南京英孚青少儿英语于2002年成立，18年来深耕南京。专注3-18岁孩子英语教育，英语启蒙、英文阅读兴趣、考试学习、出国留学来英孚就够了。我们的运行及管理遵照EF全球统一模式。50年专业英语教育经验值得信赖，关注英语，关注孩子。
Fried Rice
一碗炒饭的奥秘
中国的美食文化一直都是让歪果仁好奇的存在。在外国生活过的同学一定知道，国外的中餐厅最受欢迎的一个菜色就是炒饭。
“为什么只有中餐厅才能做出如此入味的炒饭？”
“为什么他们做出来的炒饭那么漂亮？”
“传说中的颠勺动作(Wok tossing)中包含哪些力学知识？”
带着这些疑问，美国佐治亚理工学院的物理学家Hunting Ko和David Hu通过大量观察与实验，揭开了一碗完美炒饭的秘密——这个研究也许会让你做的炒饭更好吃哦！
Wok tossing has long been suspected of causing the high shoulder injury rate among Chinese chefs.
一直以来，人们都怀疑中国厨师普遍存在的肩膀劳损是由于炒菜时的颠勺动作。
正文阅读：
Fried rice is a classic dish in pretty much every Chinese restaurant, and the strenuous（adj. 费力的；奋发的） process of tossing the rice in a wok over high heat is key to producing the perfect final product. There's always chemistry involved in cooking, but there's also a fair amount of physics. Scientists at the Georgia Institute of Technology have devised a model for the kinematics（n. 运动学；动力学） of wok-tossing to explain how it produces fried rice that is nicely browned but not burnt. They described their work in a recent paper published in the Journal of the Royal Society: Interface.
中式炒饭几乎是国外每一家中餐厅的必备经典菜式，而在高温的锅中不断翻炒米饭，才是做出完美炒饭的关键。在这个烹饪过程中，大多数都属于化学反应，不过也有很多物理知识涵盖在里面。美国乔治亚理工学院的科学家们最近就设计了一个“翻勺”的运动学模型，研究解释了如何做出一份色泽出众、不会烧焦的完美炒饭。他们在最近发表于《英国皇家学会杂志》上的一篇论文中，详细描述了他们的研究工作。
This work hails from David Hu's lab at Georgia Tech, known for investigating such diverse phenomena as the collective behavior（集体行为；集群行为） of fire ants, water striders, snakes, various climbing insects, mosquitos, the unique properties（属性，性能）of cat tongues, and animal bodily functions like urination and defecation—including a 2019 Ig Nobel Prize-winning study on why wombats produce cubed poo. Hu and his graduate student, Hungtang Ko—also a co-author on a 2019 paper on the physics of how fire ants band together to build rafts—discovered they shared a common interest in the physics of cooking, particularly Chinese stir-fry.
这项研究来自佐治亚理工学院的大卫胡工作室，这个工作室以研究火蚂蚁、水黾、蛇、爬行昆虫、蚊子等动物的集体行为、猫咪舌头的独特属性以及类似排尿排便系统——还包括获得2019年搞笑诺贝尔奖的研究“为什么袋熊会产出立方形的粪便”。胡教授和他的研究生柯同学——他也是2019年的一篇关于火蚂蚁如何聚集在一起建造木筏的物理学论文的其中一个作者——他们发现两人对烹饪中的物理学有共同的兴趣，尤其是中式炒饭。
Hu and Ko chose to focus their investigation on fried rice (or "scattered golden rice"), a classic dish dating back some 1,500 years. According to the authors, tossing the ingredients（n. 材料；佐料）in the wok while stir-frying ensures that the dish is browned but not burned. Something about this cooking process creates the so-called "Maillard reaction": the chemical interaction of amino acids and carbohydrates subjected to high heat that is responsible for the browning of meats, for instance.
胡教授和柯同学两人选择将他们的研究重点放在炒饭（或称为黄金蛋炒饭）上，这是一道拥有1500多年历史的古老经典菜肴。根据研究者的说法，炒菜时不断翻炒锅中的材料，这样可以确保做出来的饭是棕色的却不会烧焦。这个烹饪过程产生了所谓的“美拉德反应”：氨基酸和碳水化合物在高温下产生的化学反应，比如肉类变成褐色就是由这个反应导致的。
But woks are heavy, and the constant tossing can take its toll on Chinese chefs, some 64 percent of whom report chronic shoulder pain（慢性肩痛）, among other ailments. Hu and Ko thought that a better understanding of the underlying kinematics of the process might one day lead to fewer wok-related injuries for chefs.
但翻炒的锅其实很重，不断的颠勺翻锅也会让中国的厨师付出代价，大约有64%的中国厨师称自己患有慢性肩痛。胡教授和柯同学认为，如果能够更好地理解在这一过程的存在的潜在运动学，就有可能会在某天减少中国厨师因工作而受伤的情况。
In the summers of 2018 and 2019, Ko and Hu filmed five chefs from stir-fry restaurants in China cooking fried rice and then extracted frequency data from that footage. (They had to explain to patrons that the recording was for science and that they were not making a television show.) It typically takes about two minutes to prepare the dish, including sporadic wok-tossing—some 276 tossing cycles in all, each lasting about one-third of a second.
在2018年至2019年的夏天，胡教授和柯同学拍摄了五位中国餐馆厨师的炒饭画面，然后从视频中提取频率数据（他们必须向这些餐馆老板解释，录这些视频是为了科学研究，并不是制作电视节目）。一般情况下，准备这道菜只需要两分钟左右的时间，包括偶尔的翻勺——总共约276次翻勺周期，每次只有大约三分之一秒。
抛接球的数学模型示意图
Photo by Hungtang Ko and David Hu/Georgia Tech
Ko and Hu presented preliminary results of their experiments at a 2018 meeting of the American Physical Society's Division of Fluid Dynamics, publishing the complete analysis in this latest paper. They were able to model the wok's motion with just two variables, akin to a two-link pendulum, since chefs typically don't lift the wok off the stove, maintaining "a single sliding point of contact," they wrote. Their model predicted the trajectory of the rice based on projectile motion, using three metrics: the proportion of the rice being tossed, how high it was tossed, and its angular displacement.
胡教授和柯同学在2018年美国物理学会流体动力学分会的一次会议上展示了他们实验的初步结果，并在最新的这篇论文中发表了完整的分析研究。他们写道，他们能够用两个变量来模拟炒锅的运动，就类似于一个双摆，因为厨师通常不会把炒锅直接从炉子上端起来，而是利用炉边维持一个“滑动的接触点”。他们的模型基于三个基础指标：大米被抛掷的比例、被抛掷的高度和它的角位移。
The authors found two distinct（adj. 独特的，截然不同的） stages of wok-tossing: pushing the wok forward and rotating it clockwise to catch rice as it falls; and pulling the wok back while rotating it counter-clockwise to toss the rice. Essentially, the wok executes two independent motions: side to side, and a see-sawing（跷跷板） motion where the left end moves in a clockwise circle and the right moves counterclockwise. "The key is using the stove rim as the fulcrum of the seesaw motion," the authors wrote. Also key: the two motions share the same frequency but are slightly out of phase.
研究人员发现，翻勺（此处指的是大翻勺，也就是将整个锅里的菜翻过去）有两个不同的过程：将炒锅向前推，顺时针旋转，以便在米饭落下时接住；然后把锅拉回来，逆时针旋转，把米饭翻过来。本质上，锅是执行了两个独立的运动，从一边到另一边，一个跷跷板运动，其中左端以顺时针方向运动，而右端以逆时针方向运动。在报告中研究人员这样写道：“关键是将炉边作为跷跷板运动的支点。”而同样关键的是，这两个运动有相同的频率，但又有轻微的不一致。
翻勺时的物理杠杆运动
Photo by Hungtang Ko and David Hu/Georgia Tech
Hu compared the effect to "flipping pancakes or juggling（n. 杂耍，手技杂耍） with rice." The trick is to ensure that the rice constantly leaves the wok, allowing it to cool a little, since the wok temperature can reach up to 1,200 degrees Celsius. That produces fried rice that is perfectly browned but not burned. Based on their analysis, Hu and Ko recommend that chefs increase both the frequency of motion when tossing fried rice in a wok and the "phase lag" （相位滞后）between the two distinct motions. This "may enable rice to jump further, and promote cooling and mixing."
胡教授将这种效应比作“翻煎饼或者翻炒饭”。这个过程的关键就是要确保米饭不断地离开锅，让它在空中稍微冷却一下，因为锅里的温度甚至可以高达1200摄氏度。这种方法做出的炒饭是完美的褐色，但不会烧焦。根据他们的分析，胡教授和柯同学建议厨师在炒锅里翻炒时要增加动作的频率，并且在两种不同的动作之间增加“相位滞后”，这样可能“使大米进一步翻滚，促进冷却和混合。”
The mathematical model Hu and Ko developed isn't just a fun curiosity; it should also prove useful for industrial robotic designs. One goal for the authors is to develop a wearable exoskeleton（n. [昆] 外骨骼）or similar device to reduce the rate of shoulder injury among Chinese chefs. But there has been interest in automating cooking since the 1950s to perform such basic functions as cutting, boiling, frying, and pancake flipping—the latter task usually relying on reinforcement learning algorithms（n. [计][数] 算法；算法式）.
胡教授和柯同学建立的数学模型不仅仅是满足了一个有趣的好奇心；这个模型也会对之后的工业机器人设计有所帮助。作者的一个目标是开发一种可穿戴的外骨骼或类似的设备，以减少中国厨师的肩膀劳损。不过早在20世纪50年代，人们就开始对自动化烹饪产生兴趣了，自动化烹饪可以完成诸如切、煮、炸和翻炒等基本功能，而翻炒这一任务通常依赖于强化机器算法。
There have also been attempts to automate stir-frying fried rice in large batches, with limited success. Prior robotic designs have included a rotating drum（转筒）to mix ingredients, and a see-sawing wok to flip ingredients, augmented with an automated spatula（n. 抹刀，小铲）. These could mix ingredients via rotation or shaking but could not toss the rice and, thus, could not produce the ideal carbonated grains. "If there was an automated way of doing this, it could be very useful [for chefs]," said Hu.
当然，之前也有人尝试过批量自动化地制作炒饭，但成效非常有限。之前的机器人设计包括一个旋转滚筒来混合食材，一个跷跷板来翻转食材，再加上一个自动的小铲子。这些设备可以通过旋转或者摇动来混合食材，却不能搅拌大米，因此不能做出理想的美食。“如果有一种自动化的方式来做这件事，它（对厨师们）会非常有用，”胡教授这样说。
实际上，这个研究并没有那么“无聊”
这些科学家们将研究目光
放在了一道平凡的菜色、一群普通的中国厨师身上
目标是解决厨师的肩膀劳损问题
和制作更长远的人工智能美食
这样潜心研究的科研精神
是不是可爱又可敬呢？
閱讀更多 南京英孚青少兒英語 的文章
