Is human hibernation possible?

人类为什么不冬眠？

With low temperatures and a lack of food, winter is a harsh season for animals.

冬天温度较低、食物短缺，对于动物来说是一个严酷的季节。

Many animals enter hibernation to get through it.

许多动物靠冬眠来过冬。

Hibernation is when an animal goes into a state of extended inactivity.

冬眠指动物进入长时间的生命活动极低的状态。

Animals hide away from predators.

冬眠时，动物会避开捕食者，

Their metabolism will slow to less than a quarter of its normal rate.

将新陈代谢速度减慢至正常速度的四分之一以下。

This cools the creature’s body and slows its heartbeat to just a few times per minute, for up to months at a time.

这会让动物的体温降低，心跳减慢至每分钟几次，而这种状态每次会持续至数月。

But why don’t humans hibernate?

但是人类为什么不冬眠呢？

Human hibernation doesn’t exist for many reasons.

人类不冬眠有很多原因。

Our body is not designed for hibernation.

人类的身体不适合冬眠。

Our evolutionary ancestors were tropical animals with no history of hibernating:

我们进化学上的祖先是没有冬眠历史的热带动物：

Humans have only migrated into temperate and subarctic latitudes in the last hundred thousand years or so.

人类在过去大约10万年里，才迁移到温带和靠近北极地区。

That’s not quite long enough to evolve all the metabolic adaptations we would need to be able to hibernate,

这段时间还不够长，人类无法进化出冬眠所需的所有代谢适应能力。

according to the BBC Science Focus Magazine.

据英国广播公司《科学焦点》杂志报道，

For example, waste management is a huge challenge for human hibernation.

例如，处理代谢废物就是人类冬眠会面临的巨大挑战，

Animals that hibernate are able to essentially stop their urination and defecation during hibernation,

冬眠的动物基本上能够在冬眠期间停止排尿、排便，

sometimes through a process of reabsorption to preserve nutrients.

有时它们还会重新吸收废物来保存营养。

Unfortunately, humans can’t do this.

不幸的是，人类做不到这一点。

There are other challenges.

人类冬眠还面临其他挑战。

Body temperatures below 2.8 C tend to disrupt the human digestive tract and may cause pain.

人体温度如果低于2.8摄氏度，往往会损害人体的消化道，而且可能引发疼痛。

Cold temperatures can also suppress the immune system, making people more vulnerable to infections, according to Smithsonian Magazine.

据《史密森尼杂志》报道，低温还会降低免疫系统活跃性，人们会更容易受到感染。

In fact, humans don’t need to sleep through winter.

实际上，人类不需要靠睡觉过冬。

We have discovered fire, clothes, shelter, hunting and agriculture, all of which are much more effective ways of surviving the cold.

我们发现通过生火、穿衣、躲进房屋中能够避寒，依靠狩猎和农耕可以果腹，所有这些手段帮助人类更有效地度过严寒。

Could humans hibernate in the future?

在未来，人类会冬眠吗?

For long-distance space travel, it’s likely.

如果踏上长途太空旅行，人类很可能会冬眠。

A journey to Mars would take around months using current technology.

凭借目前的技术，人类去往火星需要几个月的时间。

If we hope to visit another star system, even if we could travel at the speed of light, the journey would take years.

如果我们希望去到另一个星系，即使能以光速旅行，这段旅程也需要数年。

Being able to hibernate would make such distances considerably less boring for the astronauts and conserve vital resources,

如果能够令宇航员进入冬眠，将大幅减少其在漫长航程中的无聊感，并节约重要的资源。

according to University of Oxford in the UK.

英国牛津大学研究表明，

NASA is treating this question seriously.

美国航空航天局（NASA）正在认真对待人类冬眠的问题。

Beginning in 2014, the agency funded research on long-term hibernation as a way to facilitate long-term space travel,

NASA从2014年起资助了一项有关长期冬眠的研究，希望以这种方式推动长期太空旅行发展。

according to The Atlantic magazine.

据《大西洋月刊》报道，