评论
打印
We've had the technology to reuse rockets for decades now; they were a staple of the Shuttle days.
几十年前，我们就具备重新利用火箭的技术了，那个时代是航天时期的重要组成部分。
But the Shuttle's solid rocket boosters weren't too impressive in their return home.
但航天飞机的火箭助推器在返回地球时并不是很惊艳——
They just splashed down into the ocean. Now we're in the era of rockets that can land themselves on floating platforms.
只是冲入大海中而已。如今，火箭已经可以靠自己着陆在浮式平台上了。
But that's a tricky feat, and those tiny legs at the bottom have to withstand a lot of force in the process.
但这个过程也只是看起来轻巧而已，其实底部的那些支脚在着陆的过程中需要承受巨大的冲击力。
So one team of engineers is trying to develop a new material that could lessen that force, and in turn, soften that dangerous landing.
于是，一组工程师正在努力研发一种新型材料以减缓这种冲击力，继而减小着陆的危险系数。
Last week in the journal Science Advances, they showed how they were inspired by the ancient art of paper folding: origami.
上周，《科学进展》 期刊上，这组工程师发表的文章中写道，他们受到了一种古老折纸艺术的启发—— 日本折纸艺术。
Researchers based at the University of Washington decided to try counteracting the compression waves, basically a pushing force, that would travel through a material during a collision.
这些研究人员来自华盛顿大学，他们决定尝试抵消压缩波的冲力。压缩波是一种推力，在碰撞过程中，压缩波可以穿透物质。
Like when the legs of a rocket hit the landing pad.
就像火箭腿在着陆架上着陆一样。
For that, they designed a type of mechanical metamaterial.
为了缓冲着陆的过程，这些研究人员设计了一种机械超材料。
Metamaterials are a type of artificial material built from repeating units, think Lego bricks, that engineers can manipulate to create new properties.
超材料是一种人工材料，从重复单元制造而得，跟乐高积木的原理类似。工程师可以用这种材料来实现新的特性。
It's figuring out what those bricks need to look like that's the tricky part. That's where the origami comes in.
敲定超材料的形态是棘手的难题。这时候，他们想到了日本折纸艺术。
This team used a laser cutter to form a specific pattern of creases in a piece of paper, then folded that into a cylinder-esque shape.
该团队通过一种激光切割机将一张纸分成了不同的折痕样式，然后将纸张折叠成圆筒的形状。
On either end they glued an acrylic hexagonal cap.
每一端都是粘上六角形的帽子。
So when the cap was pushed on, the cylinder buckled in a pattern determined by the creases.
帽子行进的过程中，圆筒就会扣上一个由折痕确定的样式。
But it could also spring back into its original shape. They linked 20 of these cylinders together in a column.
但超材料会反弹成一开始的形状。他们将20个这样的圆筒连成一排。
Then they subjected their column to compressive forces. And their column was able to transform that push into a pull.
然后，他们将对这一排圆筒施加压缩力。然后这一排圆筒就将推力变成了拉力。
See, even as the column was compressed, each little cylinder also resisted that push and straightened out slightly.
大家发现了吗？即便这一排受到了压缩力，每一个圆筒也会抵抗这个推力，从而产生些微的抵消力。
This created a pull within the structure, or what's technically known as a rarefaction.
这就使得结构内部产生了拉力，也就是专业上所说的稀疏。
And as both the push and pull propagated along the column, the pull actually traveled faster, so the whole structure resisted being squished.
在推力和拉力传播的过程中，拉力的速度越来越快。于是整个结构就会产生抵抗力，避免被压爆。
What's also cool about this research, besides the whole origami rocket part, is that previous strain-lessening methods required hundreds of metamaterial units.
除了火箭上利用折痕的部分，这项研究还有一个新颖的点：此前用于减少冲击力的方法都需要上百个超材料单元。
This new origami structure needed only ten. There are some limits to the research, though.
而新采用的日本折纸结构只需要10个超材料单元。不过，该研究也有一些局限之处。
The team only looked at the system in one dimension.
该团队只从一个维度观测了该系统。
Also, they had to do the paper folding themselves, so, any real-world application of this tech is going to need to develop beyond that.
他们还得亲自折纸，因为现实世界的应用远不止于折纸而已。
But this new method doesn't need to be limited to rockets, it could be applied to all sorts of situations where collisions are involved, like designing helmets.
不过，这种新方法不需要局限于火箭上，也可以应用于各种情境，只要有碰撞发生的，都可以。比如制作头盔的过程就可以用上。
It's a new way to protect against all sorts of dangers.
这是一种新方法，可以避免各种危险。
And another, more astronomical danger was in the news this week.
本周，有关太空危险的消息还有一条。
Coronal mass ejections, or CMEs, are a stream of high-energy particles thrown off the Sun with little warning.
日冕物质抛射（CME）是太阳发射的一种高能粒子，在发射前没有什么预兆。
They're the most powerful magnetic anomaly our star creates, and when the particles reach us they can interfere with electrical equipment,
CME是太阳产生的能量最为强大的磁异常现象，一旦抵达地球，会干扰电子设备，
including satellites and, if the CME is powerful enough, things like radio transmission down here on Earth.
比如卫星。而如果CME足够强大，就连地球上的无线电传输也会受到干扰。
They can often accompany solar flares. But our Sun isn't the only star that creates these blasts.
CME通常伴随太阳耀斑出现。不过，太阳并不是唯一能够产生太阳耀斑的恒星。
And this week in the journal Nature Astronomy, astronomers have turned their attention to coronal mass ejections coming from something other than our sun.
本周，在《自然天文学》上，天文学家将注意力转移到了CME身上，不过这次，发射CME的并不是太阳。
A team based out of Palermo, Italy used the Chandra observatory to study the x-ray light emitted from the star dubbed HR 9024, which is located about 450 light years away.
一个来自意大利巴勒莫的团队通过钱卓拉太空观测站研究了HR 9024恒星发射的X光线。这颗恒星距离我们450光年。
It's also a bit bigger than our Sun, as well as a bit hotter, so bluer.
这颗恒星体积比太阳大一些，温度更高一些，颜色更蓝一些。
But most importantly, it's considered active, meaning it emits way more energy per second on average.
不过，最重要的是：这颗恒星十分活跃，也就是说，它平均每秒释放的能量更多。
And they spotted a flare, analogous to a solar flare, coming from this star.
而且，他们观测到这颗恒星上有与太阳耀斑类似的存在。
By analyzing the star's spectrum, or its light signature, they were able to identify specific elements present in the flare.
通过研究该恒星的光谱，他们确认了该恒星耀斑上的特定元素。
Different elements show peaks in the spectrum at different wavelengths.
不同元素在不同光谱的不同波长上有不同的峰值。
In order to separate what's coming from the star's atmosphere and the actual CMEs, they used the Doppler effect.
为了分隔该恒星的抛射与CME，他们使用了多普勒效应。
This is the same effect that makes an ambulance siren coming toward you sound higher pitched, and one moving away from you sound lower.
多普勒效应的原理跟救护车鸣笛声的音调同理：离我们越近的救护车，其鸣笛声越尖锐；离得越远，鸣笛声越低沉。
Light or sound waves moving toward us are compressed relative to us, and those moving away get stretched out.
与此相似：向我们移动而来的光或者声音相对压缩，而离我们远去的则相对拉伸。
For sound, that changes the pitch; for light, the color.
对声波来说，距离的远近会改变音调；对广播来说，距离的远近会改变颜色。
So a light source moving toward us gets bluer, and moving away, gets redder.
因此，朝我们移动的光源，颜色会更蓝一些；而离我们远去的光源，颜色会更红一些。
By tracking specific peaks in HR 9024's spectra, comparing where they should be if they're not being ejected to where they appear, the astronomers could tell which elements were moving toward or away from us.
通过追踪该恒星光谱的特定波峰，并对比抛射方向变化后它们出现的地方，科学家就能辨别出哪些元素是向我们移动，而哪些是离我们远去。
And that's the material that's in the flare. They found sulfur, silicon, and magnesium inside a giant plasma loop, associated with the solar flare.
他们观测的是耀斑中的物质。他们在一个巨大的等离子体闭环中发现了硫、硅、镁，跟太阳耀斑类似。
On top of that, there was an additional line of oxygen that was cooler and out of step with the flare.
除此之外，他们发现了另一种氧，其温度更低，与耀斑不同步。
That, the researchers think, indicates the presence of a CME.
科学家认为，它的存在表明了CME的存在。
Based on that assumption, they estimated that CME's mass: about one billion billion kilograms.
基于该假设，他们估测，CME的质量大概在100亿公斤。
But they weren't able to determine if any of that mass successfully escaped the star's gravitational pull and would go forth to irradiate hypothetical planets.
但他们无法确定这100亿公斤重是否有哪些部分成功地逃脱了该恒星的引力作用，并照耀其他可能的行星。
In comparison with CMEs from our Sun, it released more energy, but not nearly as much as they had predicted.
在与太阳的CME对比后发现，它会释放出更多的能量，但跟科学家预测的量不一致。
This is just one initial step in actually investigating how stars different from our Sun behave.
这只是我们研究其他恒星与太阳差异的第一步而已。
Math only gets us so far, and this result might mean stellar CMEs are more different than we thought they'd be.
数学手段目前只能允许我们推测到这一步，这个结果可能意味着恒星的CME跟我们曾经的看法不一样。
Which could mean a lot of things, and even, theoretically, influence the development of life on those stars' planets.
从这一点，我们能推断出很多，甚至这一点会影响到这些恒星所有行星上的生命。
Thanks for watching this episode of SciShow Space News,
感谢收看本期的《太空科学秀》。
and thanks to our great Patreon supporters who help us make episodes like this.
感谢我们的忠实粉丝支持我们节目的制作。
If you want to join them, check out patreon.com/scishow.
如果您也想成为粉丝，可以去我们的官网patreon.com/scishow看看哦。
