Why Cats Land On Their Feet

How to use physical reasoning to solve surprising paradoxes Ever wonder why cats land on their feet? Or what holds a spinning top upright? Or whether it is possible to feel the Earth's rotation in an airplane? Why Cats Land on Their Feet is a compendium of paradoxes and puzzles that readers can solve using their own physical intuition. And the surprising answers to virtually all of these astonishing paradoxes can be arrived at with no formal knowledge of physics. Mark Levi introduces each physical problem, sometimes gives a hint or two, and then fully explains the solution. Here readers can test their critical-thinking skills against a whole assortment of puzzles and paradoxes involving floating and diving, sailing and gliding, gymnastics, bike riding, outer space, throwing a ball from a moving car, centrifugal force, gyroscopic motion, and, of course, falling cats. Want to figure out how to open a wine bottle with a book? Or how to compute the square root of a number using a tennis shoe and a watch? Why Cats Land on Their Feet shows you how, and all that's required is a familiarity with basic high-school mathematics. This lively collection also features an appendix that explains all physical concepts used in the book, from Newton's laws to the fundamental theorem of calculus.

How do cats land on their feet? Discover how this question stumped brilliant minds and how its answer helped solve other seemingly impossible puzzles The question of how falling cats land on their feet has long intrigued humans. In this playful and eye-opening history, physicist and cat parent Gregory Gbur explores how attempts to understand the cat-righting reflex have provided crucial insights into puzzles in mathematics, geophysics, neuroscience, and human space exploration. The result is an engaging tumble through physics, physiology, photography, and robotics to uncover, through scientific debate, the secret of the acrobatic performance known as cat-turning, the cat flip, and the cat twist. Readers learn the solution but also discover that the finer details still inspire heated arguments. As with other cat behavior, the more we investigate, the more surprises we discover.

Why spend one life worrying . . . when you could spend nine lives napping? Take it from artist Jamie Shelman's wry and furry felines: Cats work reasonable hours (zero), love wisely (from a distance), and live boldly (until someone starts vacuuming). Don't go without these 100 sage lessons: Be especially attentive to the one person who doesn’t like you. Get away with murder by looking cute. Ignore anyone who doesn't worship you. Be pleased with your achievements, however small. The best solution to a problem is a nap. Live better—live like your cat!

The falling cat is an interesting theme to pursue, in which geometry, mechanics, and control are in action together. As is well known, cats can almost always land on their feet when tossed into the air in an upside-down attitude. If cats are not given a non-vanishing angular momentum at an initial instant, they cannot rotate during their motion, and the motion they can make in the air is vibration only. However, cats accomplish a half turn without rotation when landing on their feet. In order to solve this apparent mystery, one needs to thoroughly understand rotations and vibrations. The connection theory in differential geometry can provide rigorous definitions of rotation and vibration for many-body systems. Deformable bodies of cats are not easy to treat mechanically. A feasible way to approach the question of the falling cat is to start with many-body systems and then proceed to rigid bodies and, further, to jointed rigid bodies, which can approximate the body of a cat. In this book, the connection theory is applied first to a many-body system to show that vibrational motions of the many-body system can result in rotations without performing rotational motions and then to the cat model consisting of jointed rigid bodies. On the basis of this geometric setting, mechanics of many-body systems and of jointed rigid bodies must be set up. In order to take into account the fact that cats can deform their bodies, three torque inputs which may give a twist to the cat model are applied as control inputs under the condition of the vanishing angular momentum. Then, a control is designed according to the port-controlled Hamiltonian method for the model cat to perform a half turn and to halt the motion upon landing. The book also gives a brief review of control systems through simple examples to explain the role of control inputs.

Orthogonal tensors are mainly used to describe rotation. They play a central role in robotics, rigid-body kinematics, and all other branches of engineering mechanics, especially for modelling elastic and inelastic behavior of materials. Whilst vast literature is available for common rotation-related tasks, such as coordinate changes, most reference books tend to cover one or two methods for handling rotations, while often neglecting relatively obscure rotation-related tasks, such as statistical sampling of rotation for multiscale constitutive modeling. Further specialized rotation-related research can be found only in disparate journal articles. Of the few books that do exist, most are aimed at mathematicians, leaving a need for this self-contained engineering focused review that covers both elementary and advanced concepts. Rotation, Reflection, and Frame Changes presents a refreshingly broad range of rotation-related research that is routinely needed in modern engineering practice. By including theorems and physical insight acquired over her 30+ career as both as laboratory and university researcher, Rebecca Brannon has created a truly practical and accessible guide for engineers and scientists in engineering mechanics. Although the book assumes familiarity with multivariate calculus, linear algebra, and elementary tensor analysis, tutorials and provided computer source code guide the reader through more advanced topics.

Did you know that European royalty once used cheetahs to hunt deer, or that caracals can capture birds by leaping six and a half feet straight up into the air from a standing start? Have you ever wondered whether domestic cats really do land on their feet when they fall, or how Canada lynx can stalk their prey in the winter without falling through the deep snow? Wild Cats of the World is a treasure trove of answers to questions like these, and many others, for anyone who's interested in learning more about the world's felids, including the ones with whom we share our homes. Mel and Fiona Sunquist have spent more than a decade gathering information about cats from every available source, many of them quite difficult to find, including scientific papers, descriptions of hunts, archeological findings, observations by naturalists and travelers, reports from government agencies, and newsletters from a wide variety of organizations. Weaving information from these sources together with their own experiences observing wild cats around the world, the Sunquists have created the most comprehensive reference on felids available. Each of their accounts of the 36 species of cat contains a description of the cat, including human interactions with it, as well as detailed data on its distribution, ecology and behavior, status in the wild, and efforts to conserve it. Numerous photographs, including more than 40 in full color, illustrate these accounts. Ranging from the two-pound black-footed cat to the five-hundred-pound tiger, and from the African serval with its satellite-dish ears to the web-footed fishing cat of Asia, Wild Cats of the World will fascinate and educate felid fans of any stripe (or spot).

Everybody knows that mathematics is indispensable to physics--imagine where we'd be today if Einstein and Newton didn't have the math to back up their ideas. But how many people realize that physics can be used to produce many astonishing and strikingly elegant solutions in mathematics? Mark Levi shows how in this delightful book, treating readers to a host of entertaining problems and mind-bending puzzlers that will amuse and inspire their inner physicist. Levi turns math and physics upside down, revealing how physics can simplify proofs and lead to quicker solutions and new theorems, and how physical solutions can illustrate why results are true in ways lengthy mathematical calculations never can. Did you know it's possible to derive the Pythagorean theorem by spinning a fish tank filled with water? Or that soap film holds the key to determining the cheapest container for a given volume? Or that the line of best fit for a data set can be found using a mechanical contraption made from a rod and springs? Levi demonstrates how to use physical intuition to solve these and other fascinating math problems. More than half the problems can be tackled by anyone with precalculus and basic geometry, while the more challenging problems require some calculus. This one-of-a-kind book explains physics and math concepts where needed, and includes an informative appendix of physical principles. The Mathematical Mechanic will appeal to anyone interested in the little-known connections between mathematics and physics and how both endeavors relate to the world around us.

‘Christopher Cricket on Cats’ is a wonderful text, penned by Anthony Henderson Euwer (1877 – 1955). As the title suggests, it is a book of wisdom for both young and old. Euwer was an American Author, and feline fanatic, who dedicated this children’s story: To all the Cats that ever Meowed On this or any Sphere,– From the beginning of all Time Unto this Present Year. This charming verse is beautifully illustrated throughout with Euwer’s graphic black-and-white illustrations. Aside from his work illustrating children’s books, Euwer was also a talented oil painter. His artistic flair is evident in the good humour and painstaking application, on show throughout this book. Presented alongside the text of ‘Christopher Cricket on Cats’, the drawings further enhance and refine Euwer’s masterful storytelling. Pook Press celebrates the great ‘Golden Age of Illustration‘ in children’s classics and fairy tales – a period of unparalleled excellence in book illustration. We publish rare and vintage Golden Age illustrated books, in high-quality colour editions, so that the masterful artwork and story-telling can continue to delight both young and old.