時(shí)差N小時(shí):機(jī)不可失失不再來(lái)

It's such a commonplace event that you probablynever asked yourself why you sleep.

睡覺(jué)是個(gè)特別自然的事兒，你大概從來(lái)沒(méi)有問(wèn)過(guò)自己為什么會(huì)睡覺(jué)。

But from a scientific point of view, this is far from a mundane matter -- in fact, for sleepresearchers, it's one of the biggest unanswered questions in the field.

但是從科學(xué)的角度來(lái)看，這是很神秘的一件事。而事實(shí)上，對(duì)于睡眠研究人員來(lái)說(shuō)，這仍是該領(lǐng)域中一個(gè)懸而未決的問(wèn)題。

Stop and think about it for a second. Why should we sleep? Is it because we get tired?

停下來(lái)仔細(xì)想想。我們?yōu)槭裁磿?huì)睡覺(jué)?是因?yàn)槲覀兝哿藛?

But we sleep every night, even when we have had plenty of rest. Furthermore, if you weredesigning an animal, would you have it lapse into prolonged periods of unconsciousnessevery twenty-four hours?

但是即使我們休息夠了，晚上還是要睡覺(jué)。此外，如果讓你設(shè)計(jì)一種動(dòng)物，你會(huì)讓它每24小時(shí)陷入無(wú)意識(shí)狀態(tài)一段時(shí)間嗎?

Shouldn't that put it at a terrible disadvantage?

那不是讓它處于很大的劣勢(shì)嗎?

There are no doubt several different answers to this question, but let's just consider oneoverall purpose sleep may fulfill: sleep as a survival strategy.

毫無(wú)疑問(wèn)針對(duì)于這個(gè)問(wèn)題會(huì)有很多不同的答案，但我們單去考慮一個(gè)能夠?qū)崿F(xiàn)的整體目標(biāo)：睡覺(jué)是一種生存策略。

Human beings are "diurnal" creatures.

人類都是白天活動(dòng)的。

That means we are normally active during daylight hours, when our senses function mosteffectively.

那意味著我們通常是白天活動(dòng)力比較強(qiáng)，那個(gè)時(shí)候我們的感官功能也是最有效率的。

At night, humans do rather poorly: we can't see objects well, our color vision is entirely lost,and we don't have the smelling or hearing acuity of other animals.

晚上，人類的活動(dòng)力相對(duì)差些。我們看不太清物體，我們的顏色辨別也完全消失了，而且我們還沒(méi)有其他動(dòng)物那么敏銳的嗅覺(jué)和聽(tīng)覺(jué)。

So it actually does make sense to have us stay put during the dangerous period when"nocturnal," or night-waking, animals are on the prowl.

所以在那些夜間活動(dòng)的動(dòng)物們出沒(méi)覓食的危險(xiǎn)時(shí)刻，我們保持原地不動(dòng)，確實(shí)是很有道理的。

And one sure way to make sure we don't stumble around and get lost or eaten is to have usimmobilized for seven or eight hours, rising again only when the light is back and our survivalchances are better.

一個(gè)確保我們不會(huì)跌跌撞撞，不會(huì)迷路或者被吃掉的穩(wěn)妥方式就是，每天休息七到八個(gè)小時(shí)，天亮了我們?cè)倨鸫不顒?dòng)，這樣我們的生存機(jī)會(huì)會(huì)更好地得到保障。

It's not the only reason we sleep; but in terms of evolution, it may have been one of the firstreasons -- perhaps even the most important one.

這還不是我們睡覺(jué)的唯一原因;但就人類進(jìn)化而言，它可能是其中一個(gè)首要原因——甚至還可能是最重要的一個(gè)原因。