首页 诺奖得主Wilczek专栏

诺奖得主Wilczek专栏

孕育了许多新物理的极低温,或许也是核算机技能获得新打破的要害。Extremelylowtemperaturesmaybethekeytonewbreakthroughsincomputing.现代制冷…

孕育了许多新物理的极低温,或许也是核算机技能获得新打破的要害。

Extremely low temperatures may be the key to new breakthroughs in computing.

现代制冷技能在许多方面改变了咱们的日子。凭借冷藏技能,咱们得以品味到来自全球各地的食物——无论是当季的仍是反季节的;有了空调,家和轿车也变成了三伏天的消暑场所。

Modern cooling technology shapes our lives in many ways. Refrigeration gives us access to food from all over the world, in and out of season; airconditioning turns homes and cars into places of refuge from sweltering summers.

Illustration: Tomasz Walenta

比较于陈旧的冰块制冷,这些技能无疑是严重的前进。在用冰制冷的时代,曾构成过工业规划的冰块挖掘。我常常漫步的当地——马萨诸塞州剑桥的弗雷什塘,就曾经是一个冰矿。

These are big improvements over the time-honored method of using ice, which used to be mined on an industrial scale. Fresh Pond in Cambridge, Mass., where I often take walks, was once an ice mine.

将物体放到冰上冷却,其物理原理是较简略直接的。由于能量总是从高能态往低能态活动,热量会从较热的物体传递到冰上,成果便是前者变冷、后者消融。

Putting something on ice to cool it is straightforward physics. Since energy flows downhill from a higher-energy state to a lower-energy one, heat is transferred from a warm object to the cold ice, causing the former to become cooler and the latter to melt.

更先进的制冷方规律更难完成,由于这需求从物体中抽取能量并转移到周围环境中,然后坚持物体比周围环境温度更低。要完成这一点,就有必要输入能量。这一点看似对立,但凭借热力学规律的确能完成。较为廉价的动力,再加上超卓的工业设计,注定了冰工业的式微。

More advanced methods of cooling are harder, because they require pumping energy out of a body to keep it cooler than its surroundings. Paradoxically, this can only be done by investing energy, as well as taking advantage of the laws of thermodynamics. Reasonably cheap energy, plus some brilliant engineering, doomed the ice industry.

极低温仍然是发现新物理的重要范畴。物体在极低的温度下呈现出显着的量子效应。量子力学的一个主要特征是能量只能取离散的值,即某个能量单位的整数倍。要观测到这种量子性, 这个倍数有必要满足小:1000002个能量单位和1000003个能量单位没有实质不同,但如果是2个和3个能量单位,就会存在根本性的差别了。超冷资料的能量极低,在这种场景中量子力学的奇特规律能够充分发挥它的法力。

Extremely low temperature is still a major discovery zone in physics. It is where quantum mechanics comes into its own. The distinguishing feature of quantum mechanics is that energy comes in discrete units. To see the effects of this discreteness, you’ve got to keep the number of units small: There’s no qualitative difference between 1,000,002 and 1,000,003 units of energy, but there is between two and three units. Ultracold materials are energy-starved, allowing the strange laws of quantum mechanics to work their magic.

在挨近绝对零度时,许多金属和一些其他物质会忽然变成超导态。超导资猜中的电流没有电阻,所以只需求很少的能耗——乃至零能耗——就能保持。这个美丽的性质赋予了超导资料许多用处,比方,它能够用于制作核磁共振成像所需的强力电磁铁。

Close to absolute zero, many metals and some other substances suddenly become superconductors. Electric currents flow through superconductors smoothly, without friction, so that it takes little or no energy to maintain them. Among many other applications, that beautiful fact makes it possible to create the powerful electromagnets used in magnetic resonance imaging (MRI).

类似地,液氦在低温下会转变成超流体,然后在没有摩擦阻力的抱负情况下传输质量。因而,液氦是制 造低温冰箱的抱负资料,而液氦超流已经成为了现代低温技能的主力军。

Similarly, liquid helium becomes a superfluid at low temperature, able to transport heat without friction. This makes it ideal for low-temperature refrigerators, and superfluid helium is the workhorse of cryogenics.

信息处理是另一个十分活泼的低温物理前沿。现代核算机是经过电流作业的,而电流的热效应是限制核算机开展的一个主要要素。现在研讨人员正在研讨怎么用信息“超流” 在没有热损耗的情况下传输数据。

Information processing is another active frontier of low-temperature physics. The heat generated by modern computers, which are powered by electric currents, is a major limitation on computing technology. Researchers are working on ways to transfer data without generating heat, using “supercurrents” of information flow.

此外,核算中的许多重要问题,比方怎么优化配电网络或许航线规划体系,都能够转化为“制冷”的问题来考虑。将一个问题数字化后,问题和答案都成了一长串由0和1组成的编码。咱们能够把这些二进制码翻译成一个物理体系:0和1别离对应一个开关的“关”和“开”,或许是电子的“自旋向上”和“自旋向下”两种状况。

In addition, many important problems in computing, such as finding efficient distribution networks or airline routing systems, can be thought of in terms of making things cold. Whenever a problem is posed digitally, both the question and the potential answers are long strings of zeros and ones. These binary numbers can be translated into physical systems: Zero and one can become the “off” and “on” positions for a switch, or “spin up” and “spin down” for an electron.

经过这种“物理化”的编程,咱们能够把问题和答案别离对应到一个物理体系和它的状况上。其间,能量最低的那个态对应的便是最佳答案。

This kind of physical programming allows us to map questions and answers into states of physical systems, where the most efficient solution will be the one that contains the least heat.

制冷需求考虑多方面的要素,例如温度的凹凸、体系是处于大自然仍是人工环境中。这些都不断地应战着人们的聪明才智。创造新的冰箱和空调或许是核算机技能获得新打破的要害。这让我在夏天游水的时分有了新的考虑方针。

The multifaceted problem of refrigeration, at high or low temperatures, in natural or engineered environments, continues to challenge human ingenuity. There are strong incentives to invent new kinds of ice and airconditioners—refreshing things to envision during my long summer swims.

Frank Wilczek:弗兰克·维尔切克是麻省理工学院物理学教授、量子色动力学的奠基人之一。因发现了量子色动力学的渐近自在现象,他在2004年获得了诺贝尔物理学奖。

本文来自网络,不代表本站立场。转载请注明出处: https://www.anewcreationchurch.com/show/3774.html
上一篇
下一篇

发表评论