In this post, we will see the book A Planet of Riddles by E. Novikov.About the book (from the back cover):This book is about our planet, the Earth we know so well. But is it then a planet of riddles? Read this book, and you will see that it is.Whence the strange names of the sections: "Embracing the Boundless", "Seeing the Invisible"? Has the author forgotten Kozma Prutkov's aphorism: "You can't embrace the boundless"? Not at all! But he does not agree.The book gives a brief history of the study of our planet. But history contains the roots of scientific novelty, of wonderful discoveries. Kozma Prutkov also said, and not without reason: "Heed the roots!"The book explores a variety of topics related to the Earth. It forays into areas of astronomy, geology, physics to ask questions and explain the physical origin of the objects and events we see on the Earth. For example, it also explains how the mud is formed. Peppered with historical anecdotes and updated with the latest scientific research (until the date of publication) this is an amazing read.The book was translated from the Russian by David Sobolev, and was first published by Mir in 1972, with a reprint in 1974. ContentsEMBRACING THE BOUNDLESSOnwards, to the Truth I 7Its Shape Was Determined at a Writing Desk, Its Size Measured Outdoors and Its Weight Indoors 24It Revolves and Vibrates 38 An Invisible Field 53The EC Mystery 75The Depths of Time 89A Rocky Ocean 110The Planet's Strange Disguise 126Facts for Thought 139 SEEING THE INVISIBLEThe Search for Exploration Methods 144Invisible Elements Hiide in the Earth 156On the Earth, in the Air, and at Sea 167Invisible Signals 186An Abstraction That Is Real 208Crossword Puzzles of the Familiar 219Is It Solid Ground We Tread on? 236Facts for Thought 253