(单词翻译:单击)
What is fire anyway?
火究竟是什么?
Well, fire is rapid oxidization.
火,即燃烧,是快速的氧化反应 。
It's the energy released whenoxygen atoms start combining with carbon and hydrogenatoms.
氧化反应是氧原子和碳原子或氢原子结合释放能量 。
Exactly, so without oxygen in the air, nothing burns.
没错,那么如果空气中没有氧气,就不会有燃烧 。
You mean there was a time before oxygen?
你是说氧气还不存在的那个时代?
Yes. By roughly a billion years ago, simple forms of plant life called “eukaryotes” were already busilyconverting carbon dioxide into oxygen gas, just like their descendants do today.
对,大约十亿年前,和眼下的植物一样,地球上最原始的植物祖先“真核细胞”忙碌地将二氧化碳转变成氧气 。
But before thisprocess had been in place for a while, there wasn't enough oxygen in the air for things to burn.
但是,在此转化之前的一段时间,空气中没有足够的氧气可以燃烧东西 。
In fact, of all the planets, moons, asteroids, and comets in our solar system, the only place whereyou can actually start a fire is right here on earth.
而事实上,整个太阳系的所有的行星、月球、小行星、彗星,你会发现唯一可以生活的地方只有地球 。
And even here, it's only been possible relativelyrecently.
而就算是地球,也是不久以前才可行 。