Lesson 17 Television Day Computers
第17課 電視日:計算機
"...the astronauts are returning to earth at exactly 5.24."
...宇航員將于5:24整回到地球,
Splash-down will be in the Pacific,427 miles west of Hawaii.
"并將在位于夏威夷西部427英里的太平洋海面上濺落。"
You have often heard announcements like this on television.
你常會從電視聽到上述的預告。
Scientists can tell us exactly
舉例說,科學家能準確地告訴我們
when a space-capsule will arrive on the moon for instance,
宇宙密封小艙何時抵達月球
and exactly when it will return.
和何時返回。
They can calculate things like this to the nearest second.
對這類事情,他們的計算可精確至秒。
How do they do it?
他們是如何做的呢?
Well,of course,they use mathematics.
當然他們運用了數(shù)學。
We can all do simple sums on paper,
我們都能在紙上做簡單的算術(shù)題,
but we must use computers for extremely difficult calculations.
但必須用計算機進行復雜的運算。
Perhaps you have seen mechanical calculating-machines in banks and offices.
你也許在銀行和辦公室見過機械計算機。
They can work very quickly,but nothing like computers.
盡管它們運算迅速,但與電子計算機截然不同。
Computers aren't mechanical.
電子計算機不是機械的。
They don't have wheels and gears in them.
它們沒有轉(zhuǎn)輪和齒輪。
Instead,they work on electrical circuits
而是通過電路工作的,
and can do difficult calculations at tremendous speed.
可以迅速進行復雜的運算。
They can work 100 million times faster than the human mind!
它們運算速度要比人腦快上一億倍。