Astronomy and Astrophysics?’ Very loosely, Astronomy might be defined as the subject of the ‘where and when’ related to the description of a celestial body with the ‘why and how’ being covered more by Astrophysics. Rather than trying to provide a hard and fast rule for the terminology, we will simply use Astronomy to cover all aspects of the description of the skies

and the Universe.

If our current theories of the Universe are nearer the truth, it is probably not that our intelligence has increased in the past six millennia. It is more likely that the main factor has been the discovery and development of the ‘scientific method’, which has led to our present civilization based on the flood of technological advantages provided by this method. This has enabled scientists in far greater numbers than ever before to devote their lives to the study of the heavens, assisted by telescopes, computers, space vehicles and a multitude of other equipment. Their attempts to interpret and understand the wealth of new information provided by these new instruments have been aided by allied sciences such as physics, chemistry, geology, mathematics and so on.

We must remember, however, that for more than nine-tenths of the last five thousand years of our study of the heavens, we have had to rely on the unaided eye. The Mediterranean people who set the constellations in the sky, the Babylonians, Egyptians and Greeks, the Arabian astronomers who flourished during the Dark Ages of Post-Roman Europe, the Chinese, the Mayan and other early American astronomers, all built their theories of the Universe on naked eye observations. And so we begin by following in their footsteps and seeing what they saw as they observed over a few minutes (see section 1.2), over a few hours (see section 1.3), over a month (see section 1.4) or over at least a year (see section 1.5). In this way, we will find it easier to understand why their cosmological theories were formulated in their particular ways.

Click here to download

Read more »

Download PDF Anti-Gravity & The Worl Grid by David Hatcher Childress

Content

1. MAPPING THE WORLD GRID
2. THE PLANETARY GRID: A NEW SYNTHESIS
3. DIAMAGNETIC GRAVITY VORTEXES
4. THE MATHEMATICS OF THE WORLD GRID
5. THE PHILADELPHIA EXPERIMENT
6. LEY LINES & THE MEANING OF ADAM
7. INTERNATIONAL HARMONY BASED UPON A MUSIC OF PLANETARY GRID SYSTEMS
8. ACOUSTIC LEVITATION OF STONES
9. SCALAR WAVES & TESLA SHIELDS
10. MORE ANTI-GRAVITY PATENTS
11. MORE HEADLINES FROM THE PAST, PRESENT AND FUTURE: OR, I MARRIED AN ALIEN
12. ANTI-GRAVITY COMIX: OR WHAT ARE YOU DOING IN THIS TIME ZONE?
13. THE ANTI-GRAVITY FILE: NAZI FLYING SAUCERS, CAPTURED ALIENS, HOMEMADE SAUCERS & MORE

Click here to download

Read more »

Download PDF INTRODUCTION TO SUPERSTRING THEORY by Elias Kiritsis

Sinopsis

String theory has been the leading candidate over the past years for a theory that consistently unifies all fundamental forces of nature, including gravity. In a sense, the theory predicts gravity and gauge symmetry around flat space. Moreover, the theory is UVfinite. The elementary objects are one-dimensional strings whose vibration modes should correspond to the usual elementary particles.

Content

1. Introduction
2. Historical perspective
3. Classical string theory
4. Quantization of the bosonic string
5. Interactions and loop amplitudes
6. Conformal field theory
7. CFT on the torus
8. Scattering amplitudes and vertex operators of bosonic strings
9. Strings in background fields and low-energy effective actions
10. Superstrings and supersymmetry
11. Anomalies
12. Loop corrections to effective couplings in string theory
13. Non-perturbative string dualities: a foreword
14. Outlook

Click here to download

Read more »

Free Download PDF Solar System Maps - From Antiquity to the Space Age By Nick Kanas

Sinopsis

In 1543, Nicolaus Copemicus iuvenled the solar system. "Hold on!" you say. Surely the solar system had been there forever, and Copemicus didn't just iuvent it. Yes and no! What Copemicus had revealed and iuvented was the arrangement of the planets-a stunningly new way of mappiug them. He revolutionized the way humankind would conceive of the planets as a system, controlled by the Sun. "Thus iudeed," Copernicus

wrote, "the sun, as though sealed on a royal throne, governs the family of planets revolving around it."

Nick Kanas has documented this revolutionary shift iu his ingeniously illustrated album of solar system images, all historical even though the modern views, ''postcards from space", are scarcely a few decades old. Joining the pictures is a rich commentary that poiuts out subtle details and places them iu a developiug astronomical context. To those of us impressed with the rapidity of change iu the 21st Century, it may seem odd that the authors and illustrators of the 16th Century were so slow to switch their astronomical imagery iu the years followiug the publication of Copemicus's epoch-makiug work. But the heliocentric system appeared to attack common sense. Beautiful as it may have appeared to cartographers who could map the heaveuly spheres with circles conveniently ringiug the Sun, the idea of living on a rapidly spiuning ball hurtliug around the Sun seemed totally ridiculous. Surely the Earth's inhabitants would be spun off iuto space!

There were alternative views. Perhaps the planets did circle the Sun, while the Sun itself carried the entire retinue around a fixed Earth. A theory of this sort was seriously proposed by the great Danish observer, Tycho Brahe. And this, too, is dncumented iu Kanas's fasciuating collection. But by the mid-1700s, such alternative views, along with the ancient geocentric system, were quaint has-beens.

In 1608, the telescope arrived on the scene. Galileo Galilei promptly converted this carnival toy iuto a scientific discovery machine, and soon there were planets with their moons, new worlds to map and depict. And more charts and maps to collect, for Nick Kanas is an astute collector, always searching for new worlds to conquer. So his quest has taken him from worldwide ancient views to popularizations iu a growiug America, where curiosity about the heavens and ever-bigger telescopes caught the public imagiuation. Surely some of that unbounded enthusiasm has fueled the Space Age, with new and different ways of depicting the solar system. Images from a decade ago are already history. It's a great trip! Get your ticket here!

Click Here To Download

Read more »