[by:可可英语～m.moreplr.com]
[00:00.04]Here’s an at-home experiment you can try.
你可以在家做这样的实验。
[00:10.42]Take a can of “classic” Coca-Cola and a can of Diet Coke, and without opening either one submerge them in water. 
把没打开过的两听可乐（含糖，无糖）放在深槽或者高桶中，
[00:17.48]A deep sink or a bucket will do the trick. You’ll find the can of Diet Coke rises to the top, while the Classic Coke stays sunk. Can you guess why?
里面的水淹没两听可乐，你会发现无糖可乐浮在水面；而含糖可乐却沉下去了。你能猜到原因吗？
[00:27.45]The answer lies in the chemical contents of the Diet Coke — in fact, in the very distinction that makes it “Diet”. 
奥秘就在于无糖可乐的成分，这也是“无糖”的原因。
[00:35.10]Although their ingredients are otherwise similar, Diet Coke is not made with real sugar: instead, 
虽然，无糖可乐和普通可乐的成分很相似，无糖可乐中添加的并非真正的糖，
[00:40.31]the makers of Coca-Cola products have replaced the sugar with a synthetic chemical called Aspartame.
而是一种做“阿斯巴甜”的合成化学物。
[00:46.30]Aspartame, which is commonly known as Nutrasweet, is a kind of substitute sugar — intended to mimic the distinctive taste of sugar without carrying the associated calories.
“阿斯巴甜”是一种常见的代糖甜味剂，不含糖的热量却有糖的甜味。
[00:56.41]High Molecular Density
高分子密度
[00:57.29]Real sugar has a high molecular density. In other words you can think of sugar molecules as being thickly packed together.
真正的糖分子密度高，也就是说糖分子紧密地排列在一起。
[01:04.47]This also means sugar molecules themselves will be relatively heavy, even when dissolved in solution. 
即使溶解在溶液中，相同体积的糖更重。
[01:10.50]In the case of the sinking Coke, the real sugar content is acting as an anchor for the can.
实验中沉下去的普通可乐，正是因为糖成分像锚般让罐子下沉。
[01:16.02]Coca-Cola Taste
可乐的味道
[01:17.21]There’s also the fact that Nutrasweet is much sweeter than sugar, and so less is needed per can to achieve that recognizable Coca-Cola taste. 
代糖比糖甜，所以更少的代糖能达到普通可乐的甜味。这样水中摇摆的无糖可乐不仅平均密度更低，
[01:25.56]Thus the bobbing Diet Coke not only has a lower average density, it also has a lower mass — there’s less “stuff” dissolved in the mixture. 
质量也比普通可乐轻——因为更少的代糖溶解在可乐中。
[01:34.28]If you were an advertising executive, you might want to market diet sodas as “Light” — it wouldn’t be far from the truth.
如果你是广告商，你可以这样宣传——无糖碳酸饮料的优点：轻。这可没有说大话。