A nanometre is a billionth of a metre .

十亿分之一米是一纳米。

How better to celebrate your billionth download than with a brand new app store ?

还有什么主意比用一个全新的软件商店来庆祝第十亿次下载更好呢？

Today 's most powerful versions can shine ten thousand times brighter than the sun , though only for a billionth of a second .

如今功率最大的激光机所发出的光瞬间可以比太阳所发出的光亮一万倍，即使维持的时间不超过十亿分之一秒。

At that height , the atmosphere has tapered away to almost nothing -- less than a billionth of the pressure it is at ground level -- but there are still gasses there .

在这样的高度，大气程锥形逐渐减少大气压力比地表的十亿分之一还小但这里仍然有空气存在。

Unfortunately for physicists , dr hawking also predicted that the typical temperature at which a black hole radiates should be about a billionth of that of the background radiation left over from the big bang itself .

不幸的是，对于物理学家来说，霍金博士还预测说，黑洞辐射的通常温度应该是宇宙大爆炸遗留的背景辐射的十亿分之一。