科学美国人60秒 SSS Model Black Hole Re-Creates Stephen Hawking Prediction
时间:2018-12-24 作者:英语课 分类:2016年Scientific American(八)月
Black holes got their name because light can't escape them, beyond a certain radius—the event horizon. But in 1974 Stephen Hawking 1 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 2 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—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 3 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 4 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 5 between particles emanating 6 into and out of the model black hole…an experimental demonstration 7 of Hawking radiation. The results appear in Nature Physics. [Jeff Steinhauer, Observation of quantum Hawking radiation and its entanglement 8 in an analogue 9 black hole]
Steinhauer also determined 10 that the partner particles had a quantum connection, called entanglement…which could help theorists investigating the information paradox 11. "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 12 towards the new laws of physics, whatever they might be."
—Christopher Intagliata
- He is hawking his goods everywhere. 他在到处兜售他的货物。
- We obtain the event horizon and the Hawking spectrumformula. 得到了黑洞的局部事件视界位置和Hawking温度以及Klein—Gordon粒子的Hawking辐射谱。
- He is a physicist of the first rank.他是一流的物理学家。
- The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。
- The two situations are roughly analogous.两种情況大致相似。
- The company is in a position closely analogous to that of its main rival.该公司与主要竞争对手的处境极为相似。
- The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。
- The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。
- The second group of measurements had a high correlation with the first.第二组测量数据与第一组高度相关。
- A high correlation exists in America between education and economic position.教育和经济地位在美国有极密切的关系。
- Even so, there is a slight odour of potpourri emanating from Longfellow. 纵然如此,也还是可以闻到来自朗费罗的一种轻微的杂烩的味道。 来自辞典例句
- Many surface waters, particularly those emanating from swampy areas, are often colored to the extent. 许多地表水,特别是由沼泽地区流出的地表水常常染上一定程度的颜色。 来自辞典例句
- His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
- He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。
- This entanglement made Carrie anxious for a change of some sort.这种纠葛弄得嘉莉急于改变一下。
- There is some uncertainty about this entanglement with the city treasurer which you say exists.对于你所说的与市财政局长之间的纠葛,大家有些疑惑。
- The gill of a fish is the analogue of the lung of a cat.鱼的鳃和猫的肺是类似物。
- But aside from that analogue standby,the phone, videoconferencing is their favorite means of communication.除了备用的相似物电话,可视对话是他们最喜欢的沟通手段。
- I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
- He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
- The story contains many levels of paradox.这个故事存在多重悖论。
- The paradox is that Japan does need serious education reform.矛盾的地方是日本确实需要教育改革。
- For many particle physicists, however, it was a year of frustration. 对于许多粒子物理学家来说,这是受挫折的一年。 来自英汉非文学 - 科技
- Physicists seek rules or patterns to provide a framework. 物理学家寻求用法则或图式来构成一个框架。