If you've ever run your fingers over a comfy blanket or buried your face in a fluffy cat after a bad day,

假如你曾在心情不好的時候，找件舒服的毯子摸一摸，或把臉埋進一隻毛絨絨的貓，

you're familiar with just how nice the sensation of softness can be.

你就會熟知柔軟的觸感有多棒，

And people are willing to pay for it.

人們甚至願意為了這觸感花錢，

You'll see bed sheets proclaiming the sumptuous goodness of Egyptian cotton

你會看到標榜使用頂級埃及棉的床單，

or cashmere scarves retailing for a small fortune.

或價格不斐的喀什米爾羊毛圍巾，

But why do cashmere and these other soft fabrics feel so soft?

不過為什麼，喀什米爾羊毛和其它這些柔軟的布料，摸起來會這麼柔軟呢？

Well, the answer isn't completely clear, but it seems to involve two main components:

雖然沒有明確的答案，但似乎有兩個主要原因：

the properties of the material you're touching, and you.

先是你所摸的，材料的特性，再來是你，

Or rather, your brain.

更確切地說，是你的大腦。

Fabric hand, or handle, is the term the textile industry uses to describe the way a fabric feels and moves when you touch it.

織物手感，是紡織業的術語，用來描述織物的觸感和觸摸時，織物的移動方式。

For years, scientists who study fabric hand have been trying to relate the subjective words we use to describe textures,

幾年以來，研究織物的科學家一直試著，將那些我們用來描述質地的主觀形容詞，

like "soft" or "crisp," to properties they can actually measure.

像「柔軟」或「柔嫩」，用可以實際量化的特性來敘述，

And it can get pretty complex.

不過這相當複雜，

The feel of the fabric can be influenced not just by the material properties

影響織物觸感的因素，除了材料特性之外，

but also by the way you touch it and whether or not you're actively moving your fingers over the material.

觸摸的方式、是否用手指搓揉，也是其中因素，

And your definition of "soft" might not match mine, which makes things even more complicated.

而對於「柔軟」的定義，你也可能跟我不一樣，所以讓這件事變得更複雜，

Despite this, scientists have pinpointed material properties that could be related to softness.

儘管如此，科學家仍已經找出與柔軟有關的材料特性，

And these can be split into two main groups: how smooth the fabric is, which includes properties like friction and surface irregularities,

可以分成主要兩種：一種是織物的平滑度，包括摩擦力、不規則表面這類特性，

and how easy it is to compress, which includes properties like the flexibility of the fabric.

另一種是壓縮織物的難易度，包括織物彈性這類特性，

So a bean bag sofa is soft not only because of its fabric casing, but also because you can squish it really easily.

懶人沙發之所以柔軟，除了沙發布套之外，你能輕易壓扁它也是一項原因，

But soft doesn't necessarily mean you have the smoothest, most compressible object in the world.

不過柔軟並非代表這東西，一定是世上最平滑、最能輕易壓縮的，

A 2006 study showed that even though alpaca fiber was 10 times as rigid as wool,

一項 2006 年的研究顯示，即使羊駝毛的纖維比羊毛還要堅硬 10 倍，

we encounter less friction when touching alpaca, so it feels softer.

因為我們摸羊駝毛的時候，摩擦力較小，所以摸起來仍比較柔軟，

So material properties are part of the story, but clearly there's more to it.

材料特性只是一部份，顯然還有「其他部分」，

And that "more" is in our brains.

而「其他部分」就在我們的大腦裡面。

We don't understand everything about how it works yet.

雖然我們還沒完全瞭解它是怎麼運作的，

But two psychology studies that examined how people rated the softness of compliant objects may provide clues as to why.

但兩項關於人們如何評定物品柔軟度的心理學研究，也許能提供線索，

Compliance, which can be measured by compressing an object,

「柔量」可以藉由壓縮物品測得，

is a way of describing how objects deform when they are subject to forces.

用來描述物品受力時如何變形，

In 1995, scientists found that your perception of softness could be related to the way that

科學家在 1995 年發現，你對於柔軟的感受度，

pressure is distributed on your fingers as you move them over an object.

和你撫摸物品時，手指上壓力分佈情形有關，

At least in the case of objects with deformable surfaces, not so much for rigid ones.

至少適用於表面可變形的物品，不易變形的物品就不太適用，

The researchers performed a series of experiments that involved, among other things,

除此之外，研究人員做了一連串的實驗，實驗中

people using their finger to press down on rubber, and having rubber pressed down on their finger.

需要人們將手指壓在橡膠上，和用橡膠壓在他們的手指上，

The results suggested that tactile information is enough to tell us whether something's soft.

實驗結果顯示，觸覺的資訊就足以告訴我們，物品是否柔軟，

This information is communicated by mechanoreceptors in our skin

這些資訊來自於我們皮膚裡的力學感受器，

that work by sensing differences in pressure on your skin when your finger touches an object.

當你用手指觸摸某個物品時，它藉由感受皮膚上的壓力改變，給予反應，

A study in 2008 extended these findings and found that people tended to rate rubber objects as soft

一項 2008 年的研究延伸這些實驗結果，發現與人類手指相比，

if they were more compliant or deformable than the human finger, and hard if they were less compliant.

橡膠物品如果更柔順、更輕易變形，人們往往會覺得它是柔軟的，反之則會覺得它是堅硬的，

So whether you're petting your dog or just gliding your hand over a bunch of luxurious cashmere scarfs,

因此，無論是你在撫摸你的狗，或只是用手拂過一條高級的喀什米爾羊毛圍巾，

there's actually a lot going on to bring you that lovely experience.

這之中發生很多變化，你才能有這麼棒的感受，

So, cashmere scarves are a treat to touch.

因此，喀什米爾羊毛圍巾算是一種觸覺饗宴，

But cream mixing with coffee can be a treat for your eyes.

咖啡混合奶油的畫面則是一種視覺饗宴，

Just picture it, a nice glass of cold brew with that perfect swirl of cream.

想像一下，精緻的玻璃杯裝著冷萃咖啡，混合恰到好處的奶油漩渦，

And if you wanted to capture that moment forever,

如果你想捕捉這美麗的瞬間，

Skillshare offers a course on how to photograph coffee swirls.

Skillshare 有提供課程，教你如何拍攝咖啡的漩渦，

In the class "Cold Brew Coffee Swirl," Tabitha Park takes you through the whole process,

在《Cold Brew Coffee Swirl 》這堂課，Tabitha Park 將全程帶領你，

from choosing the right coffee and cream to editing your shots.

一路從挑選適當的咖啡和奶油，到編輯你的拍攝作品，

And that's just one of the over 25,000 classes on Skillshare, which is an online learning community for creators.

這還只是其中之一，Skillshare 上有超過 25000 堂課， 提供給創作者的線上學習社群，

Premium members get unlimited access to those classes,

高級會員能享有無限權限，上任何課程，

so you can browse them all and find what you need to jump-start your creativity or your career.

如此一來，你就能瀏覽全部課程，然後尋找提升你創造力或事業的一切所需，

And right now, the first 500 SciShow subscribers to sign up using the link in the description will get a 2 month free trial.

現在，前 500 位 SciShow 訂閱者，使用下方介紹中連結註冊的話，就能獲得 2 個月免費試用，

So check it out and get learning!

所以快去看看，開始學習吧！