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什么是引力透镜，詹姆斯·韦伯太空望远镜如何利用它？_我的网站

穆赫兰道

一 | 来自詹姆斯·韦伯太空望远镜的第一张图片显示了SMACS 0723星系团的闪亮的星空。这张图片中发生了很多事情，但是如果凝视时间足够长，你可能会注意到，一些星系似乎“变形了”，它们的光线被拉长了。

Chinese and American college students pose for a group photo at Tsinghua University's sports complex in Beijing, capital of China, Aug. 16, 2026. (Xinhua)As the buzzer sounded, bench players sprinted onto the court, joining their Chinese and American teammates in a huddle, bumping fists and cheering, as they celebrated a hard-earned victory.
On the basketball court, young players from the two countries came together as teammates, rather than competitors.
The basketball games, held at Tsinghua University's sports complex in Beijing over the weekend, featured 16 U.S. players teaming up with their Chinese peers in separate men's and women's games, with players from both countries mixed on each team.
The games were a highlight of the 2026 Sino-U.S. Summer College Basketball & Youth Exchange, a six-day program that brought together U.S. students from universities including Stanford University, Harvard University and Yale University.
Co-hosted by China Center for International People-to-People Exchange (CCIPE) under the Ministry of Education and Tsinghua University, the program combines basketball competitions with activities including campus tours and cultural experiences to deepen exchanges, cultivate sportsmanship, and promote communication, understanding, friendship, and cooperation among younger generations on both sides.
"I'm so excited," said Lily Brown, a 20-year-old student from Bates College, after her team won. "Everyone had really good hustle, and everyone was attacking the basket really well and shooting with confidence."
After training with her Chinese teammates for several days, Brown said that despite the language barrier, they shared much in common, from movies and entertainment to social media.
"We communicate through basketball," she added.
That shared language is at the heart of the program's mixed-team format, according to J.R. Carnegie-Hargreaves, the U.S. delegation's team leader.
"The shared pursuit of basketball creates a common ground, and from that, mutual trust and friendship take root," he said.
The idea of using sports to bring people together has a long history in China-U.S. relations. In 1971, a U.S. table tennis team made a historic trip to China, marking the reopening of channels for friendly people-to-people exchanges between the two countries.
This April, Chinese and American young people gathered for events marking the 55th anniversary of Ping-Pong Diplomacy.
Today, young people are increasingly seen as vital bridges in bilateral relations. Deputy Director-General of the CCIPE Cao Diefeng said at the opening ceremony that the program was designed to help young people from both countries not only get to know each other on the court but also step into each other's thoughts and daily lives.
"Through firsthand experiences of the development story, cultural heritage and social landscape of each other's countries, they may come to see each other in a truer, fuller and more vivid light," he added.
China launched an initiative in November 2023 to invite 50,000 young Americans to visit the country for exchange and educational programs over five years. According to China's Ministry of Foreign Affairs, more than 50,000 young Americans have since visited China, reaching the target two and a half years ahead of schedule.
For many young Americans, the chance to explore China is an experience in itself. Jason Singleton, an 18-year-old student from Harvard University, said that he felt "blessed" to join the exchange program. It was his first trip to China after studying Chinese for about six years.
"Not everybody in America gets the chance to see the Great Wall," he said, delighted to get immersed in the Chinese culture during the journey.
For Cuyler Sparks, a high school student at Choate Rosemary Hall, the chance to learn more about Chinese basketball while exploring the country was one she couldn't "say no" to.
On her first trip to China, time spent with her Chinese teammates has been just as memorable, especially trying local foods. Roast duck quickly became her favorite dish.
"We don't know what some of the things are, so they explain to us how to eat them and what's really good," she said. "Just being together and trying to figure things out, even with the language barrier, has been really fun."
For some participants, the exchange was more than just a first encounter; it was a chance to continue a friendship that had already begun.
Xi Taicheng, a senior student from Tsinghua University who joined the event two years ago, was glad to meet some familiar faces again this time.
"Playing alongside the U.S. players was always a refreshing experience," he said. During several days of joint training, they chatted about their studies, training and the Chinese Basketball Association (CBA), with the Americans curious about life and basketball in China.
"I've made more new friends this time and added almost all the players on the U.S. men's team on social media," Xi said. "It's been really fun chatting and spending time together."
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二 | 然而，这并不是望远镜的人为因素--这是现实本身的扭曲，在被拍摄的空间区域内。引力与质量有着千丝万缕的联系，所以一个天体的质量越大，其引力影响就越大。这种力量是我们能站在地球上的原因，也是让地球绕着太阳转的原因。但是它的工作方式比许多人可能意识到的还要奇怪--引力使时空的结构发生了变化。詹姆斯·韦伯澳大利亚数据中心的首席科学家Themiya Nanayakkara 博士告诉 New Atlas：“假设有一组彼此靠近的大质量星系；即星系团。将会发生的是，因为这里的集体质量非常大，它将在周围的空间中产生一个弯曲--当你把一个重球放在床上时，可以在床褥上观察到类似的效果。因此，当来自背景星系的光线经过这个区域时，它所要走的路径会被弯曲。这导致背景星系的图像被拉长。”这种现象被称为引力透镜，其影响在韦伯的新图像中清晰可见。

三 | ICRAR的天文学家Robin Cook表示：“所有的物质都会在空间产生这些扭曲，包括你和我，但是只有当真正的天文数量的物质作为透镜存在时，引力透镜的效果才会明显，例如，在新的JWST图像中看到的组合星系团。

四 | 在这些图像中，我们看到来自非常遥远的星系的光线在前景星系团周围弯曲，形成了令人印象深刻和令人费解的弧线。因为星系团并不是完美的球体，这种现象往往会产生奇怪的特征，比如同一个星系的镜像。”顾名思义，引力透镜可以放大非常遥远的天体，包括一些太过遥远的天体，否则就无法看到。

五 | 这给了天文学家一个令人难以置信的窥视最遥远的空间和时间的机会。澳大利亚联邦科学与工业研究组织空间与天文学部的 Ray Norris 教授说：“这里的关键特征是，引力透镜不仅扭曲了光线，而且还放大了光线，就像一个望远镜。因此，如果你用JWST通过引力透镜观看遥远的宇宙，就好像你在JWST上安装了一个额外的镜头，让你看到比没有引力透镜更遥远的星系。”而詹姆斯·韦伯太空望远镜特别适合于利用这一现象。澳大利亚国立大学天文学和天体物理学研究学院院长Matthew Colless教授解释说：“使JWST特别善于利用这一现象的因素与使它擅长许多事情的因素相同：一个在红外波长下工作的大镜子。大镜子有两个方面的帮助，因为它不仅可以收集更多的光（所以可以看到更暗的东西），而且可以产生更清晰的图像（所以可以看到更小的东西）。在红外波长下工作也很有帮助，因为红移效应意味着宇宙中非常遥远的天体的光线会沿着光谱从可见光移到红外线。

六 | 由于天文学家在引力透镜的帮助下观察的目标是微弱的、小的和非常遥远的，JWST比在可见光波长下工作的较小的望远镜，如哈勃，有很大优势。”人们可以从詹姆斯·韦伯的空前威力中学到很多东西，结合引力透镜，它可以让天文学家研究宇宙在大爆炸后很早的时候的情况。

七 | “JWST已经在对宇宙中形成的第一代星系中的一些星系进行成像，”ARC未来研究员Cathryn Trott教授告诉 New Atlas。“它也有能力拍摄它们的光谱，据此，来自星系的光被分成其组成波长，使天文学家能够识别个别元素。来自SMACS 0723领域的凝聚星系的光谱已经向我们显示，在宇宙最初几亿年内形成的星系有氧气，这种元素只在恒星内产生。这些观测结果，结合使用低频射电望远镜对原始氢气的观测，如默奇森广域阵列，告诉我们宇宙中第一代恒星是何时形成的，以及星系如何从JWST观测到的小而结实的星系，演变到今天我们周围的星系。”“而且我们还可能通过测量光在引力透镜周围的旅行时间的差异来获得对宇宙膨胀率和年龄的新的精确测量，如爆炸的恒星或闪烁的类星体，”Colless补充说。“因此，我们预计JWST和引力透镜的结合将成为探索遥远宇宙的一种异常强大的方式。