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If the sun shines for ever?

  1. Tamilarasan123 profile image37
    Tamilarasan123posted 6 years ago

    If the sun shines for ever?

    for a long time sun have shinning if you think how much long it can shine


  2. scottcgruber profile image78
    scottcgruberposted 6 years ago

    The sun will not shine forever, but it will shine for quite a long time. In around 5 billion years, the sun will begin to run out of hydrogen fuel in its core and will become a red giant, swelling to approximately the size of Earth's orbit. For the next hundred million years or so it will fuse helium instead of hydrogen, then eject its swollen outer layers of matter and collapse to form a white dwarf. This white dwarf should continue to fuse carbon and oxygen for hundreds of billions if not trillions of years before finally exhausting all of its fuel and becoming a black dwarf.

    So the answer is yes, but it's not something you have to worry about for a few trillion years.

  3. JKenny profile image93
    JKennyposted 6 years ago

    Yep, Scott's right. The Sun is a star, and no Star lasts forever. But its not something we have to worry about on our measure of time.

  4. lone77star profile image82
    lone77starposted 6 years ago

    No star will burn forever. Why? Because no fuel source is infinite. Like a log burning on a fireplace, the log provides a goodly amount of warmth only so long as there remains fuel, oxygen and heat. The sun's heat comes not from chemical burning, but from nuclear fusion -- nuclear explosions.

    The sun "burns" hydrogen to form helium. This process of fusion gives off excess energy. Later, when the sun's core runs out of this fuel, the sun will start to collapse because of gravity and the reduced heat from the failing core. But collapsing produces heat from compression (like the compression of air being pumped into a tire makes the tire hot). Over time, the heat from compression becomes great enough to cause helium to start fusing ("burning") to form heavier elements, like carbon.

    Helium burns far hotter, so this pushes more energetically against gravity than did hydrogen, making the sun far larger. But being larger, the surface is now much farther from the source of heat energy and thus cooler, making it redder in color. That will happen in about 5 billion years as Scott says.

    But perhaps far more important for us on Earth is the steadiness of the sun's output. Over the next billion years, the sun will become warm enough to wipe out all life on Earth and eliminate the oceans. Earth will become a dry desert long before the sun becomes a red giant. Still, this is so far in the future, humanity will have plenty of time to leave Earth, if it chooses to do so.

    Even though, as Scott points out, the sun will continue to give off light for trillions of years, only a small window of that span of time will remain usable for humanity and the life on this world.