Facts about the sun known and unknown
The sun is a star-forming central body, or physical center of gravity, which represents 99.8% of the total mass of the solar system. In terms of classification of stars with a yellow-orange star average to slightly above average size. Its radius is less than 700,000 km, which is about 109 Earth radii and 330krát weight is greater than the mass of the Earth. Very simply, we can say that the sun is a ball of hot gases, particularly the lightest gases, ie hydrogen and helium. The temperature inside the solar core scientists estimate 15 million degrees, and the density of the core is approximately ten times greater than the density of lead. From Earth, the Sun distanced incredible 150 million km, the solar light to reach us in less than 9 minutes. Age of the Sun is estimated to be 4.5 billion years old, making it one of the stars of middle age.
The sun's rays as vitamin and energy supplements
Asked why the sun shines, look for answers in the past hundreds of scientists. Researches have shown that the center of the Sun thermonuclear reactions take place, allowing the sun shines. However, not fission reactions, such as nuclear power plants, which are difficult to break down into simpler carbon particles, but on the contrary. In thermonuclear fusion in the sun's core combine hydrogen with helium atoms. At the same time the interior of the sun releases an incredible amount of excess energy that travels through the layers to the photosphere, ie the surface of the sun. There invokes the solar wind or solar radiation. On Earth's surface, then flies like a stream of light particles, or photons. "Sun rays are very important for the mental health and balance of a person. Sunlight promotes the formation of the hormone seratonin, which creates a feeling of happiness. On the contrary, complicates the formation of melatonin, a hormone that induces sleep, "says Michal Kárych, chairman of the Czech Association of healthy sunbathing." With the sun so you can save significantly on energy and vitamin supplements, "says Kárych.
Scientists predict major changes: Sun engulf the planet Earth
At the beginning of October 1957 was in Earth orbit launch of the first artificial satellite Sputnik behalf. It has since been sent into space a lot of other satellites that are involved in research of the Sun. This allows scientists to predict the future evolution of the Sun. At present, its size is stable, and the force of gravity balanced by a force of pressure. Contemporary models of the Sun predict that the Sun will remain the center of our solar system for another 4-5 billion years. During further development will increase the radiant power. The cause of this phenomenon will change the chemical composition. Gradually there is the transformation of hydrogen into helium. At the moment when the solar core of most full of helium, hydrogen begins to burn occurs in the layer around the core. Further development will be greatly stormy sun and its result will be the destruction of all life on Earth. At the age of about 12 billion years the sun will burn all reserves of hydrogen in the core. It remains only pure helium, which will have the effect that the Sun begins to expand. After engulf Mercury and Venus, it is quite likely that absorbs and earth. Radiant Sun's output is greatly enlarges and becomes a red giant. Subsequently, loses most of the weight and the core begins to shrink the size of the Earth. Nuclear reactions cease, and the sun becomes a white dwarf.
The Sun has a few billion years older doppelganger
Few probably know that the sky can watch doppelganger Sun. Located in the constellation of Capricorn and divides us from it about 250 light-years. Scientists discovered it in 1997, claiming that the sun resembles like no other well-known star. It's called HIP 102152 and its age is estimated to be 8.5 billion years old. Not only scientists but also the public wants to know about the sun as much as possible, and therefore decided to Brazilian team led by astronomers to examine in detail of that double. Scientists from the observation HIPu promise further insight, not only about the past, but mainly on the further development of our parent star. Because HIP is about 4 billion years older than the Sun, it is possible to predict the behavior and predict events that are waiting for the sun late in life.
A little sun is harmful to human health
People's relationship to the Sun has a long history. Although the ancient Egyptians and other ancient peoples worshiped the Sun as the one God, and realized the dependence of all life on solar radiation, in modern times began to argue about the beneficial or harmful effects of tanning. We already know that not too much, not too little sun is healthy. Health is the best regular sensible sun exposure. Tanning It is a natural process that does not damage the skin, but rather it helps protect against sunburn. Studies examining the relationship between sun exposure and cancer has come from the sun for pardon. "Fundamental change in negative attitudes towards the sun and tanning caused The latest medical research on cancer prevention, "says Michal Kárych of the Czech Association of healthy sunbathing. These studies consider avoiding the sun not only impractical but also undesirable. Thanks to this, people often suffer from a lack of vitamin D. "To gain sufficient levels of vitamin D is optimal expose as much of the body to sunlight during high solar activity, and only for so long to avoid burning. With the gradual tan skin is advisable to extend the length of exposure, "says Kárych with the fact that the sun contributes to the preservation of bone metabolism and also to fight against certain types of cancer.
Source: tz ČAZO