干细胞如何决定自己的命运？……及其他问题 [读者来信]

大家好。

Hey there, everybody.

这只是一个小提醒：如果你正在听这个，说明你没有订阅我们的会员频道，也就是说你可能会听到一些广告。

This is just a quick reminder that if you're hearing this, you aren't listening to our subscriber feed, which means that you're gonna be hearing some ads at some point.

如果你不想听这个广告或者任何其他广告，你只需要去 patreon./tumblepodcast 支付每月1美元，或者你也可以在 Apple 上加入 Tumble Plus。

If you'd like not to listen to this ad or any other ad at all, all you need to do is go to patreon./tumblepodcast and pay just $1 a month or you can join Tumble Plus on Apple.

无论哪种方式，你都可以获得无广告的订阅源，永远不用在 Tumble 上听到广告。如果你支持我们每月5美元或更多，你还可以获得生日祝福和其他各种酷炫的东西。

Either way, you get access to an ad free feed where you never have to hear an ad on Tumble and if you support us at the $5 level or higher, you can get birthday shout outs and all kinds other cool stuff.

所以请考虑加入我们，或者，你知道的，继续收听。

So please think about joining or, you know, just keep on listening.

无论哪种方式，我们都很高兴有你。

We love having you either way.

嗨。

Hi.

我是 Lindsay。

I'm Lindsay.

我是马歇尔。

And I'm Marshall.

欢迎收听《翻滚》，这个节目探索科学发现的故事。

Welcome to Tumble, the show where we explore stories of science discovery.

今天，我们有一期超棒的听众来信特辑。

Today, we have an amazing mailbag episode.

我们会回答听众关于干细胞、变色龙和摩尔斯电码的问题。

We'll be answering listener questions about stem cells, chameleons, and Morse code.

这三样东西，我猜它们之间有很多联系吧。

Those are three things that I guess have a lot to do with each other.

是吗？

Do they?

还有，别忘了你的听众评论和评价。

Also, forget your listener comments and reviews.

好了。

Alright.

那么，实际上在我们收到听众评论和反馈之前，我们有一些事情想和大家聊聊。

Well, so actually before we get to our listener comments and reviews, we got a few things that we wanna talk to you all about.

有令人兴奋的事情要分享。

Exciting things to share.

这个夏天我们这里可没闲着。

It hasn't been quiet around here for summertime.

是啊。

No.

确实没闲着。

It really hasn't.

说实话，我都有点累了。

And kinda I'm honestly getting kinda tired.

我都盼着开学了。

I'm ready for school to start.

不过话说回来，我整个夏天都在跑图书馆。

But anyway, I've been doing library visits all summer.

我一直在新英格兰和东北部地区为观众表演，真的超级好玩。

I've been performing for audiences around New England and the Northeast, and it's been just like super fun.

超级好玩。

It's been super fun.

我前几天去了新泽西。

I've been, I went down to New Jersey the other day.

我还去了缅因州。

I was up in Maine.

我很快就要去马萨诸塞州的皮茨菲尔德了。

I'm gonna be down in Pittsfield, Massachusetts pretty soon.

他不是在环游世界，而是在东北部转悠。

He's just Northeast trotting instead of globe trotting.

对。

Yeah.

美国东北部。

Northeast US.

一方面

One way

另一方面，我一直在图书馆做小型表演，唱几首歌。

or the other, I've been showing up in libraries doing a little show, singing some songs.

真的很有趣。

It's been so fun.

如果你想让我去你的图书馆唱歌、讲故事，或者做我做的那些事，就去 sciencepodcastforkids.com 看看，那里有各种信息告诉你如何安排。

If you want me to come to your library and sing some songs and tell some stories and whatever it is I do, just go to sciencepodcastforkids.com where you can see all kinds of information about how to make it happen.

而且，我也会把日期公布出来。

And, also, I'll be putting dates up.

所以如果你在附近，可以来看我。

So if you're in the area, you can come see me.

好的。

Okay.

那么，Marshall，当你在做图书馆访问的时候，我一直在准备我们的新一季。

So, Marshall, while you've been doing library visits, I've been working on our new season.

不只是你。

Not alone.

我也一直在做。

I've been doing it too.

是的。

Yes.

在你回来的那段时间里。

In the periods when you're back.

我们收到了一些很棒的听众提问，由杰出的科学家们解答，这些访谈真的让我大开眼界。

We've got some amazing listener questions that have been answered by incredible scientists, and these interviews have truly blown my mind.

所以现在提交你的问题还不晚，为下一季做准备。

So it's not too late for you to submit your question for this next season.

事实上，马歇尔，是的。

In fact, Marshall Yes.

你将主持一场与听众的连线活动。

You're gonna be hosting a call with our listeners.

没错。

That's right.

8月13日星期四，与Patreon会员一起提交和讨论问题。

On Thursday, August 13 with Patreon members to submit and discuss questions.

我们会把它搞得很搞笑，我敢肯定。

We'll we'll, make it silly, I'm sure.

肯定会很搞笑，因为Marshall本身就挺搞笑的。

It's gonna be silly because Marshall's pretty silly.

我不知道你有没有从这些集里看出来。

I don't know if you've gotten that through the episodes.

但如果你是Patreon会员，你只需在Patreon上关于活动的帖子下评论即可RSVP，我们会在节目描述里放链接。

But if you're Patreon member, you can just RSVP by commenting on the post about the event on Patreon, which we'll link here in the episode description.

如果你还不是Patreon会员，你可以注册任意级别。

And if you're not a Patreon member yet, you can sign up at any level.

所以每月只需1美元，就能加入Marshall的这次通话。

So that's just $1 a month even to join Marshall on the call.

我觉得这会勾起大家的好奇心，而且会很好玩。

I think this is gonna, like, get people's curiosity going, and it's gonna be a fun hang.

谁知道呢？

And who knows?

说不定你会在我们的节目里听到科学家回答你的问题。

You might hear your question answered by a scientist on our show.

好了，你准备好听听众的评论和反馈了吗？

Well, are you ready to do some listener comments and reviews?

我等不及了。

I can't wait.

这是我最喜欢的部分。

This is my favorite part.

好的。

Okay.

所以，在我们看苹果评论之前，我想说点事。

So, before we do the Apple reviews, I I wanna say something.

我记得我每次都说我们卡在4.3星了，是的。

I remember I I've been saying every time that we are stuck at 4.3 stars on Yeah.

这是你的执念。

This is your obsession.

我想让我们升到4.4。

And I want us to get to 4.4.

好吧，所以我坐下来算了算。

Well, so I've sat down with, some math.

我做了些计算，发现我们需要450个新的五星好评才能升到4.4。

I I did some math, and I figured out that we need 450 new five star reviews to get up to 4.4.

所以……

So

我没想到这个野心会带我们到这么高的目标。

I had no idea the ambition was going to, lead us to such a lofty goal.

但是……

But

总之，450条新评论，而我们自从上次录节目以来只收到了大约10条。

Anyway, 450 new reviews and we have I I we got, like, 10 since the last one of these.

所以，你知道的，我们正在路上。

So, you know, we're on the way.

我们正在路上。

We're on the way.

千里之行，始于足下。

Every journey begins with the first step.

好的。

Alright.

那么，你想读第一条评论吗？

Well, so do you wanna read this first review?

当然。

Sure.

好的。

Okay.

标题是《我爱冥王星和翻滚，来自史上最烂的应用》。

It is titled I love Pluto and Tumble by the worst app ever.

那它给了几颗星？

And how many stars is it?

五颗。

Five.

五星好评。

Five star review.

谢谢。

Thank you.

谢谢。

Thank you.

史上最烂的应用。

The worst app ever.

嗨，马歇尔和林赛。

Hi, Marshall and Lindsay.

爱心表情，星星表情。

Heart emoji, star stars emoji.

那只是很多表情符号。

That's just a lot of emojis.

对。

Yeah.

Tumble让我学到了很多科学知识。

Tumble has let me learn so much about everything science.

科学表情。

Science emojis.

你们能不能多做几集天文学，还有一集关于月球形成的？

Can y'all make more astronomy episode and one about Luna, the moon's formation?

还有，矮行星也是行星，行星表情。

Also, dwarf planets are planets, Planet emoji.

还有水獭，水獭表情，并不邪恶。

And otters, otter emoji, are not evil.

你们能不能做一期叫《寻找X行星》的节目，讲讲X行星以及为什么我们认为它是行星？

Can y'all make an episode called The Hunt for Planet X about Planet X and why we think it's their planet emojis.

我们到了。

There we are.

所以我选这个评论，是因为我觉得那个动物邪恶的说法开始流行起来了。

So I chose this one because I think the the animal evil thing is, catching on.

我很高兴一个新物种，对，

I'm glad that a new species Yeah.

在我们的评论里得到了辩护。

Is being defended in our comments.

为水獭挺身而出。

Stand up for otters.

我相信你们。

I believe in you.

好的。

Okay.

我能做下一个吗？

Can I do the next one?

可以。

Yes.

这个叫“树放屁”。

This one is called trees farting.

最受欢迎的一集。

A favorite episode.

最受欢迎的一集。

Favorite episode.

来自AM 1-3-45的五星好评，那是个系外行星吗？

Five stars from AM one three dash 45, which is that an exoplanet?

也许吧。

Maybe.

我们最初是通过Yodo卡片发现这个播客的，我无法告诉你我五岁的孩子每天重复多少次“树放屁”的故事。

We first discovered this podcast via the Yodo cards, and I can't tell you how many times per day my five year old repeats the trees farting story.

很高兴播客里还有更多这样的内容。

So glad there's more of this on podcasts.

是的。

Yes.

我们有恐龙打嗝。

We have dinosaurs burping.

我们还有

We have

树放屁。

Trees farting.

对。

Yeah.

我们有动物拉屎。

We have animals pooping.

没错。

Yep.

这就是我们在Tumble播客上做的事情。

That's what we do here on Tumble.

而且知道有人在Yodo上收听然后转到我们的播客，这真的很酷。

And also really, really cool to know that people are listening on Yodo and then coming over to our podcast.

好的。

Alright.

我们还有一条来自家长的苹果播客评论，我很喜欢。

And we have one last Apple review from a parent, which I love.

标题是“Fantastic”，作者是Vin r，我就不念那个名字了。

It's titled Fantastic by Vin r I'm not gonna say that.

是Vin r h c x k k。

It's Vin r h c x k k.

就像Charlie x c x，但更复杂。

It's like Charlie x c x, but more complicated.

精彩、有趣、有教育意义。

Fantastic, delightful, educational.

作为家长，我被采访柯伊伯带发现者的那期节目所启发，很喜欢和孩子们聊这个话题。

As the parent, I'm inspired by the one interviewing the as the parent, I'm inspired by the one interviewing the discoverer of the Kuiper Belt and love talking about it with my kids.

这里还有很多其他精彩的评论。

There are so many other fantastic ones here.

非常感谢。

Thank you so much.

我真的很喜欢柯伊伯带那一集。

I really love the Kuiper Belt's episode.

那一集叫做《太阳系边缘的探索》。

That one was called the search at the edge of the solar system.

还有简·卢，她是柯伊伯带的发现者或共同发现者，我经常想起她。

And Jane Lu, who is the discoverer or the co discoverer of the Kuiper Belt's, I think about her all the time.

她非常鼓舞人心，我们想分享更多她的故事，也很高兴大家收听。

She is so inspirational, and we wanna share more of her story and glad that people are listening.

是的。

Yeah.

对。

Yeah.

她太棒了。

She's amazing.

我觉得她特别酷。

I I thought she was super cool.

是的。

Yes.

好的。

Alright.

好了，我们稍作休息，马上回来回答听众的问题。

Well, we are going to take a quick break, and we'll be back with listener questions.

这里有一条给家长的消息。

Here's a message for the parents.

Tumble节目由IXL赞助播出。

Tumble is brought to you with support from IXL.

八月是慢慢恢复学习习惯的最佳时机，而IXL可以帮助在家上学的家庭通过结构化的个性化练习，从第一天起就建立信心，为新学年开个好头。

August is the perfect time to ease back into a learning routine, and IXL can help homeschool families start the year strong with structured, personalized practice that builds confidence from day one.

IXL是一个屡获殊荣的在线学习平台，能完美融入家庭教育。

IExcel is an award winning online learning platform that fits seamlessly into homeschooling.

它提供从学前班到十二年级的数学、语言艺术、科学和社会研究等互动练习。

It offers interactive practice across math, language arts, science, and social studies from pre K through twelfth grade.

它还为学习者提供实时反馈，随着孩子的学习进度，个性化调整教学和练习内容。

It also offers learners real time feedback, personalizing instruction and practice exercises as kids learn.

在我们家，我们一直用IXL鼓励孩子们整个夏天保持挑战和更新，为新学年的挑战做好准备。

In the Tumble household, we've used iXL to encourage our kids to stay challenged and up to date all summer long to get ready for a new challenging school year.

IXL的内容按年级和科目组织得井井有条，所以你总能找到适合你孩子的内容。

IXL's content is well organized by grade and subject, so you can always find something that's right for your kid.

为孩子的学习带来积极影响。

Make an impact on your child's learning.

现在就获取IXL吧。

Get IXL now.

Tumble科学播客的听众今天在ixl.com/tumble注册，可以享受IXL会员20%的独家折扣。

And Tumble Science Podcasts for Kids listeners can get an exclusive 20% off IXL membership when they sign up today at ixl.com/tumble.

访问ixl.com/tumble，以最优惠的价格获得最有效的学习计划。

Visit ixl.com/tumble to get the most effective learning program out there at the best price.

世界上发生了太多事情。

There's so much happening in the world.

如果你有特别好奇的孩子，回答他们的问题可能会很难。

And if you have particularly, shall we say, inquisitive kids, it can be hard to answer their questions.

嗨。

Hi.

我是Ryan。

I'm Ryan.

我是Bridget。

And I'm Bridget.

我们主持《百万富翁》节目，这是Marketplace出品的一档关于金钱的播客，面向孩子和他们的家庭。

And we host Million Bazillion, a podcast from Marketplace about money for kids and their families.

我们帮助你的小家伙们深入思考一些重要但棘手的话题，比如税收、油价，甚至无现金社会会是什么样子。

We help your little ones think big about important but tricky topics like taxes, gas prices, and even what a cashless society might be like.

现在有很多新剧集上线了，所以去你最喜欢的播客应用上收听《百万富翁》吧。

There's a bunch of new episodes out now, so go listen to million bazillion on your favorite podcast app.

好的。

Okay.

我们回来了，接下来要回答一些听众的问题。

And we are back, and we're gonna do some listener questions.

第一个问题来自本。

So this first one came to us from Ben.

你好。

Hello.

我叫本，今年九岁。

My name is Ben, and I am nine years old.

我想知道干细胞是如何选择它们要变成哪种细胞的。

And I want to know how do stem cells choose which cell they want to become.

首先，我真的很喜欢干细胞有那种，嗯，像圣诞愿望一样的想法。

First of all, I really like the idea of stem cells, like, having, like, Christmas wishes.

我能变成一只蟾蜍吗？

Could I be a toad?

好吧，不管怎样，这其实是我对这集最期待的部分，因为我有机会和杰西卡·怀特德交谈，她是哈佛大学的科学家，专门研究这类事情，她非常棒，非常酷，我完全被震撼了，我们进行了一次非常棒的对话。

Well, anyhow, so this is actually the thing that I am most excited about for this episode because I got to talk to Jessica Whited, who is a scientist at Harvard who studies exactly this kind of thing, and she is amazing and so cool, and I was so blown away, and we had an amazing conversation.

而且我从来没能和科学家交谈过，因为琳赛把他们都霸占了。

And I never get to talk to scientists because Lindsay hoards that.

我确实霸占科学家，而且我要说，我首先和杰西卡谈了关于蝾螈如何教人们重新长出手指、手、手臂和四肢的那一集。

I hoard scientists, and I will say that I talked to Jessica first for the episode about how axolotls could teach people to grow back fingers and hands and arms and limbs.

这就是她的回答。

And this is her answer.

所以

So

干细胞有很多方法可以弄清楚周围发生了什么。

stem cells have a bunch of ways that they can figure out what's going on around them.

通常，干细胞会接收到来自其他细胞或损伤部位的某种信号，这就像是一种指令，告诉干细胞该怎么做。

And usually some kind of signal from another kind of cell or from an injury will get received by the stem cell and it kind of is like a destruction and it tells the stem cell what to do.

有时候，干细胞会收到一个信号，说：嘿，因为受伤了，我们需要更多某种特定的细胞。

And sometimes the stem cell will receive a signal that says, hey, we need more of this certain kind of cell because there was an injury.

然后干细胞通常会分裂。

And then what the stem cell usually does is it divides.

所以它由一个变成两个细胞，通常会保留一个作为未来的干细胞，另一个则接受指令去变成所需的那种缺失细胞。

So it makes two cells when there had only been one before and it will often reserve one as a future stem cell and the other one will get the instructions to go and become the kind of missing cell that is needed.

对。

Yeah.

所以它们就像是在偷偷接收来自其他细胞的小消息、小说明书一样。

So they're like getting little they're secretly getting little messages, little instruction manual messages from from other cells usually.

太可爱了。

That's so cute.

就像我们身体里所有这些小细胞都在等着，然后它们说：我们要做什么呢？

It's like all of these little cells are just like waiting in our bodies and they're like, what are we gonna do?

好的。

Alright.

该分裂了，我去做这个，然后你等着。

It's time to divide and I'll go do this, and then you wait.

你在这里等下一个信号。

You wait here for the next signal.

这有点像他们在课堂上传递纸条。

It's sort of like they're passing notes in class.

没错。

Exactly.

但是，她说了什么，这些信号实际上是怎么运作的？

But like, what did she say, like, what is the actual way that these signals work?

她当然对此有一些答案。

She, of course, had some answers about that.

基本上，指令信号的传递方式有点像玩传话游戏。

It's basically like the instruction signal gets sent in a way kind of like playing a game of telephone.

这个信号会一直传到细胞核里。

It goes all the way into the cell's nucleus.

然后它会让干细胞核做出新的决定。

And then it will make the stem cells nucleus make new decisions.

比如，它可能会关闭一些之前开启的基因，同时开启一些之前关闭的基因。

Like it might turn off some genes that had been on before and turn on some genes that had been off before.

然后它就会有一个计划，根据收到的信号来改变自己。

And then it'll have like a plan for how it's going to change in response to the signal that it got.

所以，细胞核是细胞中做出所谓“下一步会发生什么”的决定的重要部分。

So it's the nucleus which is a big part of the cell making quote unquote decisions for what's gonna happen next.

这真的很酷。

That is really cool.

确实很酷。

It's really cool.

想到我们身体里每天都在发生这样的事，真的很酷。

It's cool to think that's happening in our bodies every day.

对吧？

Right?

所以我和杰西卡的对话其实持续了大概四十分钟，因为她告诉我这些之后，我又问了一大堆问题，比如如果我想在背上长出巨大的皮膜蝙蝠翅膀，我该怎么做？

So my conversation with Jessica actually went on for, like, forty minutes because after she told me this, I had a ton more questions, like, including what would I do if I wanted to grow big leathery bat wings on my back?

你为什么想要那个？

Why did you want that?

谁不想要呢？

Who doesn't want that?

我。

Me.

我不想让你那样。

I don't want that to happen to you.

我们会把整个视频放到Patreon上。

We'll be putting that whole video up on Patreon.

所以如果你在patreon.com/tumblepodcast订阅，你就能看到完整的采访，包括那个问题的答案：你能用干细胞在背上长出巨大的皮膜蝙蝠翅膀吗？

So if you subscribe at patreon.com/tumblepodcast, you'll be able to see the whole interview, including the answer to the question, can you use stem cells to grow big leathery bat wings on your back?

好的。

Okay.

那我们下一个问题是什么？

So what is our next question?

下一个问题来自卡门。

Our next question comes to us from Carmen.

嗨。

Hi.

我叫卡门。

My name is Carmen.

我八岁了，我的问题是，变色龙是怎么变色的？

I'm eight years old, and my question is, how do chameleons change their color?

我觉得是因为它们体内有一种其他动物没有的化学物质。

I think it's because they have, like, a certain chemical in their body that other creatures don't have.

我觉得科学家们可以通过观察变色龙的身体来弄清楚这个问题。

I think how scientists would figure it out figure it out by looking in a chameleon's body.

好的。

Okay.

那么，为了回答卡门的问题，我采访了米歇尔·米林科维奇博士，他实际上研究了变色龙为什么会变色。

So to answer Carmen's question, I talked to doctor Michel Milinkovich, who actually studied why chameleons change colors.

而答案并不是我原本想的那样。

And the answer wasn't what I thought it would be.

在我们揭晓答案之前，米歇尔首先想纠正一些关于变色龙变色的误解。

So before we get into what the answer is, first, Michel wanted to correct some myths about chameleons changing colors.

它们不能随心所欲地变成任何颜色。

They cannot take any color they want.

那是个误解。

That is a myth.

顺便说一下，不是所有变色龙都能变色。

Not all chameleons, by the way, can change color.

不是所有种类都能有效地做到这一点。

Not all the species are able to do that efficiently.

但是变色龙，特别是我们研究最多的豹纹变色龙，非常厉害，因为它们能很好地伪装自己。

But the panther chameleon, which is really the species we have been studied the most, is spectacular in the sense that it can be very cryptic.

所以很难在树上找到它们。

So it's very difficult to find them in trees.

相信我，我说很难找到，是真的很难。

And believe me, when I say it's very difficult, I mean it.

我去过那里。

I've been there.

我走遍了马达加斯加。

I've been all around Madagascar.

有时候它们就在你面前50厘米的地方，你却看不见。

And sometimes they're just right there, 50 centimeters from you, and you don't see them.

听起来变色龙真的让他的“找找看”游戏很难玩。

So it sounds like the chameleons are really messing up his game of I Spy.

是的。

Yes.

它们就不能更容易被发现吗？

Couldn't they be easier to find?

不能。

No.

这就是它们的特点。

That's their whole deal.

它们是伪装大师，因为它们通常的绿色和周围环境融合得很好。

They are masters of camouflage, but it's because the green color that they usually are blends in so well with their surroundings.

而当它们变色时，反而更容易被发现。

And when they change, they're actually easier to find.

一旦你看到了它，当然，你会被这种动物惊艳到，并且充满热情地看着它，对吧？

Once you have seen it, of course, you are amazed by the animal and you are looking at it with passion, right?

但如果另一只雄性进入这棵树，它就会生气，想要保护自己的树，不希望其他雄性在那里。

But then if another male enters the tree, then it gets angry and it wants to protect its tree and doesn't want any other male to be there.

所以它会变色，变得非常显眼。

So it changes color and becomes very visible.

它会变得亮很多，黄很多，橙很多。

It becomes much more bright, much more yellow, much more orange.

然后你就能看得很清楚了，真的。

Then you see it very well, actually.

好。

Okay.

它们只有两种颜色，要么是非常隐蔽的绿色，可能带一些深色的条纹。

And that's the two colors they can take either very cryptic, greenish with some maybe darker bands.

但一旦它们生气，就会变得很黄，比如这样。

But then when they get angry, they become very yellow, for example.

它们就只能这样了。

And that's all they can do.

它们不能变成你想要的颜色。

They cannot take any color you want.

那不是真的。

That's not true.

那是个误解。

That's a myth.

这就像有人离我的玉米片太近时我的反应一样。

So it's kinda like me when someone gets too close to my nachos.

我会变成亮紫色，然后冲他们大喊大叫。

I turn bright purple and start screaming at them.

很高兴知道变色龙对它们的树也有同样的感觉。

It's nice to know chameleons feel the same way about their tree.

是的。

Yes.

那么，卡门的问题的答案是什么呢？

So but what's the answer to Carmen's question?

嗯，这有点复杂。

Well, it's a bit complicated.

变色龙通过调节它们特化细胞（称为虹膜细胞）中微小的鸟嘌呤晶体之间的距离来改变颜色。

So chameleons change color by tuning the distance between the tiny, tiny crystals of guanine that they have in their specialized cells called iridophores.

这会改变这些细胞的特性，使它们反射不同的颜色。

And this is changing the property of these cells that are reflecting different colors.

所以，比如它们不再只反射绿色和蓝色，而是会反射更长的波长。

So instead of reflecting, for example, only green and blue, they will reflect longer wavelengths.

那些就是变色龙愤怒时更强烈的颜色。

And those are the more strong colors of the chameleon's anger.

是的。

Yes.

当然。

Absolutely.

没错。

Absolutely.

现在我们还在研究其他方面，比如色素可能也起作用。

Now we are also investigating other aspects, how pigments also might play a role.

我们现在正在研究这个，是的。

We are into studying this now, yes.

好的，所以变色龙有魔法水晶，它们会在皮肤里移动或者什么的？

Okay, so chameleons have magic crystals and those move around or something in their skin?

我，我很抱歉。

I I'm sorry.

我，我有点糊涂了。

I'm I'm confused.

它们不是魔法水晶。

They're not magic crystals.

它们只是很神秘。

They're just mysterious.

哦，好的。

Oh, okay.

好的。

Okay.

所以变色龙产生颜色的方式真的很有趣，因为在很多动物中，是叫做色素的东西负责颜色。

So the way that chameleons produce color is really interesting because in many animals, it's something called pigments that are responsible for colors.

可能我们很多听众之前都听说过这个。

And maybe a lot of our listeners have heard about that before.

对。

Yeah.

色素就像让颜料有颜色之类的东西。

Pigments are like what makes a paint have color and stuff like that.

没错。

Exactly.

但迈克尔发现变色龙变色的主要方式完全不同。

But Michael discovered that the main way that chameleons change color is totally different.

它们实际上是改变皮肤里那些特殊神秘晶体的细胞结构。

They actually change the structure of the cells in those special mysterious crystals that are embedded in their skin.

这些细胞和晶体反射光线，而不是像色素那样吸收光线来产生颜色。

And those cells and crystals reflect light back rather than absorbing light to create color the way that pigments do.

那真有意思。

That's really interesting.

是的。

Yeah.

这很吸引人。

It's fascinating.

而且这其中的内容远不止这些。

And there's like a lot more to it than that.

但这就是基本的答案。

But that is the basic answer.

我觉得我们还在研究变色龙如何变色，这真的很酷。

And I thought it was really cool that we are still studying how chameleons change their colors.

对。

Yeah.

还有很多未知的东西。

There's still a lot to know.

所以听众朋友们，也许有一天，你们长大后会成为研究变色龙的突破性科学家。

So maybe listeners, someday, you'll be a chameleon breakthrough scientist when you grow up.

对。

Yeah.

好的。

Alright.

我们准备好回答最后一个问题了吗？

Are we ready for our final question?

我完全准备好了。

I am so ready.

你好。

Hi.

我叫安妮。

My name is Annie.

我九岁了。

I'm nine years old.

我的问题是，什么是摩尔斯电码？

And my question is what is Morse code?

我觉得这个问题问得很好，但它其实更像是一个历史问题，而不是科学问题。

I thought that this was a great question, but it's not really a science question as much as a history question.

所以就像很久以前那个花生酱和果冻的邮件袋一样，我问了我们的好朋友米克。

So just like with the peanut butter and jelly mailbag from however long ago, I asked our good friend Mick.

就是《过去与好奇》里的米克。

Mick from the Past and the Curious.

他说了什么？

What did he have to say?

这就是他说的。

Here it is.

嘿。

Hey.

我是《过去与好奇》的米克，这个问题问得真好。

It's Mick from The Past and the Curious, and what a great question that is.

摩尔斯电码是一种迷人的通讯方式，最早可以追溯到1838年，但到了19世纪60年代就变得相当普及了，而且今天还在使用一些。

Morse code is a fascinating way of communicating that dates all the way back to 1838, but became pretty universal by the eighteen sixties, And it's still used a bit today.

其实，我最近和家人一起读了一本书，叫《天才神秘会社》，书里的孩子们真的会用手电筒闪烁来发送摩尔斯电码。

Actually, I've read a book recently with my family called The Mysterious Benedict Society, and the kids in that book actually use Morse code by flickering flashlights.

非常酷。

Very cool.

总之，摩尔斯电码是以塞缪尔·摩尔斯的名字命名的，他是远距离传送信息的先驱。

Anyway, it's named after Samuel Morse who was a pioneer in sending messages over long distances.

你知道，当时人们已经厌倦和沮丧于等待信件通过陆路或船只运送。

You see, people were tired and frustrated of waiting for letters to be carried over land or by ship.

那太慢了。

That was very slow.

而且电话还远未被发明，所以人们就在各地之间安装了电报电缆，用来传输电信号。

And the telephone was a long way from being invented, so telegraph cables were installed from place to place that carried an electrical signal.

你没法通过这些电线通话，但你可以发送信号或不发送信号。

You couldn't talk over these wires, but you could send a signal or not send a signal.

这就是电报键和接收器的用武之地。

And that's where telegraph keys and receivers come in.

通过敲击一个小小的电报键，人们就能通过电缆把电信号传到其他地方。

By tapping a little telegraph key, people could send an electrical signal to somewhere else over the cable.

在那里，借助电磁铁，接收器会重复从别处传来的按键敲击声。

And there, thanks to electromagnets, the receiver would repeat the taps of the key sent from elsewhere.

所以人们必须为整个字母表开发一种编码，用不同的敲击序列来表示所有字母。

So people had to develop a code for the entire alphabet that could make all of the letters out of a different series of taps.

通过混合长敲击（称为划和长音）和短敲击（称为点和短音），莫尔斯和他的同事们创造了莫尔斯电码字母表。

So by mixing long taps called dahs and dashes or short taps called dits and dots, Morse and his colleagues created a Morse code alphabet.

消息必须一个字母一个字母地发送，但这仍然比通过陆路实际递送便条或信件要快得多。

Messages would have to be sent letter by letter, but it was still way faster than physically sending a note or a letter over land.

多年来，人们制造的电报电缆已经长到可以横跨整个大陆，或者铺设在海底，连接欧洲和美洲。

Over the years, people made telegraph cables long enough to stretch across an entire continent or run under the ocean connecting Europe to America.

后来，像马可尼这样的科学家成功创建了这种系统的无线版本。

Then scientists like Marconi were able to create wireless versions of this system.

如今，现代电信让人们可以用更简单的方式发送消息，这些方式不需要学习新的字母表，这对我们所有人来说都容易多了。

And today, modern telecommunications allow people to send messages in much simpler ways, ones that don't involve learning a new alphabet, which is a whole lot easier for all of us.