Community Magazine February 2014

Sheath RABBI ZAMIR COHEN The Midras (Beresheet Rabba 6:6) states, There is a sheath around the sun’s orb,” and explains this to be the meaning of the verse: “He has set up a tent for the sun” (Tehillim 19:5). T his sheath is mentioned several places in the Sages’writings, in which they imply that were not for its existence, life on earth would suffer terribly and perhaps even cease to exist altogether. When we look at the sun, either with the naked eye or through a filter, we see no sheath or covering. The Sages beheld the same sun, yet firmly insisted that a sheath exists, because the Torah states that it is there. In this age of spacecraft and X-ray photography of the sun, do scientists have something to tell us on this subject? The photo on the right describes the sun’s structure as revealed by modern research. Dr. N.Vidal, a senior astronomer at theGreenwich Observatory in England, Professor of Astronomy at Australia’s National University and a visiting professor at the Harvard- Smithsonian Center for Astrophysics at Harvard University, Massachusetts, explains: The sun is a giant ball of gas, whose outermost temperature is 6,000 degrees Celsius (10,832 degrees Fahrenheit). Gases at much higher temperatures flow beneath the surface. According to our estimates, the temperature continues to rise as we approach the center of the sun, where it reaches 15,000,000 °C! Today, we picture the center of the sun as a type of “nuclear reactor” that releases vast quantities of heat, which make their way slowly outward. As it moves out, the strength of this heat diminishes until it reaches the surface layer, where it is “only” 6,000 °C. The extremely high temperatures within the sun cause gas storms of tremendous proportions, which even form waves that crash against the surface gases with unbelievable force. These outer layers themselves absorb the heat being radiated from within the sun, and restrain the shockwaves caused by these waves striking it. We call this outer layer, “the sheath.” The illustration shows the sun’s structure, as we understand it today. The core area is the heart of the sun, where the temperatures are extremely high and there is the highest radiation of ultraviolet rays, X-rays, and gamma rays. If these rays were to reach the Earth directly, they would incinerate the entire world. The photosphere is the outermost sheath that restrains these rays as well as the shockwaves that burst out from the sun’s interior, and “softens” them. The photosphere’s temperature is 6,000 °C. Today we realize that just as the Earth has a surrounding atmosphere, which both provides oxygen for life and protects us from the dangerous cosmic radiation, the sun likewise has a sheath that protects the inhabitants on Earth. The Sages knew of this sheath’s existence from its source in the Torah. Furthermore, as indicated by the Midrash, they knew of its protective role, and the fact that Earth’s inhabitants would perish were the sheath to fail in its task. These facts teach us two important lessons: 1) The scientific information provided by the Torah has no human source. Through the Torah, the Creator of the universe reveals some of the mysteries of the creation to his people – among them, secrets that are invisible to the human observer. 2) We should give full credence to the Sages’ statements and grant them respect, even when, at first, they seem difficult to grasp. The Sun’s SIX LAYERS OF THE SUN 1. The corona , the sun’s halo, is comprised of gases, like the sun itself, but of a much lower density. 2. The inner atmosphere of the sun is called the chromosphere. 3. The photosphere is the sheath, which absorbs the powerful radiation and the shockwaves that burst out of the sun. 4. The convection zone is the layer throughwhich the sun’s energy travels outward via “convection.” 5. The radiation zone is the layer through which energy travels outward from the core as radiation. 6. The core is the center of the sun where nuclear reactions convert hydrogen to helium, producing energy. 42 COMMUNITY MAGAZINE