新东方在线网络课堂 托福 新东方在线 > 托福 > 托福精选 > 正文

科学美国人60秒:黑洞模型再现霍金预言-托福听力下载

2016-11-21 16:23:14 来源:科学美国人60秒托福资料下载

点击查看>>科学美国人60秒音频:黑洞模型再现霍金预言

  科学美国人60秒中英文翻译:黑洞模型再现霍金预言

  科学美国人60秒英文文本

  This is Scientific American — 60-Second Science. I'm Christopher Intagliata.

  Got a minute?

  Black holes got their name because light can't escape them, beyond a certain radius, called the event horizon. But in 1974 Stephen Hawking proposed that quantum effects at the event horizon might cause black holes to be...not completely black.

  "Hawking said that pairs of particles should be created at the event horizon." Jeff Steinhauer, a physicist at the Israel Institute of Technology. "One particle exits the black hole and travels away, perhaps to Earth, and the other particle falls into the black hole."

  Ideally, we could just study those exiting particles...which make up the so-called Hawking radiation. But that signal is too weak. We can't see it against the universe's background radiation. So Steinhauer built a model of a black hole instead. Which traps not photons, but phonons—think of them as sound particles—and it traps of using a gas of rubidium atoms, flowing faster than the speed of sound.

  "And that means that phonons, particles of sound, trying to travel against the flow are not able to go forward. They get swept back by the flow. It's like someone trying to swim against a river which is flowing faster than they can swim. And the phonon trying to go against the flow is analogous to a photon trying to escape a black hole."

  Steinhauer doesn't actually pipe sound particles into the device. He doesn't need to. He merely created the conditions under which quantum effects predict their appearance. "So the two swimmers can come into existence simultaneously without anybody supplying energy to create them."

  He ran the test 4,600 times—the equivalent of six days—and took pictures of the results. And indeed, he saw a correlation between particles emanating into and out of the model black hole…an experimental demonstration of Hawking radiation. The results appear in Nature Physics.

  Steinhauer also determined that the partner particles had a quantum connection, called entanglement...which could help theorists investigating the information paradox. "So there's the question of where does information go, if one throws it into a black hole?" This study can't answer that. But, he says, "it helps give hints, to direct physicists towards the new laws of physics, whatever they might be."

  Thanks for listening for Scientific American — 60-Second Science Science. I'm Christopher Intagliata.

  中文翻译请点击下一页

本文关键字: 科学美国人60秒 科学60秒下载 托福听力

为你特别匹配的托福超值课程,快速提分先人一步!
  • 大学生旗舰直达冲100分

    【知心托福】大学生旗舰直达冲100分

    适合人群:托福目标分数100!!!

    课程特色:推送补充相应知识点,有效提升学习效率。

    查看详情
  • 【知心托福】大学生旗舰直达冲90分

    【知心托福】大学生旗舰直达冲90分

    适合人群:托福目标分数90!!!

    课程特色:推送补充相应知识点,有效提升学习效率。

    查看详情
  • 【21天冲分】 21天直冲托福100+

    【21天冲分】 托福2018年6月临考急训25人班

    适合人群:参加过托福考试或基础段的学习,距离最新考试仅剩1个月时间,急需短期内快速高效冲分的考生。

    特点:全科直播24小时

    查看详情
  • TOEFL6月早练团

    【早练团】TOEFL6月早练团

    课程特色:高能学习的正确打开方式,早练早提分!

    课时:28课时(每天0.5小时,5月共上课28天)

    查看详情
  • 大学生旗舰直达班 (冲110分)

    【知心托福】大学生旗舰直达班 (冲110分)

    适合人群:托福目标分数110分!

    课时:343

    查看详情

课程试听换一换

  • 知心托福 大学生旗舰直达班 (冲110分)

    ¥8280

  • 知心托福 直达班(冲110分)

    ¥4380

  • 知心托福 精品直达班(冲110分)

    ¥5880

  • 知心托福 大学生旗舰直达班 (冲100分)

    ¥7980

  • TOEFL 6月早练团-单日“听力团”+双日...

    ¥28

  • 知心托福 直达班(冲100分)

    ¥4080

  • 知心托福 中学生旗舰直达班 (冲110分)

    ¥8280

  • 知心托福 直达班(冲90分)

    ¥3880

分享到:

相关推荐

交流 • 下载

精品课限量免费领

  • 托福听力备考全攻略
  • 托福考试指南_托福新生必修课
  • 新东方雅思托福GRE词汇量在线测试

提分历程更多>>

实用 • 工具

托福课程排行榜本周本月

托福公开课更多>>

新东方在线知心托福介绍说明【热】 w 04分14秒
1 新东方在线知心托福介绍说明【热】
新东方在线唐悦宁:托福词汇遗忘规律 w 07分34秒
2 新东方在线唐悦宁:托福词汇遗忘规律
新东方在线唐悦宁:词根词缀记忆法 w 04分42秒
3 新东方在线唐悦宁:词根词缀记忆法
新东方在线唐悦宁:托福听力基础预备 w 03分30秒
4 新东方在线唐悦宁:托福听力基础预备
新东方在线李镇江:托福听力场景概述-社会科学-美国历史 w 08分35秒
5 新东方在线李镇江:托福听力场景概述-社会科学-美国历史

推荐阅读