未登录,请登录后再发表信息
最新评论 (0)
播放视频

6个耗时最长的实验

6 of the Longest Experiments Ever

科学 即先提出问题 再认真地进行实验
Science is all about asking questions and then running carefully controlled experiments
以寻求答案
to find the answers.
一般而言 这些实验不会进行太久
Most of the time, it doesn’t take too long to actually run those experiments — maybe
最多两三年
a few years at most.
但有些实验却会拖很久 久到人们忘了
But some experiments can take way longer, to the point where the original question is
为什么而进行这个实验 最先提出假设的研究人员也不知所踪
almost forgotten, and the researchers who originally asked the question are long gone.
这些实验小到电铃关不了 大到铅封式微生物时间胶囊
From an electric bell that refuses to shut up to lead-sealed microbial time-capsules,
下面就是一些世界上进行时间较长的实验
here are some of the world’s longest-running experiments.
许多修理工会说 要想让开车开得顺畅 你就得
Most mechanics will tell you that to keep your car running smoothly, you should change
给车四年换一次电池
the battery every four years.
但在牛津大学物理学院的一个不起眼的角落里 有一块电池
But in a corner of the physics department in the University of Oxford, there is a battery
已经持续使用了177年
that’s been running for 177 years.
没人知道它是怎么持续使用这么久的
And no one knows how it’s lasted that long.
1840年 牛津大学物理学教授罗伯特 沃克买了一个奇怪的装置
In 1840, Oxford physics professor Robert Walker bought a weird-looking contraption consisting
它有两根长长的圆筒 圆筒上覆盖着硫磺 下面连接着两个铃
of two long, sulfur-covered cylinders attached to two bells.
电池里的电流
A metal ball slowly vibrates back and forth between the bells,
能使一个金属球在两个铃铛间来回摆动
propelled by the charge from the battery.
这种电池叫干堆原电池 与许多现在的电池不同
The type of battery it uses is called a dry pile, because unlike most modern batteries,
这种电池里促使电力流动的电解质不是液体
the electrolyte, which is the stuff that actually allows electricity to flow,
而是胶状体
is a paste rather than a liquid.
这两个铃是在第一块电池发明出来40年以后才按上的
The bells were built only 40 years after the very first battery was invented, and the batteries
给金属球提供电力的电池也最多能用4到5年
powering the metal ball were only expected to last 4-5 years.
所以 它能一直持续使用将近两百年就显得有点奇怪
So it’s pretty weird that this thing has lasted almost two centuries, and physicists
物理学家们也非常想更多的了解它的电池到底是怎么运作的
would love to know more about how its batteries work.
但很不幸 圆筒是密封的 制作手册也
But unfortunately, the cylinders are sealed, and the records of their manufacture were
很早就遗失了
lost long ago.
但我们仍对这种电池略知一二
We do have some clues about these batteries.
当时 其他干堆原电池上都覆盖着一层层的金属盘
Other dry piles made at the time had layers and layers of metal discs stacked on top of
人们用硫磺将它们封起来
each other, with sulfur sealing everything in.
这些金属盘的一侧上覆有硫酸锌
The discs were usually coated with zinc sulfate on one side,
另一侧覆有二氧化锰
and manganese dioxide on the other.
如今 硫酸锌常被用作食品强化剂 但二氧化锰
These days, zinc sulfate is mostly used as a dietary supplement, but manganese dioxide
仍在干电池制作中大量使用
is still used in modern dry-cell batteries.
但是该装置电池的制作方式却让他能持续使用这么久
But something about the way this thing’s batteries were made has let them last a ridiculously
这很不可思议
long time.
关键是 我们不打开圆筒
The thing is, until we open up the cylinders,
就无法确切地知道里面到底有什么
we won’t know for sure that’s what’s inside.
但在这点上 研究人员并不想将它打开来研究
And at this point, scientists don’t really want to crack it open and investigate — they’d
他们更愿意看看它到底能持续使用多久
rather see how long it keeps going first.
一旦它停止运转 我想研究者一定会很快对它进行研究
Once it stops though, I imagine they’ll organize the autopsy pretty quickly.
如果你跟一个农民进行交谈 他可能会告诉你杂草是他们的
Talk to a farmer, and they’ll probably tell you that one of their biggest challenges is
老大难问题
weeds.
有时 他们似乎跟杂草在打一场永无休止的战争
Sometimes it seems like they’re fighting a never-ending battle against them.
这是因为草有休眠的特性
That’s because weeds have this annoying property where they can lie dormant,
它们就那么静静的待在地面以下
chilling out just under the surface.
它们会让你觉得你已经将它们铲除干净了 就在你因此而自我满足时 砰
They lull you into a false sense of security until you get complacent and then BAM!
杂草又长的满地都是
They’re all over the place again.
农业研究者进行了许多次实验 他们想看看杂草到底
There have been plenty of studies by agricultural scientists trying to find out how long weeds
能在土壤里长多久
can hang around in the soil.
但是最早进行的也是持续时间最长的实验是在
But the oldest, and longest-running, of these experiments can be found on the grounds of
密歇根州立大学进行的实验
Michigan State University.
5瓶装满了沙子的威士忌酒瓶被倒着埋在一个绝密的地方
There are 5 whiskey bottles, filled with sand, buried upside down in a top-secret location.
别误会 它们不是十九世纪狂欢晚宴上留下来的瓶子
And no, they aren’t the leftovers of some 19th century rave.
这些都是植物学家威廉詹姆斯比尔给后人的遗赠
They’re the legacy of botanist William James Beal.
他用21种不同种类的杂草种子装进20个瓶子里
He filled 20 of these bottles with seeds from 21 different species of weeds,
再在里面装进潮湿的沙子
plus moist sand.
再把它们倒着埋起来 这样就不会有水渗透到里面
He buried them angled down so they wouldn’t fill up with water, and then planned to dig
之后 每过五年就挖出来一个 再将种子种到地里 看哪种种子能存活下来
one up every five years and plant the seeds to see which survived.
至少 他是这么打算的
At least, that was the plan.
1919年 冰冻天气来的很早 由于没有气锤 这些瓶子挖不出来
In 1919, there was an early frost and the bottle couldn’t be excavated without a jack-hammer,
所以 他们只能等到1920年才把它们挖出来 并决定从那时开始
so they waited until 1920, and decided to extend the
将挖瓶子的间隔时间延长至十年
interval to ten years from then on.
1990年 接手该项目的研究人员没有挖出瓶子而是
In 1990, instead of digging up a bottle, the researchers who’d taken over the project
将挖瓶子的间隔时间延长到了二十年
extended the interval again to 20 years.
最近的一个瓶子是在2000年打开的 埋着的还有5个
The most recent one was opened in 2000, and there are five left.
这意味着最后一个瓶子在2100年才会被挖掘出来
Which means the last bottle will be unearthed in 2100.
研究人员把他们在2000年挖出来的瓶子里的种子种在地里
When researchers planted the seeds from the bottle they dug up in 2000, seeds from only
只有两类种子发了芽
two of the original species sprouted into plants.
这并没有出乎他们的意料 因为上次种子发芽
That’s pretty much what they expected, since the last time seeds from more than three species
还是在1930年
sprouted was in 1930.
但他们好奇的是最难生长的那类种子
But they’re curious whether seeds from the hardiest species will keep sprouting when
等到挖出来之后是否还会发芽
they dig up future bottles.
如今 该实验的意义却较之前有了偏颇
By now, the point of the experiment has kind of flipped.
研究人员的目的不是想弄清楚如何去铲除杂草 而是想
The researchers aren’t trying to figure out how to kill weeds — they want to know
了解种子是如何一直存活着 从而保护其不会走向灭绝的
more about how seeds stay viable to help save plants that might be going extinct.
世界上数千人同时决定静候一件
Thousands of people all over the world have decided to sit and watch something that flows
比油漆变干更慢的事情发生
even slower than paint dries.
大家都在等着去见证该实验历经九十年的伟大时刻
All for the chance at witnessing the next big moment in a 90-year-old experiment.
该实验叫做沥青滴漏实验
It’s called The Pitch Drop Experiment.
1927年 澳大利亚昆士兰大学物理学教授托马斯帕内尔
In 1927, Thomas Parnell, a physics professor at the University of Queensland in Australia,
设定实验表明沥青事实上是可以流动的
set up a demonstration to show that pitch, aka asphalt, actually flows.
沥青看起来像是固体物 它也当做固体来使用
Even though it looks and acts like a solid.
但事实证明 沥青也确实是可以流动的 只是 流动的非常慢
And it turns out that it does flow … just, very slowly.
实验中有一个大的漏斗 漏斗里装满了黑色的沥青 缓慢的滴进
The experiment consists of a large funnel filled with black pitch that slowly drips
一个大烧杯里
into a beaker.
过了八年 第一滴沥青才滴下来 之后又过了九十年
It took 8 years for the first drop to fall, and in the ninety years since, there have
才滴了八滴
been 8 more drops.
据此 研究人员发现沥青比水要粘三百亿倍
Based on these drops, researchers found that pitch has a viscosity 30 billion times greater
意思就是 沥青比水的流动慢了三百亿倍
than water — meaning, it flows about 30 billion times more slowly than water does.
20世纪80年代 学校里的研究员们决定终止实验
In the 1980s, scientists at the university debated taking down the experiment, since
因为他们觉得该实验已经达到了他们的目的
they figured it had served its purpose.
但是后来发生了两件事
But then, two things happened.
第一 他们发现根本没人看到沥青真正滴下来
First, they realized that no one had ever actually seen the drop fall.
他们只是在第二天早上在烧杯里看到了一滴沥青而已
They’d just found another drop in the beaker the next morning.
第二 那时开始沥青往下滴的速度就跟以往不一样了
And second, the pitch started acting… weird.
前七滴沥青滴下来的速度都是一样的 但第八滴
The drops had been falling at a semi-consistent rate up until this point, but the 8th drop
滴下来的速度比前七滴都要慢
took a lot longer to fall than the previous ones.
第八滴是在2000年滴下来的 但是记录的中断表明记录沥青滴下的记录仪
It fell in 2000, but a really badly timed blackout meant the cameras set up to record
坏掉了
the drop failed.
在2014年滴下了第9滴 也被记录仪记录了下来
The 9th drop fell in 2014, and was caught on camera.
但是现在 沥青似乎滴落的更快了
But now, it seems like the pitch is flowing faster,
科学家们也不知道这是为什么
and scientists aren’t sure exactly why.
因此 该实验依旧在继续 研究人员也希望通过对沥青滴落的研究能为
So the experiment is still going, and researchers hope the pitch’s behavior will give us insights
其他像塑料 硅胶这样高粘度物质的研究提供帮助
into other super-high viscosity materials like plastics and silicone.
据疾病控制中心消息 心血管疾病是导致美国人民
According to the Centers for Disease Control, cardiovascular disease is the leading cause
死亡的主要原因 每年有600000多人死于这种疾病
of death in the United States, claiming over 600,000 people a year.
20世纪40年代的时候 科学家们就想了解如何才能防止这类事情发生
And scientists back in the 1940s wanted to know more about how to prevent it.
1948年 马萨诸塞州 弗雷明翰的5000人志愿参加一场
In 1948, about 5,000 people in Framingham, Massachusetts volunteered to be a part of
宏伟的耗时时间长久的实验
a massive, long-term study.
研究人员挑选出健康并没有心脏病迹象的人
Researchers picked healthy adults that showed no signs of heart disease and started monitoring
对他们的生活方式和身体健康进行监控
their lifestyle and physical health.
该实验研究了胆固醇 血压及吸烟等其他因素
The study linked cholesterol, high blood pressure, and other factors like smoking
和心脏病与中风的关系
to heart disease and stroke.
尽管最初的参与者所剩无几
And it’s still going, even though there are
但实验仍在进行
very few of the original participants left.
20世纪70年代 第一代被试子女长大成人并被列入研究对象 最近
In the 1970s, the adult children of the first subjects were enrolled and, more recently,
最初被试的第三代子女也加入了研究
a third generation was added to the study.
随着研究的深入 我们对于基因在心脏病方面所起的作用
And as the study continues, it’s helping us learn more about the role of genetics in
了解了更多
heart disease.
人体会进化 但发生的非常缓慢
Evolution happens very slowly.
一点点的进化要使整个人群受到影响可能要经历几代人的时间
It can take generations for a single change to spread through a population.
研究这种进化如何影响到整个人群是非常困难的
And it can be hard to study exactly how those changes spread.
与自然打交道 你不能让时间倒流来看
When you’re dealing with nature, you can’t just re-wind the clock and see if the same
同样的事情是否会发生两次
adaptations will happen again.
这也是为什么在1988年 美国生物学家理查德连斯基会培养起12种
Which is why, in 1988, American biologist Richard Lenski decided to grow 12 cultures
大肠杆菌的培养菌
of E. coli bacteria.
有一点 细菌不会活太久
The thing about bacteria is that they don’t live very long.
因此 在这30多年里 连斯基研究小组就一直不断的蓄养这些培养菌
So over the nearly 30 years that Lenski’s team has been growing these cultures,
他们已经蓄养了好几万代的培养菌
they’ve cycled through tens of thousands of generations.
在不同条件下培养菌种群发生改变的方式上
And the group has had a front-row seat in the way the populations have
该研究小组最有发言权
changed under different conditions.
由于这是一个在实验室里做的实验 所以研究员们就可以同时蓄养不同的培养菌
Since it’s a laboratory experiment, they can grow multiple cultures at the same time
然后观察它们是否能
and see if they do the same thing.
在这段时间里 大肠杆菌慢慢变大 也开始越来越频繁的发生变化 并且
Over time, the E. coli have gotten bigger, started mutating more often, and gotten better
也能越来越好的分解它们生长的培养液里的糖分
at digesting the sugar in the solution they’re grown in.
在培育了33000代培养菌后 其中一种菌自身有了一种更为复杂的变异
And around 33,000 generations in, one strain evolved a more complex mutation that allows
这使它能够分解掉柠檬酸盐(溶液中的一种混合物)
it to digest citrate, a compound in the solution,
而一般的大肠杆菌都不能完成这一点
in a way that E. coli aren’t normally able to do.
以我们的观点来看 该实验仅仅是从1988年开始的 和我刚才
From our point of view, this experiment has only been running since 1988 — which, compared
提到的其他实验比起来
with some of the other experiments I just mentioned,
这个实验根本不值一提
basically makes it a tiny baby experiment.
但是 从大肠杆菌的角度来看 它们已经生长并演化了60000代了
But from the E. coli’s perspective, they’ve been growing and evolving over 60,000 generations.
这就让这个实验成为了历史上进行时间最长的实验了 不是么
Which sort of makes it the longest-running experiment in history, right?
但是专业地说 这个实验还不能算是长久性实验
Technically, this one isn’t a long-term study … yet.
微生物学家们已经在世界上艰苦的地方奋斗了几十年了
Microbiologists have been studying life in tough places on our planet for decades, and
他们了解到 有些微生物有一种特性
they’ve learned that some microbes have a special ability:
当它们的生存条件变得及其恶劣 它们可能会生存下来 也可能会休眠或者死亡 但它们仍会
When conditions get too extreme, they can survive, dormant and dried out, while they
等待环境变好
wait for things to improve.
然后苏醒继续存活下去
Then they just wake up and go about their lives.
它们会如此往复地存活上千年 但我们依然不是
They might be able to survive this way for thousands of years, but we’re still not
完全知道它们是怎么做到这一点的
totally sure how they do it.
因此 世界上的一些研究人员成立了小组 展开了他们口中
So a group of researchers from around the globe have set up what they’re calling the
500年微生物存活史的实验
500-year microbiology experiment.
他们将一些微生物风干 用800个玻璃小瓶分成两组保存起来 放在不同的盒子里
They’ve dried out and preserved microbes in two sets of 800 glass vials different boxes.
其中 一个盒子内有铅衬以保护微生物不会收到辐射 另一个盒子只是
One box is lead-lined to protect the microbes against radiation, and the other’s just
用玻璃将它们与外界隔绝开来
using glass to keep them isolated.
这有点像前面的种子实验 但该实验没有用到沙子
It’s a little bit like the seed experiment, but with less sand,
受体是微生物而不是杂草
and microbes instead of weeds.
现在 每隔一年 研究人员就会从每个盒子里打开三个瓶子 然后给里面的微生物补充水分
For now, every other year, they’re opening up three vials from each box to rehydrate
看它们能否继续存活下来 并且分析一下DNA损伤情况
them and see if they’ve survived, and to analyze their DNA for damage.
从2038年开始 他们将每25年打开打开一次玻璃小瓶 这就意味着 假设
Starting in 2038, they’ll only open new vials every 25 years, which means that assuming
瓶中的微生物能够存活那么久并且也不会有类似僵尸天启之类的事情发生 这项实验
the microbes survive that long and there’s no zombie apocalypse, the experiment will
将会在2514年才会结束
finish up in 2514!
研究者希望这些实验的结果会让我们了解到生命在
Researchers are hoping the results of these experiments will help us understand the extremes
极端条件下的生活状态: 看简单生命体能够在
of life: how long can some of the simplest organisms survive
先被保存再被释放的情况下生活多久
being preserved and then reanimated?
对地球上在极端条件下存活的生命体了解得越多 就越能帮我们了解
Knowing more about life in the most extreme conditions on Earth will also help us learn
在其他星球上此类条件下生物发展演变的过程
more about where life could have evolved on other planets.
但该实验还有另外一方面 保存这类微生物的玻璃瓶就像
But there’s another side to this experiment, too: the vials of preserved microbes are a
一个个时间胶囊一样
sort of time-capsule.
到时候 26世纪研究微生物的研究员们将会拥有500年前
Researchers investigating them in the 26th century will have a unique snapshot of microbial
微生物群体的珍贵映像
communities from 500 years ago.
届时 能够看到它们是如何变化发展的将会是件特别有趣的事
It’ll be interesting to see what’s changed and how they’ve evolved.
不过 我们是无缘看到这些改变了
Not that we’re going to get to see those changes, though.
以后的科学家会很幸运
Lucky future scientists.
到时候将我们都已不在了
We’ll all be dead.
本段科学视频由众筹网站赞助商提供
This episode of SciShow was brought to you by our patrons on Patreon.
感谢他们 也感谢你们观看
Thank you to them, and thank you to you for watching.
Youtube.com/scishow上有很多科学视频 我们也制作了很多
There’s more SciShow, it’s at Youtube.com/scishow and we make lots more.
你可以订阅该频道 对此我们会很开心(∩_∩) 但这也意味着
You can subscribe to the channel, and that will make us feel good, but it will also mean
你的订阅频道里有大量优质科学视频 你又怎能
that you get a bunch of good science in your subscription feed, and how are you going to
对我们这个说不呢
say no to that.
订阅按钮就在视频下方
It’s a button, right under the video.

发表评论

译制信息
视频概述

该视频介绍了世界上六个进行时间最长的实验

听录译者

收集自网络

翻译译者

秋-凋零

审核员

与光同尘

视频来源

https://www.youtube.com/watch?v=ZOmt0GFXjzg

相关推荐