郑州健博激光治疗仪:葡萄酒漩涡中的物理学

       见见葡萄酒中的新口味：果味中带着一丝流体力学的味道。品酒师一直能通过在抿一口酒之前晃酒杯（使酒产生漩涡）得到最好的红酒。一个新的研究揭示了在这个晃动背后的物理学，展示出可能是决定你的梅洛（一种产自法国波尔多产区的红葡萄酒）会在杯中平滑地形成圆弧还是开始飞溅的三个因素。

Twirling a wineglass gently creates smooth arcs in the liquid that then circle, coating the sides of the glass. The gesture isn't just for appearances, says study co-author Martino Reclari, who studies fluid dynamics at the école Polytechnique Fédérale de Lausanne in Switzerland. Scientists and enthusiasts alike have long known that the swirling motion mixes oxygen into a red, enhancing its flavor.

       轻轻地快速转动一个葡萄酒杯（一种玻璃杯）可以在液体中产生平滑的圆弧，然后是覆盖着玻璃杯边缘的圆环。“这个手势不仅是表面看来那么简单。”这项研究的合作作者，在瑞士的洛桑高等理工学院研究流体力学的玛提诺?莱克拉里（Martino Reclari）说道。科学家们和葡萄酒发烧友们一样，一直都知道作漩涡运动能够将氧气混合到红酒中，增强红酒的口味。

One evening over their own bottle of wine, Reclari and colleagues decided to tackle the physics of this oenological routine. The team filled up small cylinders in a range of sizes with different volumes of a cheap merlot, then set them spinning. To keep things uniform, the researchers employed gyrating machines, commonly used to mix liquids precisely in biology or chemistry labs. This week, at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Baltimore, Maryland, the group reported a mathematical formula explaining how wine sloshes.

        一天晚上在他们自己喝葡萄酒的时候，莱克拉里和他的同事们决定看看酿酒过程中的物理学。这个团队用不同体积的廉价梅洛装满了大小一定范围内的小圆桶，然后使它们旋转。为了使情况一致，研究者使用了格栅机（通常用在生物或化学实验室中来精确地混合液体）。本周，在马里兰州的巴尔的摩（美国一座港市），每年的美国物理学会流体力学分会上，这个团队报告了描述葡萄酒晃动的数学公式。

Unlike the flavor of a perfectly aged pinot, Reclari says, the factors at play aren't overly complicated. Three factors seemed to determine whether the team spotted one big wave in the wine or several smaller ripples: the ratio of the level of wine poured in to the diameter of the glass; the ratio of the diameter of the glass to the width of the circular shaking; and the ratio of the forces acting on the wine. Those forces affecting the wine were the centrifugal force pushing the liquid to the outside of the glass and the gravitational force shoving the liquid back down.

        “不像陈年的比诺（一种法国葡萄酒），”莱克拉里说，“影响的因素并不是非常地复杂。”三个因素看来是决定了这个团队发现的是葡萄酒中的一个大的波动还是一些较小的波纹：倒入的葡萄酒的水平面与葡萄酒杯直径的比率；葡萄酒杯的直径与圆周晃动的宽度的比率；和施加在葡萄酒上的力的比率。这些影响着葡萄酒的力是将葡萄酒推出葡萄酒杯的离心力和将液体拉回来的重力。

By tweaking these factors a notch—for instance, by pouring a bit more wine into a glass or shaking that glass in tighter circles—Reclari and colleagues mastered the art of unusual wine waves. Their creations in the video above included the wine lover's standard, a single, smooth crest, all the way to four miniwaves that built in quick succession. Curiously, however, if the researchers kept all three ratios identical, they began to spot the same waves forming again and again, even in cylinders of very different sizes. "If you have a very small glass or a very big glass and you put in the same parameters, you will have exactly the same shape of the wave," Reclari says.

       将这些因素作一些小调整，比如多倒一些葡萄酒到杯子里或者在更紧凑的圆轨道上晃动杯子。莱克拉里和同事们掌握了奇异的葡萄酒波形的艺术。在以上的视频里他们的创作包括了葡萄酒爱好者的标准，一个单独的、平滑的波峰，自始至终四个小的波形很快连续地形成。可是，出于好奇，研究者保持这三个比率完全相同，他们开始反复观察同一种波形一次又一次的形成，甚至在尺寸迥异的圆桶中。“如果你有一个很小的玻璃杯或是一个很大的玻璃杯，当参数设定一致时，你会恰好的到同一个形状的波形。”莱克拉里说。

He and colleagues also landed on another important discovery: how overly enthusiastic wine swirlers manage to splash their drinks, possibly staining their sweaters. Just like an ocean crest, wine waves begin to break, turning frothy, if they're moving too quickly, he says. The breaking acceleration for a merlot is about 40% of the force of gravity, the team concluded, or nearly 4 meters per second. That acceleration, in turn, is dependent on the volume of wine in the glass, the force of shaking, and other factors.

        他和同事们也有了另一个重要的发现：葡萄酒“旋流器”是多么地狂热于想方设法地将这些酒洒出去，即使有可能弄脏他们的衣服。就像海浪的波峰，如果它们移动过快，葡萄酒波就开始瓦解，变为泡沫，莱克拉里说。“使梅洛的波瓦解的加速度大约是重力的40%，”这个团队总结道，“也可以说是4米每秒。” 反观这个加速度，它取决于玻璃杯中葡萄酒的体积，使玻璃杯晃动的力，和其它一些因素。

The team's formula is useful for more than just helping a wine taster "impress his friends," Reclari says. When growing bacterial cultures, biologists often mix cells in with nutrients in one big jar, then swirl, much like an aficionado over the latest vintage. That rotation distributes the bacterial food throughout the slurry and also removes excess carbon dioxide. Knowing just how liquids slosh in such jars may help lab technicians optimize their growing methods, he adds.

       这个团队得出的公式不仅可用于让品酒师“打动他的朋友”，莱克拉里说道。当作细菌培养时，生物学家通常将细胞和营养物质混合在一个大的广口瓶里，然后打旋，就像最近葡萄收获期的那些葡萄酒发烧友一样。这种旋转分散了遍布悬浮液细菌的事物并且挤出了多余的二氧化碳。“仅仅了解液体怎样才会从这种广口瓶中溅出就能帮助实验室技术人员优化他们的培养方法。”他补充道。

The team's analysis is "simple" but does "make sense," says Vladimir Ajaev, an applied mathematician at Southern Methodist University in Dallas, Texas. And the study illustrates well how seemingly everyday physics, such as the swirling of a glass of wine, might help scientists and engineers develop better lab tools: "At first it might seem like a matter of curiosity," he says. "But then it turns out there are some specific applications."

        这个团队的分析很“简单”但是确实“有意义”，乌拉地米尔?阿加夫（Vladimir Ajaev），一位来自德克萨斯州达拉斯的南卫理公会大学的应用数学家说道。这项研究很好地解释了日常生活中的物理学是什么样的，比如玻璃杯中葡萄酒的漩涡，这可能会帮助科学家和工程师发展出更好的实验室工具。“一开始这可能看起来是仅仅出于好奇心”，他说，“但是后来它就变成了有具体的实用价值的东西。”