字幕列表 影片播放 列印英文字幕 Space Place in a Snap! Where does the Sun's energy come from? Every 1.5 millionths of a second the Sun releases more energy than all humans consume in an entire year. Without the Sun there would be no light, no warmth and no life. It's heat influences the environments of all the planets, dwarf planets, moons, asteroids and comets in our solar system. How does a big ball of hydrogen create all that heat? The short answer is that it is big. If it were smaller it would be just a sphere of hydrogen like Jupiter, but the Sun is much bigger than Jupiter. It would take almost 1,000 Jupiter's to fill it up. That's a lot of hydrogen. That means it's held together by a whole lot of gravity, and that means there is a whole lot of pressure inside of it. In fact the pressure is so intense and the density so great that the hydrogen atoms collide with enough force that they literally meld into a new element... helium. This process called nuclear fusion releases energy while creating a chain reaction that allows it to occur over and over and over again. That energy builds up. It gets as hot as 27 million degrees Fahrenheit in the Sun's core. The energy travels outward through a large area called the convective zone. Then it travels onward to the photosphere where it emits heat, charged particles and light. That heat powers the chemical reactions that make life possible on Earth, allows gases and liquids to exist on many planets and moons and causes icy comets to form fiery halos. Those particles create a solar wind that pushes against the fabric of interstellar space billions of miles away... And that light travels far out into the cosmos, just one star among billions and billions. Not too bad for a big ball of gas no? Find out more about the Sun at NASA Space Place.
B1 中級 美國腔 究竟太陽能是從哪來的呢?(Where Does the Sun's Energy Come From?) 14 1 Sandra 發佈於 2021 年 11 月 02 日 更多分享 分享 收藏 回報 影片單字