Community Magazine July 2016

PLANET EARTH has the answers to ALL your questions... Professor Noe Ital This Month's Topic: What is Planet Earth made of? Planet Earth has multiple layers and consists of many parts. We live on the outermost layer of the planet, called the crust . The crust is composed of mostly oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium. About 71% of Earth’s surface is covered by the oceans. The layer underneath the crust is called the mantle , which is about 1800 miles deep. The mantle is made up of rock containing silicon, iron, magnesium, aluminum, oxygen, and other minerals. Below the mantle, at the center of the Earth, lies the core. The core has two parts: the inner core and the outer core . Both cores are mostly made up of iron and nickel. The outer core is in a liquid state and is about 1,400 miles thick. The inner core, however, is solid, and has a radius of about 750 miles. Although today this notion seems quite silly, it was not too long ago when many people believed that Earth was flat. After all, in any place with a wide view, the horizon looks flat. That is why so many cultures, including Ancient Egyptian, Babylonian, and Chinese cultures, believed that the world was a flat disk rather than a sphere. It was only in a much later time period (between 500 to 700 BCE) that some Greek philosophers began to realize that the world is round. But even then, the majority of mankind still believed that Earth was flat, or at best, dome-shaped. Interestingly enough, our great Sages knew that the world was not flat, from the wisdom of the Torah. They knew that the world is shaped like a ball, and is not flat, as was the belief of the science of the times. QUESTION OF THE MONTH: Good question! Many people are unaware that Earth is not a perfect sphere. Rather, it is a unique shape called a geoid - which means “Earth shaped.” This month’s question was submitted by Ralph of Long Branch, NJ. Q: Dear Professor, Is the actual shape of the Earth round - like a circle? A: What is a forest? Is it true that people once thought that Planet Earth was flat? Excerpts from “Exploring the Wisdom & Wonders of the Universe with Professor Noe Ital", by Efraim Harari, published by Israel Bookshop Publications. Available for purchase online and at all fine Judaica stores . Professor Noe Ital [AKA: Know-it-all] A forest is an ecosystem consisting mainly of tall trees. An ecosystem is a community of living things (plants, animals, microbes) interacting with non-living things such as water, rocks, and dirt. Trees play a major role in this complex environment. There are various types of forests. Some have lots of very thin trees, while others have enormous trees. Some forests are crowded, while others are “open,” allowing sunlight to reach the forest floor. Forests cover nearly one-third of all the land on earth! 92 COMMUNITY MAGAZINE