Our Sun: Biography of a Star
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Our sun is one star among 50 billion in the galaxy. Our galaxy is only one among 50 billion in the universe. With a vastness this incomprehensible, it is easy to feel like we are mere specks of sand on an endless shore. But our sun is special. Though roughly 150 million kilometers separate us, we could not be more connected. Literally, everything you see comes from the sun. The words you are reading now are really photons that left the sun about 8 minutes ago only to bounce off this page and into your eyes. We owe our very existence to our sun. It provides just enough heat to keep our fragile bodies from freezing to ice or burning to a crisp. Every bite of food we eat we owe to the sun, whose energy is converted into plants that provide sustenance for everything up the food chain.
We have understood the sun's importance for millennia. The earliest humans, awestruck by its blazing splendor, left drawings of the sun on cave walls. Nearly every civilization, no matter where it sprang up on the planet, has revered the sun. Myths about the sun were the basis of the earliest deities of ancient Sumerian, Hindu, Egyptian, Chinese, and Meso-American cultures. Before Apollo, the ancient Greeks worshiped the sun-god Helios. Before Zeus, the ancient Romans worshiped Sol.
Throughout our history, the sun has been central to humanity's quest for meaning in the universe. But our history has been a brief moment in our sun's 4.5 billion year life. Only recently, through advances in science and technology, have we begun to understand our sun - where it came from, how it functions, how it affects our lives and how it eventually will destroy our planet.
Our Sun is a comprehensive, easy-to-understand guide to everything we know about our closest star. Illustrated with stunning pictures from NASA's newly-launched Solar Dynamics Observatory, Our Sun will reveal the science behind the sun, trace its impact on human history, and reveal its growing importance to our future way of life.
version: Step 1: Under immense temperature and pressure, two hydrogen nuclei (each with a single proton) are fused together, forming helium-2. Step 2: Most of the time, helium-2 is so unstable that it quickly decays right back into hydrogen. But every now and then, helium-2 goes through a process called beta-plus decay, during which one of its protons changes into a neutron by emitting two subatomic particles: a positron and a neutrino. Helium-2, with one proton and one neutron, is called
Despite his objections, Galileo accepted the result, but his reputation had suffered a major blow and heleocentrism was formally condemned as heresy. In 1623, Urban VIII, an admirer of Galileo, was appointed Pope. After his succession to the Papacy, however, Urban was accused by the Spanish Inquisition of being too close to heretical figures like Galileo and too soft on defending the church. Partially to defend himself against this charge, Urban asked Galileo to present arguments for and against
Tonatiuh in the center. The original stone, found buried beneath Mexico City’s main square in 1790, is about 3.7 meters (12 feet) in diameter and weighs more than 24 tons. introdUction (RAY) (Text) 15 solar exploration We are fortunate to be living in a time of exciting new discoveries about our Sun. We are beginning to answer important questions about the structure of the Sun, questions that have perplexed scientists for centuries. Our expanding understanding of our Sun is due in no small
massive electric currents that follow Earth’s horizontally oriented magnetic field lines all the way from the upper atmosphere into the surface of the planet. Electrical charges always want to move from areas of high voltage to areas of lower voltage. High-voltage transmission lines, therefore, act almost like antennas, attracting electromagnetic currents like a drain attracts water. They also tend to be north-south oriented and, therefore, contain multiple points along the lines where
billion years. Theoretically, it will continue to cool until its temperature is equal to its surroundings. At this phase, when the Sun stops radiating heat altogether, it will have become a black dwarf. No black dwarfs are thought to exist yet. Scientists speculate they might look very similar to a planet but exert substantially greater gravitational pull on nearby objects. In fact, if we ever find a black dwarf, it will probably be because we have detected distortions caused by its gravitational