Physicist turns smartphones into pocket cosmic ray detectors

【双语】物理学家让智能手机摇身一变成为小型宇宙射线探测器

Source: 源自：

University of Wisconsin-Madison 威斯康星大学—麦迪逊分校

Summary:摘要

A new smartphone app can essentially turn An droid phones into pocket cosmic ray detectors. The app, DECO, uses the phone's camera to capture energetic subatomic light particles and log data.

一款新手机应用基本上能让安卓手机变身为小型宇宙射线探测器，这款DECO项目的应用程序可利用手机摄像头捕获到高能亚原子光粒子并记录数据。

Soon, the growing capability of your smartphone could be harnessed to detect cosmic rays in much the same way as high-end, multimillion-dollar observatories.

很快，借助愈发强大的功能，智能手机也可像高端昂贵的天文台那样去探测宇宙射线了。

With a simple app addition, Android phones,and likely other smartphone brands in the not-too-distant future, can be turned into detectors to capture the light particles created when cosmic rays crash into Earth's atmosphere.

多了这个简单的应用程序，安卓手机和在不久将来可能出现的其他品牌智能手机，就能变身为探测器去捕获在宇宙射线撞击地球大气层时产生的光粒子了。

"The apps basically transform thephone into a high-energy particle detector," explains Justin Vandenbroucke,a University of Wisconsin-Madison assistant professor of physics and are searcher at the Wisconsin IceCube Particle Astrophysics Center(WIPAC). "It uses the same principles as these very large experiments."

威斯康星大学麦迪逊分校的物理系助理教授、兼威斯康星州冰立方粒子天体物理中心(WIPAC)研究员贾斯汀-凡登布鲁克（Justin Vandenbroucke）解释说：“此应用程序主要是将手机转换为高能粒子探测器。其也应用了与这些大型实验相同的原理。”

Cosmic rays are energetic subatomic particles created, scientists think, in cosmic accelerators like black holes and exploding stars. When the particles crash into the Earth's atmosphere, they create showers of secondary particles called muons.

科学家们觉得，宇宙射线是在宇宙加速过程中（如黑洞和恒星爆炸）产生的高能亚原子粒子。当粒子撞击地球大气层时，它们就会产生次生粒子（称为介子）簇射。

Smartphone cameras use silicon chips that work through what is called the photoelectric effect,in which particles of light, or photons, hit a silicon surface and release an electric charge. The same is true for muons. When a muon strikes the semiconductor that underpins a smartphone camera, it liberates an electric charge and creates a signature in pixels that can be logged, stored and analyzed.

智能手机摄像头使用了硅芯片，这种芯片能解决光电效应问题，在芯片中，光粒子或光子撞击硅表面并释放电荷。介子同样如此，当介子撞击固定手机摄像头的半导体时，它就会释放出一个电荷，并在像素点中产生一个可记录、存储和分析的信号。

Cosmic rays emanate from beyond our solar system and are constantly bombarding our planet. Their origins continue to confound astrophysicists as the high-energy particles that compose cosmicrays travel vast distances and their trajectories are bent as they traverse the magnetic fields that abound in interstellar space. Cosmic rays are commonplace and frequently confound astronomical observations looking for other phenomena.

宇宙射线不断地从我们的太阳系之外撞击到地球。天体物理学家们对其起源仍然大惑不解，因为组成宇宙射线的高能粒子穿过的距离不但遥远，而且由于要穿越在布满磁场的宇宙空间中，其轨迹也相当弯曲。宇宙射线是相当常见的，总会干扰到探索其他天文现象的天文观测。

The idea behind the pocket cosmic ray detector is primarily educational, notes Vandenbroucke, who embarked on the project as a graduate student at the University of California, Berkeley, at the suggestion of classmate Kenny Jensen, who wrote an early version of the app that powers the smartphone cosmic ray detector.

“小型宇宙射线背后的想法刚开始是用在教育上的”万登布鲁克解释道，他身为加利福尼亚大学----伯克利分校的研究生时，在同学肯尼延森的建议下开始了此项目。而肯尼延森编写了早期版本的应用程序，推进了智能手机宇宙射线探测器的开端。

The project, known as DECO for Distributed Electronic Cosmic-ray Observatory, is supported by grants from the American Physical Society as well as the Knight Foundation and the Simon-Strauss Foundation. It was abetted this past semester and summer through the programming skills of recent Janesville Craig High School graduate and WIPACintern Matthew Plewa.

分布式电子宇宙射线天文台的DECO项目，获得了美国物理协会、骑士基金会和西蒙施·特劳斯基金会的资助。此项目通过了简斯维尔·克雷格高中毕业生和WIPAC实习生马修·普莱瓦近期的编程技能验证，在过去一学期和暑假里得到了大力支持。

"I'd been working in the Androide cosystem for a while and it was just one of those hobbies that happened to work out," says Plewa, who plans to study engineering at Iowa State University.

计划要去爱荷华州立大学学习工程学的普莱瓦说“我已经在Android系统方面工作一段时间了，这本来只是一个业余爱好，后来变成了工作。”

To help transform DECO into a potent educational presence, Vandenbroucke's WIPAC group -- with grant support from, anational program in particle physics and teacher professional development --plans to engage high school teachers to develop curricular materials around the use of the smartphone cosmic ray detector.

为了使“DECO项目”在教育方面发挥作用，万登布鲁克的WIPAC团队，计划雇佣高校教师编撰“有关智能手机宇宙射线探测器应用”的教材（此团队得到了“粒子物理学和教师专业发展”国家项目QuarkNet的资助）。

To turn your phone into a cosmic ray detector, Vandenbroucke explains, you need to download the app and cover the phone's camera lens with duct tape. The phone can then be placed screen up just about anywhere, even in a desk drawer as muons can penetrate matter much like X-rays. (Muon detectors are used, for example, to sketch out hidden geological features and even buried structures of archaeological interest.)

万登布鲁克解释：要使你的手机变成宇宙射线探测器，你必须先下载APP并且用胶带盖住手机镜头。然后只要手机屏幕朝上，可放在的任何地方探测，甚至在桌子抽屉里，因为介子可像X射线那样穿透物质。（比如，介子探测器可大概勾画出隐蔽的地质特征图，甚至是具有考古价值的地下建筑物。）

Left running,an idle phone can be set to record images, which are then analyzed to search for particle events. DECO works by taking an image every couple of seconds. The DECO app analyzes the image and if enough pixels light up, it gets recorded as an event. Particle tracks from both cosmic rays and radioactivity in the environment can be recorded.

除了在使用的手机，闲置的手机也可被改装来记录图像，然后分析图像以探索粒子事件。DECO每两分钟拍摄一次画面。DECO应用程序分析图像时，如果有足够的像素点亮时，就记录为一起事件。从宇宙射线和辐射线产生的粒子运行轨迹，在地球环境中都可以记录到。

Events may sometimes be matched tocosmic phenomena detected by other, more sophisticated observatories and  experiments. The DECO app platform also includes a data logger app that routes event information -- time, location and observations -- to a central database.

这些事件有时候与其他更精细的天文台和实验所发现的宇宙现象相一致。DECO应用程序平台同时还包括数据记录APP，其发送事件信息（如时间、地点、观测结果）到中心数据库。

Vandenbroucke validated the smartphone cosmic ray detector by setting it up and logging data on long-distancecommercial airline flights. Muons are more easily detectable at high altitudes,so the Wisconsin physicist would plug in the detector and switch it on once the flight reached cruising altitude.

万登布鲁克证实，智能手机宇宙射线探测器安装在长途商业航班飞机上并记录数据，介子在海拔高的地方更容易被检测到，所以威斯康星州的物理学家在 飞机一到达巡航高度时，就接上检测器，并开始检测

Pocket cosmic ray detectors are unlikely to overtake the large, sophisticated detectors astrophysicists use,but if enough people put idle or old cellphones to use to capture muons, the project initiated by Vandenbroucke could one day evolve into a meaningful"citizen science" project.

小型宇宙射线检测器不太可能比天体物理学家使用的大型精细的探测器强大，但是如果足够多的人将空置的或旧的手机用于捕获介子信息，这项由万登布鲁克发起的项目也许有一天会演变成一个极具意义的"全民科学"项目。

"It would be great to get students and the public interested in gathering data and understanding the particles around them, things they ordinarily don't get a chance to see,"says Vandenbroucke.

万登布鲁克表示：“让学生们和公众对收集数据，以及了解在他们周围的平时无法肉眼看到的粒子产生兴趣，这实在是太美妙了！”

翻译如有误，欢迎指正交流。谢谢！

英文摘自ScienceDail

 中文翻译：林少双- Susan，黄盛谋- A mo