Los juicios por brujeria en Salem

Venerado y vilipendiado a un tiempo, Lobachevski se cierne imponente sobre la matemática del siglo XIX. Al igual que sucede a la mayoría de los mitos, el Lobachevski real está oculto por capas de negligencia y desconocimiento. Su fantástica obra, argumentaban muchos, no era otra cosa que herejía matemática, una senda falsa. Lobachevski es una personalidad abrumadora, un soñador empedernido, un hacedor de mundos imposibles pero reales. Lobachevski es, para muchos, una persona desconocida. Este libro cuenta la historia de un hombre sencillo, pero sagaz, obstinado y profundo desde el...

Let’s Make a Volcano Spanish Edition. What do you know about a volcano? When a mountain erupts, it explodes! Hot melted rock, called lava, comes out of its top and flows down the side of the mountain! People need to keep away from real volcanoes, but you can have fun making your own volcano!

Where did the sunflower come from? How does it grow so tall? How can its thin stalk support such a large and heavy head? These and many other questions are answered in this dazzling book. Using lushly detailed illustrations and photographs, the book takes us inside the sunflower to examine its stem, root system, leaves, and flowering heads, proving an understanding of this unique plant's structure, growth, flowering, reproduction, and cultivation.

If you look close enough, a butterfly can grow up right before your eyes. Through the use of accessible text, readers take an exciting look at the journey butterflies make. A picture glossary helps beginning readers strengthen their vocabulary skills, and vibrant, full-color photographs show caterpillars grow to adulthood, taking flight to travel around the world.