5.Circadian Clocks Are As Old As Time
5.生物钟像时间一样古老
The Salisbury Cathedral in England is said to be home to the world's oldest clock. The mechanical device's wrought iron hands are believed to have been tracking the passage of time since at least 1386. The clock survived war, fire and inattention before being rediscovered in the early 20th century and restored.
英格兰的索尔兹伯里大教堂据说是世界上最古老的钟的发源地。至少自1386年来，装有铁的时针的机械设备就被认为是用来记录时间的。在20世纪早期被重新发现之前，索尔兹伯里大教堂里的这口钟受过战火的洗礼，以及人们的忽视，但是最终还是保存了下来。

The Salisbury Cathedral clock is but a wee whippersnapper when compared to the natural clocks that track our circadian rhythms. Scientists believe internal clocks evolved more than 3 billion years ago in cyanobacteria (what we also call blue-green algae), but they don't know exactly why it happened. Some say this was nature's way of leveling the playing field for organisms all competing for the same sources of energy. Circadian rhythms developed so that some creatures feed during the day and others do it at night. Others say the body clock evolved in algae to stagger the sludge's processes for photosynthesis—converting light into energy to be stored for later—and nitrogen fixation—in which plants convert nitrogen from the air into energy — so as not to counteract one another.
和记录我们昼夜节律的生物钟相比，索尔兹伯里大教堂里的钟根本是微不足道的。科学家认为在30亿年前的蓝细菌（我们称之为蓝藻）时期生物钟就开始演变了，但是科学家们并不知道生物钟开始的确切时间。有的人觉得这其实只是一种自然的竞争机制，因为所有的生物体都需要同样的能量。生物钟的存在确保了有些生物可以在白天觅食，有些可以在晚上觅食。而另外一些人认为在蓝藻时期就演变的生物钟利用光合作用缓慢发展，把光转换成能量，储存在身体后，又释放出氮化物，这样的话植物就把空气中的氮化物固定在体内了，以免消耗。

4.Sleep, It Does a Body Good
4.睡眠对身体有益

Perhaps the reason for circadian rhythms in humans is simpler: They help you sleep, and sleep is good for you.
或许，人类具有生物钟的原因很简单——生物钟有助于你入眠，而睡眠对你有益。
When you lay your head down and nod off to the feather ball, your body is restoring itself. That includes basic upkeep and repair like muscle growth, tissue maintenance, protein production and the release of growth hormones. Those hormones help children develop naturally — exhibit A in the case against little Johnny staying up to watch Jimmy Fallon — but also play a key role in helping adults rebuild tissue over time. In fact, it's believed that some of these functions only happen during sleep hours. Animals deprived of sleep will lose all immune function and die in just a few weeks. If you've ever popped out of bed after a nice long slumber and felt mentally refreshed, it's probably not just because you spent the night dreaming about being fanned and fed grapes by models poolside at an Italian villa. Sleep helps humans restore their mental energy and cognitive functions that often get tapped out during waking hours. Our circadian rhythms naturally make us sleepy at night.
当你安然平躺，枕着松软的枕头酣然入眠时，你的身体便开始进行自我修复，即一些基本的维护保养，如肌肉的增长、组织的修复、蛋白质的生成及生长激素的释放。生长激素对儿童的茁壮成长具有促进作用，总是熬夜看吉米·法伦节目的小不点儿就是个典型的反面例子。不仅如此，生长激素还在促进成年人的组织修复过程中起着关键作用。有分析认为，以上机能中有部分仅在睡眠时才起作用，因此，被剥夺睡眠的动物会丧失所有的免疫能力，在几周内死亡。你在经过了长时间的优质睡眠后会觉得精神焕发，或许不仅仅是因为置身豪宅、名模环绕的黄粱美梦之中。因为睡眠有助于恢复人们在清醒时消耗的心理能量及认知功能。而且，夜里那排山倒海的困意也是生物钟这只“幕后黑手”所致。

3.The Post-Lunch Dip is Natural
3.午餐后犯困很正常

Ever wonder why you have to fight the urge to sleep after lunch (unless you're lucky enough to work from home and can give into it)? Your body's circadian rhythm is in a natural resting place after your noontime meal. There's also another system called the sleep/wake homeostatis that tells your body when it's time to sleep, which also occurs after you've been awake for a long time. By 2 p.m., you've usually been awake for at least eight hours. Put those two systems together, alongside a heavy lunch, and it's no wonder you want to take a nap.
你可曾想过，为何你在午餐后总是得对抗那绵绵困意（除非你是个在家办公的幸运儿，困倦来袭便可安然入睡）？那是因为午餐过后，你体内的生物钟已经指向了休息时分。而且，睡眠/清醒体内平衡系统会在到点睡眠时或保持长时间清醒状态后，向你的身体发出讯号。到下午2点时，你至少已经保持了8个小时的清醒状态，这时，丰盛的午餐、生物钟以及体内平衡系统三管齐下，你不想打盹才怪呢！
Not everyone has this feeling to the same degree but it is a natural one. In fact, for most adults, their strongest sleep drives are at 2 p.m. and 2 a.m., thanks to their circadian rhythms. However, if you got a good night's sleep, your urge to nap at lunchtime will be lessened.
每个人的困倦程度有所不同，这很正常。由于生物钟的作用，大多数成年人往往在下午2点及凌晨2点时困意最浓。但如果夜间的睡眠质量好，午餐后的困倦会有所减轻。

2.Electronic Light Warps the Body Clock
2.电子产品的灯光会扰乱生物钟

If we've learned anything so far, it's that the body clock is wound generally to correspond to light and dark. When it starts to get dark at night, the brain tells the body it's time for a rest by releasing melatonin into the bloodstream. So, what happens when you literally flip the (light) switch in the evening?
就我们目前所了解到的，生物钟一般来说会与光明和黑暗相对应。当夜幕开始降临，大脑通过释放褪黑激素到血液中，告知身体已到休息的时间。那么，当你在晚上拨动（电灯）开关会怎样呢？
Artificial light can send mixed signals. Yes, a small and strategically located night-light may be necessary for navigating from bedroom to bathroom when duty calls. But other lights could throw your body clock into disarray. That includes illumination coming from a television, computer or smartphone. Many people like to wind down for the night by watching the ol' boob tube -- or streaming entertainment through their computers and tablets. If you bring those devices, and the artificial light that they give off, into bed, however, you may be tricking your brain into thinking it should stay awake.
人造光线会传递出复合信号。没错，也许一盏在特定位置的小小夜明灯对指引人们从卧室到卫生间以解决日常需要来说是必要的，但是其它的光线会打乱你的生物钟，这些光线来自电视机、电脑和手机。许多人喜欢在晚上通过看电视来放松自己或者将玩电脑和平板作为娱乐活动。如果你将这些电子设备带到床上，它们散发出来的人造光会影响大脑原先的运作方式。

1.The Body Clock Can Impact the Biological Clock
1.生物钟会影响生理钟

We've come right back to the "biological clock." Research shows that women who are pregnant or hoping to conceive should listen to their circadian rhythms and avoid artificial light at night. Sleep doesn't just help the body rejuvenate and promote growth in kids; it also protects a woman's eggs from stress. That's because melatonin is believed to have antioxidant qualities and defends the body against inflammation while stimulating the immune system, particularly during ovulation .
让我们回到“生理钟”这个话题上。研究人员表示孕妇或者期望怀上孩子的女性应该遵循她们的昼夜节律以及在夜晚避免接触人造光线。睡眠不仅仅有助于身体自我修复和儿童的成长发育，还可以保护女性的卵巢免受情绪压力影响。这是因为褪黑激素有抗氧化的功能，并且可以通过刺激免疫系统来抵御炎症以保护身体，尤其是在女性排卵期。
When the lights go on at night, melatonin production slows or stops. Experts say that women who are expecting should maintain steady sleep patterns that conform with the light and dark cycles going on outside. That means eight hours of darkness with little or no interruptions each night. The dark, not actual sleep, is the key. The body produces melatonin as a reaction to darkness and will continue doing so, even if you can't sleep. Among other effects, researchers have found that disruptions in this routine can lead to attention-deficit/hyperactivity disorder and autism-related disorders in young children.
在夜晚有光亮时，褪黑激素会减慢甚至停止生成。专家认为想要怀孕的女性应该养成与外界日夜交替保持一致的固定的睡眠模式。也就是说在每晚八小时的睡眠时间中，应该很少或者完全避免受到光线的干扰。保持黑暗的睡眠环境是关键，而非睡眠本身。身体产生的褪黑激素是对黑暗的条件反应，就算你没有进入睡眠，褪黑激素的产生仍会继续进行。至于其他方面的影响，研究人员发现对于幼儿来说，夜晚睡眠中受到光线的干扰会导致注意力缺陷障碍和自闭症等相关疾病

审校：围巾、烟囱 编辑：listen 来源：前十网