For anyone who has ever dreamed of exploring the heavens with a telescope.

Complete, detailed instructions and numerous diagrams for constructing a do-it-yourself telescope. No complicated mathematics are involved, and no prior knowledge of optics or astronomy is needed to follow the text's step-by-step directions. Contents cover, among other topics, materials and equipment; tube parts and alignment; eyepieces, and related problems; setting circles; and optical principles. 1973 ed. Appendixes. Index. 6 plates. 100 figures.

This book provides an introduction to the design of a variety of telescopes, mounts, and drives suitable for the home-constructor. Projects include instruments that range from a shoestring budget to specialist devices that are not commercially available. The skill level of each project is indicated and advice is provided as to what is sensible to construct, given what is commercially available. Hints and tips are included, as well as listings of reputable mail order sources of materials and components.

For children, potential is limitless, curiosity is an electrical current, and every moment is open to the possibility of the unexpected. Day-to-day life is filled with adventure. Road blocks are invitations to try new routes. And the world is vast and expansive. This book is a celebration of childhood through the crafts and activities that invite wonder and play. The twenty-five projects and activities in this book are meant to speak to the way children engage with the world. These projects are not about what is produced in the end (although that part is fun too) but rather they are stepping-off points—activities that spark curiosity, an adventure, or an investigation. They’re about the process of getting there. They’re about the conversations that happen while making things together. They’re about getting to know the world inch by inch. They’re about exploring imaginary universes and running through real forests. They’re about living in childhood . . . regardless of your actual age. They’re about being a kid.

Choosing and Using a Refracting Telescope has been written for the many amateur astronomers who already own, or are intending to purchase, a refracting telescope – perhaps to complement their existing arsenal of larger reflecting telescopes – or for the specialist who requires a particular refractor for serious astronomical applications or nature studies. Four hundred year ago, during the winter of 1609, a relatively unknown Italian scientist, Galileo Galilei designed a spyglass with two crude lenses and turned it skyward. Since then, refractors have retained their dominance over all types of reflector in studies of the Moon, planets and double stars because of the precision of their optics and lack of a central obstruction in the optical path, which causes diffraction effects in all commercially-made reflectors. Most mature amateur astronomers got started with a 60mm refractor, or something similar. Thirty years ago, there was little choice available to the hobbyist, but in the last decade long focus crown-flint achromats have moved aside for some exquisitely crafted apochromatic designs offered by leading commercial manufacturers. There has been a huge increase in the popularity of these telescopes in the last few years, led by a significant increase in the number of companies (particularly, William Optics, Orion USA, StellarVue, SkyWatcher and AstroTech) who are now heavily marketing refractors in the amateur astronomical magazines. In Choosing and Using a Refracting Telescope, well-known observer and astronomy writer Neil English celebrates the remarkable history and evolution of the refracting telescope and looks in detail at the instruments, their development and their use. A major feature of this book is the way it compares not only different classes of refractor, but also telescopes of each class that are sold by various commercial manufacturers. The author is perhaps uniquely placed to do this, having used and tested literally hundreds of different refracting telescopes over three decades. Because it includes many diverse subjects such as imaging with consumer-level digital cameras, imaging with webcams, and imaging with astronomical CCD cameras – that are not covered together in equal depth in any other single volume – Choosing and Using a Refracting Telescope could become the ‘refractor bible’ for amateur astronomers at all levels, especially those who are interested in imaging astronomical objects of every class.

When Sadiq's father leaves on a business trip, he worries he'll miss his baba too much. But Baba has a story for Sadiq: the story of the Desert Star. Learning about Baba's passion for the stars sparks Sadiq's interest in outer space. But can Sadiq find others who are willing to help him start the space club of his dreams?

Named a Best Book of 2019 by NPR “How might we mitigate losses caused by shortsightedness? Bina Venkataraman, a former climate adviser to the Obama administration, brings a storyteller’s eye to this question. . . . She is also deeply informed about the relevant science.” —The New York Times Book Review A trailblazing exploration of how we can plan better for the future: our own, our families’, and our society’s. Instant gratification is the norm today—in our lives, our culture, our economy, and our politics. Many of us have forgotten (if we ever learned) how to make smart decisions for the long run. Whether it comes to our finances, our health, our communities, or our planet, it’s easy to avoid thinking ahead. The consequences of this immediacy are stark: Deadly outbreaks spread because leaders failed to act on early warning signs. Companies that fail to invest stagnate and fall behind. Hurricanes and wildfires turn deadly for communities that could have taken more precaution. Today more than ever, all of us need to know how we can make better long-term decisions in our lives, businesses, and society. Bina Venkataraman sees the way forward. A journalist and former adviser in the Obama White House, she helped communities and businesses prepare for climate change, and she learned firsthand why people don’t think ahead—and what can be done to change that. In The Optimist’s Telescope, she draws from stories she has reported around the world and new research in biology, psychology, and economics to explain how we can make decisions that benefit us over time. With examples from ancient Pompeii to modern-day Fukushima, she dispels the myth that human nature is impossibly reckless and highlights the surprising practices each of us can adopt in our own lives—and the ones we must fight for as a society. The result is a book brimming with the ideas and insights all of us need in order to forge a better future.